Dual Energy CT as a Noninvasive Method to Screen for Gastroesophageal Varices

Study Summary

Cirrhosis leads to portal hypertension and development of gastroesophageal varices, which are the most common cause for bleeding in cirrhosis and a major cause of death. The American Association for the Study of Liver Disease (AASLD) recommends screening endoscopy every 2 years to evaluate for gastroesophageal varices, and annual surveillance for those with small varices on endoscopy. Unfortunately, endoscopy is costly, requires sedation, is poorly tolerated, is subject to high inter-observer variability, and is associated with risks that include bleeding, esophageal injury and aspiration. Noninvasive methods for evaluation of gastroesophageal varices are needed. CT is noninvasive, rapid, less expensive than endoscopy, requires no sedation, provides a quantitative measure of the size of the varices, and allows for assessment of para-esophageal varices, varices in other body locations, ascites, other signs of portal hypertension, patency of liver vasculature, and detection, diagnosis and staging of hepatocellular carcinoma. Single-Energy CT (SECT) has relatively high accuracy in prospective studies for detection of any and large varices but is associated with suboptimal contrast opacification of gastroesophageal varices. Dual-Energy CT with the GE scanners with GSI Xtream (DECT) improves the contrast-to-noise ratio by 60% compared to SECT and is currently standard of care at UAB for evaluation of cirrhosis. The primary objective of this study is to determine the accuracy of DECT for detecting any varices and high-risk varices. The study hypothesis is that the accuracy (AUROC) of DECT will be \>0.90 and \>0.95 for detecting any and high-risk varices in a prospective pilot study (N=50) that uses endoscopy as the reference standard. This will be a single-center pilot observational prospective IRB-approved study. A total of 50 adult patients presenting to UAB Endoscopy for surveillance endoscopy to detect and grade gastroesophageal varices will be enrolled.

Primary Outcome

Varices on dual energy CT will be graded as follows: 0 = no varices, 1 = small \[\<5 mm\] varices, and 2 = large / high risk \[\>= 5 mm\] varices. The reference standard for this outcome will be grading of varices on endoscopy (0 = no varices, 1 = small (\< 5 mm) varices, and 2 = large (\>=5 mm) varices.

Interventions

• DIAGNOSTIC_TEST Duel Energy CT