腰椎椎间盘后方高信号区的临床意义

 目的 通过 CT、MRI及组织学分析，探讨腰椎间盘后方高信号区（high-intensity zone，HIZ）的病理学性质。 方法 选取下腰痛患者中其 MRI T2 加权像存在局限性 HIZ患者 41例，男 23例，女 18例；年龄 33~50岁，平均年龄 38岁。按照 MRI T1 加权像 HIZ的特点分为两组，T1 加权非高信号组（29例）即 T2 加权像呈高信号，T1 加权像呈低或等信号；T1 加权高信号组（12例）即 T1、T2 加权像均呈高信号。所有病例均同时进行 X线和 CT检查，T1 加权非高信号组中 26例进行了椎间盘造影以及疼痛激发试验。T1 加权非高信号组 15例、T1 加权高信号组 7例接受了手术治疗，手术方式分别为经椎间孔椎体间融合术或后路椎体间减压融合术，并对术中切取的 HIZ区域标本进行 HE染色和（或）免疫组织化学染色进行观察。 结果 T1 加权非高信号组患者 X线、CT及 MR检查均显示椎间盘退变，26例进行椎间盘造影以及疼痛激发试验者中 21例造影阳性及疼痛复制，并显示纤维环破裂，其中 15例阳性者接受手术治疗；5例阴性。术中切取的 HIZ区域标本 HE染色显示为纤维环破裂伴随肉芽组织长入，CD34染色可见 HIZ区域内新生毛细血管，CD68见 HIZ区域内多量染色阳性的巨噬细胞，而 HIZ外区域表达较弱。而 T1 加权高信号组患者椎间盘在 CT上显示为后方纤维环钙化或骨化，HE染色可见明显的钙化灶和钙化的潮汐线形成。结论 腰椎间盘后方 HIZ，在 T2 加权像的局限性高信号、T1 加权像呈局限性较低或等信号意味着通常所指的纤维环破裂伴随肉芽组织长入；而 T2、T1 加权像均呈高信号可能是钙化或骨化灶，因此，传统 HIZ 的概念可能需要进行一定的修正，结合 CT 检查可能更有意义。

The clinical signification of high intensity zone in lumbar disc annulus fibrosus on MRI

Objective To explore the possible pathological essence of HIZ in lumbar intervertebral disc by means of CT,MRI and histomorphology analysis. Methods All of 41 patients of low back pain with the HIZ in the lumbar disc on MRI were identified. There is 23 males and 18 females with mean age of 38 years (range 33-50 years). All the patients were divided into 2 groups according to the characteristics of HIZ on MRI: group A, 29 patients with high intensity on MRI T2WI and low intensity on MRI T1WI; group B, 12 patients with high intensity both on T2WI and T1WI. All these patients underwent X-rays and CT scan on the targeted level. 26 patients in group A were performed discography and pain provocative test. 15 patients in group A and 7 patients in group B underwent operation and those samples of HIZ region were excised for HE staining and immunohistochemical analysis. Results All the patients in group A were proved intervertebral disc degeneration on CT and MRI. 21 patients in 26 who underwent discography and pain provocative test were proved positive and 15 of them underwent operation（Transforaminal lumbar interbody fusion or posterior lumbar interbody fusion）. Histomorphology examination showed annular tear combined with granulation tissue in the samples of HIZ region which were excised in operation. Neoformative blood capillary could be seen through CD34 staining. Macrophage could be found in CD68 staining, but the regions off the HIZ were less stained. In group B, all those targeted discs showed calcified or ossified lesion on the posterior annular on CT scan, HE staining showed calcification or ossification of the posterior annulus fibrosus with frontier line. Conclusion The HIZ on MRI T2WI with low intensity zone on T1WI possibly refers to annular tear combined with granulation in-growth. But the HIZ both on MRI T2WI and T1WI might be calcification or ossification. The conventional concept of HIZ might be modified as HIZ on MRI T2WI, but low intensity zone on MRI T1WI. In addition, CT scan might be helpful in the distinguished diagnosis.