大脑Broca区在冠状面磁共振图像上的定位

目的：为MR冠状面图像精确定位大脑额叶内微小占位性疾变及脑功能的影像学研究提供断层解剖学依据。方法：选用成年男性头部标本30例和活体健康成年男性6例，以经连合间线中点的垂线为基线，获得4mm层厚的颅脑连续冠状面MR图像。将扫描后的头部标本，开颅取脑，重要脑回涂以不同颜色，切制成与MR扫描一致的脑断层标本。把标本与相应MR图像对照观察，统计，确定Broca区在冠状面上的定位。结果：（1）在胼胝体膝首次出现的断面上，外侧沟前支的出现率：左侧73％，右侧63％，直而倾斜，易于辨认；（2）在侧脑室前角首次出现的断面上，双侧外侧沟前支的延长线呈印角相交于胼胝体膝上方；（30在胼胝体嘴首次出现的断面上，额下回主要为三角部，其出现率：左侧77％，右侧83％。结论：（1）外侧沟前支在胼胝体膝首次出现的断面上显示清晰，直而倾斜；（2）侧脑室前端出现时，双侧外侧沟前支的延长线呈印角相交于胼胝体膝上方；（3）豆状核出现时，外侧沟前支消失，额下回三角部后方出现的纵行脑沟为外侧沟升支；（4）纵行的中央前沟出现于额下回岛盖部后方，为Broca区的后果。

Localization of cerebral area of Broca on the coronal MR imaging

Objective To localize cerebral area of Broca on the coronal MR imaging precisely. Methods (1)Serial coronal sections and MR images of cadaver brains were prepared using MR images of 30 cadaver heads.The scan condition of T 1WI was: TR 4 277 ms, TE 20 ms, TI 400 ms. Taking the brains from the scanned cadaver heads, then painting different colors on the important cerebral gyri. The preparation of the brain slices in correspondence with MR scan took the line perpendicular to the midpoint of intercommissural line as base one. (2) The MR images of 6 living brains were prepared and the scan condition was similar to the MR images of cadaver. The localization of area of Broca on the coronal sections was studied by the comparison of MR images with serial coronal sections of the brains. Results (1) On the section of the genu of corpus callosum appearing for the first time, the appearing rate of the anterior rami of lateral sulcus was 73% on the left side and 63% on the right one. The anterior rami of lateral sulcus were straight and inclined and were easy to be recognized. (2) On the section of the anterior horn of lateral ventricles appearing for the first time, the extended lines of the bilateral anterior rami of lateral sulcus intersected on the superior aspect of the genu of corpus callosum by obtuse angle. (3) On the section of the rostrum of corpus callosum appearing for the first time, the inferior frontal gyrus was chiefly the triangular part. Its appearing rate was 77% on the left side and 87% on the right one. (4) On the section of the lentiform nucleus appearing for the first time, the anterior ramus of lateral sulcus disappeared. Meanwhile, the opercular part appeared and its appearing rate was 80% on the left side and 83% on the right one. Conclusion (1) The anterior ramus of lateral sulcus is presented on the section of the genu of corpus callosum appearing for the first time as a straight and inclined sulcus. (2) When the anterior horn of lateral ventricles appears, the extended lines of bilateral anterior rami of lateral sulcus intersect on the superior aspect of the genu of corpus callosum by obtuse angle.(3) The anterior ramus of lateral sulcus disappears when the lentiform nucleus occurs. A vertical cerebral sulcus behind the triangular part of the inferior frontal gyrus is the ascending ramus of lateral sulcus. (4) Area of Broca reaches its posterior limit as soon as the precentral sulcus appears behind the opercular part of the inferior frontal gyrus.