Osteomyelitis of the diabetic foot: MR imaging-pathologic correlation

Area of Science:

• Orthopedics
• Radiology
• Diabetic Foot Care

Background:

• Diabetic foot infections are a common complication.
• Osteomyelitis is a frequent and serious complication in diabetic patients.
• Accurate diagnosis of osteomyelitis is crucial for effective treatment and limb salvage.

Purpose of the Study:

• To assess the diagnostic accuracy of magnetic resonance (MR) imaging for osteomyelitis in the diabetic foot.
• To compare MR findings with histologic analysis of resected tissue.
• To evaluate the utility of gadolinium contrast in differentiating osteomyelitis from edema.

Main Methods:

• MR imaging was performed on 13 diabetic patients with suspected osteomyelitis.
• MR findings were correlated with histologic examination of 57 bones.
• T2-weighted and short inversion time inversion-recovery sequences were analyzed.
• The effect of gadolinium contrast on image interpretation was assessed.

Main Results:

• MR imaging showed a sensitivity of 90% and specificity of 71% for diagnosing osteomyelitis.
• Increased signal intensity on MR images was observed in both osteomyelitis and bone marrow edema.
• The signal intensity range for edema overlapped with that of osteomyelitis.
• Gadolinium contrast did not reliably distinguish between osteomyelitis and edema.

Conclusions:

• MR imaging cannot reliably differentiate osteomyelitis from bone marrow edema.
• Gadolinium contrast has limited value in this differentiation.
• Some previous false-positive MR diagnoses of osteomyelitis may have been due to edema.
• MR imaging is valuable for surgical planning in infected diabetic feet by identifying abnormal areas.