Predictive Value Of Morphological Parameters Of Bifurcation Of Middle Cerebral Artery On Aneurysm Occurrence

Objective:Intracranial aneurysms occur well at vascular bifurcations,suggesting that the occurrence of intracranial aneurysm is closely related to the vascular morphology.In this study,we explored the relationship between the morphological parameters of the middle cerebral artery（MCA）fork and the high risk factors of this aneurysm occurrence,and provided a theoretical basis for the later aneurysm screening and prediction of high-risk patients.Methods:This study retrospectively analyzed 60 patients with middle cerebral artery bifurcated aneurysm between January 2018 and December 2020,and 60 patients with aneurysm-free CT vascular imaging（CTA）of similar gender and age were selected as control groups.The resulting raw image of the head CTA was imported into the Philips3 D workstation,the vascular morphological parameters at the bilateral middle cerebral artery bifurcation were measured in the aneurysm side,aneurysm-free side and control patients,comparing the morphological parameters between the ipsilateral MCA branch（aneurysm-bearing side）,the contralateral MCA branch（aneurysm-free side）and the morphological parameters of the control group.The morphological parameters included in this study are the end of the internal carotid artery（ICA）,the diameter of the main bifurcation（D1）,the diameter of the coarser branch（D2）,the diameter of the finer branch（D3）,ICA/D1、D1/D2、D1/D3、D2/D3,bifurcation angle（γ3）,and lateral angleγ1/ lateral angleγ2.After the analysis of the above parameters,the receiver operating characteristic（ROC）curve with statistical significance was obtained,and its predictive value was investigated.Results: After statistical analysis of the above quantitative parameters,we found that aneurysm patients cerebral artery bifurcation γ3 increase,the lateral angular ratio of the fork vascular anatomy,the diameter of the bifurcation side and control group,and our study shows that aneurysm subjects often tend to the bifurcation vessel with a small lateral angle and small diameter.There were significant differences in the bifurcation angle γ3 and lateral angle ratio（γ1/γ2）between the side with aneurysm in the patient groups,the side without aneurysm,and the the middle cerebral artery bifurcation in the control groups（P<0.001）.There was no significant difference in vessel diameter and diameter ratio between the side with aneurysm and the contralateral bifurcation（P>0.05）.The ROC curve shows that γ3,lateral angle ratio（γ1/γ2）and the D3 can better predict MCA bifurcation aneurysm than other parameters,and the predictive value of γ3 is the highest.When γ3=129.8°,the maximum sensitivity and specificity of the predication are 76.7% and 96.7%.Conclusion: At the MCA bifurcation,aneurysm occurs more frequently in the bifurcation vessel with a small lateral angle and small diameter,it is found that γ3=129.8°,γ1/γ2=1.28,D3=1.63 mm are the critical values of the occurrence of MCA bifurcation aneurysm,which can be used as a theoretical reference for predicting aneurysm occurrence in high-risk patients.