关节软骨退变磁共振3D-FS-FSPGR序列成像与病理对照研究

Fat-suppressed three-dimensional fast spoiled gradient-echo MR imaging of articular cartilage degeneration

目的评价三维脂肪抑制快速扰相梯度回波（3D-FS-FSPGR）序列对膝关节软骨退变的诊断价值。方法对30例因骨关节炎行全膝关节置换患者的32侧膝关节术前行3D-FS-FSPGR序列MRI成像,按照Recht标准对MRI图像上的软骨病变程度进行分级。手术医师术中根据MRI图像上提示的软骨病变区位置,钻取软骨和软骨下骨组织,获取0~Ⅲ度病变软骨标本各15个,标本切片行HE染色,按照Collins分级标准进行病理分级,并与MRI分级对照分析;甲苯胺蓝和Ⅱ型胶原免疫组化染色,分别观察软骨内蛋白多糖（PG）和Ⅱ型胶原纤维,分析两者的变化,及其与MRI图像软骨信号变化的关系。结果病理检查结果：0级16个,Ⅰ级13个,Ⅱ级15个,Ⅲ级16个。以病理分级为标准,3D FS-FSPGR序列诊断的灵敏度为93.2%,特异度为75%,准确率为88.3%,kappa值为0.71。关节软骨病理显示：MRI分级越高软骨之间病理变化越明显;随病变加重,软骨基质破坏愈加严重,PG随着软骨病变加重,染色深度呈递减关系;Ⅱ型胶原随着软骨病变加重,染色先加深后变浅。结论 3D-FS-FSPGR序列MRI能够准确的显示关节软骨病变,反映了软骨病理和生化的变化,具备发现关节软骨早期病变的能力。

Objective To evaluate the diagnostic value of fat-suppressed three-dimensional fast spoiled gradient-echo（ 3D-FS-FSPGR） MR imaging on articular cartilage degeneration of the knee,using pathology as the reference standard. Methods Thirty patients（ 32 knees） with knee severe chronic osteoarthritis scheduled for total knee arthroplasty were imaged on a 1. 5-T superconducting magnet with 3D-FS-FSPGR sequence. Then MRI of cartilage lesions was staged by the scheme proposed by Rent. Sixty specimens of articular cartilage,which best demonstrated one cartilage lesion were obtained corresponding precisely to that of MR images,and stained by HE,Toluidine blue and collagenⅡ immunohistochemistry. Then cartilage degeneration was pathologically staged by the scheme proposed by Collins. The staging diagnosis of cartilage degeneration between MRI and pathology was compared. Results Sixteen normal cartilage samples,thirteen grade Ⅰ lesions,fifteen grade Ⅱ lesions,and sixteen grade Ⅲ lesions were confirmed by pathology. Using pathology as the reference standard,the diagnosis value of 3D-FS-FSPGR sequence was that the sensitivity,specificity,accuracy and kappa were 93. 2%,75%,88. 3% and 0. 71 respectively. Articular cartilage pathology analysis showed that the higher of the MRI classification between cartilage pathological changed more obvious; along with the exacerbation of the lesion,cartilage matrix got more serious destruction,PG along with the aggravation of the cartilage lesions,dyeing depth presentation decreased; Collagen type Ⅱ along with the aggravation of the cartilage lesions,dyeing deepening first and then became shallow. Conclusions 3D-FS-FSPGR sequence is an optimal sequence for assessing the articular cartilage degeneration. It can show the pathological and biochemical abnormality of articular cartilage including the early stage and has good veracity to the early pathological changes of articular cartilage degeneration.