Docstoc

COMPUTERS IN NUCLEAR MEDICINE

Document Sample
COMPUTERS IN NUCLEAR MEDICINE Powered By Docstoc
					                              Molloy College NMT Program, 2010.




Binary System: 1 or 0
    information is stored by computers is represented by either 1 or 0.
    Users enter and receive information to and from the computer in a visual or
     text format, not in binary system. Computers analyze and “translate” inputs
     into digital form of binary system.




                                                                                   1
                                           Molloy College NMT Program, 2010.




   Hardware:
      CPU: Central processing unit. Regulate system operation. Perform computations,
        interact with memory to execute programs.
            CU- control unit

            ALU- arithmetic logic unit

      Memory: storage of information with ready access

            ROM: read only memory.

            RAM: random access memory.

      Data Storage: storage space for information while not in use

            Hard Disk

            Floppy Disk

            Optical Disk

            Magnetic Tape

      Input/Output: devices that allow users to feed information into computer for processing
        and receive information after it has been processed.
      Camera Interface: output from the camera is fed into the computer to make an image
        and store it.
              ADC: analog to digital converter.
              Newer systems have ADC built into each detector. No outside ADC devices used.

                                                                                                 2
                                     Molloy College NMT Program, 2010.




   Software:
      System Software: (Operating systems) creates environment for other software to run
         in. Controls hardware and user interfaces. Example: Windows XP, Mac OS, Linux.
      Programming language: software that allows users to design more software. Example:
         C++, Visual Basic, JAVA.
      User Software: Programs that allow for data manipulation and task performance.
         Philips Jetstream, Pegasys, Autoquant, etc.




                                                                                            3
                                                                  Molloy College NMT Program, 2010.




                      Image Acquisition:
                      Each count that is recorded by the camera carries three signals. X, Y and Z. X and Y
                       are location coordinates, while Z is the energy pulse.




                      Matrix example and pixel depth illustration byte mode vs. word mode.



 Each pixel can store only a limited number of counts. Pixel overflow results when the number of counts exceeds the maximum value a pixel
can hold. The pixel with the highest count is assigned the brightest intensity.

    Typically, images are stored in either a byte mode or a word mode.

    8 bits make up 1 byte, 16 bits make up 1 word.

    2n-1: number of counts stored in either 1 byte or 1 word. “n” is the number of bits stored. Since the first number is always 0, we subtract 1

    Maximum number of counts in one byte: 28-1 (always starts with 0; therefore, we subtract 1) Total number of counts stored in one byte is 255

    Maximum number of counts in one word: 216-1 is 65,353


                                                                                                                                                    4
                                  Molloy College NMT Program, 2010.




Z pulse: Energy of each photon is analyzed according to the energy window
   selected. If the energy falls outside the selected window, then that photon is not
   recorded on the image. Typical window for most isotope is 20%. For Tc99m,
   the window of accepted energy is from 126 keV to 154 keV.




                                                                                        5
                                              Molloy College NMT Program, 2010.




   Two types of resolution in Nuclear Medicine:
        Spacial resolution: ability to see detail. In NM also means to able to see between two closely located
         hot spots on an image. Example, ability to see space between vertebrae on a bone scan, etc.
        Temporal resolution: ability to see detail in respect to time. Example: visualization of activity in left vs.
         right kidney or a renal scan. The actual image detail may not be as relevant as much as “how long”
         does it take for the isotope to localize in a given organ.
   Proper matrix size selection:
        Common matrix sizes: 64x64, 128x128, 256x256, 512x512.
        The larger the matrix size the higher the spacial resolution.
        The larger the matrix size the more counts are needed to create a good image.
        Higher matrix sizes can be reframed to smaller matrix sizes, but not vice versa.




                                                                                                                         6
                                                                     Molloy College NMT Program, 2010.




   Types of Acquisition:
          dynamic- ability to image a cine (movie). Example: 3 phase bone scans, renal scans, etc.




          Static - ability to obtain a single image with high resolution. Example: bone scans, Hida scans, etc.




          Gated - imaging according to physiological triggers. Example: MUGA.




                                                                                                                   7
                                              Molloy College NMT Program, 2010.




   SPECT (single photon computed tomography). – rotating the camera while acquiring images 360 degrees. Example:
    bone SPECT.




   gated SPECT- 3D imaging with physiological triggers. Example: MPI SPECT.




                                                                                                                    8
                                      Molloy College NMT Program, 2010.




   Image smoothing: ability to manipulate images in order to obtain a smoother or sharper
    image.
   Common uses:
        Eliminate noise.
        Add blur.
        Remove blur.
        Edge detection.
        Image smoothing.




                                                                                             9
                                               Molloy College NMT Program, 2010.




   Time Activity Curves (TAC)
        quantifications of activity into a curve or a function.
        curves may be compared to previous studies to see changes with time.
        curves from two same organs may be compared between each other.
   ROI: region of interest. In order for a computer to process data, a user needs to define
    where the edges of the organ are by drawing around that organ.
   Common procedures that require ROI and TAC:
        gastric emptying, renal scans, gallbladder ejection fraction, left ventricle ejection fraction, etc.




                                                                                                                10
                                        Molloy College NMT Program, 2010.




Networks: ability to share data, share printers, backup data, present data off-site
1.    Token-ring network (old). Used to connect several NM cameras and NM workstations
      only.
2.    Star network (old). Used to connect several NM cameras and NM workstations only.
3.    Bus Network (common). Used to connect all modalities and all workstations, even from
      off-site.

PACS: picture archival and communications system. Most common network found in many
      imaging facilities and hospitals.
•     All images by all modalities can be shared and are stored in one common format
      (DICOM).
•     No need to print films. Images are accessible from within the network or from outside
      the network through the internet.
•     Images are automatically archived and can be easily restored.
•     Urgent cases can be interpreted quickly from off-site.




                                                                                              11
                    Molloy College NMT Program, 2010.




 The conversion of analog signals to digital
  signals is the function of the:
 a. Scintillation camera

 b. Digital transmitter

 c. Analog to Digital converter

 d. Analog transmitter




                                                        12
                    Molloy College NMT Program, 2010.




c. Analog to Digital converter




                                                        13
                    Molloy College NMT Program, 2010.




 Temporal resolution is maximized when:
 a. Performing a Spect study

 b. Performing a Static study

 c. Performing a Dynamic study

 d. Sending the patient for a cat scan instead




                                                        14
                  Molloy College NMT Program, 2010.




c. Performing a Dynamic study




                                                      15
                        Molloy College NMT Program, 2010.




   One of the disadvantages of using a large matrix is:
   a. Image quality is decreased with low count rate
   b. Image quality is increased with low count rate
   c. None of the above
   d. Minimal memory requirement




                                                            16
                   Molloy College NMT Program, 2010.




a. Image quality is decreased with low count
  rate




                                                       17
                    Molloy College NMT Program, 2010.




 When preparing a computer for the study, a
  technologist should select this setup in order
  to maximize the temporal resolution:
 a. 3sec/frame

 b. 20 sec/frame

 c. 1 sec/frame

 d. 0.25 sec/frame



                                                        18
                    Molloy College NMT Program, 2010.




d. 0.25 sec/frame




                                                        19
                                                        Molloy College NMT Program, 2010.




   Function of Bones:
      Protection.

      Movement.

      Provides Framework.

      Contain bone marrow for blood production.

      Store minerals.

   Bone structure and composition:
        Cortex (hard component, outside surface) responsible for strength and support.
        Spongy bone (contains marrow, inside) responsible for blood formation.
        Cortical bone composition:
              5%-10% water.
              25%-30% organic matter (collagen).
              65%-70% inorganic matter (bone minerals: calcium, phosphate, hydroxyl and carbonate).
                     Organized into hydroxyapatite (crystalline structures).
   Bone types:
        Tubular bones: humerus, fumurs, etc.
        Short bones: carpals, tarsals.
        Flat bones: ribs, sternum, scapulae.
        Irregular bones: typically vertibrae.




                                                                                                       20
                                              Molloy College NMT Program, 2010.




   Bone Metabolism:
        Although bone tissue seems to be solid, it constantly remodels itself. Osteoclasts break bone tissue
         down, and Osteoblasts reform the bone matrix over again. This process allows for bone repair after
         fractures, exchange and storage of minerals, and other important functions.
   Skeleton:
        Axial Skeleton: skull, thorax, and vertebral column.
        Appendicular Skeleton: shoulders, hips, upper extremities, lower extremities.

   Joints:
         Rigid: movement between bones not allowed. After formation, sutures are formed where the bones
          are fused together.
         Freely Movable: bones are separated by articular cartlidge, with synovial fluid contained between the
          bones for cushioning.




                                                                                                                  21
Molloy College NMT Program, 2010.




                                    22
                                                      Molloy College NMT Program, 2010.




   INDICATIONS:
        Staging malignant disease (r/o metastasis).
        Infection imaging / inflammation (osteomyelitis, cellulitis).
        Evaluation of bone pain.
        Trauma (fractures, sports injury).
        Evaluation of painful joint prosthesis.
        Evaluation of primary bone tumors.
        Evaluation of bone necrosis.

   CURRENT RADIOPHARMACEUTICALS:
       Tc99m MDP (medronate) and Tc99m HDP (oxidronate) taken up in hydroxyapatite crystals of compact bone
        through heteroionic exchange. MDP has been shown to clear blood stream faster than other
        radiopharmaceticals., while HDP has shown a greater bone uptake.
       Bone is constantly being remodeled through osteolytic and osteoblastic activities. Uptake of MDP or HDP will
        be proportional to the metabolism of the bone tissue.
       Approximately 50% of injected dose will be taken up by the bone.
       Most of the radiopharmaceutical is taken up by the bone within 15 minutes, several hours are required for soft
        tissue to clear of extra isotope.

   WHOLE BODY IMAGING VS. THREE PHASE BONE SCANS:
       Whenever blood flow needs to be assessed, three phase bone scan is indicated. Otherwise, perform whole
        body scan.
       Three phase bone scan indications: osteomyelitis, cellulites, trauma, bone necrosis.
       Whole body imaging indications include: metastatic evaluation, bone pain, general evaluations.

   PATIENT PREPARATION:
        Relevant history needs to be obtained (injuries, surgeries, etc).
        Indication is reviewed, areas of interest are evaluated.
        After the injected patient is instructed to increase fluid intake and void frequently (to minimize exposure to
         bladder wall).

                                                                                                                          23
                                                     Molloy College NMT Program, 2010.




   WHOLE BODY BONE IMAGING
      15-25 mCi of Tc99m MDP or HDP injected IV
      Patient is instructed to return in 2.5 – 4.0 hours for imaging.
      Patient is instructed to increase fluid intake (if allowed) while voiding frequently.
      Patient voids right before imaging starts.
      Empty bladder allows for clear visualization of pelvic bones and sacrum.

   Image acquisition:
        Whole body mode: a long static image is taken of the patient from head to toes.
            Typical camera setup: 8-10cm/min, body contour used. Feet taped together.
            2.5 million counts per view is recommended. Slowing down speed may be necessary to achieve that.
        Spot Image technique: several static images are acquired from head to toes. Overlap body anatomy.
            Typical camera setup: either 300 sec/view or 500k-750k per image. Start with pelvis first while its empty.
        SPECT is indicated for:
            Areas of bone superimposition: facial bones, lumbar spine, pelvis.
            Whenever bone necrosis is being ruled out.
                    Cold spots (necrosis) harder to visualize than mets (hot spot), therefore use SPECT.
        Special views:
            Laterals of the skull are done with patient turning his/her head to a side, not the camera.
            Arms up view will separate scapula from ribs.
            Laterals of pelvis will separate bladder activity from sacrum.




                                                                                                                          24
                                              Molloy College NMT Program, 2010.




Interpretation of Results:
    Asymmetrical uptake is usually an indication of an abnormality.
    Metastatic disease: ordered for primary lung, breast, and prostate
     cancers. Bone imaging is superior to radiographs, since hyper metabolic
     activity shows up earlier than lesions on x-rays. Study shows: 10%-40%
     of positive bone scans will be have normal x-ray finding.
    Primary bone neoplasms: usually ordered for patients with already known
     primary bone tumors. Bone scans are required to look for abnormal
     uptake elsewhere in the skeleton. 30% of patients with Ewing’s sarcoma
     have lesions in other bones.
    Paget’s disease: greatly abnormal uptake throughout the bone.
    Superscan: no renal uptake, no bladder, increased axial decrease
     appendicular.
    RSD (reflex sympathetic dystrophy): uptake in the entire limb.
    Flare phenomenon: false positive, response to treatment.




