Role of MRI in Early Diagnosis of Ankylosing SpondylitisSIJ.ppt
Role of MRI in Early Diagnosis of Ankylosing Spondylitis,Characteristics of AS,病因和发病机理不明为血清阴性脊柱关节病（Seronegative spondyloarthropathy，SpA)之一多见于青年男性(13-31),M:F=5:1早期主要侵犯骶髂关节（sacroiliac joint，SIJ）肌腱、韧带骨附着点炎症为AS特征性表现,Symptoms and Signs,腰背/骶部不适、疼痛，晨僵病情呈慢性进行性SIJ及肌腱、韧带附着点压痛“4”字实验（+）、SIJ关节压迫实验（+）活动期血沉、C反应蛋白RF（-）HLA-B27（+）90%,HLA-B27,Human Leucocyte AntigenAS患者中阳性率90%-95%我国正常人群中阳性率2%-7%研究表明为易感基因而非直接致病基因HLA-B27阴性AS：发病年龄较大，病情轻，少有家族聚集性,骶髂关节的解剖特点,X线、CT、放射性核素骨扫描及MRI在骶髂关节炎中的应用,2,骶髂关节炎的MRI成像方法、影像表现及与临床和实验室检查的关系,骶髂关节炎的鉴别诊断,早期AS骶髂关节炎的病理特点,4,Anatomy of SIJ,Combined tightlyTrue joint:anterinferior 1/22/3(synovial joint)Strong interosseous sacroiliac ligamentsSacral surface:hyaline（透明）cartilage(relatively thicker)Iliac surface:mixture of hyaline and fibrocartilage(relatively thinner),骶骨表面：透明软骨 髂骨表面：透明和纤维软骨混合覆盖,以往：附着点炎新论断：纤维软骨自身免疫性炎症及软骨下骨炎 附着点处的纤维软骨是免疫应答攻击的主要目标和病理损伤发生的主要部位 活检及尸检：滑膜炎及关节旁骨髓炎目前：软骨下骨髓水肿/骨炎,AS的病理基础,X线、CT、同位素骨扫描及MRI在骶髂关节炎中的应用对比,X线,敏感性低不可或缺有改变时即为 中后期,CT,有相对高的敏感性对细微征象较X线确定对级SIJ炎诊断 较X线敏感一个级别,同位素骨扫描,表现血运和代谢障碍敏感性高受年龄、性别等因素 影响较多特异性差,MRI,放射学级前的早期SIJ炎中晚期的结构性改变鉴别急慢性病变 AS的急、慢性脊柱炎症避免了射线损伤，尤其适于妇女和儿童,SIJ炎的MRI成像方法、影像表现及与临床和实验室检查的关系,成像设备,高场MR体部线圈,MR scan methods,semicoronal,semiaxial,axial,Scan sequences,Semicoronal STIR(short tau inversion recovery),Semiaxial or axial STIR,Axial fast spin-echo T1WI,Pre-contrast,DWI(diffusion weighted imaging),Axial SE-T1WI with FS,Semicoronal T1WI with FS,Post-contrast,骶髂关节炎MRI表现,Staging of Sacroiliitis,Active(acute)inflammatory lesions 活动性（急性）炎性病灶Structural lesions(chronic changes)结构性损害（慢性改变）,Features of active sacroiliitis,Bone marrow edema/osteitisSynovitisCapsulitisEnthesitis,Bone Marrow Edema,Hyperintense signal on STIR/T1 FS post GdIndicator of active sacroiliitisLocated periarticular,may be associated with erosions,M，25Y/ORF（-），HLA-B27（+）,Bone marrow edema,STIR,T1+C FS,Semicoronal view,M,25y主诉：进行性双下肢无力7天，伴臀部针刺样疼痛查体：SIJ压痛、“4”字实验阳性实验室检查：ESR（-）、HLA-B27（+）、RA（-）,胸椎、腰椎MRI平扫+增强均未见异常腰穿脑脊液检查正常风湿科会诊：骨盆、胸锁关节、肩关节等多处肌腱、韧带附着点压痛,2007-12-25,2007-12-25,fs T2WI,T1WI,T1+C FS,T1+C FS,2007-12-25,STIR,T1+C FS,对症治疗（消炎痛）后患者病情缓解出院口服药物治疗+功能锻炼1个月复查,2008-1-29,T2 FS,T2 FS,T1WI,T1 FS post Gd,Axial view,Coronal view,患者出现双肩关节疼痛、僵硬临床给予糖皮质激素肩关节腔内注射及改善病情药物治疗，病情好转发病3个月后复查,STIR,SE T1WI,FSE fs T2WI,2008-3-18,Synovitis,Hyperintense signals on T1 FS post Gd in the synovial part of the SIJ STIR sequences do not differentiate between synovitis and joint fluidAs a single feature without BME is rare,not suffice for making a diagnosis,Synovitis,Capsulitis,Signal characteristics is comparable to synovitisInvole the anterior and posterior capsuleCapsulitis may extend far,Capsulitis,Enthesitis,Hyperintense signal on STIR/T1FS post Gd at sites where ligaments and tendons attach to boneThe signal may extend to bone marrow and soft tissue,FSE fs T2WI,T1WI,T1+C FS,F，25y/o，RF(-)，HLA-B27(-),Enthesitis,以往认为起止点炎为AS骶髂关节病变的特征性病理表现于 STIR/T1 FS post Gd 呈高信号可伴骨髓和/或软组织信号异常,M，23y,T1 FS post Gd,SpA骶髂关节炎病人关节后间隙的起止点炎。