A knee MRI (magnetic resonance imaging) is a routine procedure for diagnosing and monitoring patients with unexplained or suspected knee problems. With the help of an MRI, doctors can examine the inside of the joint without having to make any incisions, making it a safer and more convenient option for patients who wish to avoid exploratory surgery.
The cost of a knee MRI scan in India can range from INR 2,500 to INR 12,000, depending on the chosen facility and other factors. Keep reading to learn more about the procedure.
What is a knee MRI?
MRI, or magnetic resonance imaging, of the knee joint is an imaging test that uses magnetism and radio waves to capture detailed images of body parts. A common diagnostic procedure, the MRI of knee is performed to detect and assess any acute or chronic internal injuries of the knee. An MRI knee scan serves as an important tool in prognosis.
It allows healthcare providers to examine the bones and soft tissues and characterise injuries of the meniscus, cruciate ligament, collateral ligament, extensor mechanism, and disorders of the synovial, tendons, and articular cartilage. The test also captures better contrast images of the knee, including blood vessels.
Depending on the suspected diagnosis, the doctor may recommend the patient undergo an MRI arthrogram of the knee joint. This test involves injecting a contrast medium into the knee joint before beginning the MRI. Generally, this type of knee MRI is performed under local anaesthesia.
Why is it recommended?
A doctor may recommend a knee MRI if the patient is experiencing acute or chronic pain, weakness, or swelling around the knee or limited mobility of the affected leg. An MRI of the knee joint can detect a range of problems, including torn ligaments and tendons, osteoarthritis, tumours, infections, bone fractures, meniscal tears/damaged cartilage, fluid build-up in the knee, problems after previous surgeries, sports- or trauma-related injuries, and decreased motion of the knee.
To aid in the diagnosis, the doctor may also order other complementary tests, such as an X-ray, along with an MRI of knee. An MRI is generally a part of pre-operative procedures, such as knee arthroscopy. This surgery is a minimally invasive procedure that enables the doctor to see the inside of the knee using small incisions.
Additionally, the doctor may also recommend knee MRIs after the patient has undergone surgery to observe their progress.
Preparing for the test
Since MRI uses magnetism to produce images, the patient should not wear any metal objects as they can interfere with the machine’s magnetic field. One should avoid wearing jewelry, hairpins, clothes with zippers, body piercings, eyeglasses, etc., while going for a knee MRI. If the person has a metal implant or other medical device with metal in their body, they should inform their healthcare provider in advance.
There have been accidents involving patients with certain metal implants or objects in their bodies during an MRI. People who have cochlear implants, cardiac defibrillators and pacemakers, metal clips, etc., should not get an MRI. Patients are advised to wear shorts that are above the knee or other loose-fitting comfortable clothes that can be rolled up to the knee.
An MRI machine looks like a large hollow tube with a table in the middle that slides in and out of the machine. This may trigger a fear response in people who have claustrophobia. If the patient has an extreme fear of tight spaces, the healthcare provider will likely administer medication to calm the patient, as they need to lie extremely still during the procedure. MRIs are not recommended for pregnant women, especially during the first trimester. Additionally, contrast medium is not given to pregnant women unless it is absolutely necessary.
Thus, the patient must inform the doctor if there is any chance of her being pregnant. Some people may have allergic reactions to the contrast medium, which are generally treatable, but they must inform their healthcare provider immediately about any symptoms.
What happens during a knee MRI scan?
A healthcare provider helps the patient get ready for the MRI by getting them in the correct position on the examination table. If necessary, the patient may also be given a hospital gown to change into. Then, the patient lies on their back with their feet facing the machine. The healthcare provider then places a coil around the knee to help with clear imaging. After this, the patient’s lower body is inserted inside the machine, and the procedure starts.
The patient is left alone in the room while the healthcare provider observes them from an adjacent room while operating the machine with a computer. Some people may be given an injection of the contrast medium.
The patient will not feel anything during the MRI knee scan, but they may hear loud noises (knocking, thumping, and humming sounds) coming from the machine. It is important for the patient to lay completely still during the procedure, which takes about 15-45 minutes on average. If the images captured are not clear, the patient may need to undergo the procedure again.
The patient may ask for a headphone or earphones through the two-way intercom before or during the procedure if they feel uncomfortable about the noises.
After the test is complete, a radiologist analyses the results and shares them, along with a report, with the concerned doctor. The patients need to take no specific precaution after the exam and can drive themselves home if they feel well enough.
Risks associated with the procedure
An MRI of the knee is a safer alternative for people who need X-rays and/or CT scans for their diagnosis, as it does not use radiation. However, people who have metal implants or certain medical devices cannot undergo an MRI as it uses strong magnets. Additionally, some people may get an allergic reaction from the contrast medium used in an MRI procedure.
An MRI is also preferred to diagnose any problems with pregnant women instead of radiation imaging to prevent any possible damage to the developing foetus.
