【作者】 李炯佾；

【导师】 刘丰春；

【作者基本信息】 青岛大学 ， 人体解剖与组织胚胎学， 2007， 硕士

【摘要】 目的:采用成人端脑矢状面MRI图像与相应脑断层标本结合观察的方法,通过追踪大脑髓质发出的髓突,用表盘定位法定位脑回,为脑功能医学影像学研究及大脑皮质小病灶的早期术前病理学定位诊断和治疗提供诊断依据及形态学基础。材料和方法:选取30例成人外观无异常的颅脑标本,以正中矢状面为基线,用GEsignaMRI/i1.5Tesla超导MRI机,行矢状位MRI扫描,获得层厚6mm的颅脑连续矢状面MRI图像。将扫描后的标本开颅取脑,辨别出主要的脑回并染以不同颜色,以便与用髓突追踪出的各脑回印证。再涂以20%的明胶固定。用自制的脑切片刀和切片台作6mm层厚的连续脑切片。综合地对脑矢状位MRI图像与相应的断层标本观察分析,找出髓突的分支走行规律,借助表盘定位法在MRI矢状位图像上定位脑回。结果:在大脑矢状断面上采用表盘定位脑回的规律如下:①“兔尾征”是在旁正中矢状面上确认和定位中央前、后回的标志和依据,但随着切层外移该征象消失。借助表盘定位法,12点位与1点位之间是中央前回,1点至1点半之间是中央后回。随着切层外移,中央前、后回由右向左移动,但在最外侧岛盖层面上中央前、后回转至12点位前方。②额上、中回在矢状面上的区分是以髓突形态的变化为标志。当髓突完全为额上回或额中回时,其髓突支较清晰,或间以脑沟或向内部融合成半卵圆中心的髓质。但当在额上回向额中回过度的层面时,其髓突支模糊不清,尤其在MRI图像上以皮质信号占优势。额中回与额下回的区分是以矢状走行的额下沟为标志。③角回和缘上回的寻找标志是颞上沟和外侧裂,“蹄铁型”髓突对缘上回和角回具有特征性的定位作用。④矢状面上利用髓突定位脑回准确可靠,为一种较为实用的方法。⑤利用钟表盘使定位方法更简单、准确,容易操作。结论:表盘定位法切实可行、简便实用,在大脑的医学影像学研究和病变的定位诊断方面具有重要的临床意义和实用价值。更多还原

【Abstract】 Objective:In order to provide reliable morphological basis and new way for MRI localization of cerebral local lesion and imaging study of brain function,observing and studying cerebral medulla on 30 cranial sagittal sections and its MRI films.Then identified the corresponding gyri according to medullary pattern and its direction.According to this methods,the cerebral gyri can be accurately described by the clock localization.Material and methods:Choosing 30 normal cadaver heads to scan in sagittal plane.MRI was performed on a 1.5-T unit(G.E,signal Milwaukeee,WI) as Tl-weighted spin-echo series(parameters: TR/TE540/11);24cm field of view;6mm slice thickness;no intraslice gap,2Nex;and 320×192 display matrix.The brain was obtained from the scanned cadaver heads,then painting different water-colors on the major gyri and fasten it with 20%glutin.To cut the brain slice in correspondence with MRI scan with the brain knife on slice frame. Observing the medullary pattern and direction and localizing the corresponding gyri on sagittal section bythe comparison of the MRI images with clock localization method.Result:Through our studying,the rules of localizing gyrus through the pattern of medullary branches on the sagittal plane are described as follows:1.On the central sagittal section, rabbit-tail appearance is the key landmark of post-central gyrus. As the sections away from the medial,this sign disappear,and the rules of medullary branches’ direction are more clearly.The medullary branches of pre-central gyrus appeared on the direction of about 12 to 1 o’clock and post-central gyrus on the 1 to half past 1 o’clock.In addition to,the direction of medullary branches move anti-clockwise as the sections away from the medial.2.The medullary patterns on sagittal sections can be acted to identify superior and middle frontal gyri,when the medullary branches are all superior or middle frontal gyri,its branches are very clear. On the sections which contain superior and middle frontal gyri together,medullary branches are blur,especially signal of cortex predominate on MRI image.Inferior frontal sulcus is the landmark of middle and inferior frontal gyri.3.Supramarginal gyrus and angular gyrus can be found at the end of lateral sulcus and superior temporal sulcus respectively.Double horseshoes sign is guideline for identifying supramarginal gyrus.4.It is a reliable and accurate method to localize the gyri according to the pattern of medullary branches.5.Using of the dial plate make the localization method more simple and accurately,to manipulate is easy also.Conclusion:The gyri clock localizing method was practice, simple and very useful.It is very important in the imaging medical science and clinical imaging diagnosis.更多还原