                                                                                  25
                                                     Molloy College NMT Program, 2010.




3 PHASE BONE SCANS:
   Performed in cases of trauma, inflammatory process or infection.
   First phase: immediate flow study (dynamic imaging). 2-4 sec/frame for 1-2 minutes.
   Second phase: immediate blood pool imaging (statics). 3-5 minutes per view.
          Should be completed within 15 minutes post injection. Isotope is localized in the bone after 15 minutes.
   Third phase: delayed imaging. 3-4 hours post injection (statics). 5-10 minutes per view.
   Whole body scan may also be performed depending on history.
   Fourth phase is a 24 hour static image of the area in question. 20 minutes per view.

Technical Considerations:
   When imaging hands or arms: setup IV and inject on the opposite side of the disease.
   Always position patient so that contralateral sides are equadistant from the detector. Bones that are closer to detector
    may appear to accumulate more isotope than other bones.
   Special positioning is often applied:
          Hands and forearms are typically imaged with patient sitting in front of the camera.
          Palmer view is very useful when imaging fingers and wrists.
          Plantar view is very useful when imaging toes and feet.
          Patient can be asked to roll to a side and bend knees for lateral / medial positioning.




                                                                                                                               26
                                              Molloy College NMT Program, 2010.




Interpretation of Results:
    Cellulites: Hot flow, hot blood pool, normal bone uptake on delay (while surrounding soft tissue may still be
     hyperperfused).
    Osteomyelitis: Hot flow, hot blod pool, increased bone uptake on delay).
    In cases of trauma:
           Immediately after fracture 0-48 hours: decreased activity visualize at the site.
           Day 3 – Day 10: generally diffused increased activity at the site.
           Day 10: Focally increased activity at the site.
    Avascular necrosis: difficult to diagnose. SPECT is required. Demonstrated as decreased uptake in a
     suspected area.




                                                                                                                     27
                 Molloy College NMT Program, 2010.




                                  Foot fracture




Femur fracture




                                                     28
       Molloy College NMT Program, 2010.




mets                  mets
                                           29
          Molloy College NMT Program, 2010.




osteosarcoma




                                              30
Molloy College NMT Program, 2010.




pagets




                                    31
                Molloy College NMT Program, 2010.




                                      Legg-calve-perthes




osteoblastoma




                                                           32
                          Molloy College NMT Program, 2010.




Name three indications for performing a radionuclide blood
flow and initial blood pool images in conjunction with whole
body imaging of the bones.
Why do a 3 phase bone?




                                                               33
                         Molloy College NMT Program, 2010.




1. Infection
2. Trauma
1. Avascular Necrosis.




                                                             34
Molloy College NMT Program, 2010.




                                    35
                          Molloy College NMT Program, 2010.




• Children and young adults.
• First 30 years of life.
• Usually found at head of femur, or pelvis, may
metastasize to other bones.
• Highly vascular tumor. May look like osteomyelitis.
• Activity is intense and homogeneous.




                                                              36
                        Molloy College NMT Program, 2010.




Are bone scans more specific or more sensitive to
bone abnormalities?




                                                            37
                           Molloy College NMT Program, 2010.




Very sensitive to bone abnormalities.
Non - specific in identifying lesions.




                                                               38
                          Molloy College NMT Program, 2010.




This is the most common
cause
of a “Super Scan.”




                                                              39
                          Molloy College NMT Program, 2010.




• No renal or bladder visualization.
• Axial skeleton more intense than appendicular skeleton.
• Usually due to prostate, lung, lymphoma, breast CAs.




                                                              40
                           Molloy College NMT Program, 2010.




Visualization of one or more of the axilla or supraclavicular
lymph nodes following administration of 99mTc MDP may
be secondary to this.




                                                                41
                          Molloy College NMT Program, 2010.




Extravasation of the dose.
As radiopharmaceutical is slowly reabsorbed lymphatic
drainage may occur.




                                                              42
                                              Molloy College NMT Program, 2010.




Movement of Air:
o Air passes through nose, mouth, pharynx, larynx and trachea
where its warmed and moisted.
o Trachea divides into right and left mainstem bronchi at carina.
o Right mainstem bronchus divides into upper, middle and lower
bronchi.
o Left mainstem bronchus divides into upper and lower bronchi.
o Bronchi continue to divide irregularly 16 times from trachea to
terminal bronchioles.
o Terminal bronchioles continue to divide into alveolar ducts and
alveolar sacks.
o Bronchi have cartlidge, bronchioles do not.
o Left lung: 2 lobes divided into 8 segments.
o Right lung: 3 lobes divided into 10 segments.
o 250-300 million alveoli in adult lungs
o Terminal arterioles supply blood to alveoli and are 35um in
diameter.
o Pulmonary arteries and veins bring blood for gas exchange
o Bronchial arteries bring blood to lungs for nourishment supply.




                                                                                  43
                                             Molloy College NMT Program, 2010.




•   Tidal Volume: volume of air breathed out in a normal breath.
•   Functional Residual capacity: volume of air at the end of a normal breath.
•   Total Lung Capacity: maximum volume of air at a maximum inhalation.
•   Residual Volume: volume of air left after a maximum exhalation.

Clinical Indications for Lung Imaging:
• Pulmonary Embolism primary diagnosis.
• Pulmonary Embolism follow up to treatment.
• Evaluation of COPD.
• Preoperative Quantification.

• Pulmonary Embolism and COPD studies require ventilation and perfusion with a recent (24hr) chest x-
ray.
• For PE perfusion only studies are possible; however, ventilation studies should always be attempted.
• Lung Quantification studies require perfusion only and a recent (24hr) chest x-ray.




                                                                                                         44
                                           Molloy College NMT Program, 2010.




Perfusion Imaging:
• 2 mCi – 6 mCi Tc99m MAA (30 – 40 um in diameter) IVP will embolize terminal arterioles.
• Distribution of particles has shown to closely resemble distribution of blood.
• Patient is injected while supine for proper mixing with blood.
• Method of localization: capillary blockage
• Adult dose contains 100k-500k particles, which will block 1% of arterioles.
• Patients with right to left shunt should be approved by a physician, dose decreased.
• Patient is evaluated for pulmonary hypertension.
• Patients with pulmonary hypertension should be injected while upright.

Keep in Mind:
• Gravity will affect distribution of particles.
• MAA has affinity for plastic tubing, needs to be flushed immediately.
• MAA will form clumps if let to mix with blood for prolonged time.

Imaging Technique:
• 6 or 8 views are commonly imaged. POST, ANT, LATS, RPO, LPO (RAO and LAO are optional).
• Posterior image done first, it’s the most important one.
• 500k – 700k per image are obtained. Half for lateral views.
•




                                                                                            45
Molloy College NMT Program, 2010.




                                    46
Tc99m DTPA Ventilation Studies
• Delivered with an aerosol nebulizers.
• Deposited in the bronchial tree depending on particle size. The smaller the size the further down to
alveoli the particle travels.
• About 30 mCi of Tc99m DTPA is used. Activity may vary depending on site.
• 10%-15% of the tracer will reach the lungs.
• 6 or 8 views are commonly imaged. POST, ANT, LATS, RPO, LPO (RAO and LAO are optional).
• Posterior image done first, it’s the most important one.
• Images are typically acquired for 4-5 minutes per view (lateral views for half the time).
• Normal distribution resembles a uniform pattern.
• Obstructive disease such as COPD will prevent uniform distribution of the particles and cold areas in the
      lungs will be observed.
• Ventilation scans with aerosols are usually performed before perfusion imaging. Therefore, count rate
      must be tripled when perfusion imaging is performed.




                                                                                                          47
                                            Molloy College NMT Program, 2010.
Molloy College NMT Program, 2010.




                                    48
                                           Molloy College NMT Program, 2010.




Xe-133 Ventilation Studies
• Radioactive xenon gas is delivered through a special xenon machine.
• Energy of xenon is low (80 keV). High degree of scatter and attenuation.
• Imaging is done in one plane – Posterior only.
• Because of 80 keV, xenon ventilation is always done first and perfusion second.
• 10-20 mCi of Xe-133 used.
• Most common protocol:
     • First phase: Single Breath for 10-20 seconds. Bolus Xe-133 is inhaled by patient.
     • Second phase: Equilibrium phase. Xe-133 is inhaled and exhaled by the patient for approx. 5
     minutes.
     • Third phase: Washout phase: Xe-133 is only exhaled by the patient for approx. 5 minutes.
• Obstructive disease such as COPD will prevent uniform distribution of the gas. COPD is also visualized
     as retention of gas during washout phase.




                                                                                                       49
Molloy College NMT Program, 2010.




                                    50
                                          Molloy College NMT Program, 2010.




Krypton 81m Ventilation Studies
• Due to economical reasons krypton 81m is not currently available on the market.
• Krypton81m is produced from a parent Rubidium 81 in a generator.
• 5 mCi Rb81Generator is delivered to a department and lasts for 6 hours.
• Oxygen is delivered into a generator and Kr81m is expelled.
• No special contamination precautions are required. Kr81m t1/2 is only 13 seconds. Energy is 190
keV.
• Ventilation is done only if necessary and after perfusion.
• All 6-8 views are obtained to match perfusion.
• Images are acquired for either time or counts.
• Patients breaths Kr81m through nose canula as imaging is taking place.
• Care should be taken so that patient does not exhale towards the detector, but in the opposite
direction.
• Images closely resemble that of perfusion. Gas does not reach areas of COPD.




                                                                                                    51
                                             Molloy College NMT Program, 2010.




Image Interpretation

• Mismatching defects: positive perfusion, negative ventilation.
     • Pulmonary Embolism (most commonly cold defects in the periphery of lung(s) on perfusion.
     • Early stages of heart failure.
     • Interstitial lung disease.
     • Some lung cancers.

• Matching defects: positive perfusion, positive ventilation of the same lung region.
    • COPD.
    • Asthma.
    • Cystic fibrosis.




                                                                                                  52
                                           Molloy College NMT Program, 2010.




Lung Quantification Studies
• Indication:
     • Preoperative evaluation of lung regions in terms of function.

• Procedure:
     • Lung perfusion scan only, ventilation not necessary.
     • Recent (24hr) chest x-ray is obtained.
     • Regular lung perfusion scan is performed.

• Computer Processing:
    • Anterior and Posterior views are used to analyze function.
    • 6 ROIs are drawn, 3 on right lung and 3 on left lung.
    • Geometric Mean is applied for Anterior and Posterior views.
    • Percent function is obtained in relation to total function of both lungs.
    • Data may be manipulated to express a possible loss in function due to planned lung resection.




                                                                                                      53
Molloy College NMT Program, 2010.




                                    55
Molloy College NMT Program, 2010.




                                    56
Molloy College NMT Program, 2010.




                                    57
            Molloy College NMT Program, 2010.




CAPILLARY BLOCKADE
Molloy College NMT Program, 2010.




                                    59
Molloy College NMT Program, 2010.




                                    60
Molloy College NMT Program, 2010.




                                    61
Molloy College NMT Program, 2010.




                                    62
                                           Molloy College NMT Program, 2010.




Cancer:
• Uncontrolled overgrowth of cells with tumor nodules at remote sites.
• Some cancers may be curable, others are very difficult to detect and/or treat.
• The initial site of the cancer is referred to as the primary site.
• Remote locations of where the cancer has spread to is referred to as metastasis.
• Cancers require blood flow to grow.
• Often the center of the cancer becomes necrotic as the cancer outgrows its own blood supply.
• Surface of tumor cells contain antigen that are specific to that particular cancer.
• Labeled antibodies have demonstrated imaging and treatment advantages in the recent past.

