Magnetic resonance imaging (MRI) is a non invasive radiological technique. It produces cross sectional images of a body part by using magnetic field, radio waves and hydrogen atoms. In past few decades MRI has opened new horizon for analysis and study of any body part either in disease or in health. Unlike CT scan and X-rays, MRI does not use ionizing radiation. MRI is based on principle of nuclear magnetic resonance, a spectrographic technique that helps to decipher detailed study of a molecule.
MRI was first time used in 1977 on human being.
What Is The Procedure Of MRI Scan?
Prior to an MRI scan, patient is told to remove all metal objects on his body. This is because the magnet used produces powerful magnetic field. The computer system translates signals generated into images. Some patients who are claustrophobic and anxious are given mild sedative before MRI scan so that they feel relaxed during the procedure. The best and accurate results are obtained when the patient lies still on the MRI scanning table.
Patient has to lie in the closed magnetic machine. Patient is asked to be relaxed and breathe normally. The technician is in another room and constantly keeps interacting with the patient. At times a contrast dye may be given through intravenous injection to enhance the images of the organ under consideration. Usually the complete procedure of MRI scanning takes half hour to one hour.
What Are The Uses Of MRI Scan?
MRI is accepted as the image modality of choice in diagnosis of several medical diseases. It has wide applications that help in accurate detection of diseases involving various parts of body.
MRI of brain and spinal cord helps to detect:
- Brain tumor
- Brain injury
- Stroke
- Multiple sclerosis
- Infection in spinal cord.
- Damage of the blood vessels.
MRI of bones and ligaments:
- Infection in bone
- Bone cancer
- Damage to joints
- Herniated disc of spine
- Infection is spinal bones.
- Visualizing injury in spine and shoulder joint.
Abdomen and pelvis:
- MRI plays vital role in diagnosis of liver diseases.
- It helps to detect focal liver lesions.
- Pancreatic cancer
- Prostate cancer
- Ovarian cancer
Besides diagnosis of diseases, MRI also helps the surgeon the way to plan his surgery.
Why Is An MRI Better Than An X-Ray?
Here are some advantages of MRI over X-ray:
- MRI does not emit radiation whereas patient is exposed to ionizing radiation in X-ray.
- Images of MRI can be multiplanar that may include coronal, sagittal and axial. X-rays images are possible in only one plane.
- MRI is suitable for evaluating soft tissue such as ligaments and tendon injury, brain tumor, kidney pathology, liver and intestinal pathology. X-rays are more suitable to examine fracture of bones and in some cases detection of diseased tissues such as lungs.
- MRI is relatively costlier than X-rays.
- MRI procedure may take half hour to one hour. X-rays take few seconds.
- There is no damage to the fetus in the pregnant women. Exposure of X-rays can lead to birth defect and alteration in DNA of the fetus.
- MRI is more versatile imaging technique as the images can be developed in multiple planes or even in 3D. It has wider use in medical diagnosis and procedures as compared to X-rays.