MRI Without Contrast for Achilles Tendon Pathology Evaluation
For evaluating Achilles tendon pathology, you should order an MRI without intravenous contrast of the ankle/hindfoot. 1, 2
Rationale for MRI Without Contrast
- MRI achieves high sensitivity (>90%) in diagnosing ankle tendon tears 2
- For Achilles tendinopathy specifically, MRI detects 26 of 27 cases (96%) of tendinosis and partial rupture 1
- MRI offers 92% accuracy in differentiating full-thickness from partial-thickness Achilles tears 2
- The American College of Radiology specifically recommends MRI ankle without IV contrast as the next imaging study when tendon abnormality is suspected 1
Technical Considerations
- Include both sagittal and coronal sections to properly assess:
- Tendon integrity
- Distance between stumps in case of rupture
- Associated conditions that may mimic Achilles pathology 3
- Fat suppression sequences should be included to detect focal lesions 3
- T1 and T2-weighted sequences are necessary for comprehensive evaluation 3
MRI vs. Ultrasound
While ultrasound is an alternative option, MRI is preferred because:
- MRI is more sensitive for detecting partial tears 3
- Ultrasound results are highly operator-dependent 2
- MRI can simultaneously assess associated conditions that may mimic Achilles pathology 1
- MRI provides better postoperative assessment 3
Clinical Correlation Caution
- MRI findings should be interpreted with clinical correlation
- Up to 34% of asymptomatic patients may have tendon abnormalities on imaging 1
- MRI evidence of tendon pathology has only 48% positive predictive value for clinical findings 1
When to Consider Contrast
- Standard Achilles tendon evaluation does not require contrast
- Consider contrast-enhanced MRI only in specific situations:
- Postoperative assessment
- Suspected infection
- Suspected inflammatory arthritis
- Tumor evaluation 3
MRI without contrast provides the optimal balance of diagnostic accuracy and clinical utility for evaluating Achilles tendon pathology, making it the imaging modality of choice according to current guidelines.