Abscess:
• Localized collection of dead white blood cells and bacteria.
• Neutrophils are responsible for defense against bacteria.
• Some bacteria are able to defend themselves by releasing substances that prevent neutrophils from
coming in contact with bacteria, or even destruction of RBC in the surrounding area.
• Ultimately, increased blood flow brings more neutrophils that engulf the bacteria. Mixture of dead
bacteria, dead neutrophils, and fluid is called pus.
• Various types of infections can be imaged in nuclear medicine.




                                                                                                       63
                                             Molloy College NMT Program, 2010.




Gallium Imaging
• Ga67 Citrate is cyclotron produced, t1/2 is 3.26 days, energies are: 93 (most), 184 and 296 kev
• Method localization:
      • Binds to serum protein transferrin in blood. Exact uptake by tumors and infections is not yet
      known.
      • at 24 hours 25% remains in blood and 2% at 5 days.
      • 10-15% excreted through urine in 24%.
      • 10% excreted through stool.
• Normal distribution: nasopharynx, lacrimal glands, salivary glands, bones, colon, liver and genitalia and
      kidneys (only first 48 hours).
• Abnormal distribution: focal or diffuse uptake in other areas of the body.

Imaging Parameters:
• Usual dose is 5-10 mCi IV.
• Imaging may begin as early as 6 hours and up to 5 days post injection.
• Most commonly, 48 and 72 hour imaging most useful and most optimal.
• Delayed imaging may increase contrast and help visualize persistent activity.
• Medium energy collimators are necessary.
• Whole body scan performed. From head to knees or to toes. Slowing down scan speed is often
necessary.
• Static images are taken for 500k per view of areas in question.
• SPECT is routinely done for further diagnosis of lungs, abdomen or pelvis.
• SPECT is particularly useful when organ superimposition is possible such as colon, liver, scapula,
sternum, etc.
• Patients may be brought back 24 hr later when activity is the abdomen is visualized. If bowels, activity
      will move, if true lesion, activity will remain in place.                                            64
                             Molloy College NMT Program, 2010.




       Normal Ga67 WB scan                       Abnormal lung uptake Ga67 WB
scan



                                                                                65
                                             Molloy College NMT Program, 2010.




WBC cell imaging with In111 and Tc99m HMPAO
• Tagging neutrophils (responsible for defense against bacteria) can result in a very specific an sensitive
method of imaging infection.
• Available isotopes are In111 oxine and Tc99m HMPAO
     • In111: 67.4 hour t1/2 and energies of 173 and 247 keV.
     • Tc99m: 6 hour t1/2 and 140 keV.
• Tagging WBC has shown to be superior to Ga67 when imaging abscesses.

• PROPER PATIENT IDENTIFICATION USING A WITNESS SHOULD BE DONE!

Tagging procedure:
• Always use large bore needles to avoid rupturing WBCs.
• 60ml of whole blood is drawn with heparinized syringe to prevent clotting.
• In case of granulocytopenia or agranulocytosis donor blood may be used.
• Blood is then processed to separate RBC and plasma.
• WBC are mixed with isotope and incubated at room temperature.
• After successful QC, tagged WBC are reinjected into the patient.




                                                                                                              66
Molloy College NMT Program, 2010.




                                    67
                                                      Molloy College NMT Program, 2010.



TUMOR AND INFECTION IMAGING
In-111 WBC Imaging / Tc99m HMPAO WBC Imaging
• 500 uCi In111 WBC IV.
• 30 mCi Tc99m HMPAO IV.
Clinical Indications:
• Fevers of unknown origin.
• Localization of source of infection.
• Abscess evaluations.
• Post surgical complications.
• Evaluation of prosthesis infection.
Imaging Procedure:
• Imaging is performed at 4 and 24 hours.
• Depending on indication, whole body imaging and additional static views are performed.
• Can be combined with Tc99m SC if imaging infected prosthesis to evaluate for compacted bone marrow.
• Whole body imaging should be slow (5-7 cm/min), static views: 10 min/view.
• Due to low count rate SPECT is not done.
Normal Distribution:
• Spleen, liver, and bone marrow. Most intense activity is in the spleen.
• Infection is usually demonstrated as asymmetrical focal hot spots throughout the body.


In111 WBC vs. Tc99m HMPAO WBC
• Tc99m HMPAO WBC localizes in bowel; use restricted to extremity imaging.
• Tc99m HMPAO WBC higher count rate, better image quality.
• In111 WBC half life longer, allowing for delayed imaging.                                             68
                      Molloy College NMT Program, 2010.



TUMOR AND INFECTION IMAGING




   In111 WBC normal                             In111 WBC lung infection.




                                                                            69
                                                       Molloy College NMT Program, 2010.



 TUMOR AND INFECTION IMAGING
Lymphoscintigraphy
• Allows for visualization of sentinel lymph node responsible draining an area of interest.
• Indications:
      • Breast tumor resection. Performed prior to surgery to determine location of draining node, and help surgeons
      determine chain of lymphatic fluid flow during surgery.
      • Melanoma. Performed twice. First time to plan the surgery, second time to aid surgeons determine chain of
      lymphatic fluid flow during surgery.
      • Lymphodema. Performed for patients with unexplained swelling of extremity.
• Radiopharmaceutical:
      • Most common: Tc99m Sulfur Colloid (filtered is recommended). 100uCi per syringe, about 2-4 injections.
      • Isotope is taken up by lymphatic fluid and carried with lymphatic fluid to the nodes.
      • Injection technique:

                                                                                                Recently, intradermal injection
                                                                                                has been recommended by
                                                                                                SNM, as the uptake by the
                                                                                                lymphatic fluid is faster.




                                                                                                                              70
                                                     Molloy College NMT Program, 2010.



TUMOR AND INFECTION IMAGING
Image Acquisition:
• Breast lymphoscintigraphy:
      • 2-4 intradermal injections periareolar or in location specified by a surgeon.
      • Imaging can begin approximately 30 minutes post injection.
      • Anterior, Anterior Oblique and Lateral views are taken for 300 seconds with Co57 sheet source for patient outline.
      • If no lymph nodes are visualized, images are repeated after another 30 minutes to 1 hour until nodes are visualized.
      • After the node(s) are visualized, they are marked with either gamma probe or a point source.
• Melanoma lymphoscintigraphy:
      • 2-4 intradermal injections around the melanoma lesion.
      • Imaging begins right away in a whole body mode with transmission source.
             • Anterior view with Co67 sheet source at a fast scan speed (20-40 cm/min).
             • Posterior view with patient prone with Co67 sheet source at a fast scan speed (20-40 cm/min).
             • Lymph nodes are visualized almost immediately but the test is continued until the liver is visualized.
             • Liver uptake indicates drainage of lymphatic fluid into venous circulation, indicating complete cycle.
             • Lymph nodes are marked the day the patient is having surgery.
• Lymphodema lymphoscintigraphy:
      • 2 injections in the web of fingers/toes of affected and normal extremity for comparison purposes.
      • Imaging begins immediately with left and right extremity in the field of view with transmission source.
      • Drainage from left and right are compared. In cases of lymphodema, nodes of the affected extremity drain slower
            than of those of normal.




                                                                                                                             71
Molloy College NMT Program, 2010.




                                    72
                                       Molloy College NMT Program, 2010.




Breast Tumor Imaging:
Indications:
 Evaluation of breast tumors when mammography is nondiagnostic, calcifications, etc.

 Identification and localization of multifocal cancers.

 Evaluation of therapy.

 Sestamibi taken up by mitochondria of tumor cells.

Prep:
 No biopsy in past 4 weeks.

Imaging Procedure:
 30 mCi Sestamibi IV in contralateral arm. Imaging begins 10 minutes post injection.

 Camera setup with 10% window to reduce background.

 Patient positioned prone, with special breast holders utilized to separate the tissue
    away from the rest of the body. Detector up against the breast.
 Image lateral view for 10 minutes. Other oblique views may be indicated.

Image Interpretation:
 Focal hot uptake consistent with malignancy.

 Infiltration of the dose will cause lymphatic uptake, therefore, inject in contralateral
    arm.                                                                                   73
In-111 Octreoscan Imaging:
   Somatostatin analog. Taken up by cells with somatostatin receptors.
   Somatostatin receptors are found in primarily neuroendocrine tumors.
       Andrenal medullary tumors.
       Gastroenteropancreatic tumors: gastrinoma, insulinomas.
       Carcinoid tumors (GI tract tumors).
   Pituitary Adenomas.
   Small cell lung carcinoma.
Patient Prep:
   None necessary.
Imaging Procedure:
   5-6 mCi In111 Octreotide IV. 50% excretion in 6 hours, 85% in 24 hours. Only 2% by
    hepatic clerance.
   Whole Body Imaging 5-6 cm/min at 4 and 24 hours post injection.
   SPECT performed at 4 and 24 hours of appropriate areas.
Image Intepretation:
   Normal uptake: pituitary, thyroid, liver, GI tract, kidneys and bladder.
   Persistent focal hot uptake indicates abnormality.
                          Molloy College NMT Program, 2010.




How can bowel activity be distinguished from a true
abdominal lesion when performing a Gallium scan?




                                                              75
                    Molloy College NMT Program, 2010.




 Delay images with bowel preparation. True
  lesions will remain fixed in one spot. Activity
  in the bowel will move over time.
 Abdomen SPECT.

 Delay images important for tumor to increase
  target to background ratio.



                                                        76
                          Molloy College NMT Program, 2010.




   The technologist observes renal and bladder activity
    on gallium images performed within 24 hours of
    gallium injection. The most likely explanation for this
    activity is:



   a. Infection or inflammation of the kidneys
   b. Severe hepatocellular disease
   c. Normal finding
   d. Misadministration of the dose
   e. All of the above

                                                              77
                        Molloy College NMT Program, 2010.




   c. Normal finding




                                                            78
                     Molloy College NMT Program, 2010.




   Which of the following organs does not
    normally concentrate In-111 WBC's?

 a. Bowel
 b. Bone marrow

 c. Liver

 d. Spleen



                                                         79
           Molloy College NMT Program, 2010.




a. Bowel




                                               80
                     Molloy College NMT Program, 2010.




   Scenario: platelets have been tagged with In-
    111 instead of WBC's, and administered to
    the patient to rule out infection. What is a
    possible outcome?




                                                         81
                   Molloy College NMT Program, 2010.




Test maybe false positive




                                                       82
                                                Molloy College NMT Program, 2010.




Renal Imaging
   Anatomy and Physiology overview:
       Regulate the volume and composition of the extracellular fluid.

       Retroperitoneal organs located between 12th thoracic and 4th lumbar vertibrae.

       Right kidney is slightly lower than left due to liver.

       Ureters are attached to the kidney at hilus (an indentation in the medial border of each kidney).

       Blood supply is from renal arteries directly out of aorta.

       Cortex contain nephrons and surrounds each kidney.

       Each kidney contains more than an million nephrons each.

       Each nephron contains a glomerulus, proximal convoluted tubule, loop of henle, and distal convoluted
         tubule.
       Glomerulus is supplied by afferent arteriole and blood leaves through efferent arteriole.

       Renal medulla contains renal pyramids that empty urine into minor and major renal calices of the renal
         pelvis.
       Three processes of urine formation:

            Glomerular filtration: water and solutes enter nephron.

            Tubular reabsorption: water and other important compounds are reabsorbed into circulation.

            Tubular secretion: certain other unwanted molecules are secreted into the tubule for excretion.

            Urine then passes into renal calices, renal pelvis and the ureters.


                                                                                                                 83
                                              Molloy College NMT Program, 2010.




Clinical Indications:
    Functional Studies:
        Relative blood flow.
        Obstruction uropathy.
        Hydronephrosis.
        Renal transplant evaluation.
        Renovascular hypertension.
        Renal failure.
   Morphological Studies:
        Renal scarring due to UTI.
        pyelonephritis,
        Horseshoe kidney.
   Radiopharmaceuticals:
        Tc99m DTPA: 100% glomerular filtration. Used for functional imaging. GFR agent.
        Tc99m MAG3: 100% tubular secretion. Used for functional imaging. ERPF agent
        I-131 Hippuran: 80% tubular secretion, 20% glomerular filtration. Functional imaging. No longer used
         due to Tc99m agents superior imaging characteristics. Primarily ERFP with some GFR.
        Tc99m DMSA: binds to tubules in renal cortex. 50% binds within 2 hours. Flow study not done.
        Tc99m GH: excreted by glomerulus but is retained by tubules for several hours. Flow study possible.