,M,14y/o,Right hip pain for 4 months,HLA-B27(+),Pre-contrast,Active sacroiliitis,Post-contrast,structural lesions(chronic changes),Subchondral sclerosis low-intensity/signal free on all sequencesno signal enhancement after contrastErosions:bony defects at the joint marginPseudodilatation of the SIJsPeriarticular fat depositionIncreased signal intensity on T1WIResult from the esterification of fatty acids in inflammatoryIn SpA Indicates areas of previous inflammationAnkylosisLow signal intensity on all sequencesForm bone bridgesThe joint cavity becomes increasingly blurred,CT and X-ray findings,Mainly presented as structure change such as erosions、sclerosis and pseudodilatation of joint space,M，26岁，RF(-)，HLA-B27(),Subchondral sclerosis,Erosions,T2WI FS,T1WI,M/20y，腰、髋部僵硬、疼痛4年，加重一年。ESR：39mm/h；HLA-B27（+）,Increased signal intensity on T1WIResult from the esterification of fatty acids in inflammatoryIn SpA Indicates areas of previous inflammation,Periarticular fat deposition,Low signal intensity on all sequencesForm bone bridgesThe joint cavity becomes increasingly blurred,Ankylosis,+C,M,43y/o,with AS for 20 years,MRI评分,Bollow动态增强评分系统 SPARCC（Spondyloarthritis Research Consortium of Canada）评分,Bollow动态增强评分系统,增强因子Fenh(%)=(SImax-SI0)100/SI0 增强斜率Senh=(SImax-SI0)100/(SI0 Tmax)结果分析：无强化，Fenh Fenh 20%，且40%min Senh 10%min，曲线中度升高,表示隐性或慢性炎症；重度强化，Fenh 90%，且Senh 40%min，曲线陡高，表示严重炎症。,SPARCC评分,SPARCC：Spondyloarthritis Research Consortium of Canada参照STIR序列的MRI表现将每侧SIJ 4等分，对连续6个斜冠状层面评分每个等份正常为0，发现病变为1，病变自关节面下范围超过1cm为2，总分为72,无明显相关性，但可以肯定的是骨髓水肿与病变活动性有关临床有明显症状和体征，但与MRI表现不相对应时，可能与骨髓水肿和软骨侵蚀以外来源的疼痛有关在SIJ MRI表现异常患者中，HLA-B27阳性者较HLA-B27阴性者多且病情严重,MRI表现与临床及实验室检查的相关性,M，22岁，下腰背痛6个月，临床疑诊AS,STIR,T1WI,T1+C FS,STIR,T1+C FS,MRI的主要任务,定性诊断早期SpASIJ炎症预测破坏性改变监测治疗效果,2007-12-25,T2 FS,T1WI,T2 FS,T1+C FS,M，25岁，RF（-），HLA-B27（-）,STIR,SE T1WI,FSE fs T2WI,2008-03-18,2008-04-10,Differential Diagnosis,Rheumatoid arthritis(RA)Septic sacroiliitisCondensing osteitisOther seronegative spondyloarthropathiesPsoriasis arthritisInflammatory bowel diseaseReiter syndrome,感染性骶髂关节炎。A，T1WI,左侧骶骨和髂骨低信号，关节间隙不规则稍增宽，内见低信号。B，FS-FSE显示骨内异常信号及关节腔内液体。,小 结,强直性脊柱炎是一种慢性、进行性、炎症性病变，主要侵犯中轴骨及关节，SIJ炎为早期改变。MRI在AS诊断中的作用不容忽视，尤其对于早期骶髂关节炎有其他影像学检查无法比拟的优势。目前认为典型的SIJ炎MRI表现是诊断早期强直性脊柱炎的主要依据，且病变区骨髓水肿范围越大，病损越严重；异常对比增强越明显，病变越活动。,Thank You!,
