From the Guidelines
For most knee MRIs, a non-contrast MRI is typically sufficient and recommended as the initial imaging study. This approach is supported by the most recent and highest quality study, which suggests that MRI knee without IV contrast is usually appropriate for evaluating common knee problems such as meniscal tears, ligament injuries, cartilage damage, and bone contusions 1. The use of contrast agents, such as gadolinium, is only recommended in specific situations, such as when evaluating for infection, inflammatory arthritis, certain tumors, or after knee surgery to distinguish between scar tissue and recurrent tears.
Some of the key benefits of a non-contrast MRI include:
- Avoiding the small risks associated with contrast agents, including allergic reactions and concerns about gadolinium retention
- Reducing cost
- Shortening the examination time
- Providing sufficient information for diagnosing common knee problems, as supported by studies such as 1 and 1
It's worth noting that the American College of Radiology recommends MRI knee without IV contrast as the next imaging study for aseptic loosening or osteolysis or instability in patients with a painful knee prosthesis evaluated with radiography and when infection has been excluded 1. Additionally, MRI knee without IV contrast is also recommended for suspected periprosthetic soft-tissue abnormality unrelated to infection, including quadriceps or patellar tendinopathy 1.
Ultimately, the decision to use contrast or not should be determined by your doctor based on your specific clinical situation, symptoms, physical examination findings, and what condition they suspect. If you have any kidney problems, this should be discussed with your doctor before receiving contrast, as gadolinium-based contrast agents can pose risks to patients with impaired kidney function.
From the Research
MRI of the Knee: With or Without Contrast
The decision to perform an MRI of the knee with or without contrast depends on the specific clinical scenario and the information being sought.
- Diagnostic Accuracy: Studies have shown that MRI is a highly accurate diagnostic tool for detecting meniscal tears and anterior cruciate ligament (ACL) injuries, with sensitivity and specificity values greater than 89% 2, 3.
- Indications for Contrast: There is no clear indication in the provided studies that contrast is necessary for the diagnosis of meniscal tears or ACL injuries. In fact, the studies suggest that MRI without contrast is highly effective in detecting these injuries 2, 4, 3.
- Knee Osteoarthritis: In cases of knee osteoarthritis, meniscal damage is a frequent finding on MRI, and the use of contrast may not be necessary to diagnose meniscal lesions 5.
- Current Clinical Practice: The current clinical practice of MRI evaluation and interpretation of meniscal, ligamentous, cartilaginous, and synovial disorders within the knee does not necessarily require the use of contrast 6.
Overall, the provided studies suggest that MRI without contrast is a highly effective diagnostic tool for detecting meniscal tears and ACL injuries, and the use of contrast may not be necessary in these cases 2, 4, 3.