                                                                                                                84
                                        Molloy College NMT Program, 2010.




Functional Renal Imaging:
  Patient should be well hydrated (if not contraindicated).
  Positioning is supine and imaged posteriorly. Anterior if renal transplant is evaluated.
  No other prep is necessary for plain renogram.
  6-10 mCi TC99m MAG3 or 10-15mCi of TC9m DTPA.
  Bolus injection technique.
  Phase I: Initial flow study at 1-3 sec/frame for 1 minute.
  Phase II: Functional flow study at 30sec/frame for 30 minutes.
  Phase III (optional): prevoid and postvoid static views for 3 minutes /frame.
  Proper processing is crucial: ROI must be drawn carefully to include only the desired area.
  ROIs: aorta, bladder, L and R kidneys and their backgrounds. CHECK FOR PATIENT
   MOTION!

Image Interpretation:
  Normal findings include:
      Rapid symmetrical uptake by both kidneys with rapid clearance for blood pool.

      Symmetrical peaks and symmetrical excretion by both kidneys.

      Any deviation from typical normal findings maybe indication of disease, obstruction,
         RAS, renal failure, etc.

                                                                                                 85
                                                 Molloy College NMT Program, 2010.




Diuretic renal imaging:
   Lasix (furosemide) is often used to diagnose possible obstruction.
   Particularly useful to differentiate physical obstruction (stones) vs dilation of collecting system (physiological
    obstruction).
   Lasix is infused 10-15 minutes before the end of Phase II.
   Exact time of infusion is noted and used during processing of imaging.
   Technologists are not allowed to infuse Lasix. (only RN, MD or PA)
   Important: ask about allergies, make sure patient is hydrated, monitor BP.
   NOTE: LASIX MAY CAUSE BP TO DROP. ALWAYS MONITOR BP! LASIX CONTRAINDIATED FOR PATIENTS
    WITH SULFA ALLERGY.
Imagine finding:
  Response to diuretic is increased excretion of urine by the kidney. No response is usually
   indicative of physical (stone) obstruction.




                                                                                                                         86
                                        Molloy College NMT Program, 2010.




Renovascular hypertension
  When renal artery stenosis is present, perfusion pressure decreases in afferent arterioles.
  This leads to drop in GFR.
  Kidney(s) attempt to restore pressure by constricting efferent arterioles.
  Decrease of pressure in afferent arterioles causes release of renin from juxtoglomerular
   apparatus.
  Renin converts Angiotensin I to Angiotensin II by ACE enzyme. Angiotensin II constricts
   efferent arterioles.
  Angiotensin II also increases secretions of aldosterone which causes increased retention of
   sodium and then retention of fluids causing increase of systemic blood pressure.
  Administration of ACE inhibiting or Angiotensin II blocking medications will potentially
   decrease GFR.
  Performing two renal scans one with and one without ACE inhibitors or Angiotensin II
   blockers will demonstrate any presence of renal artery stenosis.
  If baseline and captopril renogram look identical then no RAS is present.
  If baseline is normal and captopril renogram shows poor perfusion then RAS is present.




                                                                                                 87
                                     Molloy College NMT Program, 2010.




 Commonly used Diuretics                              Commonly used ACE inhibitors
bendroflumethiazide/bendrofluazide                                  Captopril
               Aprinox                                             Zofenopril
   chlortalidone/chlorthalidone                                     Enalapril
              Hygroton                                              Ramipril
         cyclophenthiazide                                         Perindopril
              Navidrex                                              Lisinopril
            indapamide                                             Fosinopril
               Natrilix
            metolazone                                 Commonly used Angiotensin
             Metenix 5                                         blockers
              xipamide                                              Atacand
              Diurexan                                              Avapro
      furosemide/frusemide                                          Benicar
                 Lasix                                              Diovan
            bumetanide                                              Cozaar
               Burinex                                              Hyzaar
            torasemide                                              Micardis
                Torem
              amiloride
             Amilamont
            triamterene
                Dytac




                                                                                     88
                                         Molloy College NMT Program, 2010.




Morphologic renal imaging:
  No special preparation is needed.
  Usually pediatric cases, good working IV necessary, ability to work with children, lots of
   toys!
  Doses vary according to patient’s weight and/or age.
  Tc99m GH or Tc99m DMSA injected IV.
  Initial imaging begins 15 minutes post injection.
  Posterior view imaged first (most important) followed by LPO and RPO. Apply zoom.
  Images are taken 5-10 minutes per view.
  If horseshoe kidney is being evaluated, then IMAGE ANTERIORLY ALSO to avoid spine
   attenuation on posterior images.
  Delayed imaging is done 2.0 – 2.5 hours post injection. Same camera setup. Same views
   are repeated.
  SPECT maybe useful after delayed images are finished. Patient must remain still
   otherwise SPECT will be useless.
Image interpretation:
  Symmetrical uptake in both kidneys with no cold regions in renal cortex is normal finding.
  Cold regions in renal cortex implies renal scarring or infection.
  Horseshoe kidney is visualized as kidneys connected in the inferior aspect.


                                                                                                89
Molloy College NMT Program, 2010.




                                    90
                                               Molloy College NMT Program, 2010.




Indications:
• Evaluation of vasicouretal reflux.
• Two methods exist: indirect and direct. Indirect method is a modified renal scan. This method is not
    widely accepted.
Direct Method
• Patient voids prior to study.
• Patient is catheterized.
• Saline bag with 1 mCi is connected to the catheter.
• Bladder is filled to maximum capacity while patient is supine and filling is imaged as dynamic study.
Bladder volume is calculated as: (age in yrs +2) X 30mL. Patient will get very uncomfortable,       toes curl,
and catheter starts to leak.
• Catheter is removed, patient voids into a bed pan as another dynamic study is performed.
• Reflux occurs often during the voiding phase.
• Reflux is visualized as activity traveling up the ureters up towards the kidneys. Reflux could be unilateral
    or bilateral.
Technical Considerations
• Contamination is the biggest obstacle. All equipment must be covered with absorbent paper.
• A parent should be present to make the child more comfortable. Catheterization is often traumatic.



                                                                                                             91
Molloy College NMT Program, 2010.




                                    92
Molloy College NMT Program, 2010.




                                    93
Molloy College NMT Program, 2010.




                                    94
Molloy College NMT Program, 2010.




                                    95
Molloy College NMT Program, 2010.




                                    96
Molloy College NMT Program, 2010.




                                    97
Molloy College NMT Program, 2010.




                                    98
Molloy College NMT Program, 2010.




         The heart is a muscle with a special electrical conduction
         system. The system is made of two nodes and a series of
         conduction fibers or bundles (pathways).
         The normal heart beat begins with an electrical impulse
         from the sinoatrial node, located high in the right atrium.
         The SA node is the pacemaker of the normal heart,
         responsible for setting the rate and rhythm. The impulse
         spreads through the walls of the atria, causing them to
         contract. Next, the impulse moves through the
         atrioventricular node, a relay station, into the conduction
         bundles which are located in the ventricles themselves. As
         the impulse travels down the bundles, the ventricles
         contract. The cycle then repeats itself.
         This regular cycle (sinus rhythm) of atrial and ventricular
         contractions pumps blood effectively out of the heart.
         Problems may occur anywhere in the conduction system
         and interfere with effective pumping of blood. The heart
         may beat too fast (tachycardia), too slow (bradycardia), or
         irregularly. These abnormal beats are known as
         arrhythmias.


      Atrial contraction <= 0.2sec=> Ventricular Contraction




                                                                       99
                                      Molloy College NMT Program, 2010.




Left coronary artery=>     LAD=>septum, anterior wall
                           Circumflex=>Left atrium, Lateral wall
Right coronalry artery=>   Left ventricle inferior wall
                           Right ventricle
                           Right Atrium
                                                                          100
                                            Molloy College NMT Program, 2010.




Gated Blood Pool Imaging (MUGA):
•    Commonly performed to accurately assess EF of LV or RV or both.
•    Routinely ordered for patients prior, during or after chemotherapy, heart failure patients for wall
     motion and EF assessment.
•    In past was performed as a stress muga as well. Recently replaced by MPI.
Patient Prep:
•    None necessary.
Radiopharmaceuticals:
•    Tc99m RBC (ultratag) 20-30 mCi.
•    Tc99m RBC (in-vitro cold PYP) 20-30 mCi.
Imaging Prcedure:
•    Gated planar imaging of Ant, Lao, Lao 70 are acquired for 10minutes each.
•    If RV is in question, then RAO is imaged as well.
•    Gated SPECT is optional.
Processing and Interpretation:
•    Visual evaluation of wall motion should be done prior to processing.
•    ROI must be drawn with care not to include areas outside of the ventricle, or cut out the
     ventricle itself.
•    LVEF > 85% is usually unrealistic and indicates improper ROI’s.
•    LVEF <50% is considered abnormally low, and > 50% is normal.
                                                                                                           101
                                             Molloy College NMT Program, 2010.




Angina Pectoris: chest pain due to heart disease. Occurs when heart requires more
   oxygen than usual.
Stable angina: chest pain that occurs in a predictable pattern: stress, exercise, walking,
   stairs. Can be controlled by activity.
Unstable angina: (ACS) chest pain that occurs during rest or stress. Cannot be controlled
   by activity.
Atherosclerosis: fatty buildup in arteries, leading to blockage, possible clots, inability to
   dilate. Leads to ischemia.
Hypertension: increased systemic blood pressure. May lead to cardiomyopathy.
Cardiomyopathy: generalized disease of the muscle of the heart that prevents it from
   pumping blood normally.
   Congestive: overall enlargement of the heart leads to weak EF.
   Hypertrophic: enlarged septal wall, creates distortion in valves leading to leakage.
   Restrictive: muscle becomes hardened, heart unable to fill-up between beats.




                                                                                                102
                                               Molloy College NMT Program, 2010.




Radiopharmaceuticals
   Thallium 201 citrate:
  80,135 KeV, 74 hr t ½, cyclotron produced.
  10% excreted by kidneys and bowel over 10 days.
  After injection 3.5% is taken up by the heart.
  Uptake directly proportional to the coronary blood flow: healthy coronaries=>increased uptake,
   diseased coronaries=>decreased uptake.
  REDISTRIBUTION: thallium is able to re-enter circulation and get taken up by myocardium again.
  Equilibrium achieved at 3-4 hours.
  Due to high exposure, 4.0mci is the max dose.
  Method of localization: active transport through K+ pumps.




                                                                                                    103
                                                 Molloy College NMT Program, 2010.




Sestamibi (aka cardiolite) and Tetrofosmin (aka myoview):
   Although technically different radiopharmaceuticals, properties are very similar, thus mutually exclusive
    for the purpose of the certification exams.
   140 KeV, 6 hour half life, generator produced. Most commonly used isotope.
   Significantly less exposure than tl201, up to 40 mCi can be given per day.
   Method of localization: passive diffusion into mitochondria of myocytes, stay there for several hours.
   Liver and bowel uptake is significant, wait before scanning.
   NO REDISTRIBUTION.
   Lower extraction rate by myocardium than Tl201.

Tc99m Teboroxime:
   Lipophilic properties aid in very quick extraction by myocardium. Exact method of localization not
    understood, but associated with the lipophilic-hidrophobic association between myocardial cell
    membrane and teboroxime.
   Biological half life is 5.5 minutes. Low initial liver uptake. One chance to image, very fast scanner
    required.
   Didn’t become popular.




                                                                                                                104
                                               Molloy College NMT Program, 2010.




Advantages of Sestamibi / Myoview vs. Thallium:
  Higher count rate.
  Higher energy, thus less attenuation.
  No redistribution: no rush post stress, images can be repeated if necessary.

Disadvantages of Sestamibi / Myoview vs. Thallium:
   No redistribution: no ability to visualize viability.
   No lung uptake assessment.

