What is the most sensitive and specific imaging study for confirming a diagnosis of bicep (biceps) tendinitis in a patient with shoulder pain?

Imaging for Biceps Tendinitis Confirmation

MRI without contrast and ultrasound are equally appropriate (both rated 9/9) as the most sensitive and specific imaging studies for confirming biceps tendinitis, according to ACR Appropriateness Criteria. 1

Primary Imaging Recommendation

Both MRI shoulder without contrast and ultrasound shoulder are rated as "usually appropriate" (9/9) and are considered equivalent for evaluating suspected biceps tenosynovitis or tendinitis. 1 The choice between these two modalities depends primarily on local expertise and availability rather than diagnostic superiority.

MRI Without Contrast

• MRI demonstrates soft tissue abnormalities in the biceps tendon with high accuracy, showing tendinosis, partial tears, and tenosynovitis clearly 1
• For biceps tendon tears specifically, MRI has superior accuracy (86.4%) compared to ultrasound (45.5%) 2
• MRI sensitivity and specificity for biceps tendon injury are reported at 92.4% and 100% respectively for complete ruptures, and 59.1% and 100% for partial tears 1
• The FABS (flexion-abduction-supination) view optimizes visualization of the distal biceps tendon on MRI 2
• MRI is particularly useful when evaluating for associated pathology such as rotator cuff tears or SLAP lesions, which commonly accompany biceps tendinitis 3

Ultrasound

• Ultrasound performs similar to or slightly better than MRI for complete versus partial distal biceps tendon tears, with 95% sensitivity, 71% specificity, and 91% accuracy 1
• Ultrasound can be performed with concurrent therapeutic injection of anesthetic and/or corticosteroid if clinically warranted 1
• Ultrasound is operator-dependent and should only be used if local expertise is available 1
• Ultrasound has limitations in detecting partial tears and tendinopathy compared to MRI 2

Imaging Modalities NOT Recommended

CT and CT Arthrography

• CT shoulder without contrast is rated 1/9 ("usually not appropriate") for biceps tendinitis evaluation 1
• CT arthrography is also rated 1/9 and adds no value for biceps tendon assessment 1
• CT has virtually no usefulness in diagnosing soft-tissue injuries like biceps tendinitis 1

MR Arthrography

• MR arthrography is rated 1/9 ("usually not appropriate") for biceps tenosynovitis 1
• MR arthrography does not add additional information compared with noncontrast MRI for biceps tendon pathology 1
• Arthrography is reserved for intra-articular pathology like labral tears, not tendinitis 1

Plain Radiographs

• Plain radiographs should be obtained first to rule out associated fractures or bony abnormalities, but they cannot visualize tendon pathology 2

Clinical Context and Pitfalls

Common Diagnostic Challenges

• Most biceps tendinopathy is degenerative (tendinosis) rather than inflammatory (tendinitis), though the terms are often used interchangeably 4, 3
• Physical examination tests have poor sensitivity: Yergason's test (32% sensitivity), Speed's test (63% sensitivity), making imaging confirmation essential 5
• MRI has relatively low sensitivity for biceps pathology and can result in missed or misdiagnosed cases, so clinical suspicion based on history and physical examination remains crucial 6

Associated Pathology

• In 95% of cases, biceps tendinitis is secondary to impingement syndrome 7
• 55.3% of patients with biceps tendinitis have coexisting rotator cuff injury 5
• Biceps tendinitis commonly accompanies rotator cuff tears or SLAP lesions 3

Key Recommendation

For this 32-year-old swimmer with anterior shoulder pain worse with overhead movement and positive supination resistance test, order either MRI shoulder without contrast or ultrasound shoulder (if local expertise available) to confirm biceps tendinitis. 1 MRI is preferred if you need to evaluate for associated rotator cuff or labral pathology, which is common in overhead athletes. 3, 7