CT Without Contrast for Suspected Muscle Tear
For a suspected muscle tear, CT should not be performed at all—neither with nor without intravenous contrast—as CT is unable to adequately assess soft tissue injuries like muscle tears. 1
Why CT Is Not Appropriate for Muscle Tears
CT has no role in evaluating muscle, tendon, or ligament injuries. The ACR Appropriateness Criteria explicitly state there is no evidence to support the use of CT (with or without contrast) for assessment of suspected tendon, ligament, or muscle injury across multiple anatomic sites including the elbow, forearm, and hip. 1
Noncontrast CT cannot assess soft tissue pathology in the acute setting and is specifically noted as unable to evaluate rotator cuff pathology, which represents a similar soft tissue injury pattern to muscle tears. 1
CT with IV contrast adds no diagnostic value for muscle tears and only introduces unnecessary risk of contrast reactions without improving soft tissue visualization. 1
CT without and with IV contrast is similarly inappropriate for muscle injury evaluation, as the addition of contrast does not overcome CT's fundamental limitation in soft tissue characterization. 1
The Correct Imaging Approach
MRI without IV contrast is the imaging modality of choice for suspected muscle tears. 1, 2
MRI detected 100% of proximal hamstring avulsion injuries in a retrospective study, demonstrating superior sensitivity for muscle and tendon pathology. 1
MRI allows classification of location, extent, degree (partial versus complete), and chronicity of muscle injuries, which directly impacts treatment decisions and return-to-play timing. 1, 2
MRI is considered the reference standard for evaluation of muscle injuries due to its superior depiction of injury extent and higher sensitivity for detecting minimal injuries compared to all other modalities. 2
MRI provides excellent soft tissue contrast and can image directly in any plane, making it ideally suited for studying suspected soft tissue injuries. 3
Alternative Imaging Consideration
Ultrasound can provide real-time dynamic assessment and identify tears affecting the intramuscular tendon, though it is generally considered less comprehensive than MRI. 4
- Ultrasound detected only 58.3% of proximal hamstring avulsion injuries compared to MRI's 100% detection rate, demonstrating MRI's superiority for muscle injury evaluation. 1
Critical Pitfall to Avoid
Do not order CT for muscle tear evaluation under any circumstances. CT is reserved for fracture detection and characterization, not soft tissue injury assessment. 1, 5 If you suspect a muscle tear, proceed directly to MRI without contrast or consider ultrasound if MRI is unavailable or contraindicated. 1, 2