Comparison of Tc99 based tracers:
Isotope           Concentration             t1/2 myocadium
Teboroxime           3.6%           5min
Sestamibi            2.4%           6hr. Slight redistribution. Imaging
          possible up to 6hr.
Tetrafosmin          2.0%           8hr. Virtually no redistribution.
          Imaging can be done same day.
                                    Some claim lower liver uptake.



                                                                                   105
                                               Molloy College NMT Program, 2010.




Sample Tl201 Protocol (single day):
  Stress Test (treadmill, or pharmacological)
  Injection of Tl201 3.0 mCi during stress.
  Stress imaging (starts within 5 minutes post stress).
  Delay 4 hours with optional but suggested 1.5 Tl201 booster dose.
  Optional 24 hour delay to assess viability in severely diseased myocardium.
Sample Cardiolite (single day):
  Resting injection (7-10mCi)
  Wait 1.0 hour.
  Resting imaging.
  Stress Test (treadmill, or pharmacological)
  Stress Injection (x3 of rest injection)
  Wait 1.0 hour
  Stress imaging.
    ›   Stress and Rest order maybe reversed but not suggested. Why?




                                                                                   106
                                                           Molloy College NMT Program, 2010.




Two Day Protocol (Sestamibi or Myoview)
    Reserved for obese patients, or scheduling. Refer to patient weight chart.
   Day1: Rest or Stress
        30-40 mCi Sestamibi or Myoview administered.
        Wait 1.0hr.
        Image Rest or Stress.
   Day2: Rest or Stress
        30-40 mCi Sestamibi or Myoview administered.
        Wait 1.0hr.
        Image Rest or Stress.

     If stress is done on day1 and is absolutely normal, rest may not be necessary.

Dual Isotope Same Day Protocol:
    3.0 -4.0 mCi Tl201 administered for Rest.
    Wait 15 min
    Image Rest
    Perform Stress (treadmill or pharmacological)
    Inject 30 mCI of Sestamibi or Myoview at stress.
    Wait 1.0 hr.
    Image Stress.
    24 hour delay possible to assess viability. (tc99 decays, tl201 stays)




                                                                                               107
                                            Molloy College NMT Program, 2010.




   Patient Prep:
        NPO post midnight.
        Off caffeine and xanthine for 24 hours.
        Beta blockers: off 72 hours.
        Nitrates: 12 hours.
        No recent nuclear medicine exams.




                                                                                108
                                  Molloy College NMT Program, 2010.




Treadmill Stress Test
 Exercise to 85% of max predicted heart rate. 220-age = max predicted heart
   rate. (85% may be controversial).
 Every 3 minutes rate increases, incline increases. BP taken every stage.
   EKG closely monitored.
 Patient needs to exercise for at least 1 minute after the injection.
 Then recovery stage (cool-down).
 If Mibi used then patient needs to wait 30min-1hour prior to imaging.
 If Tl201 used then patient is imaged right away.
 Exercise is the best method to stress the heart. It indirectly dilates coronary
   arteries. Replicates symptoms that patient may feel in real environment.
When not to perform exercise stress test:
 Amputees.
 Unable to walk long enough sufficiently.
 Patients with recent infarction.




                                                                                    109
                                 Molloy College NMT Program, 2010.




Adenosine
 Interacts with A2a and A2b receptors found in myocardium and respiratory
   system. Once it binds, the coronaries are stimulated to dilate 3x to 4x its
   normal diameter. Only the healthy coronaries dilate, abnormal ones do not!
 Caffeine and chocolate prevent adenosine from binding to a2a receptors;
   thus foods containing xanthine and caffeine must be avoided for 24 hours.
 Symptoms: flushing, headache, nausea, chest pain, palpitations, shortness
   of breath.
 Biological half-life of Adenosine is 12 seconds. Generally antidote is not
   given. Symptoms resolve on their own quickly.
 Adenosine dose: 140 micrograms per kg per minute. Max dose 90 mg.

 Adenosine is administered for 6 minutes, tracer given at end of 3 rd minute.
   Total infused dose for 6 minutes for 100kg patient: 140microgram x 100 x 6
   minutes.
 Contraindications: asthma, severe COPD, and severe aortic stenosis.

 HR does not increase, BP may drop slightly.


                                                                                 110
                                  Molloy College NMT Program, 2010.




Persantine
 Persantine typical dose: 0.57 mg x kg. Maximum dose: 60mg.
   Administered over 4 minutes. Isotope infused at 8 minutes after starting the
   infusion of persantine. Blood pressure and EKG is assessed every minute.
 Persantine induces secretions of cellular adenosine to augment the
   coronary blood flow.
 Symptoms: flushing, headache, nausea, chest pain, palpitations, shortness
   of breath. Same as adenosine but more pronounced.
 Caffeine and xanthine block the action of Persantine.

 Aminophylline 50 mg – 250 mg given to reverse Persantine.

 Contraindications: asthma, severe COPD, and severe aortic stenosis.

 HR does not increase, BP may drop slightly.




                                                                                  111
                              Molloy College NMT Program, 2010.




Dobutamine
 Dobutamine has an indirect effect on coronary flow reserve (CFR).
  It increases myocardial flow, but less than Adenosine and
  Persantine.
 It is administered as an IV infusion starting at 10 mcg/kg/min.
 Dose is increased every 3 min by 10 mcg to a total of 40 or 50
  mcg/kg/min. until at least 85% of age predicted maximum heart rate
  is achieved. Atropine is given to increase HR during last stage. The
  radiotracer is then injected and the infusion is maintained for 2 min
  thereafter.
 Common side effects include palpitations, chest pain, headache,
  flushing, and dyspnea, and in rare occurences tachyarrhythmias
  requiring reversal with Beta Blockers.
 Contraindicated in the setting of acute MI, acute coronary
  syndromes, uncontrolled HTN, aortic stenosis, and aneurysms.
 HR increases, BP increases.




                                                                          112
                                      Molloy College NMT Program, 2010.




Regadenoson
  Regadenoson is an A2A receptor agonist that is a coronary vasodilator. Activation of
   the A2A receptor produces coronary vasodilation and increases coronary blood flow
   the same way as Adenosine and Persantine.

   Caffeine and chocolate prevent Regadenoson from binding to a2a receptors; thus
    foods containing xanthine and caffeine must be avoided for 24 hours.

   Symptoms: flushing, headache, nausea, chest pain, palpitations, shortness of breath.
    Aminophylline 50-250 mg IVP is given to attenuate severe and/or persistent
    symptoms.

   The half-life of initial phase is approximately 2-4 minutes. An intermediate phase
    follows with a 30 minute half-life coinciding with loss of pharmacodynamic effect. The
    last phase consists of a decline in plasma concentration with a half-life of
    approximately 2 hrs.

   Regadenoson dose: 0.4 mg given IVP as a bolus over 10-20 seconds. The
    radiotracer is injected 10-20 seconds after Regadenoson is administered.

   Contraindications: asthma, severe COPD, and severe aortic stenosis, high grade
    heart block (second or third degree heart block without a pacemaker)
   HR does not increase, BP may drop slightly.                                              113
                                                   Molloy College NMT Program, 2010.




Imaging Pitfalls:
  Arms down: Lateral wall attenuation. Extend imaging time, keep the same
   position of the arms during rest and stress imaging.
  Breast attenuation: Anterior/Anteroapical defect. Strap around chest may
   help.
  Hot Liver/ Bowel: Inferior wall affected. Wait more time, large amount of water
   will clear bowel.
  Prone imaging, and attenuation correction with Gd/CT may help. Often focus
   of great debate among professionals.
  Review of wall motion: May reveal if the defect is real or not. Helps
   differentiate attenuation vs. real defect.
  ALWAYS REVIEW RAW DATA!!!
  Triple vessel disease: balanced disease in all three vessels will result in
   uniform distribution of the isotope in myocardium on stress. Stress EKG, wall
   motion as well as ventricular size should all be examined carefully.
    ›   Note: Ventricular size is relevant only if the patient exercised. If pharmacological stress, then its
        meaningless.



                                                                                                                114
                                                        Molloy College NMT Program, 2010.




Thallium Viability:
Irreversible tissue: MI
Reversible tissue: Ischemia, Stunning, Hibernating.
     Hibernation: chronic reduction in coronary blood flow leading to decrease in     contractile function that can be
     reversed by improving coronary flow. Thallium will show hibernation as delayed filling in.
     Stunning: altered metabolic and contractile function that follows an ischemic     episode. The only true way to
     diagnose stunning is to re-image the patient several months after the original scan to visualize stunning reversibility.
Patient selection:
     Recent MI.
     Patients who are unstable to be stressed.
     Low EF
     Recent stress test (positive).
Imaging Protocol
•    4.0 mCi Tl201 injected
•    30min delay, image.
•    24 hour delay, image.
•    Image interpretation is done same way as myocardial perfusion.




                                                                                                                                115
                         Molloy College NMT Program, 2010.




MPI imaging- diaphragmatic attenuation is most commonly
visualized in this cardiac wall?




                                                             116
                        Molloy College NMT Program, 2010.




Inferior Wall. Prone imaging may help by stretching the
diaphragm lower down away from inferior wall.




                                                            117
                           Molloy College NMT Program, 2010.




What is the method of localization for         201
                                                     Thallous chloride into
myocardium?




                                                                              118
                            Molloy College NMT Program, 2010.




Similar to potassium, distributes with the Na/K pump within 20
minutes post administration
Not fixed within the myocardial cells, it seeps in and out of the
cells.
Term: redistribution




                                                                119
                        Molloy College NMT Program, 2010.




What is the most common cause of a false negative
myocardial perfusion study?




                                                            120
                         Molloy College NMT Program, 2010.




Submaximal stress is the most common cause of a false-
negative myocardial perfusion study.




                                                             121
                         Molloy College NMT Program, 2010.




What term is used to describe paradoxic wall motion outward
movement during systole?




                                                              122
                        Molloy College NMT Program, 2010.




Dyskinesis (aneurysm)




                                                            123
                         Molloy College NMT Program, 2010.




What term is used to describe reduced wall motion?




                                                             124
              Molloy College NMT Program, 2010.




Hypokinesis




                                                  125
                         Molloy College NMT Program, 2010.




This pharmacologic stress agent has the shortest biological
half life of all the stress pharmaceuticals.




                                                              126
                           Molloy College NMT Program, 2010.




Adenosine, 13 second biological half-life.




                                                               127
                                                    Molloy College NMT Program, 2010.




Salivary Gland Imaging:
    Mechanical and chemical digestion. Three pairs of glands. Only parotids have Stensen’s ducts, the rest of glands
     empty directly into oral cavity.
    Tc99m pertechnetate is trapped by salivary glands and actively secreted into saliva.
Indications:
    Evaluation of tumors.
    Dryness (xerostomia) of mouth.
    Various blockages
Patient Prep:
    None necessary.
    Imaging:
          Patient is either seated in front of detector or supine.
          Patient’s head overextended to separate submandibular from sublingual glands.
          Tc99m pertechnetate 1-5 mCi injected IV.
          Flow study at 1 sec/frame imaged anteriorly.
          Immediate statics views for 3 minutes are obtained in Anterior, and Lateral views.
          Delayed imaging may be performed in Anterior and Lateral views for 5 minutes.
Gustutary stimulation:
    Performed to evaluate emptying.
    Patient swishes lemon juice in the mouth for 5 seconds and spits out into a disposable container (store in
     radioactive waste).
    Anterior and Lateral views are taken for 3 minutes at 10 minutes and 20 minutes post stimulation.
    Image interpretation:
          Symmetric uptake and emptying is normal.
          Any retention, lack of activity or anything asymmetric is abnormal.
          Warthin’s tumors are visualized as focal areas of increased uptake.
          Metastatic lesions are seen as focal cold areas.
          Poor overall emptying after gustutary stimulation is seen after recent radiotherapy.
          One sided retention after gustutary stimulation is seen in cases of obstruction.
                                                                                                                        128
                                                   Molloy College NMT Program, 2010.




