致密性骨炎与ax-SpA骶髂关节骨髓T2WI-FS高信号MRI征象分析.pdf

磁共振成像 2023年6月第14卷第6期 Chin J Magn Reson Imaging,Jun,2023,Vol.14,No.6http:/临床研究Clinical Articles致密性骨炎与ax-SpA骶髂关节骨髓T2WI-FS高信号MRI征象分析刘超然，李文娟，祝云飞，何小俊，张珂，洪国斌*作者单位：中山大学附属第五医院放射科，珠海 519000*通信作者：洪国斌，E-mail：中图分类号：R445.2；R681 文献标识码：A DOI：10.12015/issn.1674-8034.2023.06.008本文引用格式：刘超然,李文娟,祝云飞,等.致密性骨炎与ax-SpA骶髂关节骨髓T2WI-FS高信号MRI征象分析J.磁共振成像,2023,14(6):52-58.摘要 目的探讨致密性骨炎（osteitis condensans ilii,OCI）与中轴型脊柱关节炎（axial spondyloarthritis,ax-SpA）T2WI脂肪抑制序列（fat-saturated T2WI,T2WI-FS）高信号改变特点及鉴别。材料与方法回顾性分析2017年1月至2021年12月间确诊的OCI女性患者23例和ax-SpA女性患者34例，分析其在骶髂关节MRI上T2WI-FS高信号的发生率及影像学征象，着重分析T2WI-FS高信号的位置、范围、形态和信号强度。结果与ax-SpA组相比，OCI组骶髂关节T2WI-FS高信号总体发生率更低56.5%（13/23）vs.85.3%（29/34）；2=5.857，P=0.016，双侧骶髂关节T2WI-FS高信号发生率较低26.1%（6/23）vs.55.9%（19/34）；2=4.946，P=0.026，单侧骶髂关节T2WI-FS高信号发生率无明显差异30.4%（7/23）vs.29.4%（10/34）；2=0.007，P=0.934。OCI 组与 ax-SpA 组骶髂关节 T2WI-FS 高信号分布侧别、上/下份、象限及内侧缘位置均差异无统计学意义（P0.05），形态上OCI组以条带状分布为主，ax-SpA组以片状为主，差异具有统计学意义（P0.001）。OCI组与ax-SpA组骶髂关节 T2WI-FS 高信号范围、信号强度差异具有统计学意义（P0.001）；OCI 组内骶侧与髂侧、上份与下份、各象限间T2WI-FS高信号范围、信号强度差异无统计学意义（P0.05）。结论T2WI-FS高信号可见于OCI，多表现为紧邻骨质硬化缘的、范围较小、以条带状为主的稍高信号，有助于与ax-SpA相关骨髓水肿的鉴别。关键词 致密性骨炎；中轴型脊柱关节炎；骶髂关节；磁共振成像MRI features of sacroiliac joint bone marrow fat-saturated T2WI high signal in osteitis condensans iliiLIU Chaoran,LI Wenjuan,ZHU Yunfei,HE Xiaojun,ZHANG Ke,HONG Guobin*Department of Radiology,Fifth Affiliated Hospital,Sun Yat-Sen University,Zhuhai 519000,China*Correspondence to:Hong GB,E-mail:Received 2 Sep 2022,Accepted 9 Jun 2023;DOI:10.12015/issn.1674-8034.2023.06.008ACKNOWLEDGMENTS National Natural Science Foundation of China(No.82272104);The Science,Technology Project in the Social Development Field of Zhuhai City(No.ZH22036201210066PWC);Clinical research IIT project of the Fifth Affiliated Hospital of Sun Yat-sen University(No.YNZZ2020-06).Cite this article as:LIU C R,LI W J,ZHU Y F,et al.MRI features of sacroiliac joint bone marrow fat-saturated T2WI high signal in osteitis condensans iliiJ.Chin J Magn Reson Imaging,2023,14(6):52-58.Abstract Objective:To explore the features and rules of sacroiliac joint bone marrow fat-saturated T2WI(T2WI-FS)high signal in osteitis condensans ilii(OCI)and axial spondyloarthritis(ax-SpA).Materials and Methods:Twenty-three female patients diagnosed with OCI and thirty-four female patients diagnosed with ax-SpA between January 2017 and December 2021 were retrospectively enrolled.The incidence and imaging features of sacroiliac joint bone marrow T2WI-FS high signal were assessed,with