内耳道底神经管孔发育不全的CT仿真内镜观察

目的:用多层螺旋CT仿真内镜成像方法显示内耳道底神经管孔的正常解剖及发育异常,并分析各种内耳道底神经管孔发育不全的仿真内镜表现。方法:收集25例(50耳)志愿者高分辨率CT颞骨扫描图像(正常组)和8例(13耳)高分辨率CT和MRI检查示内耳道底发育畸形扫描图像(异常组),用仿真内镜观察内耳道底正常结构及畸形,下限阈值900~1 200 HU,上限阈值3 071 HU。结果:正常组:仿真内镜均显示了50耳各神经管孔的形态和位置。异常组:内耳道底结构紊乱、神经孔缺如9耳,其中内耳道底仅显示单个神经孔1耳;显示2个神经孔4耳,1孔为面神经孔,4个位听神经孔融为1孔;显示3个神经孔2耳,1孔为面神经孔,位听神经孔融为2孔;显示4个神经孔2耳,均为耳蜗神经孔闭锁。单纯神经孔形态异常4耳,均为耳蜗神经孔形态异常,其中非螺旋孔列2耳,蜗轴消失2耳。并发内耳道其他异常3耳。并发内耳畸形8耳。结论:仿真内镜可立体显示各神经孔的形态及位置,显示内耳道底神经管孔发育异常的类型,结合多平面重组(MPR)具有较大的临床应用价值。

Observation of foramina hypoplasia within internal auditory canal fundus with CT virtual endoscopy

Objective:To observe normal and abnormal findings of foramina within internal auditory canal(IAC) fundus with Virtual Endoscopy of multisection helical Computed Tomography.Method:CT scanning of temporal bone was undergone in 25 volunteers(50 ears) in the normal group,in 8 cases(13 ears) with foramina hypoplaisa within IAC fundus which were shown on CT and MRI images.CT virtual endoscopy(CTVE) findings were observed in the normal and abnormal groups.The lower threshold value was 900~1 200 HU,the upper value was 3 071 HU in CTVE definitions.Result:The shape and position of foramina within IAC fundus were shown on the CTVE image, 50 foramina within IAC fundus were shown in all normal cases.In abnormal group,9 ears were shown as IAC fundus disorder and foramina absent,only 1 foramina was shown in 1 ear,2 foramen in 4 ears,3 foramen in 2 ears,4 foramen in 2 ears;Abnormal shape of cochlear nerve foramina was seen in 4 ears.Other malformations were also shown,including IAC malformations in 3 ears and inner ear malformations in 8 ears.Conclusion:CTVE is useful to show the shape and position of normal foramina and pathological changes in the patients with foramina hypoplasia within IAC fundus.