强直性脊柱炎髋关节改变的X线、CT和MRI对比研究

目的 探讨强直性脊柱炎(AS)髋关节受累的影像表现,比较X线平片、CT和MRI显示AS髋关节受累的敏感度.方法 对55例AS患者行骨盆X线平片和MR检查,其中29例行髋关节CT检查.MR平扫均包括冠状面T1WI、T2WI、STIR、附加水激励的三维稳态快速梯度回波序列(3D-BTFE-WATS),其中24例同时行脂肪抑制T1WI增强检查.分析患者的影像资料,应用x2检验对X线平片、CT和MRI显示AS髋关节受累改变的敏感度进行分析.结果 55例AS患者110侧髋关节中,X线平片和MRI显示异常分别为13侧和85侧；X线平片改变包括关节面下骨侵蚀破坏13侧、关节间隙变窄4侧、韧带骨赘5侧；MRI显示关节面下骨侵蚀破坏31侧、关节间隙变窄4侧、关节少量积液80侧、骨髓水肿32侧、脂肪沉积28侧、韧带附着点炎21侧,24例行MR增强检查患者中19例见双侧滑膜异常强化.CT检查29例共58侧髋关节,CT在显示X线平片和MRI所显示的骨破坏同时,发现X线平片未能显示的10侧骨破坏和MRI未显示的1侧骨破坏.X线平片、CT、MRI显示异常分别为10.3％ (6/58)、27.6％ (16/58)和77.6％ (45/58),MRI显示髋关节受累的敏感度优于X线平片和CT(x2值分别为53.22和29.08,P值均＜0.05).MRI除显示X线平片和CT所能显示的慢性骨结构改变外,还发现X线平片和CT未能显示的急性炎症改变.结论 MRI能显示X线平片和CT不能显示的AS髋关节受累的急性炎症改变,滑膜炎所致的少量积液和滑膜异常强化是髋关节受累最常见的MRI表现.

Comparative study of radiography, CT and MRI in the identification of hip involvement in patients with ankylosing spondylitis

Objective To study the imaging findings of hip involvement and to compare the sensitivity of radiography,CT,and MRI in the identification of hip involvement in patients with ankylosing spondylitis(AS).Methods Anteroposterior radiography of the pelvis and MRI of hip were performed in 55 patients with AS.CT scan of hip was performed in 29 of 55 patients.T1-weighted,T2-weighted,short tau inversion recovery (STIR) and three dimensional balanced turbo field echo with water selective excitation (3D-BTFE-WATS) coronal sequences of hips were obtained in all patients,of which fat-saturated contrastenhanced T1-weighted sequence was performed in 24 patients.The imaging data of 55 patients were analyzed.The chi-square test was used to analyze the sensitivity in the identification of hip involvement among radiography,CT,and MRI.Results Among 110 hips in all 55 patients,abnormal changes were detected in 13 hips by radiography,85 hips by MRI.The findings of radiography included bone erosions in 13 hips,joint space narrowing in 4 hips,syndesmophytes in 5 hips.MRI revealed bone erosive destruction in 31 hips,joint space narrowing in 4 hips,joint effusion in 80 hips,subchondral bone marrow edema in 32 hips,fat accumulation of bone marrow in 28 hips,enthesitis in 21 hips.Bilateral synovial enhancement was showed in 19 of 24 patients who underwent fat-saturated contrast-enhanced T1-weighted sequence.Of the 58 hip joints in 29 patients who underwent CT examination,not only did CT show all bone erosions detected by radiography and MRI,but CT revealed bone erosive destruction that were not identified by radiography in 10 hips and by MRI in 1 hip as well.Abnormal changes were detected in 10.3％ (6/58)by radiography,27.6％ (16/58) by CT,and 77.6％ (45/58) by MRI.The sensitivity of MRI in the identification of hip involvement is higher than that of radiography and CT ( x2 =53.22 and 29.08,P ＜ 0.05 ).In addition to chronic bone structural changes,MRI depicted acute inflammatory changes which could not be detected by radiography and CT.Conclusions MRI can detect early acute inflammatory changes of hip joint that can not be showed by radiography and CT.Effusion of joint and synovial enhancement caused by synovitis are the most common MRI findings of the hip in patients with AS.