Takeshi Nakaura MD, Presenter: Nothing to Disclose

Takaaki Ogata, Abstract Co-Author: Nothing to Disclose

Shinichi Nakamura MD, PhD, Abstract Co-Author: Nothing to Disclose

Kazunori Harada, Abstract Co-Author: Nothing to Disclose

Shouzaburou Uemura, Abstract Co-Author: Nothing to Disclose

Yasuyuki Yamashita MD, Abstract Co-Author: Nothing to Disclose

Kiyota Naoto, Abstract Co-Author: Nothing to Disclose

With the development of bone-subtraction technique, MDCT can be the primary method for evaluating intracranial aneurysms. Additionally, the latest generation of MDCT scanners has a possibility to perform arterial phase CT angiography (CTA) without confounding contrast enhancement of the cerebral veins. The purpose of study is to evaluate the usefulness of 80 kVp and compact contrast material protocol for arterial phase subtracted cerebral 3D-CTA at a 256-row CT scanner.

This prospective study received institutional review board approval; prior informed consent to participate was obtained from all patients. We randomly assigned 88 patients with suspected or a past history of intracranial aneurysms undergoing subtracted cerebral 3D-CTA to one of three protocols. Twenty seven patients were scanned with 100kVp and received a contrast dose of 370 mgI/kg body weight over 15 sec (Protocol A). Twenty eight patients were scanned with 100kVp and received a contrast dose of 296 mgI/kg body weight over 10 sec (Protocol B). The other 33 patients were scanned with 80kVp and received a contrast dose of 296 mgI/kg body weight over 10 sec (Protocol C). We compared arterial attenuation, artery to venous contrast, image noise and contrast noise ratio (CNR) of each protocol using Tukey's multiple comparison test.

Arterial attenuation was significantly higher under protocols A (425.3 ± 71.0 HU) and C (442.7 ± 79.3 HU) than protocol B (357.4 ± 106.8 HU) (p < 0.05). There was no significant difference in image noise among the protocols. Arterial-to-venous contrast and CNR of protocol C (299.6 ± 72.5 HU and 26.1 ± 6.1) were significantly higher than of protocol A (214.5 ± 89.1 HU and 20.3 ± 8.3) (p<0.01 and p=0.01), and there was no significant difference in other pair-wise comparisons with protocol B (251.6 ± 103.6 HU and 22.8 ± 9.0).

The 80-kVp plus compact contrast protocol is well suited for arterial phase subtracted cerebral 3D-CTA without confounding venous enhancement at 256-row CT scanning.

The 80-kVp plus compact contrast protocol is well suited for arterial phase subtracted cerebral 3D-CTA.

Nakaura, T, Ogata, T, Nakamura, S, Harada, K, Uemura, S, Yamashita, Y, Naoto, K, Subtracted 3D CT Angiography for the Evaluation of Intracranial Aneurysms at 256 Row CT: Usefulness of the 80-kVp-plus Compact Contrast Bolus Protocol.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11011935.html