招收飞行学员腰椎峡部裂的X线诊断

X Ray Diagnosis of Lumbar Spondylolysis in Screening for Aviation Trainees

目的探讨招收飞行学员体检中腰椎峡部裂的X线诊断要点。方法以27例诊断L5双侧峡部裂为研究对象,采用CR或DR机行立位拍摄腰椎正、侧、双斜位X线片,10例加做腰椎X线计算机断层扫描（X ray computedtomography,CT）并二、三维重建。结果正位片X线征象：①＂裂隙征＂显示率18.5%（5/27）;②椎弓根下方密度增高及结构紊乱显示率48.1%（13/27）。侧位片X线征象：①峡部上下缘连续性中断,显示率85.2%（23/27）;②峡部裂隙低密度影显示率85.2%（23/27）;③脊柱1度滑脱占48.1%（13/27）;④椎体后缘连线与棘突上缘连线交角：L5〉L4型占44.4%（12/27）,对照组除1例均L5〈L4型。斜位片X线征象：①峡部上下缘连续性中断,双侧和单侧中断的显示率85.2%（23/27）;②峡部裂隙低密度影,双侧和单侧总显示率88.9%（24/27）;③与L4椎弓峡部比较,21例椎板及峡部发育细小。10例腰椎CT检查均诊断腰椎峡部裂。结论腰椎峡部裂的X线诊断要点：①峡部上下缘连续性中断;②峡部裂隙低密度影;③脊柱滑脱;④椎体后缘连线与棘突上缘连线交角L5〉L4;⑤正位片＂裂隙征＂;⑥正位片椎弓根下部分密度增高及结构紊乱;⑦斜位片椎板及峡部发育细小。①~②是诊断腰椎峡部裂的直接征象,③~⑦是诊断腰椎峡部裂的间接征象。侧位或斜位片有①或②任1项,腰椎峡部裂的诊断即可成立。侧位片有①或②任何1项加③,腰椎双侧峡部裂的诊断即可成立。

Objective To investigate the key points in X ray diagnosis of lumbar spondylolysis in screening of aviation trainees.Methods Twenty-seven candidates for aviation students with spondylolysis were studied.The front,lateral and double oblique views of the lumbar spine were acquired in the erect position using CR or DR.Ten subjects underwent computed tomography（CT） examination and two-or three-dimentional reconstruction.Results The posteroanterior X ray radiograph exhibited that ① the visualization rate（vr） of cleft sign was 18.5%（5/27）,② the vr of increased density and bone trabeculae derangement at the lower part of pedicle was 48.1%（13/27）.The lateral X ray radiograph exhibited that ① the vr of laminar isthmus with discontinuity in the upper or lower margin was 85.2%（23/27）,② the vr of decreased density at the lumbar spondylolysis was 85.2%（23/27）,③ 48.1%（13/27） patients had Ⅰ° spondylolisthesis,④ based on the angle between the posterior margin of the lumbar and the superior margin of the spinous process,44.42%（12/27） subjects in the study group and only 1 subject（1/47） in the normal control group exhibited L5 L4.The oblique X ray radiograph exhibited that ① the vr of bilateral or unilateral discontinuity in the upper and lower margin of lumbar was 85.2%（23/27）,② the vr of decreased density at the bilateral or unilateral lumbar spondylolysis was 88.9%（24/27）,③ 21 cases had slender and smaller isthmus compared with L4.CT scan conducted in 10 subjects confirmed the diagnosis of spondylolisthesis.Conclusion The key points in diagnosis of lumbar spondylolysis are：① discontinuity of superior or inferior margins of lumbar laminar isthmus,② decreased density at the lumbar spondylolysis,③ the presence of spondylolisthesis,④ L5L4 according to the angle between the posterior vertebral margin and the superior margin of the spinous process,⑤ cleft sign on the frontal view,⑥ derangement of bone trabicula and increased density at the lower part of the pedicle,⑦ development abnormality with slender and smaller isthmus on the oblique view.① and ② are direct signs,and ③-⑦ are indirect signs.The diagnosis of spondylolysis can be ascertained on either single sign of ① and ② on lateral or oblique views,and bilateral spondylolysis can be ascertained on sign ③ plus ① or ②.