MRI Imaging Anatomical Study Of Cerebral Gyri On Sagittal Section With Dial Plate Method

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.