超低场MRI诊断腰椎间盘病变的价值与限度

Estimation of the Diagnostic Values and Limits of Lumbar Disc Disease with ULF—MRI

本文以35例手术证实的腰椎间盘病变为基础,回顾性对照分析超低场 MRI 结果和手术所见,并与腰椎平片和椎管膜外碘中造影进行比较,从而了解超低场 MRI 对本病的诊断价值和限度。结论为超低场 MRI 诊断椎间盘突出.髓核变性和(或)膨出,黄韧带肥厚等价值较高,与手术所见完全相符。唯因超低场 MRI 信噪比低,T_1相横断面空间分辨率亦低,影响椎管内组织间细节的辨别而不能满意显示椎管内髓核逸入蛛网膜下腔,肉牙组织修复粘连等组织内容物。对估价侧隐窝狭窄,小关节突骨质增生.韧带和髓细微钙化等亦不及 X-CT 横断面清晰。综上情况,我们认为对腰椎间盘病变诊断,宜先拍腰骶椎 X 线平片,用超低场 MRI 查出盘突,变性等病变,如有必要再对某时空节段做 X-CT 检查,可使术前诊断更为完善。

This study is based on operation—proved 35 patients.Through reviewing,analizing and com-parig the results of ULF—MRI with the operation and comparing with the lumbar sacral plain filmand epidurography with iodine liquid,we would like to obtain a through understanding of the diag-nostic values of ULF—MRI as well as its limits.We found that in diagnosing protrusion of lumbardisc degenerative changes and/or protrusion of pulpous nucleus and thickness of ligament flavin etc.the value of ULF—MRI is rathr high,being same with those seen in the operation.But,owing to thelow field strength and low signal—noise ratio,discrimination of the fragments of pulpous nucleus in-truding into the spinal canal,granulomatous and adhesive tissues seen in operation could not befound when the MR imaging is reviewed.Narrowing of the lateral lacuna of the spinal canal,hyper-ostosis of superior and inferior articular process,minute calcified in ligament and/or nucleus,etc.can not be seen as clearly as in the X-CT transaxial view.Therefore,we think the best way is totake a lumbosacral plain film first and then an ULF—MRI for ruling out disc or pulpous nucleuspathologic change.An X-CT canning should be made if neccessary.In this way,the diagnosis oflumbar disc disease made before operation can be more correct and perfect.