Reproducibility of foot structure measurements in neuropathic diabetic patients using magnetic resonance imaging

Purpose: To assess the intra- and interobserver agreement of commonly reported foot structure measurements in diabetic patients with neuropathy using magnetic resonance imaging (MRI). Materials and Methods: In 23 neuropathic diabetic patients and five age-matched healthy controls, sagittal-plane MR images of the forefoot were obtained to assess joint configuration and plantar fat-pad thickness on two different occasions by the same observer and once by a different observer. The degree of intrinsic muscle atrophy was scored from coronal plane images on two different occasions by two observers. Results: The intraclass correlation coefficients (ICCs) between occasions and between observers were > 0.94. The mean differences (bias) and the limits of agreement (LoA = mean +/- 2 SDs) were small for the metatarsal-phalangeal (MTP) joint angle. toe angle, and plantar fat-pad thickness (bias <= 0.8 degrees or 0.2 mm, LoA <= 3.8 degrees or 0.8 mm), but larger for interphalangeal joint angles (bias <= 3.4 degrees, LoA <= 8.8 degrees). The weighted kappa for intrinsic muscle atrophy was 0.94. Conclusion: Static foot structure data can be assessed reliably using MRI. Because changes in foot structure contribute to the development of foot ulcers in neuropathic patients. MRI may be a useful technique to assess risk of ulceration in these patients.