Esophageal Transit Studies:
Indications
• Dysphagia (difficulty swallowing)
• Tumors obstructing esophagus.
• Pulmonary aspirations.
• Achalasia vs. Scleroderma evaluation

Imaging Procedure
• Patient is NPO for 2 hours.
• 300 uCi of Tc99m SC in 15 mL of water.
• Patient is sitting or supine, stomach positioned at the bottom of the field of view.
• Patient takes the 15mL of Tc99m SC in water in mouth swallows only when instructed.
• Dynamic imaging at 0.25 sec/frame for 1 minute starts.
• Patient swallows the entire radiopharmaceutical and continues to dry swallow for several minutes after.
• Second dynamic imaging: 15 sec/frame for 9 minutes.
• 24 hour static of the chest is imaged for 20 minutes if need to r/o pulmonary aspiration.

Image Interpretation
• Qualitative Analysis: images are inspected for any retained activity and a uniform passage of the bolus from mouth to
stomach.
• Quantitative Analysis: esophagus is broken down into 3 ROI’s. Proximal, Middle and Distal regions. Three curves are
generated to display the passage of activity.
• Normal: smooth progression of the bolus with very little (background) activity remaining after several swallows.
• Achalasia: loss of smooth muscle peristalsis. Observed as delayed passage of activity into stomach.
• Scleroderma: autoimmune disease attacks GI organs. Most of the activity makes it into the stomach.




                                                                                                                      129
                                                Molloy College NMT Program, 2010.




Gastroesophageal Reflux Studies
• Occurs when contents from the stomach or duodenum enter the esophagus.
• Occurs when lower esophageal sphincter becomes weakened, etc.
• One of the most sensitive studies available.
• The only study that can quantify results.
Indications:
• R/O gastroesophageal reflux.
• Follow up to therapy.
Imaging Procedure:
• Patient needs to be NPO for 8 hours.
• Esophageal transit study is done first.
• 300 uCi of Tc99m SC in orange juice is administered PO.
• Abdominal binder is then fitted onto the patient.
• Don’t crack ribs or xyphoid process. Ask about recent abdominal surgeries, etc.
• Patient is supine under the camera.
• A combination of acidity, large volume and abdominal pressure can induce reflux.
• Stomach is positioned at the bottom of the field of view.
• 6 static images for 3-5 minutes each are taken in Anterior and Posterior views.
• 1: 0 mm Hg
• 2: 20 mm Hg
• 3: 40 mm Hg
• 4: 60 mm Hg
• 5: 80 mm Hg
• 6 100 mm Hg
Image Interpretation:
• Reflux is visualized at any stage during the study.
• ROI’s may be drawn to assist in quantifying any possible reflux.
• Normal reflux may be present at 4% or lower. Anything above 4% is abnormal.

                                                                                     130
                                                        Molloy College NMT Program, 2010.




Gastric Emptying Studies:
• Divided into three regions: the fundus, the corpus, and the antrum.
• Motion of the smooth muscle of the stomach is coordinated so that food is propelled from the fundus towards antrum.
• Functional regions:
      • Fundus: controls the rate of liquid emptying.
      • Antrum controls the rate of solid emptying.
• Gastrin, Secretin and Cholecystokinin regulate function of the stomach.
Indications
• Evaluation of nausea, vomiting, abdominal fullness, distention, weight loss.
• Evaluation of gastroparesis.
Patient Prep
• NPO for 8 hours.
Standardized Meal:
• The standardized meal needs to be the same from patient to patient.
• Various standardized meals are available from meat and potatoes, chicken liver, etc. However, a standardized meal should
be    easily prepared, easily replicated from patient to patient, and easily stored in a department.
• Most common standardized meals: egg sandwich, or instant oatmeal.
• When preparing the meal, Tc99m SC (1.0 mCi) needs to be added prior to cooking.
• For liquid gastric emptying 125 uCi In-111DTPA in 300 mL of water is used.

                                                                                                                        131
                                                  Molloy College NMT Program, 2010.




Imaging Procedure
   Meals should be consumed within 5 minutes. Imaging should start immediately.
   Solid and Liquid:
         The patient eats the meal and drinks 300 mL of water with In-111 DTPA (for solid and liquid emptying).
   Solid only:
         The patient eats only the meal and drinks plain water (4-6 ounces)
   Liquid only:
         The patient drinks In-111 DTPA in water only.
   Use separate energy windows if performing solid and liquid emptying.
   Dual head cameras:
         Anterior and Posterior imaging for 1.5 – 2.0 hours dynamic mode (various protocols available)
         Geometric Mean applied.
   Single head cameras:
         Anterior or LAO projection. Patient may be at about 70 degrees reclining positioning.
Processing
   Assess for patient motion.
   ROI around stomach.
   TAC generated.
Image Interpretation:
   Normal
         Liquids: 10min – 45min
         Solids: 60min – 105min
   Slow emptying: peptic ulcers, diabetic gastroparesis, scleroderma.
   Fast emptying: Zollinger-Ellison sydrome, duodenal surgery, malabsorption.

                                                                                                                   132
                                                     Molloy College NMT Program, 2010.




Liver:
         •
        Beneath the diaphragm.
         •
        Four total lobes: right, left, caudate, quadrate.
         •
        Two principal lobes: left and right. Divided by Falciform ligament.
         •
        Dual blood supply: venous and arterial. (75% portal vein, 25% hepatic artery).
         •
        Two major cell types: hepatocytes and reticuloendothelial cells.
           • Hepatocytes: convert billirubin into bile.
           • Reticuloendothelial cells (Kupffer cells) engulf foreign particles and toxins.
• Spleen:
      • Located in the left upper quandrant of the abdomen.
         • Contains lymphatic tissue, part of reticuloendothelial system not digestive system.




                                                                                                 133
                                                    Molloy College NMT Program, 2010.




Liver / Spleen Study:
Indications:
• Evaluation of cirrhosis, hepatitis and metabolic disorders.
• Evaluation of fatty liver.
• Evaluation of liver morphology and hepatomegaly.
• Uptake by reticuloendothelial cells allows imaging.
Patient Prep:
• None needed.
Imaging Procedure:
• 5-10 mCi of Tc99m Sulfur Colloid I.V. Method of localization is phagocytosis.
• Flow study obtained for 2-3 seconds per frame for 1-2 minute in Anterior projection.
• After 15 minute delay static views are obtained. (15 minutes wait is necessary to maximize liver and spleen uptake).
• Static views: Ant, Rao, Rlat, Rpo, Post, Lpo, Llat, Lao are taken for about 500k.
• Marker view in Ant projection is obtained for 500k with lead marker placed along costal margin.
Image Interpretation:
• Marker view is used to estimate relative size, shape and location of the liver and spleen.
• Abnormalities are associated with focal or diffuse photopenic areas in the liver.
• Lack of isotope uptake indicates disease and loss of function depending on the clinical history.



                                                                                                                         134
                                                 Molloy College NMT Program, 2010.




Liver Hemangioma Imaging:
    Most common benign tumors of the liver.
    Often seen as uknown lesions on US, CT and MRI, and need further evaluation with Nuclear Medicine.
    Biopsy not possible due to possible severe bleeding from hemangioma.
    Do not perform after contrast studies to avoid attenuation from barium.
Patient Prep:
    None necessary.
    Radiopharmaceutical:
          20-30 mCi Tc99m RBC’s tagged IN-VITRO method.
    Imaging Procedure:
          Flow (in projection closest to the lesion ) 1-2 sec/frame for 1 minute.
          Early statics: Ant, all Obliques: 500-1000k, Laterals: 250k-500k.
          Early SPECT. 20sec/frame 64 stops.
          Delayed statics (2hours) Ant, all Obliques: 500-1000k, Laterals: 250k-500k.
           Delayed SPECT: 30sec/frame 64 stops.
               Statics views must be acquired for counts and not time to accommodate for decay.

               Increase time per frame for SPECT to accommodate for decay.

    Image interpretation:
          Hemangioma: cold on flow (with possible hot rim around lesion), hot on delay.
          Cysts: cold flow, cold delay.
          Tumor: hot flow, hot or normal delay.




                                                                                                          135
Molloy College NMT Program, 2010.




                                    136
                                                          Molloy College NMT Program, 2010.




Hepatobiliary Imaging
     IDA agents tagged with isotope are cleared by hepatocytes as the bilirubin and converted into bile.
Indications:
     Evaluation of acute and chronic cholecystitis.
     Evaluation of bile flow obstruction.
     Post surgical complications.
     Evaluation of biliary atresia.
     Patient prep:
            NPO for 4 hours: recent food ingestion will stimulates production of CCK and thus the contraction of gallbladder. If the
             gallbladder is contracted, the isotope may not be able to be localized there. (false positive finding).
            NPO for longer than 24 hours will result in full gallbladder with no more room for the isotope.
     Imaging Protocol:
            5-10 mci IDA agents
            Immediate flow maybe performed to evaluate for perfusion abnormalities (1 sec/frame for 60 sec)
            Functional flow (for 60 min. Ex: 12 frames 5min/frame, or 60 frames 1 min/frame).
            Additional views: RLAT, LAO RAO maybe taken to evaluate for gallbladder vs. looping bowel. RLAT is the view of
             choice.
            Additional images are taken until 4 hours post injection is reached.
     CCK (or fatty meal) infusion: will stimulate GB contraction and allow evaluate of GB wall motion. Infused only after small
      bowel is visualized.
     Morphine: Since acute cholecystitis is associated with cystic duct obstruction, visualizing gallbladder will rule this condition
      out. Morphine is infused only after the small bowel is visualized.
     Image Interpretation:
            Normal Liver, Gallbladder and small bowel visualized with in 1 hour.
            Chronic Cholecystitis: visualization of liver and small bowel, delayed visualized of gb (2-4 hours after injection)
            Acute Cholecystitis: visualization of liver and small bowel, no visualization of gb at 4 hours.
            Obstruction of Common Bile duct: no visualization of small bowel at 4 hours.
            Obstruction of Hepatic Duct: no visualization of anything below the left and right hepatic ducts at 4 hours.
Interventional drugs:
            CCK – naturally produced, Sincalide – synthetic form of CCK.
            Fatty meal may also be used to induce natural CCK production: stimulates contraction of gallbladder and relaxation of
             sphincter of Oddi.                                                                                                          137
                                                    Molloy College NMT Program, 2010.




Meckel’s Diverticulum Imaging:
   Outpouching of the intestine, located usually in distal ileum. It is a remnant of an embryonic duct and is found in
    2% population with only 25% of those show symptoms.
   The diverticulum may contain gastric mucosa which secretes hydrochloric acid and pepsin. GI bleeding and pain
    may occur when those secretions cause ulcers around the diverticulum.
   Patient Prep:
         Preferred NPO.
         Potassium perchlorate should not be used as it may block gastric mucosa. (false negative)
         Pentagastrin is administered to stimulate gastric secretions thus increases isotope uptake. OR,
         Cimetidine is administered which helps retain isotope in gastric mucosa after the uptake.
   Radiopharmaceutical:
         Tc99m pertechnetate, 10mci IV.
   Imaging Procedure:
         Functional flow study for 60 minutes, with optional delay images.
   Image Interpretation:
         Meckel’s diverticulum is usually visualized within 20 minutes.
         Whole entire abdomen must be placed in the field of view.




                                                                                                                          138
Molloy College NMT Program, 2010.




                                    139
                                                    Molloy College NMT Program, 2010.




Gastrointestinal Imaging:
   GI bleeding scan is a very sensitive and accurate study to determine gi bleeding.
   It can detect bleeding as slow as 1ml/hr.
   The most important and useful aspect of GI bleeding studies is the ability to pinpoint the exact location of the
    bleeding site either in small or large bowel.
   Radiopharmaceuticals:
          Tc99m SC: used only for active bleeding. Imaging possible for the first 20 minutes as the isotope is taken up
           by the liver and clears the circulation. Small bowel bleeding is difficult to assess as the liver may obscure
           the site.
          Tc99m RBC’s: in-vitro should be used. Allows for imaging up to 36 hours post injection. Patient positioning
           should include the tip of the heart in the upper field of view to ensure that entire abdomen is in the view.
           Visualization of stomach signifies free technetium.
Patient Prep:
    None necessary.
    Imaging Procedure:
         3 min/frame for 20 frames in Anterior view.
         Delay dynamic imaging as necessary up to 36 hours post injection.
    Image Interpretation:
         Normal: Visualization of major blood vessels and outline of organs.
         Abnormal: Increased focal uptake that continues to increase in intensity and moves down the GI tract.




