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veo a new Breakthrough is re-writing the rules of low-dose Ct imaging

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					                                                                                 CliniCal valUe                                            U lt r a - l o w D o s e




                                                              veo: a new Breakthrough is re-writing
                                                              the rules of low-dose Ct imaging
                                                              0.05 mSv Follow-up Exam                                                       Picture a world where Ct dose is no longer a significant concern. where clinicians
                                                              for Cystic Fibrosis                                                           can use Ct to obtain more information about human anatomy and conduct every
                                                                                                                                            exam at 1 msv or less. and, where clinicians and patients are confident that a
 images courtesy of University Hospital, Brussels (Belgium)




                                                                                                                                            routine Ct exam will provide the detailed diagnostic information at currently
                                                                                                                                            unheard of doses.
                                                                                                                                            Picture that world taking the first step to emerging today.
                                                                                                                                            veo*§ is the amazing advance from Ge Healthcare in Ct model-based image
                                                                                                                                            reconstruction that has enabled clinicians to achieve a remarkable breakthrough
                                                                                                                                            in ultra-low dose for Ct imaging.** several clinicians from around the world
                                                                                                                                            have experienced the ultra-low dose and high image quality capabilities
                                                                                                                                            of veo and believe this reconstruction technique may enable a breakthrough
                                                                                                                                            in low-dose imaging.
                                                                                                                                            the Discovery* Ct750 HD is the first Ge system with this new game-changing
                                                                                                                                            technology. the University Hospital, Brussels, was also one of the first clinical
                                                                                                                                            sites worldwide to use veo. Johan de Mey, MD, PhD, Chair of the radiology
                                                                                                                                            Department, and nico Buls, PhD, radiation Physicist, began testing the
                                                                                                                                            reconstruction technique with a phantom to see how low they could get dose
                                                                                                                                            to go and still expect to be able to view the simulated anatomy and pathology.
                                                                                                                                           “with a clinical chest Ct at 0.05 millisieverts, we produced images where we could
                                                                                                                                            see and analyze pathology,” Prof. de Mey says. “achieving that ultra-low dose
                                                                                                                                            with readable images was quite amazing.”
                                                              Figure 1. veo images demonstrate high image
                                                              quality at ultra-low dose of 0.05 msv (obtained                               and while it already offers the dose-lowering technology asir* (advanced statistical
                                                              by eUr-16262 en, using an adult chest factor                                  iterative reconstruction), Kwek Boon Han, MBBs, FrCr, FaMs, radiologist with
                                                              of 0.017 DlP) for 26-year-old patient with cystic
                                                                                                                                            asia HealthPartners (aHP) (singapore) says, “with veo, the image quality is
                                                              fibrosis. acqusition parameters: 80 kv, 10 ma,
                                                              0.4 sec rotation. (top) veo coronal image with                                outstanding even as the dose is dramatically lowered.” He explains that veo takes
                                                              lung window width and window level settings.                                  into account the three-dimensional nature of the X-ray source, image voxel,
                                                              (Bottom) volume rendering with segmentation                                   and the detectors in the modeling of the final image rather than assuming these
                                                              of the lobes of the lungs and bronchi.
                                                                                                                                            factors to be mere single-dimensional points in space.
                                                                                                                                           “Ge Healthcare has taken the leadership role in reducing radiation dose in Ct,
                                                                                                                                            culminating in the ultra-low dose Ct with veo,” Dr. Kwek adds.


                                                                                                                                            Changing imaging protocols
                                                                                                                                            long recognized for providing greater clarity and more detail than conventional X-ray
                                                                                                                                            exams, Ct has changed the way clinicians diagnose disease and monitor patient
                                                                                                                                            treatment. Yet, the invaluable information Ct provides has contributed to increased
                                                                                                                                            use and rising concerns over dose in recent years. Healthcare professionals,
                                                                                                                                            following alara principles, are required to take every reasonable effort to
                                                       §
                                                              veo is 510(k) pending at FDa. not available for sale in the United states.    minimize exposure to ionizing radiation. veo represents one of the most significant
                                               **
                                                              in clinical practice, the use of veo may reduce Ct patient dose
                                                              depending on the clinical task, patient size, anatomical location
                                                                                                                                            breakthroughs providing the ability for a step change in dose reduction.
                                                              and clinical practice. a consultation with a radiologist and a
                                                              physicist should be made to determine the appropriate dose
                                                              to obtain diagnostic image quality for the particular clinical task.



