Value of 13-MHz high-frequency ultrasound of the lateral ankle ligaments and the anterior tibiofibular ligament

Purpose: Determination of the value of 13-MHz high-frequency ultrasound in the diagnosis of acute injuries of the lateral ankle ligaments and the anterior tibiofibular ligament by comparison with MRI. Method: Sonography was performed prospectively in 64 acutely injured patients using a mechanical 13-MHz sector probe; for diagnosis of the anterior tibiofibular ligament a 15-MHz sector probe was employed during the course of this trial. Using a 0.2-T unit for MRI examination, T1 -weighted (TR 580 ms, TE 24 ms) and T2-weighted (TR 3000 ms,TE 80 ms) spin-echo sequences were obtained in various oblique axial imaging planes. Results: In the differentiation of intact and injured ligaments, ultrasound and MRI agreed in 95.3% of cases for the anterior fibulotalar ligament, in 88.3% for the fibulocalcanear ligament and in 85.0% for the anterior tibiofibular ligament. Conclusion: lesions of the anterior talofibular and fibulocalcanear ligament can be accurately demonstrated by ultrasound if a 13-MHz sector scanner is used. The detection of lesions in the anterior tibiofibular ligament is more difficult. With increasing experience and by using a 15-MHz sector scanner, better results can be expected for this ligament.