Dan Wang, Presenter: Nothing to Disclose

Qiaowei Zhang MD, PhD, Abstract Co-Author: Nothing to Disclose

Wenming Zhang, Abstract Co-Author: Nothing to Disclose

Renbiao Chen, Abstract Co-Author: Nothing to Disclose

To investigate the image quality of cerebral dual energy CT angiography (DECTA) using a non-linear image blending technique as compared with the conventional linear blending method in patients with spontaneous subarachnoid hemorrhage (SAH).

Thirty consecutive spontaneous SAH patients undergone a dual-source, dual energy (80kV and Sn140kV mode) cerebral CTA were retrospectively reviewed with ethical committee permission. Optimized images using non-linear blending method were generated and compared with the 0.6 linear blending images by evaluating cerebral artery enhancement, attenuation of SAH, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) respectively using paired Student t test. Two radiologists independently assessed subjective vessel visualization per-segment on maximum intensity projection (MIP) images using a 5-point scale (5 = excellent, 1 =un-diagnosable). The inter-observer agreement was calculated by kappa test; and the segmental scorings of the two image sequences were estimated by Wilcoxon-Mann-Whitney (WMW) tests.

The non-linear blending images obtained higher cerebral artery enhancement (307.24±58.04HU) but lower attenuation of SAH (67.07±6.79HU) and image noise (7.18±1.20HU), thus achieving better SNR (43.92±11.14) and CNR (34.34±10.25), compared to those of linear blending images (235.47±46.45HU for cerebral artery enhancement, 70.00±6.41HU for attenuation of SAH, 8.39±1.25HU for image noise, 28.86±8.43 for SNR and 20.37±7.74 for CNR) (all p<0.01). The segmental scorings of the non-linear blending image (31.6% segments with score of 5, 57.4% 4, 11% 3) ranged significantly higher than those of linear blending images (11.5% 5, 77.5% 4, 11% 3) (p<0.01). The inter-observer agreement was excellent (kappa=0.762).

The non-linear image blending technique improved vessel visualization of cerebral DECTA by optimizing contrast enhancement in spontaneous SAH patients.

Use of non-linear blending technique with DECT optimizes vessel visualization of cerebral CTA for patients with spontaneous SAH. 

Wang, D, Zhang, Q, Zhang, W, Chen, R, Using Non-linear Blending Technique Optimizes Vessel Visualization of Cerebral Dual Energy CT Angiography in Spontaneous Subarachnoid Hemorrhage Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011809.html