a particular focus on the characteristics such as location,range,shape,and signal intensity.Results:Compared with the ax-SpA group,the overall incidence of high T2WI-FS signal in the sacroiliac joint was lower in the OCI group 56.5%(13/23)vs.85.3%(29/34);2=5.857,P=0.016.The incidence of high T2WI-FS signal in the bilateral sacroiliac joint was also lower 26.1%(6/23)vs.55.9%(19/34);2=4.946,P=0.026.However,there was no significant difference in the incidence of high T2WI-FS signal in unilateral sacroiliac joint 30.4%(7/23)vs.29.4%(10/34);2=0.007,P=0.934.There were no significant differences between the OCI group and the ax-SpA group in terms of the side,upper/lower part,quadrant and medial margin of high signal distribution in the sacroiliac joint(P0.05).In terms of morphology,the OCI group mainly exhibited a ribbon-like shape,while the ax-SpA group mainly showed a flaky morphology,and the difference was statistically significant(P0.001).The high signal range and signal intensity of sacroiliac joint T2WI-FS were also statistically significant between the OCI group and the ax-SpA group(P0.001).However,there were no significant differences in the high signal range and intensity of T2WI-FS between the sacral and iliac sides,superior and inferior parts,and among quadrants in the OCI group(P0.05).Conclusions:Sacroiliac joint bone marrow T2WI-FS high signal can be seen in OCI,which is usually presented as a small ribbon adjacent to the sclerotic margin with slightly high signal,and contributes to the differential diagnosis of bone marrow edema associated with ax-SpA.Key words osteitis condensans ilii;axial spondyloarthritis;sacroiliac joint;magnetic resonance Imaging0前言致密性骨炎（osteitis condensans ilii,OCI）较常见于育龄期女性骶髂关节髂骨侧，发生率约为0.9%2.5%1，在临床拟诊为脊柱关节炎而接受影像收稿日期：2022-09-02 接受日期：2023-06-09基金项目：国家自然科学基金（编号：82272104）；珠海市社会发展领域科技计划重点项目（编号：ZH22036201210066PWC）；中山大学附属第五医院临床研究IIT项目（编号：YNZZ2020-06）52磁共振成像 2023年6月第14卷第6期 Chin J Magn Reson Imaging,Jun,2023,Vol.14,No.6http:/临床研究Clinical Articles学评估者中发生率更高达8.9%2。OCI的特征性影像学表现是骨盆 X 线平片和电子计算机断层扫描（computed tomography,CT）上骶髂关节髂骨耳状面“三角形”的骨质硬化3。然而，有关OCI的骶髂关节磁共振成像（sacroiliac joint magnetic resonance imaging,SIJ-MRI）研究相对较为少见，对于OCI在骶髂关节骨髓的 T2WI 脂肪抑制序列（fat-saturated T2WI,T2WI-FS）表现高信号的深入影像学研究则更为 少 见。高 度 提 示 中 轴 型 脊 柱 关 节 炎（axial spondyloarthritis,ax-SpA）的 骨 髓 水 肿（bone marrow edema,BME）在 T2WI-FS 序 列 上 亦 表 现 为T2WI-FS高信号，被认为是一种可复性、非特异性的活动性炎症征象。临床易将伴有骶髂关节骨髓T2WI-FS高信号的 OCI误诊为提示 ax-SpA的骶髂关节炎4。随着SIJ-MRI在临床的日益广泛应用，文献报道5OCI患者中亦可见T2WI-FS序列高信号。