The role of 99mTc-diphosphonate bone SPECT/CT in the ankle and foot.

The evaluation of the osseous ankle and foot pathology often poses a clinical and diagnostic challenge because of the complex anatomy and structural biomechanics of the region. Further investigation involves a multimodality imaging approach. Although both structural and functional imaging techniques have their strengths, namely, the high specificity of the former and superior sensitivity of the latter, they also have a number of limitations when used in isolation. These include the inability to determine the functional significance of pathological anatomical abnormalities or to further characterize or localize abnormal metabolic activity. The development of integrated single-photon emission computed tomography/computed tomography systems has aimed to overcome the limitations of separate anatomical and functional imaging techniques. This may be of particular value in ankle and foot assessments, in which multiple joints may be affected by different pathologies. This review article aims to highlight the role of both structural and functional imaging techniques, with particular emphasis on the incremental value of single-photon emission computed tomography/computed tomography in evaluation of this complex anatomical region.