【作者】 栾丽菊；

【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， 2002， 硕士

【摘要】 目的 通过成人端脑矢状断面MR图象与相应断层标本的结合观察，追踪髓质发出的髓突，根据其形态走行规律，确定出相应脑回，为脑影像学研究的功能定位及术前准确地病理学定位提供客观依据及形态学基础。 材料和方法 选取30例外观无异常的颅脑标本，以正中矢状面为基线，用GesignaMR／il.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图象。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图象与相应的断层标本观察分析，找出髓突的分支走行情况，以确定相应的脑回、脑叶。 结果与结论 通过本次研究，在矢状断面上通过髓突定位脑回的规律如下：①中央前、后回旁正中矢状面上，“兔尾征”是中央后回的特征性标志。随着切层偏离半球内侧，该征象消失，但是髓突方向有一定规律可循：12点左右是中央前回的位置，12点半左右是中央后回的方向，且随着切层偏外，其方向沿逆时针移动。至脑岛外侧份层面时，12点位正好是中央沟，再向外切时，中央沟基本保持该方向不变。②额叶额上、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顶叶顶上、下小叶的区分与额叶上、中回的区分相似。在顶枕沟消失的层面中，顶枕叶的区分是以2点位为界，之前为顶叶，之后为枕叶。角回和缘上回的寻找标志是颞上沟和外侧裂，“蹄铁型”髓突形态对缘上回具有特征性的定位指导作用。④矢状面上利用髓突定位脑回、脑叶准确可靠，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。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 functions, observing and studying cerebral medulla on 30 cranial sagittal sections and its MRI film, Then identified the corresponding gyri according to medullary pattern and its direction. According to this method, the cerebral lobe and gyri can be accurately described.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) 5 24cm field of view? 6mm slice thickness; no intraslice gap,2Nex;and 320X 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 MR scan with the brain knife on slice frame. Observing the medullary pattern and direction and localizing the corresponding gyri and sulci on sagittal section by the comparison of the MR images with serial sagittal sections of the brains.Results Through our studying, the rules of localizing gyrus through the pattern of medullary branches on the sagittal plane are described as follows:(1)Pre- and post-central gyri: On the central sagittal section, rabbit-tail sign 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 o’clock and post-central gyrus on the half past 12 o ’clock. In addition to, the direction of medullary branches move anti-clockwise as the sections away from the medial. On the section cutting insula, central sulcus locate exactly 12 o’clock direction and outward is ultimately changeless. (2)Frontal lobe 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)Parietal lobe I-dentification of superior and inferior parietal lobe is equal to that of superior and middle frontal gyri. Another 2 o’clock direction can be acted as borderline of parietal lobe and occipital lobe. Supramarginal gyrus and angular gyrus can be found at the end of lateral sulcus and superior temporal sulcus respectively. Horseshoe sign is guideline for identifying supramarginal gyrus.(4)It is a reliable and accurate method to localize the gyri and lobes according to the pattern of medullary branches.(5)Using of the dial plate make the methods of localization more simple and accurately , To manipulate is easy also.更多还原