Is contrast necessary for a knee Magnetic Resonance Imaging (MRI)?

Contrast is NOT Necessary for Most Knee MRI Examinations

MRI of the knee without IV contrast is the standard imaging approach for the vast majority of clinical indications, including meniscal tears, ligament injuries, cartilage evaluation, bone marrow edema, tendinopathy, and post-surgical assessment. 1, 2

When Contrast is NOT Needed (Standard Practice)

Routine Musculoskeletal Pathology

• Sports injuries including meniscal tears, ligament injuries (ACL, PCL, MCL, LCL), and cartilage defects do not require contrast enhancement 3
• Tendon pathology including patellar and quadriceps tendinopathy or tears are adequately evaluated without contrast 1
• Bone marrow edema patterns, stress fractures, and subchondral insufficiency fractures are well-visualized on non-contrast sequences 1
• Osteochondritis dissecans (OCD) and loose bodies are effectively identified without contrast 1, 2
• Post-operative evaluation after total knee arthroplasty, including assessment of aseptic loosening, osteolysis, instability, and periprosthetic soft-tissue abnormalities 1

Osseous Pathology

• Osseous fragments have inherent signal characteristics that provide excellent contrast against surrounding tissues without gadolinium 2
• Plain radiographs should be obtained first, followed by non-contrast MRI if clinical suspicion remains high 2

When Contrast MAY Be Considered (Selective Use)

Inflammatory and Synovial Conditions

• Quantifying synovitis in chronic knee pain when precise grading is needed, though contrast-enhanced MRI correlates only moderately with histology (r = 0.56) 1, 4
• Pigmented villonodular synovitis (PVNS) evaluation benefits from contrast to assess extent and vascularity 1
• Hoffa's disease and deep infrapatellar bursitis may be more accurately diagnosed with contrast, particularly when enhancing synovitis >2mm correlates with peripatellar pain 1

Soft Tissue Masses

• Neoplastic masses and inflammatory pseudotumors require contrast for characterization 1, 3
• Bone and soft tissue tumors are the primary indication where contrast is recommended 3

Complex Infections

• Chronic or complex infections may benefit from contrast, though routine infection evaluation does not require it 3

Important Clinical Caveats

Contrast Limitations

• The ACR explicitly states there is no relevant literature documenting additional benefit of contrast over non-contrast MRI for assessment of impingement, tendon abnormalities, or most intraarticular pathology 1
• Contrast-enhanced MRI tends to underestimate synovitis severity compared to histology in some studies 5
• The Society of Skeletal Radiology recommends judicious use of gadolinium, restricting it to cases with demonstrable added value 3

Alternative Non-Contrast Techniques

• Quantitative DESS sequences show good agreement with contrast-enhanced MRI for synovitis assessment without gadolinium (AC2 = 0.74) 5
• T2 mapping, T1ρ imaging, and sodium imaging can assess cartilage composition without contrast agents 6, 7
• MR arthrography (intra-articular gadolinium) is reserved for patients with prior meniscal surgery, chondral lesions, or suspected loose bodies—not routine evaluation 1

Post-Arthroplasty Specific Guidance

• MRI without contrast using metal artifact reduction techniques is the appropriate study for painful knee prosthesis evaluation 1
• Ultrasound is an equivalent alternative for soft-tissue abnormalities including tendinopathy and arthrofibrosis 1