Knee MRI: Preparing for your Appointment and What to Expect

If you have been scheduled for a knee MRI (magnetic resonance imaging), you may have questions about what to expect at your appointment. This guide will detail what conditions an MRI may reveal, how the MRI scan works and how to prepare for your scan, both beforehand and on the day of.

While this guide provides helpful information about knee MRIs, your doctor will give the official interpretation of your results during a follow-up appointment or phone call. However, if you’d like early access to your results, PocketHealth offers secure, instant access to your report when it is available. This allows you to review the findings in advance and prepare any questions for your follow-up.

 

 

What is an MRI of the Knee?

An MRI (magnetic resonance imaging) is a medical scanning technique that uses magnets and radio waves to create detailed internal images of the knee or other areas. These images are captured on a computer so the results can be interpreted by a physician.

What is a knee MRI used for?

Often, a knee MRI is used when the patient has swelling, pain or other physical symptoms in the knee area. It helps to discern the sources of these symptoms in ways that other imaging techniques, like X-rays, may miss. Some possible conditions it may reveal include:

• Soft tissue injuries: Examples include ligament, tendon or cartilage damage.
• Tumors and growths: Tumors, masses, cysts, etc. Note that these are often benign.
• Bone fractures: MRIs can see bone injuries and fractures.
• Infections: Inflammation and infections will be visible on an MRI.
• Assessment of medical implants: This can be used to evaluate the placement or malfunction of the implant.
• Buildup of fluid: There are many medical reasons for fluid buildup, such as arthritis or injuries.

Knee MRI vs X-ray

MRIs show aspects of the knee that X-rays may miss. X-rays primarily show bones and bony structures, whereas an MRI can see bones and tissues, such as muscles, ligaments, cartilage and tendons. X-rays can be useful for initial imaging, especially if bone injuries are suspected, but MRIs provide in-depth soft-tissue views or reveal other conditions too subtle to see on an X-ray. Physicians may also choose an MRI instead of an X-ray if they want the patient to avoid unnecessary radiation exposure, as MRIs do not emit radiation but X-rays do.

 

What happens during a knee MRI?

The MRI machine looks similar to a tube, but it is hollow inside, and a sliding exam table can be moved in or out of the machine for patient access. Some MRI machines have gaps in the sides of the “tube,” leaving them open. Unsurprisingly, these are called open MRIs. Regardless of the type, the process is the same:

1. You will change into a hospital gown at your appointment. It’s also possible you could be allowed to stay in your clothes if they don’t have any metal on them, such as buttons or zippers. You will be given hearing protection to wear, as the MRI machine can be quite loud with lots of banging and vibrating sounds. Some clinics even provide music to listen to.
2. For a knee MRI, you will lie on the table and be slid into the machine feet first. For many, only the lower body is actually within the machine. Sometimes a contrast agent will be administered through an IV, which provides more contrast and greater visibility in the images. It’s common to feel a little cold after this, but it should be brief.
3. During the scan, the MRI technician will be in an adjoining room, controlling the MRI machine from a distance. They will be able to communicate with you via intercom to give instructions and answer questions, if needed.
4. You will be asked to hold still for the exam, sometimes in increments of time, such as three minutes or five minutes. Many MRI technicians will tell you what to expect throughout the appointment, so you know when and how long to hold still. They may also ask you to hold your breath for short periods of time.
5. After the scan is complete, the IV will be removed (if one was used), and the technician will help you off the table. You can then go about your day as normal.

 

How to prepare for a knee MRI

There are some preparations you can make both beforehand and on the day of the appointment to make the experience more comfortable. Here are some tips to keep in mind.

Tips before the scan

• Tell your doctor if there is any chance of your being pregnant: It is usually recommended to avoid MRIs during the first trimester of pregnancy. Contrast agent injections should also be avoided, so let your doctor know in advance so they can accommodate you.
• Let your doctor know if you have any metallic implants: Because MRIs utilize magnets, it’s important to inform your physician beforehand if you have metal implants, such as a pacemaker.
• Let your doctor know if you have any known allergies: This could include allergies to medications, latex, or even the contrast agent. Knowing this in advance allows the doctor to make any necessary adjustments.
• Inform your doctor if you have veins that are difficult to find: If you’re expecting contrast to be administered via IV but have a history of challenges with injections, the technician may need you to arrive early.

Tips during the scan

• Wear comfortable clothing: If your clothes don’t have any metal, such as zippers or buttons, you may be allowed to keep your own clothes on during the scan instead of changing into a medical gown. Regardless, it is recommended that you wear clothes that are easy to get in and out of.
• Bring your requisition: It can be helpful to bring your MRI requisition in case the imaging facility doesn’t already have it. Also, bring your ID and health cards.
• Avoid wearing metal to your appointment: If possible, avoid wearing anything metallic to your appointment. If you have important metallic items you can’t leave at home, a locker will be available to store them during the scan.
• Bring extra medication patches: If you wear medication patches, you will likely need to remove them before the scan. Bringing an extra patch allows you to apply it after your appointment to minimize time without it.
• Focus on relaxing if you’re claustrophobic: If the MRI technician lets you listen to music, select something soothing, if possible. When you’re not being asked to hold your breath, focus on taking calming, deep breaths.
• Let the technician know if you’re uncomfortable: Try to communicate this before the scan begins. It’s important that you feel comfortable so staying still is easier. The technician may be able to provide pillows or other support to improve your comfort.

