MR imaging of the normal ligaments and tendons of the ankle.

The 10 major ligaments and nine major tendons of the ankle were evaluated in 17 ankle MR studies to determine the incidence of visualization of each structure in each of the three orthogonal planes. High-resolution technique was used, with 3 mm slice thickness and an in-plane resolution of 0.6 mm. Of the 19 ligaments and tendons evaluated, 18 demonstrated more than 70% frequency of visualization in at least one imaging plane. However, seven ligaments and three tendons demonstrated 0% visualization in at least one of the three orthogonal planes. Seven ligaments showed more than 70% visualization in only one plane (three coronal, two axial, two sagittal). Only the Achilles tendon and anterior tibial tendon demonstrated 100% visualization in all three planes. We conclude that all three orthogonal planes are essential to achieve optimal visualization of all of the major ligaments and tendons of the ankle. For specific evaluation of selected ligaments or tendons, only one or two planes may be required.