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MAGNETIC RESONANCE IMAGING MAGNETIC RESONANCE IMAGING MRI is a

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MAGNETIC RESONANCE IMAGING MAGNETIC RESONANCE IMAGING MRI is a Powered By Docstoc
					MAGNETIC RESONANCE
           IMAGING
MRI is a powerful imaging technique
 because of its high resolution and
  potential for chemical specific
              imaging
• Similar to x-ray computed tomography
• It uses magnetic fields and radio frequency
  signals to obtain anatomical information.
• Easily distinguish health and diseased
  tissues.
• Avoids ionizing radiation, hence radiation
  hazards are eliminated.
• Can penetrate through bone and air without
  attenuation make it a non-invasive imaging.
• CT provides details about bone and tissue
  structure of an organ
   MRI highlights the liquid like areas on the
  organs and detect flowing liquids
• CONVENTIONAL X-RAY MACHINE
  CAN PRODUCE IMAGE ONLY AT
  RIGHT ANGLES TO THE AXIS OF THE
  BODY, WHERE AS THE MRI SCANNER
  CAN PRODUCE IMAGE ANY DESIRED
  CROSS SECTION/
                                 PRINCIPLE
• 1. Patient placed in external magnetic field which
  causes magnetization of protons in the body.
• 2.Due to magnetization these protons align and
  precess about the external magnetic field.
• 3.A RF pulse at resonant frequency is transmitted
  into the patient under controlled and prescribed
  conditions.
• 4. Due to resonant condition the individual protons
  responds by emitting a radio frequency signal.
  This is called nuclear magnetic resonance signal.

• 5.These emitted signals by the protons, during
  their return from the higher energy state to ground
  state, are picked up by the RF coils and processed
  by the computer using Fourier Transforming
  techniques to produce an image.
          ADVANTAGES OF MRI
                   IMAGING
• 1. SUPERIOR CONTRAST RESOLUTION.

2. DIRECT MULTIPLANNAR IMAGE SLICES IN
      SAGITTAL, CORONAL AND OBLIQUE
        DIRECTIONS CAN BE OBTAINED
                 DIRECTLY.
   3. ABSENCE OF HARMFUL RADIATIONS
          MAKING IT NON-INVASIVE.