1. A method, comprising: obtaining, from a scanner, first computed tomography (CT) image information for scanning of a first article at a first radiation dosage level, wherein the first CT image information exhibits one of a first noise level or a first image signal contrast; applying, in a processor, signal processing to the first CT image information, the applied signal processing based on a machine-learning model trained using CT training images, wherein the CT training images correspond to scanning of one or more second articles at each of the first radiation dosage level and a second radiation dosage level higher than the first radiation dosage level; and producing, from the processor as a result of the applied signal processing, second CT image information that exhibits one of a second noise level lower than the first noise level or a second image signal contrast higher than the first image signal contrast.