对临床医生来说，区分OCI和伴有明显骨质硬化的ax-SpA仍然具有挑战性，尤其是孕妇等不宜接受CT或X线等放射学检查的患者6。因此，本研究深入探究OCI相关T2WI-FS高信号的发生率及MRI特点，将有助于加深对其认识，更有助于与ax-SpA相关BME的鉴别诊断，减少误诊和过度诊断。1材料与方法1.1 研究人群本研究遵守 赫尔辛基宣言，已获中山大学附属第五医院伦理委员会审批，免除受试者知情同意，伦理批文编号：中大五院2021伦字第（K14-1）号。回顾性分析2017年1月至2021年12月在中山大学附属第五医院经骨盆X线片或CT检查并随诊6个月以上，临床综合确诊为OCI的2055岁女性患者的临床及影像资料，所有患者均完成骶髂关节MRI检查。OCI组患者入组标准：（1）满足PARPERIS等32020年总结的OCI诊断标准（骨盆X线片或CT可见髂骨特征性三角形硬化，且骶髂关节面无侵蚀，关节间隙无狭窄或强直）；（2）临床明确排除脊柱关节炎、其他类型骶髂关节炎、代谢性骨病及Paget病；（3）MRI扫描序列完整齐全。OCI组排除标准：（1）肿瘤患者、骨盆外伤史、手术史或放化疗病史；（2）随诊过程中进展为脊柱关节炎；（3）图像质量不佳，无法满足诊断。回顾性纳入同期行SIJ-MRI检查的女性ax-SpA患者作为研究对照组，ax-SpA组纳入标准：（1）依据国际脊柱关节炎评估协会（Assessment in SpondyloArthritis International Society,ASAS）专家组 ax-SpA 最新诊断标准7明确诊断为ax-SpA；（2）MRI扫描序列完整齐全。ax-SpA组排除标准：（1）肿瘤患者、骨盆外伤史、手术史或放化疗病史；（2）同时患有其他风湿免疫系统疾病或骶髂关节发育异常、手术、外伤、感染等；（3）图像质量不佳，无法满足诊断。1.2 MRI扫描序列及参数采用 3.0 T MRI 扫描设备（GE SIGNA Pioneer 3.0 T，美国；MAGNETOM Verio 3.0 T，德国）或 1.5 T MRI扫描设备（MAGNETOM Verio 1.5 T，德国）进行骶髂关节扫描。患者取仰卧位，定位中心通过线圈中心及双侧髂前上棘连线中点，平行于骶1骶3椎体背侧，扫描范围包括双侧骶髂关节，其骶骨、髂骨及 周 围 组 织 均 清 晰 显 示。扫 描 序 列 包 括 轴 位T2WI-FS及斜冠状位T1WI、T2WI-FS序列。GE SIGNA Pioneer 3.0 T 扫 描 参 数：轴 位T2WI-FS（TR 2498 ms，TE 74 ms，FOV 240 mm240 mm，层厚 4.0 mm，层间距 5.0 mm）；斜冠状位 T1WI（TR 428、830 ms，TE 7 ms，FOV 240 mm240 mm，层厚3.0 mm，层 间 距 4.0 mm）；斜 冠 状 位 T2WI-FS（TR 2498 ms，TE 73 ms，FOV 240 mm240 mm，层厚3.0 mm，层间距4.0 mm）。MAGNETOM Verio 3.0 T扫描参数：轴位T2WI-FS（TR 2700 ms，TE 37 ms，FOV 320 mm320 mm，层厚3.0 mm，层间距3.3 mm）；斜冠状位T1WI（TR 600 ms，TE 9.3 ms，FOV 320 mm320 mm，层厚3.0 mm，层间距3.3 mm）；斜冠状位T2WI-FS（TR 5000 ms，TE 48 ms，FOV 320 mm320 mm，层厚3.0 mm，层间距3.5 mm）。MAGNETOM Verio 1.5 T扫描参数：轴位T2WI-FS（TR 4060 ms，TE 33 ms，FOV 320 mm320 mm，层厚4.0 mm，层间距4.4 mm）；斜冠状位T1WI（TR 810 ms，TE 23 ms，FOV 324 mm384 mm，层厚 3.0 mm，层间距3.3 mm）；斜冠状位T2WI-FS（TR 4000 ms，TE 33 ms，FOV 270 mm320 mm，层厚3.0 mm，层间距3.3 mm）。1.3 图像分析采用图像存储与传输系统（picture archiving and communication system,PACS）。由两名分别具有2年和5年工作经验的放射科住院医师和主治医生分别独立评估，意见不一致时，由第3位具有10年经验的肌骨专业放射科主任医师进行再次评估，获得最终意见。为便于分析，在斜冠位图像上平行于第5腰椎下缘，在左右两侧分别作2条分割线上下平分骶髂关节滑膜部；平行骶髂关节间隙，在左右两侧分别作2条分割线左右平分骶髂关节滑膜部，将每侧骶髂关节平分为4个象限进行分析，即骶侧上份、骶侧下份、髂侧上份、髂侧下份（图1）。以 T2WI-FS 高信号作为主要观察的征象，借鉴2019年ASAS MRI工作组对SIJ-MRI影像学定义7，以骶骨椎间孔间骨髓信号作为正常骨髓信号的参考，定义T2WI-FS高信号为T2WI-FS序列上高信号，T1WI序列上呈低信号，且明确可见。观察并记录T2WI-FS高信号的发生率及MRI征象，包括T2WI-FS高信号的位置、范围、形态和信号强度。（1）位置：骶侧以骶孔为边缘，将同层面骶侧及髂侧非骨质硬化区各划为3等份，53磁共振成像 2023年6月第14卷第6期 Chin J Magn Reson Imaging,Jun,2023,Vol.14,No.6http:/临床研究Clinical Articles记录T2WI-FS高信号内侧缘位于近关节面1/3内为近部，紧邻硬化缘/关节面；位于远离关节面1/3为远部，远离硬化缘/关节面；位于中份1/3为中部，与硬化缘/关节面分离（图2A、2B、2C）。（2）范围：T2WI-FS高信号范围小于1/3为范围小，大于1/3不超过2/3为范围中，超过2/3为范围大（图2D）。（3）形态：记录T2WI-FS高信号形态为片状、条带（图3）。