蝶鞍区薄层横断面解剖与MRI对照研究

Thin transverse sectional anatomy of the sellar region with corresponding MRI

目的研究蝶鞍区的薄层断层解剖与对应的MRI图像，探讨该区域结构在薄层断层解剖上的变化规律，为影像学诊断及临床开展该区手术提供详细的形态学资料。方法取2例成人头部标本，用1．5TMRI以眦耳线为基线进行扫描获取薄层MRI图像，经冷冻包埋后采用铣削精度为O．001mm的SKC500型数控机床由下往上铣削层厚为0．1mm的薄层标本，其中蝶鞍区层厚为0．05mm。从标本中选取典型断面，与相应的MRI图像相对照，观察蝶鞍区的重要解剖结构。结果共获得MRI图像TI加权40幅和41幅，T2加权40幅和41幅，薄层断层图像304张和310张。在薄层断层标本上进行连续追踪，并与相应的MRI图像对照，总结其规律。在垂体层面能清楚地显示海绵窦内结构及其相互关系：1．颈内动脉弯曲走行于海绵窦内，且与海绵窦之间形成几个问隙；2．第Ⅲ、Ⅳ、Ⅵ脑神经以及三叉神经的眼神经支、上颌神经支在海绵窦外侧壁由前向后依次排列。在视交叉层面能够清楚地看到垂体柄穿过鞍膈与垂体相连。结论冷冻数控铣削技术获得的超薄断面与MRI图像对照能精确显示蝶鞍区的微细解剖结构，为该区病变的断层影像诊断和临床治疗提供实用的亚毫米断层解剖学依据。

Objective To explore the anatomy of the sellar region and its adjacent structures so as to provide intimate morphological data for clinical image diagnosis and surgical operation. Methods Two Chinese adult male cadavers were examined along canthomeatal line with a 1.5T magnetic resonance（MR） imaging unit by using a spin echo sequence. After being embedded with 5 % gelatin and frozen to - 40℃ for a week, the specimens were sliced into 0. lmm continuous sections on transverse plane along canthomeatal line from down to up with SKC500 computerized freezing milling machine （milling accuracy of 0.001mm） in a - 15~C laboratory, the slices of the sellar region were as thin as 0.05mm, subsequently, the serial cross-sections were photographed with high-resolution digital camera and imported into an animation computer. Typical slices were selected to investigate important structures with the eorresponding MR images. Results Forty and forty-one T1 and T2 MR images, 304 and 310 thin sectional images were obtained separately. Comparing the MR1 with thin sectional images, we investigated the sectional anatomy of the sellar region： 1. The internal carotid artery run sinuously in the cavernous sinus and formed some gaps with it. 2. The Ⅲ、Ⅳ、Ⅵ cranial nerves and trigeminal branches ophthalmic nerve, maxillary nerve displayed one by one from anterior to posterior in the lateral wall of cavernous sinus. In the section through the optic chiasm we could observe the stalk of hypophysis crossing the diaphragma sellae and connecting with the pituitary body which could seldom be shown in the thick sections. Conclusion Combination of slices obtained from computerized freezing milling technique and magnetic resonance images offers a better understanding of the complex anatomy structures and provides pragmatic deuto-millimeter anatomical data for image diagnosis and clinical treatment of the pathological changes in the sellar region.