Magnetic Resonance Imaging (MRI) is a non-invasive medical imaging technique that uses strong magnetic fields and radio waves to generate detailed images of the body’s internal structures. For the knee, an MRI provides high-resolution pictures of bones, cartilage, tendons, ligaments, and muscles, helping diagnose the source of pain, swelling, or dysfunction.
Understanding “Abnormal”
Receiving an “abnormal” MRI result can be concerning, but it does not automatically indicate a severe condition. The term “abnormal” simply means the scan detected something deviating from a typical, healthy knee structure. These deviations can range from minor findings that may not require treatment to more significant issues. An MRI is highly sensitive and can identify subtle changes, some of which are common and do not cause symptoms. Findings must always be correlated with a patient’s symptoms and physical examination.
Common Findings
Common findings on a knee MRI include:
- Meniscus Tears: The menisci are C-shaped cartilage pieces that cushion the knee joint. Tears appear as bright signals or disruptions to their normal shape.
- Ligament Injuries: Ligaments stabilize the knee. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are frequently injured, often showing as a tear or signal change. Medial collateral ligament (MCL) and lateral collateral ligament (LCL) tears also occur.
- Cartilage Damage: Articular cartilage covers bone ends, enabling smooth joint movement. Damage appears as thinning, fraying, or lesions, ranging from minor changes to full-thickness loss.
- Bone Edema or Bone Bruises: These are areas within the bone marrow showing increased fluid due to trauma or microfractures. They are common findings, especially after acute knee injuries.
- Tendinopathy: This involves inflammation or degeneration of tendons, such as the patellar or quadriceps tendons. MRI can show signal changes within the tendon.
- Fluid Accumulation (Effusion): Joint effusion, or fluid buildup within the knee joint, can indicate inflammation or injury. It appears as bright signal on fluid-sensitive MRI sequences.
- Osteoarthritis (Degenerative Changes): MRI can reveal signs like focal loss of articular cartilage, bone spurs (osteophytes), subchondral marrow lesions, and joint effusion. MRI provides detailed information on the extent of these changes.
Deciphering Your Report
An MRI report is a detailed document written by a radiologist for medical professionals, often containing technical terminology. The report typically includes sections like “Clinical History,” “Technique,” “Findings,” and “Impression.” The “Findings” section lists all observations, while the “Impression” or “Conclusion” provides the radiologist’s summary and interpretation of the most significant findings. This “Impression” is often the most important part, translating complex imaging data into a concise conclusion. Reviewing the report and making a list of questions to discuss with your doctor is helpful, as the report is one piece of the diagnostic puzzle.
What Comes Next
After receiving an abnormal knee MRI result, the next step involves a consultation with a healthcare provider, such as an orthopedic specialist or sports medicine doctor. This allows for a comprehensive discussion of the MRI findings in the context of your symptoms, physical examination, and medical history. Your doctor will explain the implications of the findings and how they relate to your overall condition.
Treatment options vary based on the specific findings and severity. Conservative management, such as rest, ice, compression, elevation (RICE), physical therapy, or injections, is often the first approach. In some cases, surgical considerations might be discussed, ranging from minimally invasive arthroscopic procedures to more extensive interventions like knee replacement, depending on the injury. Shared decision-making with your doctor is important to determine the most appropriate course of action for your needs.