Using Head And Neck CTA Combining Craniocerebral CTP To Evaluate The Cerebral Blood Flow Perfusion Of The Posterior Circulation Variation Of Scull Basicranial Arterious Cycle

Objective:to assess the cerebral blood flow perfusion of basicranial artery posterior circulation variation with the combined application of head and neck CT angiography (CTA) and craniocerebral CT perfusion (CTP).Methods:patients suffering posterior communicating artery variation in unilateral basicranial arterious circle were screened out with head and neck CTA, and divided into advantageous variation-side group and disadvantageous variation-side group. Then based on whether or not there was anterior circulation variation, the patients were divided into intact anterior circulation group and non-intact anterior circulation group. Next, with the application of craniocerebral CTP technologies, the brain tissue CBV in bilateral posterior cerebral artery blood supplying areas was measured, along with CBF, MTT and contrast medium TTD. Besides, paired t test was conducted on the advantageous variation-side group and the disadvantageous variation- side group with statistical methods.Results:Of the 90 patients with basicranial artery posterior circulation variation, 30 ones suffered dysplasia or deficiency in right posterior cerebral communicating artery,5 ones dysplasia or deficiency in right posterior cerebral artery,49 ones thin or deficient left posterior cerebral communicating artery, and 6 ones deficiency in left posterior cerebral artery. The intact anterior circulation group included 73 patients, while the non-intact anterior circulation group 17 ones. Of them,7 ones suffered anterior communicating artery deficiency, and 10 ones dysplasia in section A1 of unilateral anterior cerebral artery. According to paired t tests on CBV, CBF, MTT and TTD between the advantageous posterior circulation side and disadvantageous posterior circulation side of the intact anterior circulation group, there was no statistically significant difference (p>0.05). Paired t tests on CBV and TTD between the advantageous posterior circulation side and disadvantageous posterior circulation side of the non-intact anterior circulation group showed that there was no statistically significant difference (p>0.05); however, there was statistically significant difference (p<0.05) in MTT and CBF between the two groups.Conclusion:1. The inspection method using head and neck CTA combining craniocerebral CTP is convenient and effective, with the popularity using of multi-slice spiral CT, which can be widely carried out in clinical examination.2. The Willis circles have a high incidence of variation, which most is posterior circulation variation. For the intact anterior circulation group with posterior circulation variation in basicranial arterious circle, there is no significant difference in cerebral blood flow perfusion between the advantageous variation side and the disadvantageous variation side; for the non-intact circulation group with posterior circulation variation in basicranial arterious circle, the disadvantageous variation side has greater MTT and smaller CBF than the advantageous variation side. This may be correlative to clinical syncope with unknown causes.3. Although in the non- intact anterior circulation group, the disadvantageous variation side of posterior circulation has greater MTT and smaller CBF than that of the advantageous variation side, however the sample size is less, there may be some of bias to infer to this is independent factor of the related to clinical symptoms, it still needs to continue to study by large sample size.