32                                                              a Ge Healthcare Ct publication • June 2011
                                                                                                                                        U lt r a - l o w D o s e           CliniCal valUe




                                                                                                                                                                                                   Dr. Jean-Louis
                                                                                                                                                                                                   name of author
                                                                                                                                                                                                   Sablayrolles

                                                             the challenge of low-dose imaging is to perform a Ct scan with the lowest possible
                                                             dose that enables a clinical diagnosis, says Dr. Kwek. it’s a balance between noise
                                                             levels that result from lower dose and image quality. so, he selected dose reductions
                                                             that commensurate with the comfort level of the reporting radiologists.                                  info about clinic, etc.
                                                                                                                                                                      Jean-louis sablayrolles, MD, is a radiologist
                                                                                                                                                                      at Centre Cardiologique du nord (CCn) in
                                                             “we perform Ct studies with reduced radiation dose around 0.3 msv for paranasal
                                                                                                                                                                      saint-Denis, France, where he has been chief
                                                              sinuses, 1 msv for head, 0.5 msv for thorax, 1.5 msv for renal stone, 3 msv for                         of the Ct and Mri Department since 1988.
                                                              thorax, abdomen and pelvis, and 2.0 msv for Ct colonography, including prone
                                                                                                                                                                      About the facility
                                                              and supine studies with intravenous contrast,” Dr. Kwek says.
                                                                                                                                                                      CCn is a private clinic created by a cardiology
                                                             the implications of ultra-low dose Ct imaging are far reaching, particularly in                          group in 1973 in saint-Denis, north of Paris,
                                                             pediatric imaging. “we would like to do more Ct imaging of pediatrics and young                          France, that is dedicated to the treatment of
                                                                                                                                                                      cardiovascular pathologies. with more than
                                                             adults, but they are more sensitive to issues of dose,” Prof. de Mey explains. while                     180 beds, CCn performs over 1,000 cardiac
                                                             Mr is an option for these young patients, he often finds the need to administer                          interventions each year and is considered one
                                                             general anesthesia to obtain quality images in small children, primarily due                             of the finest cardiovascular centers in the world.
                                                                                                                                                                      the facility has performed Ct cardiac exams since
                                                             to the fact the exam takes much longer than Ct. For some patients, Mr may
                                                                                                                                                                      March 2000 and acquired a Discovery* Ct750 HD
                                                             not be suitable.                                                                                         in July 2008.

                                                             “with veo, we can conduct lower dose Ct scans in children, too, and this
                                                              is particularly important in groups that require continued follow-up, such
                                                              as those with cystic fibrosis or lymphoma,” Prof. de Mey says.
                                                             in fact, the hospital has changed its pediatric protocols—first considering using
                                                             ultra-low dose with veo for children receiving a Ct study. according to Dr. Buls,
                                                             the revised hospital’s pediatric protocols have resulted in lower pediatric doses.
                                                             “in two months we’ll review the patient data to see if we can continue to reduce                                                      Prof. Johan de Mey
                                                              dose in a step-by-step manner. Based on our phantom data, we believe we can
                                                              achieve a further reduction in dose.”
                                                             at Keio University Hospital (tokyo), Masahiro Jinzaki, MD, assistant Professor
                                                             in the Department of Diagnostic radiology, is also impressed in the ability
                                                             of veo to reduce dose yet improve image clarity for routine studies.                                     Johan de Mey, MD, PhD, is Chair of the radiology
                                                                                                                                                                      Department at University Hospital, Brussels, and
                                                             “we have drastically reduced dose without any impact on image clarity,” he says.                         a Professor at Brussels University where he is also
                                                             “veo is completely different than any current dose lowering technique because                            the coordinator for radiology resident training.
                                                                                                                                                                      Prof. de Mey earned both doctorate degrees at
                                                              we can reduce dose and maintain contrast noise ratios and spatial resolution.”                          the vrije Universiteit Brussel; his PhD thesis was
                                                                                                                                                                      Ct fluoroscopy in interventional radiology. as
                                                                                                                                                                      Professor, he lectures on radiology anatomy, normal
images courtesy of University Hospital, Brussels (Belgium)




                                                                                                                                                                      and pathologic radiology and emergency radiology.

