Comparison of Ultrasound and Unenhanced CT for diagnosis of Hepatic Steatosis

Abstract

Background: Hepatic steatosis, characterized by pathologically increased fat deposition in the liver, is a growing health concern, with Non-Alcoholic Fatty Liver Disease (NAFLD) being the most common manifestation. This condition, which may escalate to cirrhosis and steatohepatitis, underscores the need for effective diagnostic strategies. Various non-invasive imaging techniques are pivotal in detecting hepatic steatosis (HS). Objective: The aim of this study was to compare the efficacy of ultrasound and unenhanced CT in the diagnosis of hepatic steatosis, to determine the most reliable non-invasive imaging technique for early detection. Methods: A cross-sectional study was conducted at the Radiological Department of Combined Military Hospital (CMH), Lahore, using a convenience sampling method from April to June 2023. The study involved 100 participants who underwent both ultrasound (USG) and CT scans. Data collection was facilitated through structured performa, and the analysis was executed using SPSS version 26. Results: The study diagnosed hepatic steatosis through both USG and CT scans. Ultrasound assessments revealed that 23% of patients had Grade I HS, 38% had Grade II, and 20% had Grade III. Notably, 19% of the ultrasound examinations showed no signs of HS. In contrast, CT imaging results indicated 24% of participants had no disease with an L/S index greater than 1, while 62% presented with an L/S index between 0.5 to 1, indicative of HS. A critical finding was that 14% were diagnosed with Grade III steatosis, progressing to cirrhosis with an L/S index of less than 0.5. Discrepancies between imaging modalities were highlighted as 20% of patients displayed smooth liver parenchyma on USG contrasted with irregular textures on CT scans. Conclusion: Ultrasound emerges as a viable initial imaging modality for diagnosing hepatic steatosis in early stages due to its accessibility and non-invasiveness. However, for precise quantification of liver fat content, unenhanced CT scans provide superior accuracy. Such insights direct clinicians towards a tailored approach in the management of HS.