Imaging Guidelines for Shoulder Pain

Initial Imaging

• The American College of Radiology recommends obtaining plain radiographs of the shoulder as the first imaging study for every patient with shoulder pain, irrespective of the suspected cause. 1

Advanced Imaging for Specific Conditions

• Occult fracture (normal or nondiagnostic radiographs): CT of the shoulder without IV contrast is superior for detecting subtle nondisplaced fractures, while MRI without IV contrast can demonstrate bone‑marrow edema and associated soft‑tissue injuries. Strong evidence (high diagnostic accuracy). The American College of Radiology supports either modality. 1

• Confirmed fracture on radiographs: CT of the shoulder without IV contrast should be performed to delineate fracture planes and guide surgical planning. The American College of Radiology endorses this approach. 1

• Suspected dislocation or glenohumeral instability: MRI of the shoulder without IV contrast is the primary modality because post‑traumatic joint effusion provides natural contrast for soft‑tissue evaluation. The American College of Radiology recommends this as first‑line. 1

• If MRI is unavailable or inadequate for bone assessment in dislocation/instability: CT without contrast may be used; MR arthrography is advised for detailed labral evaluation in sub‑acute or chronic cases when natural effusion has resolved. The American College of Radiology provides these alternatives. 2

• Acute traumatic labral tear (≤ 2 weeks): MRI without IV contrast is preferred. The American College of Radiology recommends this because the effusion supplies sufficient joint distention. 1

• Sub‑acute or chronic labral pathology: MR arthrography or CT arthrography is required due to insufficient natural effusion. The American College of Radiology advises these techniques. 1

Rotator Cuff Assessment

• Full‑thickness rotator cuff tear: MRI without IV contrast offers high sensitivity and specificity and allows evaluation of concomitant intra‑articular pathology (e.g., labral or cartilage lesions). It is especially indicated in patients with large body habitus, restricted ROM from acute pain, or suspicion of multiple pathologies. The American College of Radiology cites strong diagnostic performance. 3

• Ultrasound for rotator cuff tears: Provides 90‑91 % sensitivity and 93‑95 % specificity for full‑thickness tears, comparable to MRI, and is the preferred modality when metallic hardware would cause MRI artifact. The American College of Radiology notes comparable accuracy for full‑thickness tears. 3

• Partial‑thickness rotator cuff tear (sub‑acute/chronic): MR arthrography should be reserved for cases where standard MRI is inconclusive, offering superior detection of partial‑thickness lesions. The American College of Radiology recommends this as a second‑line study. 2

Management of Fracture and Dislocation

• Do not skip radiographs even when soft‑tissue injury appears clinically evident; radiographs may reveal unexpected bony abnormalities or arthritis that change management. The American College of Radiology emphasizes this precaution. 1

Common Pitfalls

• Timing of arthrography: In acute trauma, natural joint effusion makes arthrography unnecessary and potentially harmful; defer arthrography until the sub‑acute phase if required. The American College of Radiology advises this timing. 1

• Routine IV contrast in shoulder MRI: No evidence supports the routine use of IV contrast for shoulder pain evaluation; it is not recommended. The American College of Radiology discourages routine contrast administration. 2

Imaging Recommendations for Adhesive Capsulitis (Frozen Shoulder)

Initial Radiographic Evaluation

• The American College of Radiology recommends that plain shoulder radiographs (minimum two views, e.g., AP internal/external rotation and axillary or scapular‑Y) be obtained first in any patient with shoulder pain to rule out fractures, arthritic changes, or calcific tendinitis before making a clinical diagnosis of adhesive capsulitis. 4

Advanced MRI Imaging

• When the clinical picture is atypical or there is a need to exclude rotator‑cuff tears, labral pathology, or other soft‑tissue injuries, the American College of Radiology advises obtaining an MRI of the shoulder without intravenous contrast. This approach is especially useful in older adults where concomitant rotator‑cuff disease is common and may alter management. 4

Ultrasound Utilization

• The American College of Radiology states that dynamic ultrasound is the preferred imaging modality when MRI is contraindicated or unavailable; it can simultaneously evaluate for rotator‑cuff pathology while confirming adhesive capsulitis by demonstrating limited supraspinatus tendon sliding. 4

Imaging Modalities Not Indicated

• CT without contrast has no diagnostic role in adhesive capsulitis except when specifically assessing for an occult fracture, according to the American College of Radiology. 4

Diagnostic Imaging Algorithm (American College of Radiology)

All recommendations are based on expert consensus from the American College of Radiology; specific levels of evidence were not provided in the source material.