Evaluating the relationship between incidental non-alcoholic fatty liver disease on CT imaging and risk of coronary artery disease

Abstract

Body: Non-alcoholic fatty liver disease (NAFLD) is a common condition that histologically ranges from simple steatosis, to steatohepatitis and advanced fibrosis. NAFLD is an increasingly common cause of chronic liver disease and affects up to 30% of the adult population in western countries. Furthermore, NAFLD has been associated with an increased risk of fatal and non-fatal cardiovascular events compared to those without NAFLD. CT Abdominal and Kidney, Ureter and Bladder (KUB) imaging has lower accuracy in diagnosing NAFLD compared to ultrasonography, magnetic resonance spectroscopy and magnetic resonance imaging. However, CT abdominal and KUB scans are performed in much higher volumes in imaging departments and due to the large amount of additional radiological data acquired in these scans, these patients may benefit from additional screening for incidental NAFLD with possible outcomes for individual patient cardiac risk stratification and reporting. Purpose: Conduct a retrospective analysis to evaluate the relationship between incidental nonalcoholic fatty liver disease on CT KUB and correlation with risk of coronary artery disease. Methods and materials: A retrospective study was performed whereby CT KUB imaging data was collected for patients over 2010 to 2017 for patients presenting to the Nambour General Hospital Radiology Department. Two quantitative indices will be used for assessing hepatic steatosis including an absolute liver attenuation value (HUliver) of 48, and a liver-to-spleen difference in attenuation (CTL-S) of -2. These indices and threshold values are reported in literature to have 100% specificity in diagnosing moderate-to-severe hepatic steatosis. The presence of steatosis was then compared to the patient's history of coronary artery disease from online records. Results and conclusions: Future routine screening for incidental NAFLD on routine CT imaging for unrelated conditions may aid in cardiac risk stratification of patients who would otherwise would remain undetected. Although CT imaging is not ideal in identification of mild hepatic steatosis, the high volume of CT KUB imaging performed in most radiology departments allows for clinically relevant screening of moderate-to-severe hepatic steatosis and through this screening may allow for earlier identification of patients who have an increased likelihood of future coronary artery disease.L618977065 <br />