Willis环三维CTA分型及解剖测量探讨

Study of Classifications of Circle of Willis and Anatomical Measurements on CTA Images

目的探讨Willis环的CT血管造影(CTA)新的分型,并进行相关解剖测量。方法搜集头颈CTA未发现Willis环明确病变者114例,根据其完整性与发育分三型:完整型、相对完整型及不完整型,测量Willis环相关动脉内径并计算其比例关系。结果 CTA显示Willis环完整型26例,相对完整型9例,不完整型79例。发育不良Willis环88例,占77.19%,其中后循环占64.8%,两支占47.7%;变异环49例,占42.98%,其中后循环占71.4%,一支占69.4%。颈内、大脑中、前、后动脉及前、后交通动脉内径比为1.00∶0.74∶0.54∶0.51∶0.41∶0.40。结论本研究Willis环新的分型克服单一考虑环的完整或发育,增加相对完整型,形成分型间联系。进行发育不良与变异的定位与定量,结合Willis环内径测量可为相关疾病诊疗与血流动力学研究提供解剖依据。

Objective To discuss the new classification of circle of Willis(CW)and to apply the anatomical measurements on CT angiography(CTA) images. Methods 114 cases of CW without any lesion were observed. They were classified into three types based on the integrity and development:the complete type,the comparatively complete and the incomplete type. The interior diameter and the ratio of the related artery of CW was calculated. Results There was the complete type in 26 cases,the comparatively complete type in 9 and the incomplete type in 79. The hypogenetic circle accounted for 77.19%,of which 64.8% were posterior circulation and 47.7% were two arteries. The variant circle accounted for 42.98%,of which 71.4% were posterior circulation and 69.4% was one artery. The interior diameter ratio of internal carotid artery,middle cerebral artery,anterior cerebral artery,posterior cerebral artery,anterior and posterior communicating artery was 1.00, 0.74, 0.54, 0.51, 0.41, 0.40,respectively. Conclusion The new classification of CW overcomes the unilateral consideration of the integrity or development of CW and adds the comparatively complete type in order to generate associations between different types. In addition,dysplasia and variation were established and quantified. Combined with the interior diameter measurements of CW,the anatomical basis will provide for the diagnosis and treatment of CW disease as well as the study of the hemodynamics.