正常人和股骨头缺血性坏死的髋关节腔液体的MRI

MRI of Hip Joint Fluid in Normal Individuals and Patients with Avascular Necrosis of Femoral Head

目的 探讨正常人和股骨头缺血性坏死的髋关节腔液体的MRI。材料与方法 2 5 2个正常人及 31个股骨头缺血性坏死的髋关节。所有病例均作SE序列T1、T2 加权 ,横断位及冠状位扫描。所有股骨头缺血性坏死的髋关节加作冠状位脂肪抑制序列。结果 关节腔液体于T2 加权和脂肪抑制序列冠状位扫描显示最清楚。于以上两个序列上 ,关节腔液体呈现比脂肪高的信号。关节腔液体分 4级 :0级 ,无液体 ;1级 ,少量液体 ;2级 ,液体达股骨头周围的关节囊 ;3级 ,液体延伸到关节隐窝。正常人 2 1%髋关节内无液体 ,79%的正常人髋关节内可见 1～ 2级的液体 ,其中只有 15个 (6 % )正常人髋关节内可见 2级液体 ,无 1例髋关节内为 3级液体。而股骨头缺血性坏死组 ,均可见不等量的关节腔液体 ,其中 6 2 %的髋关节腔内可见 2～ 3级的液体 (P <0 .0 0 5 )。结论 髋关节腔内少量液体可见于正常人或股骨头缺血性坏死的髋关节腔内。MRI是显示髋关节腔内液体的敏感方法。股骨头缺血性坏死的髋关节腔内液体增多 ,可出现在平片发生改变之前 。

Objective To study MRI features of hip joint fluid in normal subjects and in patients with ischemic necrosis of femoral head.Materials and Methods Using SE sequence, T 1WI and T 2WI of both coronal and axial MR images of 31 hips with documented avascular necrosis and 252 hips without evidence of joint disease were performed. For all patients, coronal images with inversion recovery sequence were also conducted.Results Hydrarthrosis was best seen on T 2 weighted and IR coronal MR images. Fluid showed higher signal than that of fat. The fluid volume was graded as 0 (none), 1 (minimal), 2 (surrounding the femoral neck) and 3 (filling up capsule recesses). Joint fluid was found in 79% normal hips, of which only 15 hips (6%) were graded 2 and none was graded 3. While all 31 diseased hips carried a certain amount of fluid, and among them 19 (62%) showed grade 2 or grade 3 (P<0.005).Conclusion Small amount of fluid is present in normal hips as well as in hips with avascular necrosis. MRI is very sensitive to the hip fluid. Increased fluid may be demonstrated on MRI before plain Xray film can show any abnormal sign.