（4）信号强度：以正常骨髓信号为参考，记录稍高于骶骨椎间孔间骨髓信号为稍高（图4A），明显高于正常骨髓信号且与液体信号类似为极高，介于二者之间为高（图4B、4C）。1.4 统计学分析采用SPSS 19.0软件进行统计学分析。正态分布的计量资料以均数标准差（x s）表示，组间比较采用独立样本t检验；计数资料以频数（%）表示，采用卡方检验或 Fisher 精确概率法进行比较。应用Kappa系数及加权Kappa系数评价不同观察者间观察图1骶髂关节分区图例。1A：骶髂关节分区示意图。a、b线（细线）分别平行左右两侧骶髂关节间隙，左右平分同侧骶髂关节滑膜部，c、d 线（粗线）平行于第5腰椎下缘，上下平分左右两侧骶髂关节滑膜部，将单侧骶髂关节分为骶侧上份、骶侧下份、髂侧上份、髂侧下份。1B：女，31岁，反复腰痛、髋部疼痛1年余。右侧骶髂关节骶侧上份可见T2WI-FS高信号（箭）。2C：女，39岁，长时间行走后，左髋部疼痛4年余。右侧骶髂关节髂侧下份可见T2WI-FS高信号（箭）。T2WI-FS：T2WI脂肪抑制序列。Fig.1Sacroiliac joint zoning.1A:Diagram of sacroiliac joint zoning.The lines a and b(thin lines)parallel the left and right sides of the sacroiliac joint space,bisecting the synovium of the ipsilateral sacroiliac joint.The lines c and d(thick lines)are parallel to the lower margin of the fifth lumbar vertebrae,bisecting the synovium of the left and right sacroiliac joints,and a unilateral sacroiliac joint is divided into the superior part of the sacral side,the lower part of the sacral side,the superior part of the ilium and the lower part of the ilium.1B:Female,31-year-old,with recurrent low back pain and hip pain for more than 1 year.T2WI-FS high signal(arrow)can be seen in the upper sacral part of the right sacroiliac joint.1C:Female,39-year-old,with left hip pain for more than 4 years after a long walk.T2WI-FS high signal(arrow)can be seen in the lower iliac side of the right sacroiliac joint.T2WI-FS:fat-saturated T2WI.图2T2WI-FS高信号位置及范围定义图例。2A：骶侧以骶孔为边缘（黑色虚线），髂侧以髂骨外缘为边缘，沿硬化带边缘（白色虚线）及关节面将骶侧及髂侧非骨质硬化区分别划为3等份。a区紧邻硬化缘，为近部；b区与硬化缘分离，为中部；c区离硬化缘，为远部。2B：女，31岁，反复腰痛、髋部疼痛1年余。右侧骶髂关节骶侧可见T2WI-FS高信号（箭），紧邻硬化缘，位于近部；2C：女，22岁，反复腰痛、右侧髋部酸痛2年余。右侧骶髂关节骶侧可见T2WI-FS高信号（箭），与硬化缘分离，位于中部；2D：女，29岁，腰痛3月余。右侧骶髂关节骶侧可见T2WI-FS高信号。右侧骶髂关节骶侧T2WI-FS高信号（直箭）范围中，髂侧T2WI-FS高信号（弯箭）范围大。T2WI-FS：T2WI脂肪抑制序列。Fig.2Definition of T2WI-FS high signal location and range.2A:The sacral side takes the sacral foramen as the edge(black dotted line),the iliac side takes the outer edge of the ilium as the edge,along the edge of the sclerotic zone(white dotted line)and the articular surface,the sacral and iliac non-osteosclerotic areas are divided into 3 equal parts respectively;zone a is close to the hardened edge and is proximal,zone b is separated from the hardening edge and is in the middle,zone c is distal from the hardening margin.2B:A 31-year-old female with recurrent low back pain and hip pain for more than 1 year.T2WI-FS high signal(arrow)can be seen on the sacral side of the right sacroiliac joint,which is close to the sclerotic margin and is located in the proximal part.2C:A 