摘要
目的:探讨MR弛豫时间反映软骨生化成分变化的可行性及两者的相关性。材料和方法:离体牛软骨用胰蛋白酶处理10例、胶原蛋白酶处理7例、胰蛋白酶和胶原蛋白酶混合处理7例,并设置相等数量的对照组,然后测量软骨T1值、T2值及延迟钆增强软骨MR成像指数(T1Gd)。结果:①胰蛋白酶导致软骨氨基葡聚糖(glycosamin-oglycan,GAG)明显下降,但胶原网络无显著改变;胶原蛋白酶和混合酶处理均导致GAG明显下降并胶原网络破坏。②胰蛋白酶处理后,软骨T2(43.1±5.4ms)与对照组(40.5±6.1ms)无统计学差异,T1明显增高(1009.4±93.1ms与872.0±79.8ms),T1Gd明显降低(124.3±39.8ms与145.8±54.3ms)。③胶原蛋白酶处理后,处理侧T2(167.6±27.4ms)和T1(1351.9±205.2ms)均明显高于对照侧(44.0±8.1ms,788.0±71.3ms),而T1Gd(112.1±12.9ms)明显低于对照侧(153.4±22.7ms);混合酶处理后,处理侧T2(184.9±69.5ms)和T1(1356.6±253ms)也明显高于对照侧(40.9±4.9ms,783.3±43.7ms),而T1Gd(106.7±2.6ms)也明显低于对照侧(172.1±53.7ms)。④胶原蛋白酶处理和混合酶处理的T2及T1均无统计学差异,但均显著高于胰蛋白酶处理组。三种酶处理的T1Gd无统计学差异。结论:MR弛豫时间(T2、T1、和T1Gd)均可反映软骨生化成分的早期改变。其中,T2主要反映胶原的变化,T1Gd主要反映GAG的含量,而T1则同时受胶原和GAG的影响。
Purpose To verify the feasibility of MR relaxation times reflecting changes of the cartilage extracellular matrix and to analyze the correlation between MR relaxation times and biochemical components. Materials and Methods Twenty-four bovine cartilage samples were digested by either trypsin （n= 10）, collagenase （n= 7） or combined enzymes （n=7）. Equal numbers of normal cartilage samples were served as the control. Cartilage T1 and T1Gd （index of the delayed Gadolinium-enhanced MRI of Cartilage） were measured by a turbo spin echo inversion recovery sequence. Cartilage T2 was measured using a multipleecho spin echo sequence. Results ① Trypsinization resulted in marked loss of cartilage glycosaminoglycan（GAG）and preserved collagen network on histological examination. Both treatments by collagenase and combined enzymes induced not only loss of GAG but destruction of collagen network. ② Compared with the control, cartilage treated by trypsin showed insignificantly changed T2 （43.1 ± 5.4ms versus 40.5 ± 6.1ms）, significantly increased T1 （1009.4±93.1ms versus 872.0 ± 79.8ms） and significantly decreased T1Gd（ 124.3 ± 39. 8ms versus 145.8±54.3ms）. ② Samples digested by collagenase had significantly higher T2 （167. 6±27.4ms versus 44.0±8. lms） and T1（1351.9±205.2ms versus 788. 0±71.3ms） , but less TIGd（112. 1±12.9ms versus 153. 4±22. 7ms） than the control. Samples treated by combined enzymes also showed higher T2 （184. 9 ± 69. 5ms versus 40. 9 ± 4. 9ms） and T1 （1356.6±253ms versus 783. 3±43.7ms）, but less T1Gd（106. 7±2. 6ms versus 172. 1±53. 7ms） than the control. ④ As far as T2 or T1 was concerned, samples digested by collage nase and by combined enzymes showed no significant differences, but both differed from those treated by trypsin. There was no significant difference of T1Gd among the three kinds of enzymic treatment. Conclusion Quantitative MR relaxation times had the ability to reveal early biochemical changes within cartilage. More specifically, T2 was able to provide information about the change of cartilage collagen; TIGd was mainly correlated with the content of GAG, whereas T1 was affected by both collagen and GAG.
出处
《中国医学影像学杂志》
CSCD
北大核心
2010年第4期336-341,共6页
Chinese Journal of Medical Imaging
基金
国家自然科学基金资助(基金编号:30600139)
作者简介
通讯作者：郑卓肇 E—mail：zzhuozhao@yahoo．com．cn
