MRI uses radio frequencies and strong magnetic fields to produce detailed images of soft tissues in the body. It was developed from nuclear magnetic resonance, which uses magnetic fields to detect atomic nuclei and study their properties. Flex Bloch proposed the concept of nuclear magnetism and described how atomic nuclei behave like tiny magnets in an external magnetic field. MRI has several advantages over other imaging techniques, including excellent soft tissue contrast, multi-planar imaging capabilities, and the ability to perform in vivo spectroscopy without using ionizing radiation. However, MRI has some drawbacks such as longer imaging times, high equipment and procedure costs, and an inability to image bone details. The basic components of an MRI system include a magnet, RF and gradient coils, a

1. MAGNETIC IMAGING
RESONANCE
MAAJID MOHI UD DIN MALIK
M.SC RADIOLOGY

2. MRI: Magnetic Imaging
Resonance
• MRI(magnetic imaging resonance) are made with radio frequency pluse in the range from 1-80Mhz.Nuclear
magnetic resonance (NMR) magnetic imaging resonance and spectroscopy are the terms used alternatively.
• NMR is the spectrosopic study of magnetic property of the nucleus of the atom.
• Flex Bloch is the father of MRI. Bloch proposed that the nucleus behaves like a tiny magnetic. He described this
nuclear magnetism by what is known as Bloch's equation. NMR is not a imaging technique but rather a method
to provide spectroscopic data concerning a sample placed in device.
• Advantage of MRI:
1. It provides excellent soft tissue contrast resolution.
2. It's ability to obtain direct transverse, SAGITTAL,coronal and oblique image regardless of plane.
3. Another advantage of MRI is possibility of doing in vivo spectroscopy.
4. MRI advantage over x-ray imaging I.e MRI does not use lionizing radiation.
5. MRI does not produce bone/air artifacts.

3. DRAWBACK OF MRI
1. Longer imaging time.
2. Equipment and sitting cost is high .
3. Limited spatial resolution as compared to ct.
4. Inability to demonstrate dense bone details.
5. Claustrophobic patients requires sedation.
6. Cardiac peacemaker, dental implant, heart valve
prosthesis,aneurysm clips etc may be pore contra
indications for MRI.
7. Higher cost than x-ray,ct and USG.

4. BASIC COMPONENTS OF MRI
• The basic components of MRI system are
1. The magnet which is key of element of the MRI system
which also includes the (a) the RF AND(b) Gradient system.
2. Power supply.
3. A computer system.
4. A documentation system.
5. Cooling system.
6. Monitoring system.
• Camera can be placed to monitor a patient inside the
magnetic bore.
• Magnetic room has to be shielded with a Faraday's cage to
prevent interference between outside frequency waves and
those used with in MR equipment.