早期强直性脊柱炎骶髂关节病变的X线、CT和MRI对比研究

目的 比较X线平片、CT和MRI在早期强直性脊柱炎(AS)骶髂关节病变中的诊断价值.方法 对53例临床拟诊为AS的患者行骶髂关节X线平片和MR检查,MR平扫均包括骶髂关节斜冠状面T1WI、T2WI、短时反转恢复序列(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；25例患者同时行CT检查.分析患者的影像资料,应用x2检验对X线平片、CT和MRI显示骨侵蚀破坏敏感度进行统计学分析.结果 53例患者的106侧骶髂关节中,X线平片和MRI显示关节面下骨侵蚀病变分别为16侧和63侧；25例CT检查中显示26侧骶髂关节面下存在骨侵蚀破坏.CT和MRI显示骨侵蚀敏感度相近(x2=0.16,P＞o.05),两者均优于x线平片(x2值分别为14.44和17.36,P值均＜0.05),在所应用的MR序列中,3 D-BTFE-WATS显示骨侵蚀破坏最佳.MRI除显示AS骶髂关节慢性骨结构改变外,显示骨髓水肿 32例、滑膜增厚和(或)异常强化35例,脂肪沉积16例、韧带附着点炎15例、被膜炎9例和关节软骨破坏31例.结论 MRI能发现X线平片和CT不能显示的骨髓水肿和滑膜炎等急性炎性改变,早期诊断价值优于X线平片和CT.

Comparison of X-ray, CT and MRI in detection of abnormal sacroiliac joint changes in patients with early stage of ankylosing spondylitis

Objective To compare X-ray,CT,and MRI in detection of abnormal sacroiliac joint changes in patients with early stage of ankylosing spondylitis (AS).Methods Fifty-three patients with clinical suspected early stage of AS underwent X-ray and MRI scan.MR scan sequences for the sacroiliac joints consisted of T1-weighted,T2-weighted,short time inversion recovery (STIR) and three dimensional balance turbo field echo with water selective excitation (3D-BTFE-WATS) in all patients.In 24 of the patients,fat-saturated contrast-enhanced T1-weighted was used.Twenty-five of 53 patients underwent CT scan.The Chi-square test was used to analyse the uniformity of bone erosions detected by X-ray,CT,and MRI.Results Of the 106 sacroiliac joints in 53 patients,16 sacroiliac joints with bone erosions were detected by X-ray and 63 sacroiliac joints by MRI.Of the 50 sacroiliac joints in 25 patients,26 sacroiliac joints with bone erosions were found by CT.With regard to the detection of bone erosions,there was no difference between CT and MRI (x2 =0.16,P ＞0.05 ) and there was significant difference between CT and X-ray or MRI and X-ray ( x2 =14.44 and 17.36,P ＜ 0.05 ).3D-BTFE-WATS was better than other sequences in detection of bone erosions.Acute inflammatory changes were determined by MRI,which included subchondral bone marrow edema in 32 patients,synovitis in 35 patients,fat depositions in 16 patients,enthesitis in 15 patients,capsulitis in 9 patients,and cartilaginous disruption in 31 patients.Conclusions MRI can detect acute inflammatory changes that can not display by X-ray and CT.Compared with radiography and CT,MRI is more useful in detection of abnormal sacroiliac joint changes in patients with early stage of AS.