Virtual Monoenergetic Images from Spectral Detector CT Enable Radiation Dose Reduction in Unenhanced Cranial CT

• DOI: 10.3174/ajnr.a6220
• Publication Date: 2019-09-19T15:15:13Z
• Authors: R.P. Reimer; D. Flatten; T. Lichtenstein; D. Zopfs; V. Neuhaus; C. Kabbasch; D. Maintz; J. Borggrefe; N. Große Hokamp
• Keywords: Image noise

Our aim was to evaluate whether improved gray-white matter differentiation in cranial CT by means of 65- keV virtual monoenergetic images enables a radiation dose reduction compared conventional images.One hundred forty consecutive patients undergoing 171 spectral detector CTs the head between February and November 2017 (56 ± 19 years age; male/female ratio, 56%/44%) were retrospectively included. The tube current-time product reduced during study period, resulting 61, 55, 55 being examined with 320, 290, 260 mAs, respectively. All other scanning parameters kept identical. volume index recorded. ROIs placed gray white on copied identical positions images. contrast-to-noise ratio calculated. Two radiologists blinded reconstruction technique evaluated image quality 5-point Likert-scale. Statistical assessment performed using ANOVA Wilcoxon test adjusted for multiple comparisons.The mean 49.8, 44.7 mGy Irrespective index, noise significantly lower (65- images/conventional images: extraocular muscle 49.8 mGy, 3.7 1.3/5.6 1.6 HU, P < .001). Noise slightly increased (eg, 5.3 1.4/5.6 1.6/6.1 2.1 HU). Overall, superior that irrespective (P Particularly, 65-keV showed higher than Subjective analysis confirmed better images, even mGy.The from allow CT. While this proof concept included 19%, our data suggest greater appears achievable.