摘要目的:研究嗅球和嗅束的断面特点与MRI表现,为相关病变的影像学诊断和外科手术提供形态学依据。方法:选取国人成年尸头标本69例,经防腐和冷冻后,以电动断层带锯分别切制成连续横断层标本36例、矢状断层标本18例和冠状断层标本15例;采用SE序列,获取12例自愿者的头部1.5 T MRI横、矢、冠状图像;利用3.0 T MRI扫描仪,获取了10例自愿者的SE序列和3D-CISS序列头部断层图像;将上述连续断层标本和MRI图像相对照,观察、分析嗅球与嗅束的断面形态、MRI信号、位置及其毗邻关系等。结果:在冠状断面上,嗅球位于嗅束沟或直回与筛板之间,呈上方凹陷略扁的椭圆形;嗅束位于直回和嗅束沟下方,呈扁平的椭圆形。在矢状断面上,嗅球走行在颅前窝底直回下方,周围环绕以嗅池,其中上部嗅池较宽大。在横断面上,嗅束位于直回与眶回之间的嗅束沟内,视交叉的前外侧。MRI横断层、矢状断层和冠状断层图像均可显示嗅球、嗅束,其周围被嗅池环绕。结论:横断面、矢状断面和冠状断面均可清晰显示嗅球、嗅束的形态、位置和毗邻关系,其中以冠状断面为佳。
Abstract:Objective:To explore the features of olfactory bulb and olfactory tract on the sections and MRI images in order to provide morphologic data for the imaging diagnosis and surgery of the related lesions. Methods:69 adult cadaveric heads were selected, preservatized and frozen. With an electric bandsaw, we made 36 sets of continuous transverse sections, 18 sets of continuous sagittal sections and 15 sets of continuous coronal sections. The head transverse, sagittal and coronal 1.5T MRI images of 12 volunteers were collected by SE sequences. The head SE and 3D-CISS sequences images of 10 volunteers were gathered by 3.0 T MRI scanner. Then, the sectional morphology, MRI signal, position and adjacent relations of the olfactory bulb andolfactory tract were investigated by the serial sections and MRI images.Results:On the coronary section, the olfactory bulb was located between the olfactory sulcus or gyrus rectus and cribriform plate, which was oval and had a hollow on the upper margin. The olfactory tract was flat oval and located beneath gyrus rectus and olfactory sulcus. On the sagittal section, the olfactory bulb was surrounded by olfactory cistern under gyrus rectus. The olfactory cistern above the olfactory bulb was comparatively larger than the one beneath the olfactory bulb. On the transverse section, the olfactory tract situated in olfactory sulcus between gyrus rectus and orbital gyri anterolaterally to the optic chiasma. The olfactory bulb and olfactory tract both surrounded by olfactory cistern were clearly showed on the transverse, sagittal, and coronal MRI images.Conclusions:The transverse, sagittal and coronal sections can demonstrate the morphology, position and adjacent relations of the olfactory bulb and olfactory tract well. However, the coronal section is the best plane for showing the olfactory bulb and olfactory tract.