ROLE OF MAGNETIC-RESONANCE-IMAGING IN THE DIAGNOSIS OF OSTEOMYELITIS IN DIABETIC FOOT INFECTIONS

Purpose: The role of magnetic resonance imaging (MRI) in the diagnosis of osteomyelitis in foot infections in diabetics was investigated. Th e accuracy, sensitivity, and specificity of MRI, plain radiography, an d nuclear scanning were determined for diagnosing osteomyelitis, and a cost comparison was made, Methods: Twenty-seven patients with diabeti c foot infections were studied prospectively. All patients underwent M RI and plain radiography. Twenty-two patients had technetium bone scan s, and 19 patients had Indium scans. Nineteen patients had all four te sts performed. Patients with obvious gangrene or a fetid foot were exc luded. Results: The diagnosis of osteomyelitis was established by path ologic specimen (n = 18), bone culture (n = 3), or successful response to medical management (n = 6). Osteomyelitis was confirmed in nine of the pathologic specimens. The diagnostic sensitivity specificity and accuracy for MRI was 88%, 100%, and 95%, respectively, for plain radio graphy it was 22%, 94%, and 70%, respectively for technetium bone scan ning it was 50%, 50%, and 50%, respectively and for Indium leukocyte s canning it was 33%, 69%, and 58%, respectively. The data were analyzed statistically with the two-tailed Fisher's exact test. MRI was the on ly test that was statistically significant (p < 0.01). Conclusions: MR I appeared to be the single best test for the diagnosis of osteomyelit is associated with diabetic foot infections. It had a better diagnosti c accuracy than conventional modalities and appeared to be more cost-e ffective than. the frequently used Indium scan.