                                                                                                                                                                      About the facility
                                                                                                                                                                      located in the heart of europe, the University
                                                                                                                                                                      Hospital Brussels is one of Belgium’s premier
                                                                                                                                                                      centers of excellence in healthcare, biomedical
                                                                                                                                                                      research and medical education. one of seven
                                                                                                                                                                      University Hospitals in Belgium, it is closely
                                                                                                                                                                      associated with the Brussels University. University
                                                                                                                                                                      Hospital Brussels has gained recognition at both
                                                                                                                                                                      a national and an international level. with its 700
                                                             Figure 2. abdomen pelvis Ct with veo on patient with Crohn’s Disease. Compared to the FBP images         beds and staff of 3,000, close to 30,000 inpatients
                                                             on left, note the significant noise reduction with the veo image on the right, achieved with an ultra-   and 500,000 outpatients are treated every year.
                                                             low dose of 1.9 msv** at 100 kvp (obtained by eUr-16262 en, using an adult abdomen factor of
                                                             0.015 x DlP and an adult pelvis factor of 0.019 x DlP).

                                                                                                                                                                       a Ge Healthcare Ct publication • June 2011           33
                 CliniCal valUe                                                                      U lt r a - l o w D o s e




                                                                                                      Dr. Jinzaki also sees greater potential for implementing ultra-low dose studies,
                                                                                                      such as those used for lung studies, Ct colonography, and Ct urography. “with
                                                                 Dr. Kwek Boon Han
                                                                                                      lower dose, we may be willing to replace more conventional X-ray studies to
                                                                                                      gain the greater information provided from Ct.”
                                                                                                     Jean-louis sablayrolles, MD, Chief of the Ct and Mri Department at the Centre
                                                                                                     Cardiologique du nord (CCn) (saint-Denis, France), has been able to achieve his
                                                                                                     goal for common chest Ct exams below 1 msv. with the additional information
Dr. Kwek Boon Han (MBBs, FrCr, FaMs)
is a radiologist at asia HealthPartners (aHP)                                                        gleaned from Ct, the clinical value is compelling to Dr. sablayrolles and he sees
(singapore) since the centre was established                                                         potential to replace current imaging methods with ultra-low dose chest Ct using veo
in 2006. Prior to aHP, Dr. Kwek started                                                              in his practice.
the Heart and vascular Center for asiaMedic
limited in 2005. in 2003, Dr. Kwek completed                                                         “the impact of lowering dose, particularly for oncology and cardiovascular patients,
a cardiac and chest research fellowship
at Massachusetts General Hospital and Harvard
                                                                                                      is immeasurable,” he says. “if we are conducting follow-up exams every three
under a government scholarship (HMDP). His                                                            or six months, it is very important to reduce the dose as much as possible.”
primary clinical interests are in the applications
of advanced Ct and Mri imaging techniques.
                                                                                                      Greater image clarity
About the facility
                                                                                                      while lowering dose is a primary advantage of veo, Dr. sablayrolles also sees
asia HealthPartners Pte ltd is a modern medical
                                                                                                      what he believes are significant image quality improvements.
center in singapore, conveniently located in the
                                                                                                     “in oncology studies with veo, we can also increase the conspicuity of the tumor
heart of orchard road, which offers medical,
surgical, and diagnostic imaging services.                                                            for tissue characterization,” he explains. “in vascular studies, it is possible
aHP is the training centre and luminary site                                                          to differentiate stenosis from occlusion and reduce the blooming effect that
of Ge Healthcare, south-east asia. asia                                                               results from the presence of a stent or calcified plaque.
HealthPartners was awarded the “reference
Center for advanced imaging, Ge Healthcare”                                                          “there are instances where a higher quality study is most important, and veo
as a commitment to deliver the latest in technology
                                                                                                      enables us to increase spatial and contrast resolution to visualize very small
that enhances patient care as well as to provide
advanced Ct and Mri training for regional doctors.                                                    lesions,” Dr. sablayrolles adds.
the imaging centre has been an early adopter
of Ge Healthcare Ct technologies, including the                                                       at aHP, Dr. Kwek attributes greater image quality to the fundamental design of the
lightspeed* vCt in June 2006, the lightspeed                                                          veo algorithm. “with veo, there is improvement in the spatial resolution of tiny
vCt Xt in June 2007, the Discovery Ct750 HD                                                           structures, such as the distal small airways in the patient,” (Figure 6).
in December 2010, and veo on april 2, 2011.
                                                                                                      similarly, he attributes the ability to resolve small foci of calcification, particularly
                                                                                                      in patients with nephrocalcinosis, to veo being able to accurately discriminate
                                                                                                      and separate the density of the image voxel.
                           images courtesy of CCn (saint-Denis, France)




