腰椎间盘髓核退变的MRI表现与病理学的相关性研究

Correlation between MR imaging and pathological features of nucleus pulposus degeneration in the lumbar disc

目的探讨腰椎间盘髓核退变的MRI表现与病理学之间的相关性,为临床应用MRI相对信号强度评价腰椎间盘髓核退变提供病理学依据.方法病例组标本取自腰椎间盘疾患手术患者,共91例101个椎间盘;对照组标本取自既往无明显腰痛史的年轻腰椎骨折患者和新鲜脑死亡患者,共6例16个椎间盘.所有标本均于术前测量MRI相对信号强度,并予以HE染色、Alcian blue临界电解质浓度(CEC)染色和水分含量测定,分析MRI相对信号强度与硫酸软骨素指数、MRI相对信号强度与水分含量、硫酸软骨素指数与水分含量之间的相关性.结果两组间的MRI相对信号强度、硫酸软骨素指数和水分含量差异均有显著性,而硫酸角质素指数差异无显著性.MRI相对信号强度与硫酸软骨素指数、MRI相对信号强度与水分含量、硫酸软骨素指数与水分含量均有明显相关性,其r值分别为0.659、0.752和0.592,P值均＜0.001.根据髓核的水分含量和病理学改变,可将髓核退变大致分为四个阶段,每个阶段的MRI相对信号强度依次为:＞0.82,0.73～0.82,0.64～0.72,＜0.64.结论Mm相对信号强度不仅能反映髓核的水分含量,而且还能反映髓核退变过程中的病理特征.MRI相对信号强度四级定量分级法是一种评价髓核退变较好的方法.

Objective To investigate the correlation between MR imaging and pathological features of nucleus pulposus degeneration in the lumbar disc, and to provide a reliable evidence to evaluate the nucleus pulposus degeneration by MR imaging relative signal intensity. Methods From January 2001 to December 2001, 91 patients who underwent operative treatment for lumbar disc diseases were recruited for the study, while 4 lumbar fracture patients with no previous low back pain and 2 fresh brain-injury cadavers were recruited for contrast study. Before operation, the relative signal intensity was measured in MRI T2WI images. All 117 specimens were dyed with HE and Alcian blue CEC. The water content was also detected. The correlation between MRI relative signal intensity and chondroitin sulfate index, water content was analyzed with SPSS 10.0 software, the correlation between chondroitin sulfate index and water content was analyzed as well. Results There was significant difference between the above mentioned two groups when MRI relative signal intensity, chondroitin sulfate index and water content was compared. Whereas there was no significant statistical difference when keratin sulfate index was compared between the two groups. MRI relative signal intensity positively correlated with water content and chondroitin sulfate index, and the chondroitin sulfate index positively correlated with water content. Conclusion The MRI relative signal intensity reflects not only the water content, but also the pathological characteristics of nucleus pulposus degeneration. The quantitative classification of relative signal intensity in MRI is a method to identify the grades of nucleus pulposus degeneration.