The Value Of MSCTA In The Diagnosis Of Persistent Carotidvertebralbasilar Artery Anastomoses And Its Clinical Significance

Objective This study is to explore the imaging characteristics of persistent carotidvertebralbasilar artery anastomoses by multi-slice spiral CT angiography, to analysis and classification the image findings, to improve the understanding of these abnormal vascular anastomoses, and it can provide help for clinical work.Material and Methods MSCTA data from 1230 patients who had undergone intracranial and cervical arteries examination from September 2012 to November 2013 in CT section of Chuzhou clinical hospital of Anhui Medical University were retrospectively reviewed, using a variety of vascular image processing technique, intracranial and cervical vascular reconstruction images were studied. Two experienced radiologists read the images together.The original axial images,VR and MIP images were analysis, and6 patients were diagnosed of persistent carotidvertebralbasilar artery anastomoses by CT angiography(CTA).Results Among 6 patients,5 had persistent trigeminal artery(PTA),with the prevalence of 0.406%, and 1 proatlantal intersegmental artery(PIA), with the prevalence of 0.081%.According to the Salas standard(divided into lateral type and the medial type)and Saltzman standard(divided intoⅠtype、Ⅱtype andⅢtype) to classify the persistent trigeminal artery.Of 5 PTA patients, 4 patients were the lateral type, 1 was the medial type. 4 cases were Saltzman typeⅠ, CTA showed bilateral superior cerebellar artery and posterior cerebral artery blood supply by persistent trigeminal artery, 1 caseaccompanied near side of basilar artery and on both sides of the vertebral artery intracranial period of stunted growth or rudimentary. 3 cases accompanied with one side vertebral artery intracranial period of stunted growth or rudimentary, bilateral posterior communicating artery was absent, including 1 case with basilar artery fenestration.1 case was Saltzman type Ⅲ. CTA showed the near side of basilar artery stunted growth, on both sides of the superior cerebellar artery and the contralateral posterior cerebral artery blood supply by persistent trigeminal artery, the ipsilateral posterior cerebral artery continued by posterior communicating artery. Saltzman typeⅡdid not appear in this group of cases.On the basis of origin and direction, proatlantal intersegmental artery divide into two type. TypeⅠoriginated from the dorsal side of internal carotid artery,through the foramen magnum into cranial, not through any cervical vertebral transverse foramen in the process. TypeⅡoriginated from the Lateral side of external carotid artery, and more lateral position upward than the typeⅠPIA, it also through the foramen magnum into cranial. The only one PIA patient belonged to type Ⅱ, accompanied by intracranial vascular multiple narrow and the M3 period of aneurysm in the left middle cerebral artery,etc.Conclusion Persistent carotid-vertebralbasilar artery anastomoses were more complex, which persistent trigeminal artery is the most common, and the most types. In the past we used conventional angiography(DSA) to examine the variation. MSCTA with the noninvasive and multi-angle three-dimensional imaging, make it become the first choice for the current examination. MSCTA can clearly, quickly and accurately demonstrate the course of persistent carotid-vertebral- basilar artery including PTA and PIA and its adjacent structure accurately and clearly, thus providing anatomic data for clinical diagnosis and therapy.