Purpose: To compare conventional CT angiography (CTA) and CTA reconstructed from CT perfusion source data (perfusion CTA) acquired on a 320-section CT scanner for the evaluation of intracranial arteries.
Materials and methods: Our study included 7 patients who had undergone trapping of an intracranial aneurysm and placement of a bypass. All underwent conventional and perfusion CTA and digital subtraction angiography (DSA). Using DSA as the gold standard, 2 radiologists evaluated 10 arterial segments on conventional and perfusion CTA images. On a 4-point scale they independently scored the image quality and vascular visualization of the intracranial arteries on the conventional and perfusion CTA images. The effective radiation dose to each patient was also recorded.
Results: A total of 65 arterial segments without apparent abnormalities were assessed. While the mean image quality score tended to be slightly higher for conventional than perfusion CTA, there was no significant difference. The effective dose for perfusion and conventional CTA with unenhanced CT was 4.2 mSv and 3.1 mSv, respectively, for all patients.
Conclusion: For the evaluation of intracranial arteries using DSA as the gold standard, perfusion CTA yields image quality and vascular visualization similar to conventional CTA at an acceptable radiation dose.