Magnetic resonance imaging of ankle tendons and ligaments: part I - anatomy.

Magnetic resonance imaging is an excellent technique for imaging the tendons and the ligaments of the ankle. Owing to the advantage of detailed demonstration of soft-tissue structures and capability for multiplanar demonstration of the ankle ligaments and tendons, MRI has been increasingly used in the evaluation of the ligamentous and the tendon injuries of the ankle. Knowledge of normal anatomy and of MRI appearances are essential to recognize pathological appearances. In this pictorial essay, the first of a three part series, we review the normal MRI appearances of the ankle tendons and ligaments. The anterior, lateral and medial tendon groups, the Achilles tendon and the lateral, the syndesmotic and the medial ligament groups are described and illustrated. Anatomy of the sinus tarsi is also described. Tendon and ligament pathology will be illustrated in the second part of the series, and imaging approach to ankle injuries will be outlined in the final part of this series.