Patrick McLaughlin FFRRCSI, Presenter: Nothing to Disclose

Graeme John McNeill MRCP, FFRRCSI, Abstract Co-Author: Nothing to Disclose

Shamir Rai BSC, Abstract Co-Author: Nothing to Disclose

Taryn Leah Reddy FRANZCR, Abstract Co-Author: Nothing to Disclose

Teresa Liang MD, BSc, Abstract Co-Author: Nothing to Disclose

Nivmand Khorrami-Arani MBBS, BSc, Abstract Co-Author: Nothing to Disclose

John R. Mayo MD, Abstract Co-Author: Speaker, Siemens AG

Hugue A. Ouellette MD, Abstract Co-Author: Nothing to Disclose

Savvas Nicolaou MD, Abstract Co-Author: Nothing to Disclose

Accurate and reliable differentiation between cerebral grey and white matter structures demands both high contrast and spatial resolution from a CT system. Recently 3rd generation CT detectors, which employ integrated (IC) rather than discrete (DC) electronic circuits, have been introduced into clinical practice. Phantom studies demonstrate reduced electronic noise and increased spatial resolution but the clinical benefits of IC detectors for head CT have yet to be evaluated.

853 consecutive patients underwent non-contrast helical Head CT over a 28 day period in the ED using a dual source 128-slice CT system with IC detectors (Stellar; Siemens Healthcare, Forcheim, Germany). 77 patients who were previously imaged using the same CT system and protocol (120kv, ref mAs 350, 128x0.6 mm) with DC detectors were included in this retrospective intra-individual study. Subjective analysis of deep and superficial grey and white matter differentiation (GWD) was independently performed by 1 general and 1 subspecialty neuroradiologist using a semi-objective 5 point scoring scheme at a standardized window width, level and slice thickness (W=48, L=40HU, 3mm). Objective analysis of image noise was also performed for all datasets.

Mean GWD scores were significantly higher for images acquired using IC detectors in the frontal (4.29±0.9 vs 4.05±1, p=0.021), parietal (3.72±1 vs 3.51±1, p=0.043) and insular regions (3.93±0.97 vs 3.66±1, p=0.004). GWD scores of the basal ganglia were not significantly different between IC and DC images (p=0.293). Interrater agreement between the general and neuroradiologist was moderate for the DC (κ =0.3, p=0.034) and fair for the IC images (κ =0.114, p<0.001). No significant difference was found between CTDIvol (p=0.210) or objective noise (p=0.64) between the IC and DC datasets.

The use of integrated 3rd generation CT detectors results in improved subjective grey and white matter differentiation in the frontal, parietal and insular regions on helical CT head examinations.

The use of integrated 3rd generation CT detectors results in improved subjective grey and white matter differentiation in the frontal, parietal and insular regions on helical CT head examinations.

McLaughlin, P, McNeill, G, Rai, S, Reddy, T, Liang, T, Khorrami-Arani, N, Mayo, J, Ouellette, H, Nicolaou, S, Non-contrast Head CT with 3rd Generation Integrated Circuit CT Detector: Subjective Improvement in Grey-white Matter Differentiation in the Acute Setting.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13024810.html