Current concepts review: 3T magnetic resonance imaging of the ankle and foot

The increasing technological advances in MR imaging continue to expand the clinical applications and increase the diagnostic accuracy of this modality. The MR evaluation of the foot and ankle has benefited substantially from the implementation of 3T scanners and associated imaging techniques. From this topical review, the main points to summarize 3T scanning include: • The implementation of 3T MR scanners, combined with specialized coils and novel imaging techniques, have yielded superior image quality with potential for enhanced diagnostic accuracy. • A good quality 3T MR imaging examination encompasses predominantly spin-echo type contrast, thin section T1-weighted (T1W) and fsT2W images, uniform fat suppression, higher echo times to avoid magic angle artifacts and higher resolution. • Metal artifacts markedly degrade imaging; therefore in patients with hardware, in the field of view, 1.5T MR scanning is preferred. • 3T images can depict the various bundles of the small ankle ligaments and tendons, such as the various components of the spring ligament, Lisfranc ligament, bifurcate ligament, as well as the superficial and deep deltoid ligaments, which are visualized with consistency. • Tendon and ligament injuries as well as nerve entrapments are better depicted on 3T MR imaging as opposed to low-field scanner images. • 3T MR imaging better depicts the cartilage fissures, flaps and areas of delamination with secondary bone marrow changes in native or repaired osteochondral lesions as opposed to low-field MR images, in which bony changes are the predominant discernable finding implying overlying cartilage abnormality.