The role of SPECT/CT in imaging the Charcot foot

Objectives To assess the diagnostic value of hybrid imaging (SPECT/CT) in what is a common condition in diabetes mellitus, and compare this to the use of SPECT only.

Methods We reviewed 14 patients who presented with red swollen foot. Foot and ankle x-rays at presentation did not reveal structural bone/joint damage. All patients had triple phase bone scanning with conventional planar views as well as SPECT followed by CT of the feet and ankles.

Results The planar/SPECT component was reported initially, followed by the full SPECT/ CT data set interpretation. On SPECT/CT imaging 11 patients had changes that were thought consistent with Charcot, with positive perfusion and early phase imaging. In 3 patients an unexpected (and not seen on plain radiographs) fracture was identified (a tibial, a metatarsal head fracture and base of metatarsal fracture). In a further patient a subtle osteochondral fracture of the talar dome was identified, and later confirmed on MRI.

Conclusions SPECT/ CT is of crucial importance in the diabetic foot, where there may be a muted response to trauma and ill defined symptomatology. It should be noted that the Charcot feet presented in these cases were early with very few of the classically described changes. Certainly diagnosis of an unsuspected fracture changed the management in a third of our patients. The hybrid technique is recommended to enhance the accuracy of assessing Charcot disease in its active phase