What is the recommended initial imaging modality for a bicep (biceps) tear?

MRI is the Recommended Initial Imaging Modality for Bicep Tears

MRI without contrast is the recommended initial imaging modality for suspected biceps tendon tears, with superior accuracy (86.4%) compared to ultrasound (45.5%). 1, 2

Diagnostic Imaging Algorithm

1. Plain radiographs

   • Should be the first imaging study to rule out associated fractures or other bony abnormalities 1, 2
   • Limited in providing information about soft tissue injuries 3

2. MRI without contrast

   • Most accurate imaging modality for diagnosing biceps tendon tears 1
   • Superior sensitivity (76%) and specificity (50%) compared to ultrasound 1
   • Overall sensitivity of 92.4% and specificity of 100% for detecting distal biceps tendon ruptures 4
   • Particularly useful for distinguishing between partial and complete tears 2
     • 100% sensitivity and 82.8% specificity for complete tears 4
     • 59.1% sensitivity and 100% specificity for partial tears 4

3. FABS (flexion-abduction-supination) view

   • Specialized MRI technique recommended for optimal visualization of the distal biceps tendon 1, 2
   • Patient positioned prone with elbow flexed at 90°, shoulder abducted, and forearm supinated 2
   • Allows visualization of the entire tendon on a single image 2
   • Particularly helpful in challenging cases of high-grade partial versus complete tendon tears 5

4. Ultrasound

   • Alternative when MRI is contraindicated 1, 2
   • Limited accuracy (45.5%) compared to MRI (86.4%) 1
   • Less reliable for detecting partial tears and tendinopathy 2
   • Medial imaging approach preferred by radiologists when using ultrasound 1

Strengths of Evidence

The American College of Radiology's guidelines provide the most authoritative recommendations, clearly favoring MRI as the imaging modality of choice for biceps tendon tears 5, 1. The 2025 Praxis Medical Insights summary reinforces this recommendation with specific accuracy statistics comparing MRI to ultrasound 1.

The research evidence supports these guidelines, with Festa et al. (2010) demonstrating high overall sensitivity (92.4%) and specificity (100%) for MRI in detecting distal biceps tendon ruptures 4. However, it's important to note that while MRI is excellent for complete tears (100% sensitivity), it has limitations for partial tears (59.1% sensitivity) 4.

Common Pitfalls to Avoid

• Relying solely on ultrasound for diagnosis

  • Ultrasound has significant limitations in accuracy compared to MRI, particularly for partial tears 1, 2
  • May lead to misdiagnosis and inappropriate treatment planning 2

• Failing to distinguish between partial and complete tears

  • This differentiation is crucial for treatment planning and requires accurate imaging, preferably MRI 1, 2
  • Complete tears typically require surgical repair, while partial tears may be managed conservatively or with debridement depending on severity 6

• Not using specialized MRI techniques

  • The FABS view significantly improves visualization of the distal biceps tendon 5, 2
  • Standard MRI views may miss subtle pathology or mischaracterize the extent of injury 5

• Missing associated pathologies

  • Biceps tendinitis and tendinosis are commonly accompanied by rotator cuff tears or SLAP lesions 7
  • Comprehensive imaging is necessary to identify all relevant pathology 2

• Inadequate imaging planes

  • Axial MR images are more valuable than sagittal images for accurately grading distal biceps tendon injury 8
  • Using inappropriate imaging planes may lead to inaccurate assessment of tear severity 8