Contribution of 3-T Susceptibility-Weighted MRI to Detection of Intraarticular Hemosiderin Accumulation in Patients With Hemophilia

OBJECTIVE. The purpose of this study was to assess the feasibility of 3-T susceptibility-weighted imaging (SWI) for detecting intraarticular hemosiderin accumulation in patients with hemophilia. SUBJECTS AND METHODS. Forty-one joints in 24 patients with hemophilia were imaged with conventional MRI and SWI sequences. Two experienced musculoskeletal radiologists and one general radiologist (reader 3) interpreted the images for hemosiderin accumulation. The final decision was determined in consensus by readers 1 and 2 using both conventional MRI and SWI sequences. The diagnostic consistencies of each MRI sequence with the reference and pairwise agreements between interpreters were assessed. RESULTS. For conventional MRI sequences, the diagnostic consistencies of the two experienced musculoskeletal radiologists with the reference were substantial (kappa = 0.63 and 0.62), whereas the consistency of the general radiologist with the reference was moderate (kappa = 0.47). The SWI interpretations of all readers had almost perfect agreement with the reference (kappa = 1, kappa = 1, kappa = 0.97). Interobserver agreement also improved at SWI interpretations. CONCLUSION. SWI contributes to more accurate grading of intraarticular hemosiderin accumulation than is achieved with conventional MRI sequences.