What imaging should I do for left shoulder pain?

Imaging for Left Shoulder Pain

Plain radiography should be the initial imaging study for all patients with left shoulder pain, followed by MRI without contrast or ultrasound if rotator cuff pathology is suspected. 1

Initial Imaging Approach

• Plain radiographs should always be the first imaging study performed for shoulder pain evaluation, regardless of suspected etiology 1
  • Standard views should include anteroposterior (AP) views in internal and external rotation and an axillary or scapula-Y view 1
  • Radiographs can identify fractures, dislocations, arthritis, calcific tendinitis, and other bony abnormalities 1
  • Upright positioning is preferred as malalignment can be underrepresented on supine radiographs 1

Follow-up Imaging Based on Clinical Suspicion

If Rotator Cuff Pathology is Suspected:

• MRI shoulder without contrast or Ultrasound shoulder are equally appropriate and only one study is needed 1
  • Both have high sensitivity and specificity for full-thickness rotator cuff tears (90-95%) 1
  • MRI is preferred when:
    • Patient has large body habitus
    • Restricted range of motion due to acute pain
    • Suspicion of concurrent intra-articular pathology like labral tears 1
  • Ultrasound is preferred when:
    • Patient has metallic hardware causing MRI artifacts
    • MRI is contraindicated
    • Immediate results are needed 1

If Labral Tear is Suspected:

• MRI shoulder without contrast is usually appropriate in acute settings 1
  • In acute trauma, post-traumatic joint effusion typically provides sufficient visualization of soft tissue structures 1
• MR arthrography should be considered in subacute or chronic settings when joint effusion is minimal 1
  • Superior for detecting partial-thickness rotator cuff tears and labral injuries 1

If Occult Fracture is Suspected:

• MRI shoulder without contrast or CT shoulder without contrast are both appropriate 1
  • CT provides detailed evaluation of osseous anatomy with high spatial resolution 1
  • MRI can demonstrate bone marrow edema and identify soft tissue injuries 1

If Glenohumeral Instability is Suspected:

• MRI shoulder without contrast is usually appropriate 1
  • Can assess both soft tissue and bony components of instability 1
  • CT shoulder without contrast may be appropriate when MRI assessment of bone loss is limited 1

If Septic Arthritis is Suspected:

• Ultrasound-guided or X-ray-guided arthrocentesis is the procedure of choice 1
  • Both guidance methods are equally appropriate 1
  • MRI with contrast may be appropriate if clinical concern warrants but should not delay aspiration 1

Age-Specific Considerations

• In patients under 35 years, instability is more common, and MRI or MR arthrography is recommended 1
• In patients over 35 years, rotator cuff disease predominates, and MRI without contrast or ultrasound is recommended 1

Common Pitfalls to Avoid

• Failure to obtain adequate radiographic views (especially axillary or scapula-Y views) can miss shoulder dislocations 1
• Relying solely on ultrasound for comprehensive shoulder evaluation may miss labral tears and other intra-articular pathologies 1
• Using MR arthrography in acute trauma settings is unnecessary as natural joint effusion provides adequate contrast 1
• Performing CT as initial imaging for soft tissue injuries is inappropriate as it has limited value for evaluating tendons, ligaments, and labrum 1