Broca区在成人大脑横断面的定位

Transverse Sections localization of the Speech Area of Broca of Adult Cerebrums

目的 探讨Broca区在大脑半球横断面上的准确定位,为颅内占位性病变和脑功能的影像学研究提供形态学依据。 方法 选用正常成人头部标本30例,以AC PC线为基线,获取4mm层厚连续横断层MR图像和脑横断层标本。在连续断层标本上对Broca区的断面表现进行连续追踪观察、分析和统计。 结果 (1)在AC PC线断面上,外侧沟前支出现率为左侧13.6 % ,右侧16 .7% ;三角部出现率为左侧2 0 % ,右侧4 0 % ;岛盖部出现率为左侧2 6 .7% ,右侧30 %。(2 )在首次切及胼胝体压部的断面外侧沟前支出现率为左侧6 0 % ,右侧5 3.3% ;升支出现率为左侧90 % ,右侧83.3% ;三角部明显增宽,出现率为左侧93.3% ,右侧86 .7% ;岛盖部出现率为左、右侧均为86 .7%。(3)在切及穹窿联合断面外侧沟前支消失,升支出现率为左侧10 0 % ,右侧96 .7% ;三角部和岛盖部出现率左、右侧均为10 0 %。(4)在胼胝体即将消失的断面上,三角部出现率为左、右侧均为10 % ;岛盖部出现率为左侧30 .7% ,右侧2 6 .7% ;升支消失。 结论 Broca区首次出现在前后连合平面至胼胝体即将出现的1～2个断面上,外侧沟前支出现是三角部和岛盖部首次出现的信号,穹隆联合平面是显示Broca区的最佳断面,至胼胝体消失后1～2个断面Broca区才消失。

Objective To approach the localization of the speech area of Broca on the transverse sections of the cerebrums. Methods Serial transverse sections of 4 mm thick and MR imagines of 30 audult cadavers brain specimens are prepared. The brain slices in correspondence with MR scan took the line parallel to the intercommissural(AC-PC) line as base line. Results (1)On the section through the intercommissural line, the appearing rate of the anterior ramus of the lateral sulcus was 13.6% on the left side and 16.7% on the right one, the appearing rate of the triangular part was 20% on the left side and 40% on the right one, the appearing rate of the opercular part was 26.7% on the left side and 30% on the right one. (2)On the section of the splenium of corpus callosum appearing for the first time, the appearing rate of the anterior ramus was 60% on the left side and 53.3% on the right one, the appearing rate of the ascending ramus was 90% on the left side and 83.3% on the right one, the appearing rate of the triangular part was 93.3% on the left side and 86.7% on the right one, the appearing rate of the opercular part was 86.7% on the left side and the right one. (3)On the section through the commissure of the fornix, the anterior ramus will disppear, the appearing rate of the ascending ramus was 100% on the left side and 96.7% on the right one, the appearing rate of the triangular part and opercular part was 100% on the left side and the right one. (4)On the section when the corpus callosum disappear, the appearing rate of the triangular part was each 10% on the left side and the right one, the appearing rate of the opercular part was 30.7% on the left side and 26.7% on the right one; the ascending ramus disappeared. Conclusion The speech area of Broca appeares on the 1～2 sections between the intercommissural plane and the plane of the splenium of corpus callosum appearing for the first time. The appearing of the anterior ramus of the lateral sulcus is an important signal. The plane through the commissure of the fornix is the most ideal section, the speech area of Broca will disappear on the 1～2 sections after the corpus callosum disappeared.