                                                                                                                           140
Molloy College NMT Program, 2010.




                                    141
                            Molloy College NMT Program, 2010.




A curved band of increased activity along upper rim of the
gall bladder (rim sign) on hepatobiliary with subsequent
non visualization of the gall bladder is associated with this
condition.




                                                                142
                        Molloy College NMT Program, 2010.




Acute cholecystitis – most common
Less common- perforated or gangrenous gall bladder.




                                                            143
                             Molloy College NMT Program, 2010.




This is the effective half life of   99m
                                          Tc Sulfur Colloid in the liver.




                                                                        144
                        Molloy College NMT Program, 2010.




6 hours
99m
    Tc sulfur colloid is not cleared from the body,
therefore the effective half life is equal to the
physical half life.




                                                            145
                    Molloy College NMT Program, 2010.




Name two reasons why a patient may be given
synthetic of CCK. (kinevac, sincalide) in
conjunction with hepatobiliary imaging?




                                                        146
                          Molloy College NMT Program, 2010.




• Gall bladder Ejection Fraction
• If the patient has been NPO the GB may be in shock/
filled with sludge. CCK may be given to stimulate GB at some
point prior to injection of radiopharmaceutical




                                                               147
                          Molloy College NMT Program, 2010.




In cases of visualization of liver and bowel but no
visualization of gallbladder, which pharmaceutical may be
used to avoid delay imaging?




                                                              148
                        Molloy College NMT Program, 2010.




Morphine Sulfate, 0.04 mg/kg.




                                                            149
                          Molloy College NMT Program, 2010.




On liver/spleen perfusion images, normally a first hint of
activity is seen in the liver, followed by a second, more
pronounced influx of activity approximately 3-5 seconds
later. What is this related to?




                                                              150
                          Molloy College NMT Program, 2010.




Arterial flow through the hepatic artery followed by venous
flow through the portal vein.




                                                              151
                                       Molloy College NMT Program, 2010.




Thyroid Uptake and Scan
• Located between suprasternal notch and thyroid cartlidge.
• Two lobes connected by isthmus, each lobe is 3-4cm pole to pole.
• Thyroid produces T3 and T4 hormones from iodine contained in food.
• Iodine is trapped by follicular cells (iodine pump).
• Monoidotyrosine (MIT) and Diiodotyrosine (DIT) are building blocks of T3 and T4.
• T3 and T4 are stored in thyroid and released into blood stream when necessary.
• Negative feedback system:
     • Anterior pituitary regulates thyroid function by secreting TSH.
     • Low levels of T3 and T4 cause more TSH to be released, and vice versa.
Radiopharmaceuticals:
• Method of localization is trapping by thyroid gland.
• I 131 capsule: 15-30 uCi. Used for uptake only, needs pertechnetate for imaging.
• I 1234 capsule: 200 – 400 uCi. Used for uptake and scan.
• Tc99m Pertechnetate: 5-10mCi IV. Scan only. Usually combined with I 131 uptake.
                                                                                     152
                                     Molloy College NMT Program, 2010.




Patient Prep:
• Iodine Containing Products:
     • Lugol’s Solution, Kelp, Vitamins, Cough Medicine: 2-4 weeks.
• Contrast Media
     • IV contrast: 2-4 weeks.
     • Oral Contrast: 4-6 weeks.
• Thyroid Medications:
     • Thyroxine 4-6 weeks.
     • Triiodothyronine: 2-3 weeks.
• Antithyroid Medications:
     • Propylthiouracil 2-8 days.
     • Methimazole 2-8 days.
• Others:
     • ACTH, adrenal steroids 8 days.
     • Perchlorate 1 week.
     • Pertechnetate 1 week.

Iodine Administered, patient is instructed not to eat for 1 hour, and return for uptake and
scan at a scheduled time.

                                                                                          153
                                      Molloy College NMT Program, 2010.




Indications:
• Evaluation of nodules.
• Evaluation of hyperthyroidism or hypothyroidism.
• Evaluation of thyroiditis.
• Evaluation of Graves disease.
• R/O ectopic thyroid tissue.
Procedure:
• I 131 uptake with Pertechnetate for Imaging:
     • I131 15-30 uCi P.O.
     • 4 hour uptake.
     • 4 hour scan with 5-10 mCi Tc99m Pertecnetate.
          • Ant, Ant Mark SS notch, Lao, Rao, Chest unzoomed for ectopic.
          • 5-10 minutes per frame, use largest zoom or pinhole collimator.
     • 24 hour uptake.
• I 123 uptake with scan.
     • I 123 200 – 400 uCi P.O.
     • 4 hour uptake.
     • 4 hour scan (either 4 hour or 24 hour scan is done)
          • Ant, Ant Mark SS notch, Lao, Rao, Chest unzoomed for ectopic.
          • 5-10 minutes per frame, use largest zoom or pinhole collimator.
     • 24 hour uptake.
     • 24 hour scan if the scan at 4 hours was not done.
                                                                              154
                                     Molloy College NMT Program, 2010.




Image Interpretation
• Normal: butterly shaped, symmetrical uniform distribution. No other focal uptake
outside the thyroid gland. Pyramidal lobe may be detected.
• Abnormal:
     • Gland enlargement.
     • Ectopic tissue.
     • Hot nodule(s) generally benign.
     • Cold nodule(s) many => benign or cysts, single => usually malignancy.

Technical Considerations:
• Oblique views are taken with the camera turned, not patient’s head turned.
• If ectopic tissue detected, consider repeating uptake to include the ectopic tissue into
     calculations.




                                                                                             155
Molloy College NMT Program, 2010.




                                    156
                                      Molloy College NMT Program, 2010.




Parathyroid Imaging:

• Four glands, located posteriorly to the thyroid.
• Can also be ectopic.
• Produce parathyroid hormone that regulates calcium and phosphorus content in the
    blood by:
    • Regulating osteoclastic activity.
    • Regulates tubular reabsorption of phosphorus in the kidneys.
    • Regulates absoption of calcium in the intestine.
• Parathyroid gland is regulated by levels of calcium and phosphorus in blood (negative
    feedback system)

Indications:
• Identification of adenoma in patients with hyperparathyroidism.
• Localization of adenomas prior to surgery.

Radiopharmaceutical:
• Tc99m Sestamibi: taken up by both thyroid and parathyroid. Washes out of normal
     tissues, retention of isotope in adenomas for several hours post injection.
• Tc99m Pertechnetate: taken up only by the thyroid. Allows for subtraction of thyroid
     image from thyroid and parathyroid image.

                                                                                          157
                                     Molloy College NMT Program, 2010.




Special Considerations:
• Patient’s neck should be hyperextended, but remains comfortable to minimize motion.
• Neutral neck position is acceptable if risking motion.
Imaging Procedure:
• Sestamibi Method:
     • 25-30mCi Tc99m Sestamibi IV.
     • 30 min delay. Early Images: Ant neck with zoom and without, 5-10 minutes.
     • 2 hour delay. Delay Images Ant neck with zoom and without 5-10 minutes.
     • SPECT of neck: important to visualize location of the adenomas.
• Sestamibi with Pertechnetate subtraction:
     • 4-5 mCi Tc99m pertechnetate injected IV.
     • After 20 minutes, Anterior image of the neck is acquired.
     • 25-30 mCi Sestamibi is injected.
     • 30 min delay. Early Images: Ant neck with zoom and without, 5-10 minutes.
     • 2 hour delay. Delay Images Ant neck with zoom and without 5-10 minutes.
     • SPECT of neck: important to visualize location of the adenomas.
     • Subtraction technique is performed:
          • Sestamibi (thyroid and parathyroid) – Pertecnetate (thyroid) = parathyroid
          adenoma.
          • Patient must not move for pixel coregistration.
          • Images must be normalized for subtraction to work properly.

                                                                                         158
                                     Molloy College NMT Program, 2010.




• Normal Image Findings: Uniform and symmetrical distribution of the isotope. No
         retention as focal hot spots on delay imaging.
• Abnormal Image Findings: Retention of isotope seen as hot focal uptake. Confirmed
on       SPECT.




                                                                                      159
                                        Molloy College NMT Program, 2010.




Adrenal Imaging
• located at the superior poles of the kidneys.
• Contain outer cortex and inner medulla.
• Cortex produces aldosterone, cortisol, etc.
• Medulla produces epinephrine and norepinephrine.
• Tumors of adrenal glands are called pheochromocytomas.
• Pheochromocytomas produce excess amounts of epinephrine and norepinephrine,
and could be malignant or benigh.
• Unused epinephrine and norepinephrine is reabsorbed by adrenal glands.

Radiopharmaceutical:
• I131 MIBG is an analog of norepinephrine. Does not create response but is
reabsorbed by adrenal glands.

Indications:
• Evaluation of pheochromocytomas.

Patient Prep:
• Lugol’s solution prior to injection to block thyroid uptake.



                                                                                160
                                    Molloy College NMT Program, 2010.




Clinical Procedure:
• 0.5 mCi I131 MIBG IV.
• Whole body imaging at a very slow rate (5cm/min) at: 24 hours, 72 hours and 7 days
post injection.
• SPECT not done due to low count rate.
• Static views of specific areas maybe performed.
• Patient voids prior to imaging.

Image Interpretation:
• Normal: liver, spleen, heart, salivary glands, bladder.
• Abnormal: Hot focal uptake that persists over time is an indication of abnormal uptake.




                                                                                        161
                            Molloy College NMT Program, 2010.




A term is used to describe a normal variation of the thyroid in
which a narrow strip of thyroid cells extend upward from the
isthmus?




                                                                  162
                 Molloy College NMT Program, 2010.




Pyramidal lobe




                                                     163
Molloy College NMT Program, 2010.




                                    164
Molloy College NMT Program, 2010.




                                    165
Molloy College NMT Program, 2010.




                                    166
Molloy College NMT Program, 2010.




                                    167
Molloy College NMT Program, 2010.




                                    168
Molloy College NMT Program, 2010.




                                    169
        Molloy College NMT Program, 2010.


The blood-brain barrier (BBB) is a membranic structure that acts
primarily to protect the brain from chemicals in the blood, while still
allowing essential metabolic function. It is composed of endothelial
cells, which are packed very tightly in brain capillaries. This higher
density restricts passage of substances from the bloodstream much
more than endothelial cells in capillaries elsewhere in the body.




                                                                      170
                                            Molloy College NMT Program, 2010.




Indications:
    –      Brain Death
    –      Primary and metastatic tumors
    –      Intracranial inflammatory
    –      Cerebrovascular disease: hemorrhage and occlusion
    –      Hemotoma (post trauma)
Radiopharmaceuticals:
(NORMALLY DO NOT CROSS BLOOD BRAIN BARRIER):
    –      Tc99m: least desirable due to uptake in choroid plexus. Require potassium perchlorate.
    –      Tc99m DTPA or Tc99m GH: best to use. Clear far away from the brain, and offer optimal
           imaging characteristics.
Imaging:
    –      Flow: 1sec/frame for 1-2 minutes
    –      Immediate Blood Pool: 180 sec/frame immediately after the flow study
    –      Delays: 300 sec/frame depending on the indications may be done 15 min. – 2 hrs. after blood
           pool.


                                                                                                         171
                                             Molloy College NMT Program, 2010.




Patient Positioning:
   Vertex view is the ideal position for flow and statics. Lead shield over shoulders is required to
    block background radiation from the shoulders and below. If vertex view is not possible then:
   Anterior/Posterior positioning is acceptable .
   Laterals and Obliques may be helpful when imaging blood pool and delayed views.

Image Findings:
  Normal: Symmetrical distribution of the isotope in the right and left carotid arteries and
   visualization of the anterior cerebral artery. Visualization of the superior sagittal sinuses indicates
   that isotope is entering venous circulation. Sagittal, transverse and sigmoid sinuses will be
   visualized on the delayed images.
  Abnormal: any disruption of BBB is an abnormal finding.
      Brain Death: no activity visualized above carotid arteries on flow, bp, or delayed images.
      Inflammation: increased activity on flow and statics around the suspected area. (less focal
         than hematoma).
      Hematoma: increased focal uptake around the suspected area. (more focal than
         inflammation).
      CVA: occlusion of blood vessels demonstrated by narrowing of the affected blood vessels on
         flow study.
      Flip-flop: one hemisphere is receiving more isotope in the beginning of the flow study.
         Pattern reverses by the end of the flow study.
      Luxury perfusion: affected area is attempting to restore flow by dilating vessels responsible
         for CVA seen as increased flow to the affected area.
                                                                                                             172
                                              Molloy College NMT Program, 2010.