22-year-old female with recurrent low back pain and right hip pain for more than 2 years.T2WI-FS high signal(arrow)can be seen on the sacral side of the right sacroiliac joint,which is separated from the sclerotic margin and is located in the middle.2D:A 22-year-old female with low back pain for more than 3 mouths.T2WI-FS high signal was seen on the right sacroiliac joint,with the medium range on the sacral side(straight arrow)and large range on the iliac side(curved arrow).T2WI-FS:fat-saturated T2WI.图3T2WI-FS高信号形态定义图例。3A：女，29岁，确诊ax-SpA 6年余。双侧骶髂关节可见T2WI-FS高信号（箭），呈片状。3B：女，22岁，反复腰痛2年余。右侧骶髂关节骶侧可见T2WI-FS高信号（箭），呈条带状。3C3D：女，39岁，长时间行走后，左髋部疼痛4年余。右侧骶髂关节髂侧可见T2WI-FS高信号，部分层面呈斑片状（3C；箭），部分层面呈条带状（3D；箭）。T2WI-FS：T2WI脂肪抑制序列；ax-SpA：中轴型脊柱关节炎。Fig.3Definition of T2WI-FS high signal morphology.3A:A 29-year-old female diagnosed with ax-SpA for more than 6 years.T2WI-FS high signal(arrow)can be seen on the sacral side of both sacroiliac joints,which are flaky.3B:A 22-year-old female with recurrent low back pain for more than 2 years.T2WI-FS high signal(arrow)can be seen on the sacral side,which show ribbon.3C-3D:A 39-year-old female with left hip pain for more than 4 years after long walking.T2WI-FS high signal can be seen on the iliac side of the right sacroiliac joint,some of which appear flaky(3C;arrow)and some appear ribbon-like(3D;arrow).T2WI-FS:fat-saturated T2WI;ax-SpA:axial spondyloarthritis.54磁共振成像 2023年6月第14卷第6期 Chin J Magn Reson Imaging,Jun,2023,Vol.14,No.6http:/临床研究Clinical Articles的一致性及可靠性，判定标准为：Kappa0.2，一致性较差；0.2Kappa0.4，一致性一般；0.4Kappa0.6，一致性中等；0.6Kappa0.8，一致性较强；0.8Kappa1.0，一致性程度很强。2结果2.1 患者入组结果本研究共纳入 23 例女性 OCI 患者病例，年龄2055（338）岁，34例女性ax-SpA患者病例，年龄2252（337）岁，年龄差异无统计学意义。2.2 观察者间一致性分析结果两名观察者的一致性检验结果良好（表1）。2.3 OCI与ax-SpA患者T2WI-FS高信号MRI征象分析与ax-SpA组相比，OCI组骶髂关节T2WI-FS高信号总体发生率更高56.5%（13/23）vs.85.3%（29/34）；2=5.857，P=0.016，双侧骶髂关节T2WI-FS高信号发生率较高26.1%（6/23）vs.55.9%（19/34）；2=4.946，P=0.026，单侧骶髂关节T2WI-FS高信号发生率无显著差异30.4%（7/23）vs.29.4%（10/34）；2=0.007，P=0.934（表2）。OCI组与ax-SpA组骶髂关节T2WI-FS高信号位置及形态比较分析显示：骶髂关节T2WI-FS高信号分布侧别、上/下份、象限及内侧缘位置差异无统计学意义（P0.05；表3、4），形态上OCI组以条带状分布为主（图5），ax-SpA组以片状为主，差异具有统计学意义（P0.001；表 4）。其中 4 例OCI 组骶髂关节骶侧可见沿脂肪沉积边缘条带状图 4T2WI-FS 高信号强度定义图例。4A：女，22岁，反复腰痛 2年余。右侧骶髂关节骶侧可见 T2WI-FS 高信号（箭），信号强度为稍高。4B：女，39岁，长时间行走后，左髋部疼痛4年余。右侧骶髂关节髂侧可见T2WI-FS高信号（箭），信号强度为高；4C：女，33岁，腰背部疼痛伴活动受限1年余。双侧骶髂关节髂侧可见 T2WI-FS 高信 号，信 号 强 度 为 极 高（箭）。T2WI-FS：T2WI脂肪抑制序列。