                                                                           A                                 B                                 C                                  D
                                                                          Figure 3. vascular run-off study using veo illustrates the image quality and lumen visualization improvement of popliteal stent
                                                                          compared to FBP technique. (a) FBP vessel tracking; (B) veo vessel tracking; (C) FBP MiP vessel tracking; (D) veo MiP vessel tracking.

34   a Ge Healthcare Ct publication • June 2011
images courtesy of asia HealthPartners (singapore)                                                                                                                        U lt r a - l o w D o s e                                                                       CliniCal valUe




                                                                                                images courtesy of asia HealthPartners (singapore)
                                                                                                                                                                                                                                                                                                name of author
                                                                                                                                                                                                                                                                                                Dr. Nico Buls




                                                                                                                                                     A                                                                                                              info Buls, clinic, a medical physicist
                                                                                                                                                                                                                                                                    nicoaboutPhD, isetc.
                                                                                                                                                                                                                                                                    in medical sciences at University Hospital,
                                                                                                                                                     Figure 5. a 38-year-old male known to have                                                                     Brussels. His research in medical imaging
                                                                                                                                                     nephrocalcinosis, presenting with microscopic                                                                  spans translational projects in medical
                                                                                                                                                     haematuria. the foci of faint calcification in the                                                             imaging physics, radiation dosimetry,
                                                                                                                                                     renal pyramids are apparent in the veo image.                                                                  engineering, and diagnostic radiology.
                                                                                                                                                     the Ct KUB (Kidney Ureter Bladder) scan was                                                                    Dr. Buls has presented internationally
                                                                                                                                                     performed with DlP of 118.79 mGy cm.                                                                           and has authored one book chapter
                                                                                                                                                                                                                                                                    in an international textbook and more
                                                                                                                                                                                                                                                                    than 25 peer-reviewed articles.




                                                     Figure 4. a 58-year-old female with left
                                                     mastectomy for breast cancer currently
                                                     undergoing chemotherapy. the Ct scan
                                                     was performed with DlP of 156.48 mGy cm.
                                                                                                                                                                                                          images courtesy of asia HealthPartners (singapore)




                                                     Benefits outweigh reconstruction time
                                                     as veo uses a powerful new class of new reconstruction algorithms that more
                                                     accurately model noise statistics, system optics, and radiation physics in the data
                                                     acquisition process, it requires additional time to reconstruct images.
                                                     even with extended reconstruction time, Prof. de Mey has been able to incorporate                                                                                                                          A
                                                     veo into his facility without impacting workflow in the radiology department.
                                                     as the scan is performed, the technologist has immediate access to images
                                                     reconstructed with asir, and, there is no change in radiologist efficiency as
                                                     the veo reconstruction is completed in the background. Prof. de Mey uses the
                                                     analogy of a blood test—it may take an hour for results, yet it doesn’t stop the
                                                     provision of care or the flow of patients in the department. in his experience,
                                                     the patient and diagnostic benefits from the ultra-low dose veo exams justify
                                                     the increase in reconstruction times.                                                                                                                                                                      B

                                                     advances in computing power will continue to speed up the veo reconstruction                                                                                                                              Figure 6. a 72-year-old male with inoperable lung
                                                     experienced by today’s pioneering users. “veo has the potential to open new                                                                                                                               cancer, currently undergoing chemotherapy. the
                                                                                                                                                                                                                                                               distal small airway is better appreciated with the
                                                     fields in Ct imaging. we are only at the beginning of this new application and                                                                                                                            veo (a) compared to the asir 50% image (B). the
                                                     anticipate rapid advancement as typically seen in Ct development,” adds                                                                                                                                   Ct thorax and abdomen was performed with DlP
                                                     Dr. sablayrolles.                                                                                                                                                                                         of 108.25 mGy cm.




