What is MRI Scan?
Magnetic resonance imaging is the process of visualising the human body through images created by magnetic resonance of radiowaves. It is a non-invasive procedure and requires the patient to enter a field of magnetic and radio waves that are reflected by different organs of the human body as they pass through the body; and are captured on imaging screens to decipher the shape and size of the internal organs. MRI scan results are derived from the computer that captures these images of target internal organs.
Why is MRI Scan performed?
MRI scan is performed when internal details pertaining to the human body have to be studied thoroughly. It is important to note that the extent of detailing available through computer generated MRI scans is not attainable through the use of X-rays and CT scans. MRI scans provide clear and precise cross sectional images on internal anatomy including details of soft tissue, organs and bone. MRI scans allow doctors to find out early stages of any disease or ingrowth.
Types of MRI Scan?
Although the basic technology is the same, the different types of MRI scans that exist in the radiology are differentiated on the basis of the target body part that they scan. These are as follows:
- Abdominal MRI: Scans the abdominal area of the body.
- Chest MRI: Scans the chest or thoracic area of the body.
- Cranial MRI: Scans the head including the brain and skull.
- Heart MRI: Scans the heart and its different compartments for specific pictures.
- Spine MRI: Scans the spine area. There could be partial spine scanning or complete scanning depending upon the need.
Preparation for MRI Scan?
The MRI scan is a non-invasive process and therefore, there is minimal amount of preparation required for the scan. The patient body is not directly exposed to radiation during the scan. Patients are asked to change into hospital gown and may be allowed to eat or drink before the MRI scan. The directives of the ordering doctor will decide whether eating is allowed before the scan.
For scanning with a contrast agent, the patient might be injected with a contrast agent through an IV line. MRI scanning continues after the injection. Images before and after the injection is given are important for complete scanning. For patients who suffer from claustrophobia or fear of entering closed spaces, proper counselling is provided to prepare them for the scan. Some of them might ask for a mild sedative to help the patient feel drowsy. Ear plugs are often provided to the patient so that he or she is unaffected by the continuous clicking noises inside the MRI scanner machine.
What happens during an MRI Scan?
The MRI scan machine is located in a segregated room that is walled by glass on one end and has a satellite phone for the technologist to speak to the patient in the scanner. The patient is asked to lie down comfortably on the padded scan table.
After the patient is comfortable, the table is slowly moved into the opening of the large cylindrical MRI scanner which houses the magnet. As the machine allows the radiowaves to pass into the patient’s body, the machine click images of different parts of the body constantly.
The patient can hear continuous knocking around him when the images are being clicked. The technologist converses with the patient continuously and updates him of next steps. All through the imaging process, the patient is required to stay completely still to avoid blurring of images being taken and stored in the computer. The radiologist checks all the images for clarity and completion of doctor’s order before declaring the MRI scan complete.
How long does MRI Scan take?
A MRI scan can take anything between twenty minutes to sixty minutes, depending upon the extent of details and scanning ordered by the doctor who has prescribed the test.
What happens after the MRI Scan?
After the MRI scan is complete, the patient can leave immediately and resume normal daily activities. If the patient has taken mild sedation then there must be a responsible adult accompanying him to drive him home.
What are the possible risks of MRI Scan?
Most MRI scanners are highly maintained and do not suffer from technical snags during the scan. In case of one, the technologist immediately issues an order for the patient to move out of the scanner, which he can do by sliding out. Other than technical snags, the other risk involved in MRI scanning is the presence of electronic or metallic devices in the patient’s body.
The patient must inform the technologist if he has a metallic implant in the body like in limbs, ear or dental apertures. Patients who have a pacemaker implant are not usually allowed to undergo MRI scanning. The patient must also inform the technologist for any medication that he is taking regularly and has taken before the test. The contrast agent injected during the scan has no side effects and rarely causes allergy. People with kidney problems, however, must inform the radiologist before taking the contrast agent since it is a dye and is not suitable for humans with kidney problems.
Cost of MRI Scan?
The cost of a MRI scan in a public hospital ranges between Rs. 2000 to Rs. 3500; while in a private hospital it ranges between Rs. 8000 to Rs. 11,000.
The only other names of MRI scans are Magnetic Resonance Imaging and Nuclear Magnetic Resonance Imaging (NMRI).