Beyond the bones and joints: a review of ligamentous injuries of the foot and ankle on Tc-MDP-SPECT/CT.

Tc-MDP-single photon emission computed tomography (SPECT)/CT has established itself as a useful modality in the assessment of the painful foot and ankle, owing to its ability to depict anatomical and functional information simultaneously. Despite its growing popularity, much of the literature describing the utility of Tc-MDP-SPECT/CT of the foot and ankle is limited to osseous and articular pathology, with descriptions of ligamentous pathology limited to just a handful of cases. Though assessment of soft tissues using a combination of bone tracer and CT is limited, with a sound understanding of the regional anatomy, it is certainly within the scope of Tc-MDP-SPECT/CT to accurately identify ligamentous injuries based on focal tracer uptake patterns and suspected ligamentous injuries should be reported as such. This article provides a case-based pictorial review of the Tc-MDP-SPECT/CT appearances of the various ligamentous injuries of the foot and ankle with case examples and MRI correlation where available, most of which have yet to be described. The typical patterns of bone tracer uptake and associated CT abnormalities that may be observed are discussed.