MRI is a powerful imaging technique
because of its high resolution and
potential for chemical specific
• Similar to x-ray computed tomography
• It uses magnetic fields and radio frequency
signals to obtain anatomical information.
• Easily distinguish health and diseased
• 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
• 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
• 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
• 1. SUPERIOR CONTRAST RESOLUTION.
2. DIRECT MULTIPLANNAR IMAGE SLICES IN
SAGITTAL, CORONAL AND OBLIQUE
DIRECTIONS CAN BE OBTAINED
3. ABSENCE OF HARMFUL RADIATIONS
MAKING IT NON-INVASIVE.