Magnetic Resonance Imaging (MRI) is an imaging procedure used mainly to
create high quality images of the inner organs of the human body. The problems which cannot be detected in
any other method such as ultra sound, computerized tomography scan etc can be detected in an MRI scan. It is
based on the principles of Nuclear Magnetic Resonance (NMR) a spectroscopic technique used by scientists to
acquire microscopic chemical and physical information on molecules. MRI is a highly developed volume imaging
technique that can be done for detection of many problems like tumours, blood vessel diseases, injury
An MRI scan of head/brain is performed for detecting problems like aneurysm, bleeding in brain
or injury. It can also help in detection of problems concerning optic and auditory nerves. Magnetic Resonance
Angiography is a process in which the flow of blood through the blood vessels can be seen. By this procedure,
problems of the arteries and veins, a blocked vessel, or dissection (torn lining of a blood vessel) can be
seen. An MRI can identify problems of the bones and joints (arthritis), bone tumors, cartilage problems, and
problems of temporomandibular joint, torn ligaments etc. When X-ray results are not clear, MRI can find if a
bone is broken. It can check the nerves of the spine and the discs for conditions like spinal stenosis, disc
bulges and spinal tumors.
Magnetic Resonance Imaging plays an important role in detection of problems in abdomen and
pelvis. It can find problems in the abdomen such as liver, gall bladder, pancreas, kidneys and the bladder.
Bleeding, tumors or blockage can be detected accurately. A prostate MRI is generally used after the prostate
biopsy in order to conclude if the cancer is restrained or propagated outside of the prostate gland. Rarely
MRI evaluates other prostate problems such as prostatitis, benign prostatic hyperplasia (BPH). In some cases,
in order to show certain organs and structures more clearly, contrast material containing gadolinium may be
used during an MRI scan. Depending on the organ to be scanned, an MRI procedure may take 30 minutes to 2
MRI – Imaging Techniques
Gradient-Echo Imaging - Imaging with this technique is more sensitive to magnetic field due to the use of wind-up
gradient or refocusing gradient.
Multi-slice Imaging – Multi-slice imaging is the normal mode on a clinical scanner as it enables voluminous imaging
of anatomy within shortest time.
Volume Imaging (3D Imaging) – This imaging technique refers to acquirement of magnetic resonance data from volume instead of
single tomographic slice.
Oblique Imaging – This is a common imaging technique because most of the diagnostically useful imaging planes
are not perpendicular.
Spin-Echo Imaging - The advantage of this technique is that it gives presentation in the form of a timing
Chemical Contrast Agents - Chemical contrast agent (CA) is a chemical substance that is introduced inside the body to
alter the contrast between the tissues.
MRI Side Effects
There are no harmful side effects from the magnetic field of MRI. There is a slender risk of an
allergic reaction, especially if contrast material is used at the time of MRI. But generally reactions are
gentle and can be treated easily. There also is a slight risk of an infection that easily subsides with