Indications:
•    Cerebrovascular disease: acute stroke, transient ischemic attacks.
•    Dementia: Alzheimer’s disease, multi-infarct dimentia.
•    Schizophrenia.
•    Seizires: location of epileptic foci.
•    Head trauma.

Radiopharmaceuticals (ALL CROSS BBB):
I123 iodofetamine not available in U.S.
Tc99m HMPAO (Ceretec) 30mCi
Tc99m Neurolite (ECD) 30mCi
     All of the above isotopes are lipid soluble allowing them to cross BBB. Once across BBB the solubility
     changes and the agents remain in the brain tissue.
Injection technique:
•    IV access ready (no direct sticks)
•    Dim lights, eyes open, room quiet.
•    Inject isotope wait 10 minutes
•    Remove IV, let the patient go.
•    Image 1-2 hours post injection.



                                                                                                          173
                                                   Molloy College NMT Program, 2010.




Imaging Procedure:
   Prone positioning, head immobilized with straps and cushions. No pillow under patient’s head.
   Triple head or double head cameras with highest resolution collimators.
   SPECT positioning should be as close to the patient as possible.
   Brain SPECT study is a long procedure, use your judgment when setting up the scan.

    Suggested SPECT setup:
        128x128.16 matrix
        128 views 30 sec/frame

Processing:
         Proper orientation must be achieved
         Coronal, sagittal, and transverse slices are generated..

Image Interpretation:
   Normal: symmetric distribution of isotope in both hemispheres. Gray matter concentrates much more isotope than
    the white matter.
   Abnormal:
         Infarct: large defect directly related to the location of the CVA
         Alzheimer’s: decreased perfusion in the parietal and temporal lobe of both hemispheres
         Multi-infarct dementia: random cold spots in both hemispheres
         Schizophrenia: decreased uptake in the frontal lobe, with increased activity in the basal ganglia and
          temporal lobes
         Epilepsy:
              Injection during seizure: foci will concentrate isotope (intra-ictal)

              Injection immediately after seizure: hypoperfusion of the foci (inter- ictal)                       174
                                          Molloy College NMT Program, 2010.




   SPECIAL STUDIES:
   Acetazolamide (Diamox) may be used to increase the sensitivity of brain perfusion imaging for
    cerebrovascular ischemia (TIA’s). Easy to remember hint: “DIAMOX IS TO BRAIN AS ADENOSINE
    TO THE HEART”
   1. Contraindications for Diamox Study:
   a) allergy to sulfonamide.
   b) Current active transient ischemic attacks.
   2. Side effects - occur in about 50% of patients & last for about 15 minutes:
      a) numbness around mouth or fingers.

      b) lightheadedness or blurred vision.

      C) flushed feeling around face and neck.

   3. Inject 1 gm of acetazolamide intravenously over 10-15 minutes.
   4. Wait 15-20 minutes and then inject the radiopharmaceutical.
   5. Wait 20 minutes and acquire images in the usual manner.
   6. A baseline brain perfusion study without acetazolamide is performed one or more days later.
   Quantification: Activity in the tomograms may be quantitated on a regional basis.




                                                                                                     175
                                              Molloy College NMT Program, 2010.




CSF is produced in lateral ventricles of choroid plexus. From lateral ventricles CSF flows into third
   ventricle, then into fourth ventricle, and finally into subarachnoid space. CSF flows around the
   spinal cord and the brain in the subarachnoid space and is reabsorbed into venous circulation in
   the sagittal sinuses. CSF is produced and reabsorbed at the same rate to maintain constant
   pressure.

Indications:
    Evaluation of atrophy vs. normal pressure hydrocephalus
    CSF leaks
    Ventricular shunt patency

Patient Prep and Injection (Cysternography):
   In111 DTPA, 1.0 mCi in injected intrathecally into subarachnoid space between 3rd and 4th
    vertebrae. The tracer will follow the flow of the CSF. Injection is usually performed by a radiologist
    or a neurologist.
   After the injection, the patient remains supine for several hours to prevent leakage from the
    injection site.
Imaging:
   4 hour images: ANT/POST of injection site. Tracer should be visualized in the subarachnoid
    space. If only a hot spot is seen and/or uptake in the kidneys, then the dose may have been
    infiltrated.
   24 and 48 hours: ANT/POST of head, chest and abdomen. Lateral s of the head may be useful.
Image findings:
    NPH: activity in the ventricles and cisterns is seen on 24 hours but is resolved by 48 hours.
    Atrophy: activity does not resolve from the ventricles or cisterns by 48 hours.
                                                                                                             176
                                              Molloy College NMT Program, 2010.




CSF Leak studies:
  In patients with suspected trauma and/or reported possible clear discharge from nose (otorrhea) and/or
   ears (otorrhea), cotton swabs are inserted into ears and nose immediately after injection of In111 DTPA.
  Swabs are replaced and counted every time the patient returns for imaging.
  The background needs to be counted as well.

Shunt imaging:
In many cases, ventricular shunting of the CSF into the circulatory system or abdominal cavity is used to
    treat cases of NPH. Injection of the In111 DTPA or Tc99m directly into the shunt reservoir will clearly
    demonstrate shunt patency. Persistent tracer uptake in the shunt indicate partial or complete
    obstruction of the shunt.




                                                                                                          177
                    Molloy College NMT Program, 2010.




This condition of the brain will demonstrate a
 “hot nose” or rim sign following injection of
 radiopharmaceutical for cerebral perfusion
 images.




                                                        178
                    Molloy College NMT Program, 2010.




 Brain death
 No intracranial blood flow from base of skull
  up.




                                                        179
                          Molloy College NMT Program, 2010.




What is the method of localization utilized for
cisternography imaging using
 111
    In DTPA?




                                                              180
                   Molloy College NMT Program, 2010.




Compartmentalization.
Intrathecal injection into the
subarachnoid space.




                                                       181
                                     Molloy College NMT Program, 2010.




Thyroid Carcinoma: given to kill thyroid cells remaining after surgery, treat
   hyperthyroidism, kill mets.

Patient Prep:
-   doses over 30 mCi require hospitalization
-   Patients must not be pregnant or breast feeding
-   If nursing an infant then arrange a way to stay away
-   Flush twice, keep utensils separate, minimize time with others, maximize
    distance from others
-   Patient is fasting before the pill
-   When patient is admitted visitors and nursing staff monitored for exposure
-   2mr/hr NRC limit for visitors




                                                                                 182
                                  Molloy College NMT Program, 2010.




Calculations for discharge:
-     when calculated dose remaining drops below 30 mCi patient may be released
-     Measurements are taken 3 meters away
Discharge Instructions (NRC regulations)
ASSUMPTION: iodine is excreted for 1 week post discharge
1.    Intimate personal contact to be avoided
2.    Use separate bathroom if possible
3.    Keep eating utensils separate
4.    Wash hands often




                                                                                  183
                                       Molloy College NMT Program, 2010.




Sodium Phosphate p-32 (CLEAR)
-  used to treat polycythemia vera and control bone pain from mets
-  Doses : 1-20 mCi
-  Pure beta emitter (shielding: glass and plastics only)
-  Make sure right patient, right dose, right isotope, right diagnosis
-  Mets and bone pain:        larger dose
-  Polycythemia vera: smaller dose
-  Make sure clear isotope
-  Pure beta: no precaution once injected!

Chromic Phosphate p-32 (blue-green)
-  intracavity injection only
-  Treats tumors found within cavities
-  If injected IV, liver uptake will occur with severe damage
-  Blue-green color = reminder of route of administration
-  Drainage from injection site presents a contamination hazard




                                                                           184
                                        Molloy College NMT Program, 2010.




Strontium89
-   relieves bone pain from mets
-   Method of localization: calcium analog related to bone metabolism. Mets sites will take up
    more isotope
-   Dose is 4.0 mCi
-   Depending on response may be given at 3 month intervals
-   Pure beta emitter: plastic shielding, no lead
-   2/3 of dose is excreted via urine
-   Bathroom needs to stay clean, flushing 3 times
-   Flare effect: approximately 2 weeks past injection bone pain worsens. This is an
    indication that the therapy is working. Sr-89 does not kill mets cells, but ablates nerve
    endings near mets sites – easing the pain.




                                                                                            185
                                      Molloy College NMT Program, 2010.




Zevalin Therapy (ibritumomab)
-  Murine monoclonal antibody.
-  Ibritumomab induces cell apoptosis.
-  Can be tagged to In-111 for diagnostic purposes.
-  Can be tagged with Y-90 for treatment purposes.

Method of Localization
-  antibody/antigen concept based on Cd20 expression.
-  Rituximab is given first to increase uptake of ibritumomab.
-  Ibritumomab without rituximab = 18% uptake of ibritumomab.
-  Ibritumomab with rituximab = 56-92% uptake of ibritumomab.
-  70% of ibritumomab is excreted through urine.




                                                                          186
                                     Molloy College NMT Program, 2010.




Commonly Accepted Protocol:
• Step1:
    • 250mg of rituximab infused at rate 50mg/hr.
    • 4 hour delay.
    • 5.0 mCi In111 Zevalin (ibritumomab) infused over 10minutes.
    • Imaging takes place over 7 day period.
    • Normal Distribution of In111 Zevalin (proceed to step2):
         • Day 1: blood pool.
         • Day 6: diseased cells, very little blood pool.
    • Abnormal Distribution of In111 Zevalin (do not proceed to step2):
         • Day 1: blood pool.
         • Day 6: persistent blood pool.
• Step2:
    • 250mg of rituximab infused at rate 100mg/hr.
    • 4 hour delay.
    • 0.4 mCi/kg of Y90 Zevalin infused. Maximum dose = 32 mCi.




                                                                          187
                  Molloy College NMT Program, 2010.




Which of the following is blue/green in color?


A. 32 P Chromic Phosphate
B. 32 P Sodium Phosphate
C. 89 Strontium Chloride
D. 90 Y microspheres




                                                      188
                 Molloy College NMT Program, 2010.




32 P Chromic Phosphate




                                                     189
                  Molloy College NMT Program, 2010.




Which of the following are pure beta
 emittors?
A. 32 P chromic Phosphate
B. 32 P sodium Phosphate
C. 89 Strontium Chloride
D. 90 Y microspheres
E. 131 I
F. 153 Sm EDTMP (Quadramet)
                                                      190
                    Molloy College NMT Program, 2010.




A, B, C, D are pure beta emitters, E and F are
  not.




                                                        191
                   Molloy College NMT Program, 2010.




Which isotope is used to treat polycythemia
 vera?
A. 32 P Chromic Phosphate
B. 32 P Sodium Phosphate
C. 89 Strontium Chloride
D. 90 Y microspheres
E. 131 I
F. 153 Sm EDTMP (Quadramet)
                                                       192
                     Molloy College NMT Program, 2010.




32
     P Sodium Phosphate

What is P32 Chromic Phosphate used for?
Answer: intracavity installation for Peritoneal
  and
        pleural effusions.



                                                         193
                   Molloy College NMT Program, 2010.




Which of the following are not administered IV?
 A. 32 P Chromic Phosphate
 B. 32 P Sodium Phosphate
 C. 89 Strontium Chloride
 D. 90 Y micro spheres
 E. 131 I
 F. 153 Sm EDTMP

                                                       194
                      Molloy College NMT Program, 2010.




A.    32
        P chromic Phosphate
           No, intra cavity
 B.    32
          P sodium Phosphate
          Yes,
 C.    89
          Strontium Chloride
          Yes, slow
 D.     90
           Y microspheres
          No, intra arterial
 E.    131 I
        No, oral
 F.    153 Sm EDTMP
        Yes,
                                                          195

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:24
posted:9/10/2011
language:English
pages:195