Abstract
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Objectives: To determine the effect of SPECT CT imaging on the interpretation of bone scans in patients referred for the evaluation of foot pain.
Methods: Patients referred for 99m-Tc-HDP bone scan imaging of the feet who had abnormalities found on planar imaging were imaged with high resolution SPECT CT for localization of the abnormalities. Patients with metatarsal stress fractures did not undergo this imaging since the diagnosis was apparent on planar imaging. Fifteen cases were reviewed retrospectively. Final interpretations were compared against the pretest clinical impression.
Results: In all cases, the general location of activity was apparent from planar imaging and SPECT imaging, but the SPECT CT images were able to differentiate between bony activity and uptake in the joint space, effectively distinguishing bone trauma from arthritis. In 11 cases, the data confirmed the clinical impression. In 4 of the cases, a change in clinical management was immediately apparent. One patient with a suspected stress fracture had a tarsal coalition which was unsuspected by plain x-ray, proven on CT scan. A second patient with a suspected tarsal coalition proved to have a Shepherd's fracture. In a patient with chronic midfoot pain, planned fusion was avoided when the patient proved to have activity between two cuneiforms which was successfully treated with injection of anesthetic. In a fourth patient, fusion surgery was limited by the finding that only three bones in the midfoot were involved in the inflammatory process.
Conclusions: In this preliminary study, 4 of 15 patients referred for bone scans had a change in management as a result of the more accurate localization of HDP uptake using SPECT CT.
- Society of Nuclear Medicine, Inc.