MR和DWI对腰椎间盘感染诊断价值的实验研究

目的利用新西兰白兔制作椎间盘感染模型,分析MR不同序列对椎间盘感染的诊断价值.方法新西兰白兔10只,通过穿刺针将0.3 m L金黄色葡萄球菌液注入到椎间盘内,制作椎间隙感染模型.实验动物分别在细菌种植前及后5,10,15,20,30 d进行磁共振T1WI,T2WI,T2脂肪抑制及DWI成像.实验动物分别在30 d扫描后取椎间盘病理并进行观察,分析磁共振成像各病例检出时间的差异.结果术后5 d,MR各序列并未发现感染灶,10 d T2脂肪抑制序列、DWI序列观察到感染灶,表明T2脂肪抑制、DWI序列对观察腰椎感染敏感,术后15 d各序列都能观察到感染灶,但各序列观察率比较有显著差异.结论 MR可以在椎间隙感染10~15 d观察到感染灶,尤其是T2脂肪抑制序列、DWI序列更敏感.

Experimental Study of Value of MR and DWI in Lumbar Intervertebral Infection

Objective New Zealand white rabbits were used to produce an intervertebral disc infection model for the analysis on the diagnostic value of different MR sequences on this disease. Method Liquid staphylococcus aureus with 0 . 3 mL was injected into the intervertebral disc of 10 New Zealand rabbits through a puncture needle respectively,to generate the intervertebral disc infection model. Before the bacterium injection and on day 5,10, 15,20 and 30 after it,the experimental animals were examined by the MRI T1WI,T2WI,T2 fat suppression and DWI imaging. After 30 days, the animals were scanned and the tissue of disc was taken for the pathological observation,in which differences in the detection time of magnetic resonance imaging were analyzed among the cases. Results Five days after the infection,no infection was found in patients examined with each sequence of MR,and some infection were seen in those examined with T2 fat suppression sequences and DWI sequence on day 10,indicating that fat suppression T2 and DWI sequences should be more sensitive for the observation on the lumbar infection. On day 15 after the infection,the foci could be observed with each sequence,but the observation rate of each sequence showed a significant difference. Conclusion Lumbar intervertebral infection can be observed with MR during 10~15 days after the infection of staphylococcus aureus,especially,T2 fat suppression sequence and DWI sequence are more sensitive for the observation.