Purpose: To evaluate the utility of a novel Dual-Energy Computed Tomography (DECT) system in quantifying the degree of macrovesicular hepatic steatosis in explant animal livers with histopathology correlation.

Materials and Methods: Explant livers from a variety of animals (duck, goat, and beef) with variable hepatic fat content were obtained. Livers were scanned in a water phantom simultaneously at 80 and 140 kVand the data analyzed with a post-processing algorithm, which included data filtering and setting cut-off thresholds. The average attenuation in each liver at 80 and 140 kV was measured manually by obtaining at least 10 regions of interest (ROI) measurements from each liver. The absolute difference between the measured attenuation at 140 and 80 kV and the quotient between attenuation at these levels (80/140) was calculated manually and automatically by the algorithm. For gold standard, the livers were then sectioned and 5 -10 separate sections per liver were histologically scored on H & E stains with regard to macrovesicular fat content by a pathologist blinded to other data. Samples were also obtained for iron stains.

Results: For each liver, the average absolute change in attenuation (HU140 - HU80) increased with liver fat content. The average ratio of dual energy attenuation (HU80/HU140) also increased with liver fat content. Dual energy images of each liver obtained simulaneously at 80 and 140 kV and the resulting ratio images between the two energy levels provided a simple and intuitive way of visualizing the varying fat contents of different livers.