Grading of Fatty Liver Based on Computed Tomography Hounsfield Unit Values versus Ultrasonography Grading

Abstract

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) ranges from hepatic steatosis to nonalcoholic steatohepatitis and may lead to liver cirrhosis. This study aimed to assess the feasibility of numerical grading MASLD using noncontrast computed tomography (NCCT). Methods: In a retrospective study of 166 patients diagnosed with MASLD between June 2020 and January 2024, MASLD was graded by ultrasonography, and liver density was measured on NCCT. The MASLD grades and NCCT densities were compared. Results: The MASLD grades were distributed as follows: grade 0 (n = 79, 47.6%), grade 2 (n = 48, 28.9%), grade 1 (n = 25, 15.1%), and grade 3 (n = 14, 8.4%). The mean liver density was 57.75 Hounsfield units (HU) ± 6.18 (range: 48.9–78.2), 51.1 HU ± 4.7 (range: 41.4–59.7), 39.3 ± 6.4 (range: 21.4–48.9), and 22.87 ± 7.5 (range: 12–36.4) in the grade 0, grade 1, grade 2, and grade 3 patients, respectively. An analysis of variance test showed significant variance in the distribution of mean liver density in the different MASLD grades (p < 0.001). Conclusions: After ultrasonography diagnosis of MASLD, NCCT offers an objective, numerical, and calculable method for MASLD grading that is available for radiologists, radiologic technologists, and interested physicians away from experience dependence. NCCT determined that grade 2 had a specific density from 36.4 to 41.4 HU that significantly overlapped with grade 1 (41.4–48.9) HU and with grade 3 (21.4–36.4 HU). Grade 1 showed a significant overlap with the normal liver (48.9–59.7 HU).