The Diagnostic Value of 99mTc-IgG Scintigraphy in the Diabetic Foot and Comparison with

Diabetic foot infection is the most common etiology of non-traumatic amputation of the lower extremities, and early diagnosis is of great importance in its management. The aim of this prospective study was to evaluate the strength of 99mTc-IgG scintigraphy in diagnosis of osteomyelitis of the diabetic foot and to compare 99mTc-IgG scintigraphy with 99mTc-meth-ylene diphosphonate (MDP) scintigraphy.Methods: A prospec-tive university hospital–based study was performed over 24 mo. Eighteen patients with type II diabetes and foot ulcers (15 men and 3 women; age range, 45–80 y) were referred for imaging because of clinically suspected osteomyelitis. Early (5-h) and late (24-h) 99mTc-IgG scanning and 3-phase skeletal scintigra-phy were completed for all patients at a 3- to 4-d interval. Regions of interest over the involved bony sites and the con-tralateral normal sites were drawn, and the abnormal-to-normal ratios were acquired for both 99mTc-IgG and 99mTc-MDP stud-ies. Results: From a total of 23 lesions, we observed 10 sites of osteomyelitis, 10 sites of cellulitis, and 3 sites of aseptic inflam-mation confirmed by MRI, clinical presentation, histopathologic examination, and follow-up evaluation as a gold standard. Both 99mTc-IgG and 99mTc-MDP scanning showed excellent sensitiv-ity for diagnosis of osteomyelitis, but the specificity was signifi-cantly lower (69.2 % and 53.8%, respectively). Sensitivity, specificity, and accuracy in the diagnosis of osteomyelitis were