与乙状窦相关的螺旋CT影像三维定量测量

A three-dimensional quantitative measurement related to sigmoid sinus by using multi-slices spiral CT

目的为岩骨后入路手术及手术中准确定位与乙状窦相关结构提供影像解剖依据，减少手术并发症的发生。方法收集2007年10月至2008年10月在辽宁医学院第一附属医院行螺旋CT颅底三维重建而无颅底疾病的成年人数据资料119例（238侧），其中男80例（160侧），女39例（78侧）；年龄19—69岁。在ADW4．2重建工作站上利用多平面重建技术重建出轴位和冠状位图像，通过旋转显示出所要测量的解剖结构。定量测量与乙状窦相关的解剖结构问的距离，分析性别和侧别等因素对结果的影响以及各测量结果之间的关系，并将测量结果与文献中的尸头标本和干性颅骨标本上测量的数据对比，进行统计学分析。结果解剖结构问螺旋CT影像的定量测量以元±s（以下同）表示，乙状窦沟宽（11．14±2．13）mm，乙状窦沟深（6．04±1．67）mm，乙状窦沟底至乳突外表面的距离（9．74±2．95）mm，乙状窦沟前缘至外耳道后壁的距离（12．98±2．71）mm，后半规管最后部至乙状窦沟前缘的距离（9．87±2．60）mm，后半规管最后部至岩骨后壁的距离（3．18±1．30）mm，外半规管长轴后端至岩骨后壁的距离（5．46±1．38）mm，外半规管长轴后端至乙状窦沟前缘的距离（13．17±2．59）mm，外半规管至颈静脉球窝顶垂直距离（6．69±3．08）mm，面神经垂直段至颈静脉窝最短距离（5．32±2．13）mm。CT测量结果与文献中尸头标本和干性颅骨标本上测量的数据比较，无明显差异。乙状窦沟前缘至外耳道后壁的距离与外半规管至颈静脉球窝顶的垂直距离、面神经垂直段至颈静脉球窝最短距离、乙状窦沟底至乳突外表面的距离呈现出正相关趋势（r值分别为0．284、0．145、0．208，P值均〈0．05）。结论利用多平面重建，多排螺旋cT定量测量的结果可以代表实际的相关解剖结构间的距离；重建图像能准确显示颞骨的解剖特征和变异，从而为手术人路的选择及术中准确定位有关结构提供依据。乙状窦前置时，乙状窦更易发生外移，面神经垂直段至颈静脉球距离更短；乙状窦前置的程度与颈静脉球的高度呈正相关趋势。

Objective To provide a valuable imaging anatomic method for operation of the posterior transpetrosal approach and accurate positioning among relative structures in order to reduce the incidence of surgical complications. Methods The clinical information of 119 adult cases （238 sides） was analyzed. All the cases underwent 16 layer helix CT scaning and three-dimensional image reconstruction of skull base without a skull base disease. Axial and coronal images were reconstructed using muhiplanar reconstruction technique of ADW 4.2 workstation, and the anatomic objective structure were displayed by rotating imaging slices. The data were analyzed in statistically and compared with the published cadaver data. Results Quantitative measurement of anatomic structure was shown as below： The distance of width of sigmoid sinus was （ 11.14± 2.13） ram, the distance of depth of sigmoid sinus was （6.04 ± 1.67 ） mm; the distance from the lateral wall of sigmoid sinus to the surface of mastoid process was （9.74 ±2.95）mm; the distance from the anterior wall of sigmoid sinus to the posterior wall of external auditory meatus was （ 12.98 ± 2.71 ） mm; the distance from the most posterior portion of the posterior semicircular canal to the anterior wall of sigmoid sinus was （9.87 ＋ 2.60） mm ; the distance from the most posterior portion of the posterior semicircular canal to the posterior pyramidal wall was （3.18 ± 1.30）mm; the distance from the posterior extremity of long axis of the lateral semicircular canal to the anterior wall of sigmoid sinus was （ 13.17±2.59）mm; the distance from the posterior extremity of long axis of the lateral semicircular canal to the posterior pyramidal wall was （ 5.46± 1.38 ）mm; the vertical distance from the lateral semicircular canal to the jugular bulb was （6.69 ± 3.08） ram; and the distance from the vertical portion of facial nerve to the jugular bulb was （5.32±2.13 ） mm. Statistically, there were no significant differences between imaging quantitative measurement and published cadaver data. However, the t result, included the distance from the lateral wall of sigmoid sinus to the surface of mastoid process and the distance from the lateral semicircular canal to the jugular bulb as well as the distance from the vertical portion of facial nerve to the jugular bulb, were found a positively correlated to the distance from the anterior wall of sigmoid sinus to the posterior wall of external auditory meatus （ r value was 0.284, 0. 145, 0.208, respectively, all P 〈 0.05）. Conclusions The result of three-dimensional quantitative measurement by using multiplanar reconstruction technique of 16 layer spiral CT could represent a real distance of anatomic structures. The reconstruction of spiral CT images could display a anatomic feature of temporal bone accurately, and it may provide a valuable method for surgical approach and accurate positioning of relative structure in operation. As the location of sigmoid sinus moving forward, the lateral shift of it may occur more easily and the jugular bulb become closer to the vertical portion of facial nerve, while the extension of anterior location in sigmoid sinus should be a positively correlated to the height of jugular bulb.