BMeAll MR imaging examinations showed BMe, which was demon-strated as a high signal intensity area on fluid sensitive sequences.One hundred and thirty six out of 155 hips (87.7%) displayed sparingof the medial bone marrow of the femoral head, whereas subchon-dral fractures were present at 76/155 (48.7%) (Figs. 1–4).The mean duration of symptoms before the first MR imagingexamination was 4.5 weeks (95% CI from 3.85 to 5.14 weeks). Statis-tical analysis proved a statistically significant association betweenthe duration of symptoms and the presence of sparing, with a meanduration of 4.3 weeks (95% CI from 3.63 to 4.94) for cases withsparing, compared to 6.8 weeks for cases where BMe had totallyoccupied the femoral head (P = 0.005) (Figs. 2 and 5). However, therewas no statistically significant association between the duration ofsymptoms and the presence of subchondral fractures (P = 0.419).In 17 (11.0%) out of 155 hips BMe was restricted to the femoralhead, in 62 (40%) BMe was present also in the femoral neck and in76 (49%) hips BMe was extending distally to the proximal shaft ofthe femur (Figs. 2–5). Interestingly, the bone marrow of the greatertrochanter was affected only in 6 hips (3.9%) (Figs. 3 and 4).Inter-rater agreement was high for both the presence of bonemarrow sparing by BMe and the presence of subchondral fractures,with a kappa coefficient for sparing of 1.0 (95% CI from 1.0 to 1.0)and for fractures of 0.8 (95% CI from 0.54 to 1.0).