What is MRI?
MRI (Magnetic Resonance Imaging) is an advanced investigative test which involves using magnetic waves and radio waves together to create images of internal organs in the body. These images are then used to analyze whether any abnormal changes have taken place in any organs.
A machine that emits a magnetic field of pre-determined strength is used to perform an MRI scan. When the human body is exposed to magnetic waves, particles and ions present within the human body react by emitting radio waves. A combined effect of these waves highlights the internal organs. Thus, the internal organs can be visualized in great detail to diagnose any abnormality. These images that are visualized on a computer screen can also be printed using a specially designed machine, to be used for diagnosis purpose.
What is Closed MRI?
MRI scan can be performed by two methods, viz. open method and closed method. Closed MRI is done more commonly than the open method. As the name suggests, machinery required for closed MRI is more enclosed and has lesser free space than open MRI. The detailed procedure of how closed MRI is performed has been described below:
- The machine used to perform an MRI consists of a wide hollow cylindrical tube-like structure within which a magnetic field of a specific strength is generated.
- The patient whose MRI is to be performed is made to lie on a bed. The position in which the patient is asked to lie down depends on the body part which has to be examined under MRI scanner.
- After the patient is comfortable, the bed slides inside the hollow tube and stays in position till the entire procedure is over.
- The magnetic field is focused on the body part which is to be examined. Eg: if MRI Brain is required, patient's skull and neck will only be exposed to the magnetic field.
- As soon as the magnetic waves interact with the patient's body particles, the particles emit radio waves. This highlights the internal organs.
- Images of internal organs are displayed on a computer screen, which are then studied by radiologists.
- The process can take anywhere between 45 minutes to 1 hour for completion.
What are the pre-requisites for closed MRI?
MRI scan is an advanced investigation which takes into consideration minute details about a patient's internal organs. It requires planning and preparation and cannot be done as a spontaneous procedure. The following steps are essential to be taken before proceeding for a closed MRI:
- A detailed physical examination is done by the doctor to ensure whether an MRI is needed for the patient.
- The doctor will take a detailed medical and health history of the patient before proceeding with MRI.
- It is essential for the doctor to know entire history of any ongoing or previous illness suffered by the patient.
- A list of all medicines the patient may be taking needs to be studied by the doctor. Some medicines might need to be stopped for a couple of days prior to and after MRI is done.
- Special precautions need to be taken while performing MRI if the patient is a small child or a pregnant woman.
- Women who are planning a pregnancy but are not currently pregnant should inform about the same to their doctor before proceeding with MRI scan.
- Patients who have a pacemaker, chemoport, cardioverter defibrillator, or stent implanted within their body, should inform about the same to their doctor. Patients who have undergone orthopedic surgery and have screws, nails or artificial joints fitted in their body, should also mention about the same to their doctor.
After clearing all these preliminaries, the patient can be certified to be medically fit for undergoing a closed MRI scan.
Following are the steps to be taken on the day of MRI:
- The patient is expected to arrive before time for the closed MRI scan, as there are a few procedures to be completed before the actual scan is done.
- A clean, sterile surgical gown is worn by the patient for the procedure.
- On some occasions, a contrast dye is required to be injected prior to MRI scan. The dye is injected through a vein in the patient's arm from where it will circulate to the entire body.
- After the dye reaches the target organ, the scan begins.
The entire procedure of closed MRI scan has been explained previously in the article. It is a completely non-invasive procedure, therefore there is no need for any surgical cuts to be given on the patient's body. There is no waiting period or observation period after the procedure is complete. Patient can go home immediately after the scan is completed.
Benefits of Closed MRI:
MRI scan is an advanced investigative technique and provides a very good chance of achieving a 100% accurate diagnosis. It has the following benefits:
- No exposure to radiation:
As opposed to CT scan or X-ray that involve use of radiation to perform the procedure, MRI does not involve radiation at all. This makes it a relatively safer procedure; specially for patients who might suffer harmful effects if exposed to radiation.
- Widespread utility:
Because MRI does not use radiation of any harmful beams for diagnosis, it can be used as an investigation procedure for almost all patients. Pregnant women, aged people, small children, or babies can be made to undergo this procedure rather safely, but under constant supervision of a doctor.
- Detailed diagnosis:
Closed MRI is a rather advanced and time consuming technique in comparison to X-ray or sonography. All body tissues including muscles, blood vessels, heart, or lungs are visualized with greater clarity in closed MRI scan. Deep seated pathological changes can be diagnosed easily and their exact location is pinpointed during MRI scan.
- No harm to healthy body tissues:
During MRI scan, the magnetic field is focused only on that part of the body which is to be studied. This completely excludes any possibility of some healthy body tissue suffering from harmful effects due to magnetic radiation. Otherwise too, magnetic radiation has no harmful effect on any body tissues if exposed for a short duration.
- No harm to unhealthy body tissues:
While creating images of a person's internal organs, the magnetic radiation does not cause any harm to the unhealthy tissues which are being studied.
- Guidance tool:
Closed MRI is not only a good investigative test, but also an excellent guidance tool. Ovarian biopsy, pleural tap, lung biopsy, lumbar puncture are minimal access procedures that require great skill and precision to perform. MRI scanning is sometimes used as an aid to guide the surgeon while performing these procedure. It helps the surgeon to visualize internal organs properly and avoid damaging any surrounding healthy tissue.
Closed MRI scan is a highly advanced technique and requires pre-procedure and post-procedure precautions. It is important that patients follow these instructions to ensure good health and a successful outcome of the scan. For patients who are uncomfortable to be within the hollow tube during closed MRI scan, an alternative is available, and open MRI scan. This procedure is quite similar to closed MRI and is designed to suit claustrophobic patients. Patients are advised not to undergo the scan without a doctor's guidance and prescription.