膝关节腔及周围滑膜囊积液的MRI定量测定

Effusion quantification in the knee cavity and peripheral synovial bursa: MRI determination

背景:MRI是目前膝关节疾病影像诊断的金标准,但还不能对膝关节积液准确定量。目的:对膝关节腔内注入不同量对比剂的标本进行MRI观察,为临床确诊膝关节腔及周围滑膜囊内不同量积液提供客观依据和定量标准。设计、时间及地点:金标准定量观察,于2008-10/12在成都医学院第一附属医院影像科MRI室完成。材料:选取新鲜成人尸体正常膝关节10件。方法:对10件无积液、积气、结构正常的成人尸体膝关节腔内穿刺留针,通过穿刺针向关节腔内依次注入1,5,10,15,20,30,40mL对比剂,分别于每次注射后行冠状面、矢状面、横断面T2WI,厚度4mm,间距1mm,MRI扫描。主要观察指标:在膝关节冠状面、矢状面和横断面上,观察不同量对比剂在膝关节腔及周围囊内的分布位置。结果:①在膝关节冠状面MRI扫描:注入10mL对比剂时,经膝关节内侧中点处,关节腔内均可见高信号;注入15mL对比剂时,经股骨和髌骨间,关节腔内均可见高信号;20mL对比剂时,经股骨内、外侧髁后缘处,80%股骨后上内、外侧隐窝内出现高信号。②在膝关节正中矢状层面内侧1.5cm处MRI扫描:5mL对比剂时,高信号区呈前粗后细达髁间隆起前缘,70%胫骨内侧髁后上方可见高信号区;10mL对比剂时,髌上囊下1/3段出现高信号;15,20mL对比剂时,80%髌上囊中1/3段出现高信号;30,40mL对比剂时,膝关节后上内、外侧隐窝均可见高信号区。③在膝关节横断面经髌骨尖下缘处MRI扫描:对比剂5mL时,90%关节腔后1/3段可见高信号;对比剂>10mL,70%股骨前缘平面出现高信号区。结论:通过对膝关节腔及周围滑膜囊注入不同量对比剂,可建立不同量积液的参照标准,对MRI诊断膝关节腔及周围滑膜囊积液具有重要价值。

BACKGROUND： MRI is a gold standard for imaging diagnosis of knee joint disease, but it cannot accurately quantitate effusion of knee. OBJECTIVE： To investigate different volume of contrast-medium in the cavity of knee with MRI scanning to provide objective evidence and quantitaive standard for clinical diagnosis of effusion in the cavity of knee. DESIGN, TIME AND SETTING： Quantitative observation was performed in the MRI Room, the First Affiliated Hospital of Chengdu Medical College from October to December 2008. MATERIALS： Ten samples of fresh normal adult knee joint. METHODS： Puncture with the needle retaining in the cavity of knee of normal adult corpse without effusion or pneumatosis was performed, and 1, 5, 10, 15, 20, 30, 40 mL contrast-medium was injected into the cavity. Coronal section, vertical plane and transect were scanned with T2W1, 4 mm thickness and 1 mm interval by MRI. MAIN OUTCOME MEASURES： The distribution of different amounts of contrast agent in the knee cavity and peripheral synovial bursa in knee coronal plane and sagittal cross-sections. RESULTS： ①MRI scanning from coronal section： after 10 mL contrast-medium injection, in the center of medial knee joint, high visual signal was seen in the cavity of joint; after 15 mL contrast-medium injection, scanning between femora and patella, high visual signals were observed; after 20 mL contrast-medium injection, scanning by posterior internal and external condyle of knee, high visual signals were found in 80% of internal and external recess of posterosuperior of thighbone. ②MRI scaning at 1.5 cm from internal vertical plane of middle knee： after 5 mL contrast-medium injection, high visual signal area appeared in intercondylar eminence, narrowing gradually, and 70% of posterosuperior internal condyle of tibia; after 10 mL contrast-medium injection, high visual signals appeared at the 1/3 point under suprapatellar bursa; after 15 and 20 mL contrast-medium injection, high visual signal appeared in 80% of 1/3 point of suprapatellar bursa; after 30 and 40 mL contrast-medium injection, high visual signal was seen both internal and external recess of posterosuperior knee. ③MRI scanning from inframarginal Apex of patella of knee transect： after 5 mL contrast-medium injection, high visual signal appeared in 90% area at 1/3 point posterior articular cavity; after more than 10 mL contrast-medium injection, high visual signal was seen in 70% area of anterior thighbone facet. CONCLUSION： By injecting different volumes of contrast-medium into the knee cavity and peripheral synovial bursa, reference standard can be constructed according to different volumes of effusion, which is significant for diagnosis of effusion of knee cavity and peripheral synovial bursa with MRI.