个体化AC-PC线体表投影在脑立体定向手术中的应用

Application of individual AC-PC line surface projection in stereotactic brain surgery

目的:探讨基于高分辨磁共振(MRI)的个体化大脑前连合后缘中点至后连合前缘中点的连线(AC-PC)体表投影在提高立体定向头架安装精度方面的价值。方法:选取在我科进行立体定向手术的患者18例,列入个体化投影组,利用3D Slicer计算个体化AC-PC体表投影,作为安装头架的基线。对照组选取既往按照常规方法安装头架的病例18例。利用Leksell SurgiPlan系统量出AC-PC线与头架基线的角度,比较两组差异。收集40例无神经系统疾病成年人的3D磁共振数据。计算AC-PC线体表投影,寻找更好的体表参考标志并测量AC-PC长度。结果:(1)个体化投影组AC-PC线与头架基线夹角(1.7±1.0°)显著低于对照组(4.6±2.4°,P<0.05)。(2)测量AC-PC线与外眦-对耳轮下脚下缘连线夹角。平均夹角为-1.12±4.61°,取绝对值后平均夹角为3.32±3.35°,男女无明显差异。(3)男性AC-PC长度为23.28±0.98 mm,女性AC-PC长度为22.45±1.16 mm,二者无显著性差异。结论:基于高分辨磁共振的个体化AC-PC体表投影,可显著提高立体定向头架安装精度。外眦-对耳轮下脚下缘连线有可能成为新的AC-PC平行线体表标志。

Objective: To investigate whether individual surface projection of anterior commissure-posterior commissure(AC-PC) line based on high resolution MRI can improve the installation accuracy of stereotactic head frame. Methods: Eighteen patients who underwent stereotactic surgery in our department were assigned to the individual projection group. High resolution MRI was performed before surgery. In 3 Dslicer software, individual sagittal surface projection of AC-PC line was calculated by using raw data of MRI. The individual surface projection of AC-PC line was used as a baseline for mounting the head frame. In the control group, 18 patients who had been mounted the head frame by conventional method were selected. Leksell SurgiPlan system was used to measure the angle between AC-PC line and the head frame baseline, and its absolute value was taken to compare the difference between the two groups. We collected 3 D MRI data from 40 adults without central neuropathy, aged 18-24 years, 20 males and 20 females, who underwent high resolution MRI scans. Sagittal surface projection of AC-PC line was calculated, and the best surface reference markers were determined. The length of AC-PC line was Measured. Results:(1) The angle between AC-PC line and head frame baseline was 1.7±1.0° and the maximum angle was 3.8° in the individual projection group, while the average angle was 4.6±2.4° and the maximum angle was 10.2° in the control group. The average angle between AC-PC line and head frame baseline in individual projection group was significantly lower than that in control group(P<0.05, n=18).(2) The average angle between the AC-PC line and the line from outer canthus to the lower foot of the opposite auricle was-1.12±4.61°, and the absolute value of that was 3.32±3.35°. There was no significant difference between male group and female group(P>0.05, n=20).(3) The length of AC-PC was 23.28±0.98 mm in male group and 22.45±1.16 mm in female group. There was no significant difference between two groups(P>0.05, n=20). The average length of AC-PC was 22.85±1.15 mm in two groups. Conclusion: Individual surface projection of AC-PC line based on high resolution MRI could significantly improve the installation accuracy of stereotactic head frame, and thus improve the accuracy of surgery. The line from outer canthus to the lower foot of the opposite auricle may be a new surface marker of AC-PC parallel line.