Rotator cuff disorders: interobserver and intraobserver variation in diagnosis with MR imaging

Area of Science:

• Orthopedics
• Radiology
• Musculoskeletal Imaging

Background:

• Rotator cuff disorders are common causes of shoulder pain and dysfunction.
• Accurate diagnosis is crucial for effective treatment planning.
• Magnetic resonance (MR) imaging is a primary modality for evaluating rotator cuff pathology.

Purpose of the Study:

• To assess interobserver and intraobserver variability in interpreting MR images of the rotator cuff.
• To evaluate the diagnostic accuracy of MR imaging for various rotator cuff pathologies.

Main Methods:

• Retrospective review of shoulder MR images from 97 patients by multiple observers.
• Images were reviewed twice with a 3-week interval to assess intraobserver agreement.
• Surgical findings served as the gold standard for diagnosis.

Main Results:

• High accuracy (89%-98%) and good agreement (kappa = 0.67-0.92) were observed for diagnosing full-thickness rotator cuff tears.
• Sensitivity and specificity varied widely for tendinitis, partial tears, and normal cuffs.
• Poor interobserver (kappa = 0.12-0.60) and intraobserver (kappa = 0.35-0.78) agreement was noted for these less severe conditions.

Conclusions:

• MR imaging is reliable for diagnosing full-thickness rotator cuff tears with consistent interpretation.
• Distinguishing between normal rotator cuff, tendinitis, and partial tears using MR imaging presents significant observer variability.
• Further refinement of MR imaging techniques or interpretation guidelines may be needed for subtle rotator cuff pathologies.