Improved Detectability of Hyper-Dense Nodules Using Dual-Energy Computed Tomography Scanning: Phantom Study Using Simulated Liver Harboring Nodules

The purpose of this study was to evaluate the detectability of hyper-dense nodules using dual-energy computed tomography (DECT) in a phantom. Arterial-phase hepatic dynamic computed tomography (CT) was conducted on small, medium, and large liver-simulating phantoms harboring simulated hypervascular tumors. We acquired 150 single-energy CT (SECT) and 150 DECT scans and measured the contrast-to-noise ratio (CNR) of the nodules. Alternative free response receiver observer characteristic (AFROC) curves of five radiologists’ readings of the SECT and DECT scans were compared to assess detectability of the hyper-dense nodules. For all phantoms, the CNR of nodules measured using DECT was significantly higher than that by using SECT (p < 0.001, all). In the AFROC study, DECT showed a significantly larger area under the curve than that with SECT (0.778 vs 0.499, p = 0.012). Detectability of high-density nodules was better with DECT scans than with SECT scans.