While the MRI technician can’t legally answer your medical questions, they can address questions regarding the scan itself. Feel free to speak up at your appointment if you need clarification on anything, as knowing what to expect could make the experience more positive.

 

Getting my results

Understandably, patients frequently want their knee MRI results back as soon as possible. This section will cover common questions regarding when to expect your results and who deciphers them.

Who interprets my results?

A medical imaging specialist, called a radiologist, will interpret your MRI images. They will communicate any findings or recommendations, at which point your referring physician will receive your report. If your physician has additional insights or diagnostic interpretations based on your medical history, they may add this to your records as well.

When will I get my results?

Your results may take up to a week or longer, depending on the schedules of the radiologist and your referring doctor. Most patients receive their results during their follow-up appointment with their doctor.

If you’d like to view your report before your appointment, PocketHealth provides faster access, allowing you to see the results as soon as they are officially released, often before your follow-up appointment. This gives you time to review the findings and prepare for your next medical visit.

MyCare Navigator is especially helpful for offering personalized insights and identifying any recommended follow-up steps. PocketHealth also generates personalized questions to ask your doctor based on the findings in your report, ensuring you make the most of your consultation.

 

 

Understanding my results

Although your doctor will provide an official explanation of your results, accessing your report before your appointment can give you an early glimpse. It’s common to find medical terminology complex and confusing, but PocketHealth Report Reader makes it easier by offering clear, straightforward definitions for medical terms—simply tap or click on any underlined words to reveal their meaning.

 

Frequently asked questions

This guide will discuss some commonly asked questions regarding knee MRIs, including details on abnormal results. Remember, this is only general information; your personal results should be interpreted by your physician.

Do I need a referral for a knee MRI?

In most cases, yes, you would need a referral for an MRI. Exceptions include emergency rooms or same-day clinics, which often have on-call physicians who can authorize these scans. Otherwise, you’ll need to establish care with a medical provider who can issue a referral. The time it takes for this process depends on the referring doctor’s schedule and the imaging clinic’s availability. Some facilities can schedule appointments quickly, while others may be booked out. The severity of your condition may also affect the timeline. For acute injuries, most doctors will try to expedite the process.

What does an abnormal knee MRI look like?

• Abnormal growths: Examples include cysts and tumors. Many of these are benign, but further testing will be performed for confirmation.
• Meniscus injuries: The meniscus is triangular-shaped cartilage within the knee that helps stabilize and cushion the joint. Injuries can be detected when the triangular shape looks different or has shifted. Note that sometimes these shifts can be a normal sign of aging. If there is any uncertainty about the cause, other testing can be performed.
• Tendon conditions: Tendons are the fibers that connect bone to muscle. Irregularities, scarring and inflammation in this area can suggest injury.
• Fluid buildup: This often appears bright white on an MRI and can indicate damage to the knee’s internal structures, such as from an injury or arthritis.
• Bone spurs: Indicative of osteoarthritis, these smooth projections often occur where two bones meet, such as in the knee. Depending on the severity, they may not require treatment, may be treated with pain medication or they may be treated with knee surgery.
• Bone injuries: Fractures, dislocations and other skeletal injuries can be seen on an MRI, although these are also commonly identified on an X-ray scan.
• Ligament tears or injuries: Ligaments are how a bone attaches to another bone via fibrous connective tissue. There are various ligaments around the knee joint, with the most common injury being to the anterior cruciate ligament (ACL), which is especially frequent among athletes.

What are the risks of a knee MRI?

MRIs are considered non-invasive and low-risk. Rarely, patients may experience an allergic reaction to the contrast dye. If you experience any allergic symptoms after the contrast agent is administered, let your technician know immediately so they can treat you. Symptoms include:

• Difficulty breathing
• Changes in heartbeat
• Itching skin or rash

How long does a knee MRI take?

Typical knee MRIs take 30 to 60 minutes, varying depending on whether contrast dye is being administered. For more complex medical conditions, the process can sometimes take up to two hours, especially in cases of severe knee injury.

Does your whole body go in for a knee MRI?

Commonly, only your lower body goes into the MRI machine, with the upper half of the table and your torso remaining outside. This may provide a less stressful experience for patients with claustrophobia, as you are not fully enclosed.

What if it’s too painful to have a knee MRI?

Lying still for a long period may seem daunting if you’re experiencing knee pain. Conditions like arthritis and injuries can cause discomfort, even when simply holding still. If you have concerns about this, consider speaking to your doctor beforehand. They may prescribe pain medication to make the appointment easier.

You can also contact the imaging clinic in advance to discuss your needs. They might find ways to shorten your appointment, such as skipping the contrast agent if deemed unnecessary, or prepare methods to enhance your comfort during the scan. Some clinics may even allow you to bring a support person into the room, as MRI scans do not emit radiation. However, be sure to check on this beforehand, as policies can vary.

 

Take control of your health journey

In summary, discuss any concerns with your doctor in advance, such as claustrophobia or necessary accommodations. Day-of preparations, like avoiding metal, can simplify the process. Additionally, communicate any discomfort during the MRI, as comfortable positioning helps you stay still, improving image quality.

PocketHealth makes it simple to keep track of your medical reports and MRI scans. All of your vital imaging is in one secure location and can be accessed online anytime. If needed, reports can also be easily shared with other physicians in your care team. When used in conjunction with your medical provider’s professional advice, it is a powerful tool for organizing and understanding your imaging results and your health.