T2 Mapping MRI for Differentiation of Hemarthrosis and Nonhemorrhagic Joint Effusion in Patients with Hemophilia

< .001). A T2 cutoff value of 361 msec differentiated hemorrhagic (14 of 30 [47%]) from nonhemorrhagic (16 of 30 [53%]) effusions with 100% sensitivity (14 of 14 [100%; 95% CI: 77, 100]) and 100% specificity (16 of 16 [100%; 95% CI: 79, 100]; area under the receiver operating characteristic curve, 1.00). Conclusion T2 mapping MRI at 3 T enabled noninvasive differentiation of hemarthrosis and nonhemorrhagic joint effusion in participants with hemophilia, with excellent diagnostic performance. © RSNA, 2026 See also the editorial by Oca Pernas in this issue.