What is the recommended MRI protocol to evaluate an elbow Ulnar Collateral Ligament (UCL) injury?

Recommended MRI Protocol for Evaluating Elbow UCL Injury

For optimal evaluation of elbow Ulnar Collateral Ligament (UCL) injuries, 3T MR arthrography is the recommended imaging modality, as it provides superior accuracy compared to conventional MRI for detecting collateral ligament injuries. 1

Optimal MRI Protocol Components

Positioning

• FEVER view (Flexed Elbow Valgus External Rotation) - This specialized positioning technique significantly improves UCL visualization by:
  • Placing the elbow in valgus stress position
  • Aligning the UCL parallel to its long axis
  • Increasing ulnotrochlear joint space width (average 1.80 mm wider than standard views) 2

Sequences

1. Coronal fat-saturated proton density-weighted sequence in FEVER position 2
2. High spatial resolution intermediate-weighted fast spin echo (FSE) in oblique coronal plane - provides highest overall image quality with excellent interobserver reliability 3
3. Fat-suppressed T1-weighted spin echo with intra-articular gadolinium - offers highest sensitivity for complete UCL tears 3
4. T2-weighted sequences - recommended for evaluation of loose bodies in the elbow 1

Diagnostic Performance

• MR arthrography provides:

  • Sensitivity: 81%
  • Specificity: 91%
  • Accuracy: 88% for UCL tears 1
  • Superior ability to differentiate between partial and complete UCL tears 1

• FEVER view advantages:

  • Higher intrareader agreement on joint space measurement (ICC 0.92 vs 0.54 for standard views)
  • Increased diagnostic confidence for UCL abnormalities
  • Ability to detect additional UCL injuries not visible on standard views 2

Clinical Considerations

• MR arthrography is particularly valuable for:

  • Detecting soft tissue and bone marrow edema (more common in symptomatic patients)
  • Identifying the "T sign" (distal ligamentous insertion of UCL) which suggests repetitive overhead activity injury 1
  • Evaluating posterolateral rotatory instability by assessing the ulnar band of the radial collateral ligament 1

• Alternative imaging options when MR arthrography is not available:

  • Ultrasound with valgus stress has sensitivity of 96% and specificity of 81% for UCL tears 1
  • CT arthrography has 86% sensitivity (100% for full-thickness tears, 71% for partial tears) 1

Pitfalls to Avoid

• Standard MRI positioning provides suboptimal rendering of the UCL 2
• Conventional MRI without arthrography is less accurate than MR arthrography for UCL evaluation 1
• Low-field MRI may miss subtle partial tears that could progress to complete tears if not properly diagnosed and treated
• Failure to use specialized positioning (like FEVER view) may result in missed diagnoses of UCL injuries in throwing athletes 2

The FEVER view is generally well-tolerated by patients, with most reporting no pain (66%) or minimal pain (25%) during the positioning procedure 2, making it a practical addition to standard elbow MRI protocols for athletes with suspected UCL injuries.