Multi–Detector Row CT Attenuation Measurements: Assessment of Intra- and Interscanner Variability with an Anthropomorphic Body CT Phantom

Abstract

Purpose: To determine the dependence of absolute computed tomographic (CT) attenuation values on multi–detector row CT scanner type, convolution kernel, and tube current by using an anthropomorphic phantom. Materials and Methods: A customized phantom was designed with tissue-equivalent materials to simulate contrast material–enhanced liver, spleen, pancreas, aorta, kidney, 0- and 50-HU cylindric renal cysts, muscle, and fat. The phantom was scanned with five multi–detector row CT scanners (LightSpeed QXi, GE Healthcare, Milwaukee, Wis; MX8000, Philips Medical Systems, Best, the Netherlands; and Volume Zoom, Sensation 16 and Sensation 64, Siemens Medical Solutions, Forchheim, Germany) on five separate occasions with 120 kVp, low and high tube current settings, 3.00–3.75-mm section thickness, 50% overlap, and standard and high-spatial-resolution kernels. Standardized regions of interest (ROIs) were used to obtain 3510 attenuation measurements. Attenuation dependence on scanner, kernel, and tube current was ...