X线导引下针刺诱导兔椎间盘退行改变的研究

Needle puncturing-induced intervertebral disc degeneration: an experimental study in rabbits

目的采用X线导引下针刺诱导建立兔椎间盘退行性变(退变)模型,并对椎间盘进行T2Mapping检测,为深入研究椎间盘退变的磁共振(MR)定量检测奠定基础。方法选择新西兰大白兔5只,在X线导引下采用穿刺髓核和穿刺软骨终板两种手术方式,分别在穿刺前、穿刺后30 min、4和8周进行常规T2WI、T2Mapping成像和CT三维重建等影像学检查,8周时对诸椎间盘进行病理学分析。结果造模后30 min,各椎间盘MR信号未见明显异常;4周穿刺髓核组T2WI信号明显降低,高信号区范围缩小;T2Mapping显示高值范围明显缩小;8周髓核变化与4周类似,未见明确退变进展;正常对照组和穿刺软骨终板组的椎间盘信号和量值改变不明显。病理学检查发现穿刺髓核组的髓核组织发生非常明显的退变,而穿刺软骨终板组发生轻度退变。结论采用X线导引下针刺椎间盘髓核的方式成功建立兔椎间盘退变模型,此模型具有操作简单、经济、并发症低、影响因素少等优势,并且证明了T2Mapping技术可用于兔椎间盘退变的检测,为深入研究MR定量技术对椎间盘退变的价值奠定了基础。

Objective To establish a reproducible rabbit model of intervertebral disc degeneration by needle puncturing under X-ray guidance,to check the intervertebral disc with T2 mapping technique in order to lay the foundation of MR quantitative technology.Methods Five healthy New Zealand white rabbits were used in this study under the approval from Institutional Animal Care Use Committee.The nucleus pulposus and cartilage endplates were destructed respectively through needle puncturing under X-ray guidance.The degeneration of intervertebral disc was evaluated by using MR T2WI,T2 mapping and CT 3-D reconstruction techniques at the following points of time：pre-puncturing,30 minutes,4 weeks and 8 weeks after the procedure.Pathological examination of the intervertebral discs was conducted at 8 weeks after the procedure.Results On T2WI and CT images obtained at 30 minutes after the treatment,no changes of intervertebral disc was found.At 4 and 8 weeks after the procedure,the signal intensity of the punctured discs decreased obviously,while the signal intensity at other disc levels showed no any difference when compared with the control group.T2 mapping showed that the values of nucleus pulposus of punctured discs became significant lower at 4 and 8 weeks after the procedure,while the values of other discs remained the same as before.Conclusion Under X-ray guidance needle puncturing to destroy the nucleus pulposus can successfully establish the model of intervertebral disc degeneration in rabbits.This technique is simple,economical and reproducible with fewer complications.T2 mapping technique can quantitatively evaluate the extent of disc degeneration in rabbits.This study has laid the foundation for further study on the degeneration of intervertebral disc with MR quantitative technology.