Fig.4Definition of T2WI-FS high signal strength.4A:A 22-year-old female with recurrent low back pain for more than 2 years.T2WI-FS high signal(arrow)can be seen on the sacral side of the right sacroiliac joint,with sightly high signal strength.4B:A 39-year-old female with left hip pain for more than 4 years after prolonged walking.T2WI-FS high signal(arrow)is seen on the iliac side of the right sacroiliac joint,with high signal strength.4C:A 22-year-old female with low back pain and limited mobility for more than 1 years.T2WI-FS high signal(arrow)is observed on the iliac side of the bilateral sacroiliac joints,with extremely high signal strength.T2WI-FS:fat-saturated T2WI.表1 两名观察者的Kappa及加权Kappa系数的检验值Tab.1 The Kappa and weighted Kappa coefficients test values of two observersT2WI-FS高信号特征分布区域髂侧/骶侧单侧/双侧骶侧髂侧上份/下份上份下份象限骶侧上份骶侧下份髂侧上份髂侧下份形态分布内侧缘位置范围信号强度OCI组0.7990.8540.8020.7650.8620.8580.6430.8260.7840.7210.8370.7080.788ax-SpA组0.8450.8750.9410.8880.8480.8890.7800.8240.8080.9240.7790.8880.848注：T2WI-FS为T2WI脂肪抑制；OCI为致密性骨炎；ax-SpA为中轴型脊柱关节炎。单侧是指仅左侧或右侧骶髂关节发现T2WI-FS高信号，双侧是指左侧及右侧骶髂关节均发现T2WI-FS高信号。表2 OCI与ax-SpA的患者年龄及骶髂关节T2WI-FS高信号发生率Tab.2 The age and the incidence of T2WI-FS high signal in the sacroiliac joint of patients with OCI and patients with ax-SpA组别OCI组（n=23）ax-SpA组（n=34）t/2值P值年龄（x s）/岁33.178.0133.067.240.0560.956T2WI-FS高信号/例（%）单侧7（30.4）10（29.4）0.0070.934双侧6（26.1）19（55.9）4.9460.026合计13（56.5）29（85.3）5.8570.016注：OCI 为致密性骨炎；ax-SpA 为中轴型脊柱关节炎；T2WI-FS 为T2WI脂肪抑制。单侧是指仅左侧/右侧骶髂关节发现T2WI-FS高信号，双侧是指左侧及右侧骶髂关节均发现T2WI-FS高信号。表3 OCI与ax-SpA骶髂关节T2WI-FS高信号分布位置比较Tab.3 The comparison of the range of T2WI-FS high signal distribution in the sacroiliac joint between patients with OCI and patients with ax-SpA组别OCI组ax-SpA组2值P值侧别/例（%）骶侧15（53.6）42（60.0）0.3400.560髂侧13（46.4）28（40.0）总计28（100.0）70（100.0）分布/例（%）上份25（69.4）68（59.6）1.1140.291下份11（30.6）46（40.4）总计36（100.0）114（100.0）象限/例（%）骶侧上份15（41.7）42（36.8）1.7050.636骶侧下份4（11.1）23（20.2）髂侧上份10（27.8）26（22.8）髂侧下份7（19.4）23（20.2）总计36（100.0）114（100.0）注：OCI为致密性骨炎；ax-SpA为中轴型脊柱关节炎；T2WI-FS为T2WI脂肪抑制。上份是指包括骶侧上份及髂侧上份；下份是指包括骶侧下份及髂侧下份。55磁共振成像 2023年6月第14卷第6期 Chin J Magn Reson Imaging,Jun,2023,Vol.14,No.6http:/临床研究Clinical ArticlesT2WI-FS高信号（图6）。2.4 OCI患者骶髂关节不同区域T2WI-FS高信号MRI征象分析OCI组与 ax-SpA组骶髂关节 T2WI-FS高信号范围、信号强度差异具有统计学意义（P0.001；表5）；OCI组内骶侧与髂侧、上份与下份、各象限间T2WI-FS高信号范围、信号强度差异无统计学意义（P0.05），详见表6。表4 OCI与ax-SpA骶髂关节T2WI-FS高信号形态、内侧缘位置比较Tab.4 The comparison of morphology and position of medial margin of T2WI-FS high signal distribution in the sacroiliac joint between patients with OCI and patients with ax-SpA组别OCI组（n=28）ax-SpA组（n=70）2值P值形态/例（%）片状3（10.7）64（91.4）62.0520.001条带状22（78.6）4（5.7）片状+条带状3（10.7）2（2.9）内侧缘位置/例（%）近部24（85.7）50（71.