                                                                                                                                                                                                                                                                     a Ge Healthcare Ct publication • June 2011     35
                 CliniCal valUe                                          U lt r a - l o w D o s e




                                                                                                  Beyond comparison
                           Dr. Masahiro Jinzaki
                                                                                                  the true power of veo will be found in the ability to allow a lower dose examination
                                                                                                  while still delivering outstanding image clarity.
                                                                                          “veo may enable a greater impact on dose than many other techniques,” Dr. Buls
                                                                                           explains. “For example, adaptive collimation in spiral Ct reduces dose by just a few
Masahiro Jinzaki, MD, PhD, is an assistant                                                 percentage points. with veo, we are seeing dose reduction of an entirely new
Professor in the Department of Diagnostic                                                  order.” By developing dose reduction techniques via new reconstruction algorithms,
radiology at Keio University school of Medicine
                                                                                           Ge Healthcare has opened up new possibilities for much greater dose savings.
(tokyo). He received both his medical degree,
with honors, and post-doctoral degree from Keio                                                   veo will impact how and when radiologists decide to utilize Ct imaging. “a key
University. Dr. Jinzaki has completed a research
fellowship in the Department of surgical
                                                                                                  concern with Ct is the radiation dose; however, veo may reduce that concern,” says
Pathology at Keio University and in the                                                           Dr. Jinzaki. “there will be changes in the preference of Ct imaging versus other
Department of radiology at Brigham and                                                            exams, such as general radiography and Mri,” he explains.
women’s Hospital (Boston). He specializes
in abdominal diagnostic imaging. Dr. Jinzaki                                                      Dr. sablayrolles has no doubt that veo will make a major difference in Ct imaging.
also takes special interests and leads research                                                   after three months experience with veo, he has repeatedly demonstrated dose
in cardio-vascular and urology imaging. His
experience with Ge Ct includes lightspeed                                                         reduction and excellent image quality in study after study.
Plus, lightspeed Ultra, lightspeed Ultra16,
and lightspeed vCt. Dr. Jinzaki has been using
                                                                                          “we are at the beginning of a very interesting advancement in Ct imaging,” says
Discovery Ct750 HD since December 2008,                                                    Dr. sablayrolles, “and the future of veo lies in every application. in my opinion,
and veo since March 2011.                                                                  veo is one of the major advancements in Ct imaging—it is as important as the
                                                                                           development of helical and multi-detector Ct.” n
                                                   images courtesy of CCn (saint-Denis, France)




About the facility
Keio University Hospital was established
by Yukichi Fukuzawa in 1858 and celebrated
its 150th anniversary in 2008. in 1917, the
medical school was launched as a medical
preparatory course with Dr. shibazaburo
Kitazato, who became the University’s first
dean, and three years later the University                                                                                                   Figure 7. veo ultra-low dose chest Ct conducted
Hospital was opened. today, the hospital                                                                                                     at 0.48 msv (obtained by eUr-16262 en, using
has 27 diagnosis and treatment departments                                                                                                   an adult chest factor of 0.017 DlP) at 100 kvp.
and 13 central treatment departments with                                                                                                    veo coronal (top left); veo fusion of volume
over 800 clinical doctors (including resident                                                                                                renderings with lobes segmentation (top right);
physicians). an average of 4,000 patients walk                                                                                               veo sagittal (bottom left).
through the hospital’s doors each day with
approximately one-fourth hospitalized.
on average, the emergency Department treats
over 20,000 patients and performs 13,000
operations each year.




36   a Ge Healthcare Ct publication • June 2011
images courtesy of Keio University Hospital (tokyo)                                                                             U lt r a - l o w D o s e                  CliniCal valUe




                                                      Figure 8. Coronal image of the abdomen and pelvis comparing FBP (left) to veo (right). veo image demonstrates higher image quality and less noise
                                                      compared to the FBP image at 0.97 msv (obtained by iCrP Publication 102, using a one-year-old abdomen and pelvis factor of 0.03 x DlP).




                                                      Figure 9. Coronal image of the abdomen and pelvis with low density lesions in the liver comparing FBP (left) to veo (right). lesions are better demonstrated
                                                      in the veo image at 1.88 msv (obtained by eUr-16262 en, using an abdomen factor of 0.015 x DlP and a pelvis factor of 0.019 x DlP).




                                                                                                                                                                      a Ge Healthcare Ct publication • June 2011     37

				
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