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.