An MRI for your knee involves lying on a table that slides into a tunnel-like machine, with a special coil placed around your knee, requiring you to stay very still for 30-60 minutes while it makes loud banging/humming noises (earplugs/headphones provided) to capture detailed images of bones, cartilage, and ligaments, with no pain, only potential warmth or claustrophobia. You'll communicate with a technician and can use a call bell if uncomfortable, but must remain still for clear pictures, and results are reported to your doctor later.
How is the test done?
Does your whole body go in for a knee MRI? Only your lower body will enter the MRI machine for your knee exam. Your upper body will remain outside the machine, as the technologist will not need these images. You will need to stay as still as possible to allow the machine to take the clearest pictures.
Leave all jewelry and other accessories at home or remove them prior to the MRI scan. Metal and electronic items are not allowed in the exam room. They can interfere with the magnetic field of the MRI unit, cause burns, or become harmful projectiles.
You will wear a hospital gown or clothes without metal zippers or snaps (such as sweatpants and a t-shirt). Please remove your watches, glasses, jewelry, and wallet. MRI can pull on any metal objects.
Eating or drinking triggers processes in the body to digest what has just been ingested. This involves peristalsis - involuntary muscle contractions throughout the digestive tract to move the food through the digestive system. These muscle movements can cause smearing or anomalies in the MRI image (known as artifacts).
1. You aren't moving enough. One of the biggest mistakes we see patients with knee pain make is to begin using their knees less. For example, if you have osteoarthritis and moving your knee hurts, you may think the best approach is to rest your joint and let it heal.
Intravenous fentanyl, butorphanol, and midazolam are among the commonly used sedatives for MRI procedures [5]. Each medication possesses distinct pharmacological properties and mechanisms of action that influence its sedative effects and side effect profile.
Knees: A knee MRI can give a much more detailed picture of changes in arthritic joints, such as the knees, than X-rays can. They can show early, subtle changes and inflammation, too.
You can be as active as you like after the MRI unless you were given a sedative.
This article highlights five knee injuries that, in the author's experience, are commonly overlooked by readers inexperienced in knee MRI: ramp lesions, meniscocapsular tears, meniscal root ligament tears, posterior capsular ligament tears, and partial anterior cruciate ligament tears.
You will lie on a table which will slide into the MRI machine feet first. Only the lower part of your body will go into the tube. The test may take 30 to 60 minutes. Expect that there will be loud sounds within the tube so you can ask for earplugs or headphones, but there will be no pain.
Magnetic resonance imaging (MRI).
It's the best imaging study to detect a torn meniscus.
Not only does MRI help confirm a suspected diagnosis, but it also rules out any potential weird/rare/'nasty' pathology in the joint. MRI is also an important tool in helping to plan what might actually need to be done inside a knee surgically, in terms of what equipment and what procedures might be required.
If you're dealing with a fresh knee injury—especially one with knee swelling or sharp pain—it's important to give your knee a break. Rest doesn't mean total inactivity, though. It just means avoiding high-impact movements or weight-bearing exercises for a few days.
Identifying Knee Pain Red Flags
Severe swelling: If your swollen knee feels warm and looks red, it might be a condition requiring medical evaluation. Inability to bear weight: If you have difficulty putting weight on your knee, it may indicate a serious injury.
Patients are not completely enclosed, which significantly reduces anxiety for claustrophobic individuals. Open MRI technology has advanced over the years, allowing it to provide high-quality images comparable to those of a closed MRI machine for many types of scans.
MRI can depict ligament injuries and has been used to differentiate ligament tears from other causes of ankle pain, such as fracture, osteochondral injury, or tendon injury. Appropriate treatment planning for ankle injury requires differentiation between the various types of ligament injury.
Specifically for a knee MRI, you will likely go in feet first and can generally expect the lower half of your body to be inside of the tube. It is important to anticipate the scan taking between 30 and 90 minutes depending on the types of scans and images requested by your doctor.
Greasy foods should be avoided even if you aren't required to fast because they can upset your stomach and make it difficult for you to lie still. Avoiding caffeine-filled drinks will also help you remain still for the duration of your MRI.
You may need an injection of MRI contrast (or gadolinium) as part of this scan. MRI contrast is a colourless liquid injected into your blood stream during the scan. It will be injected via a small needle (cannula) into a vein in your arm. The contrast agent improves the quality of the images produced by the scan.
Questions to ask your doctor
“Is there any reason why I shouldn't have an MRI scan?” (If you have any implanted devices (such as a pacemaker, stents, an insulin pump, or an artificial joint), be sure your doctor knows about them.) “Will my exam involve contrast agent?