An experimental study of cerebral basilar artery vasospasm on CT angiography in a rabbit model

Objectives To investigate the basilar arteries of rabbits by using the techniques of multi-slices CT angiography (MSCTA) and to establish a new evaluation method for cerebral vasospasm (CVS) of a rabbit model. Methods Twenty-five Japanese white rabbits were randomly allocated into contrast medium control group (n=5) and subarachnoid hemorrhage (SAH) group (n=20). A rabbit basilar artery CVS model was developed by injection of autologous arterial blood into the cisterna magna twice, and non-ionic iodinated contrast medium (Omnipaque 300 mgI/mL) was injected through posterior auricular central venous puncture at a dosage of 2.6 mL/kg weight. High pressure syringe was used at an injection speed of 0.4 mL/s, and CT scan began with a delay time of 15 seconds. Two to five MSCTA examinations were performed in SAH group on day 1,4,7 and 11 after blood iniection into the cisterna magna. 3D post processing technology of original image used volume rendering (VR). Results The diameters of basilar artery in SAH group on day 1,4,7 and 11 were 1.28±0.36, 0.82±0.24, 0.83±0.20, and 0.95±0.28 mm. The mean transverse diameter of basilar artery in the 25 experimental rabbits measured by VR was 1.30 mm. CVS occurred at day 1, and it reached the peak at day 4. Basilar artery vasospasm was observed to have been improved moderately at day 11. Conclusions MSCTA techniques can more ideally display the basilar arteries of rabbits, and it is a novel approach for evaluating CVS in living animal models.