Ultrasound measurements of the bile ducts and gallbladder: normal ranges and effects of age, sex, cholecystectomy, and pathologic states.

Abstract

The objectives of this study were to determine the normal values and ranges for bile duct and gallbladder measurements, adjusted for demographic data, and to assess the effects of a variety of pathologic states on these values. Four thousand one hundred nineteen abdominal ultrasounds were retrospectively analyzed. The values for the extrahepatic bile duct (EHD), left (LIHD) and right (RIHD) intrahepatic ducts, gallbladder wall thickness, and gallbladder volume in "normal" patients were evaluated with respect to age, sex, ethnicity, and cholecystectomy status. These values were compared using multivariate analysis to those in a variety of diseased states, including cirrhosis, fatty liver, gallstones, sludge, cholecystitis, and biliary obstruction. One thousand four hundred eighty-four of the 4119 examinations were classified as normal. The mean EHD, RIHD, LIHD, and gallbladder wall thickness and volume measurements in normal patients were 3.8 ± 1.6 mm, 1.9 ± 1.9 mm, 1.9 ± 1.1 mm, 2.6 ± 1.6 mm, and 242 ± 234 mL, respectively.There were small increases in EHD diameter with age (+0.02 ± 0.11 mm/y, P < 0.001), female sex (+0.3 ± 1.6 mm, P < 0.0001), and cholecystectomy (+1.0 ± 1.6 mm, P < 0.0001) and a small decrease with fatty liver (-0.4 ± 1.6 mm, P = 0.0003). The gallbladder wall was thicker in patients with gallstones (+0.4 ± 1.4 mm, P = 0.0049), sludge (+0.5 ± 1.4 mm, P = 0.0019), and acute cholecystitis (+3.1 ± 1.6 mm, P < 0.0001). With biliary obstruction, the mean EHD, RIHD, LIHD, and gallbladder volume measurements were 6.0 ± 2.1 mm, 4.2 ± 1.4 mm, 4.1 ± 1.4 mm, and 171 ± 207 mL, respectively (P < 0.0001 for all values). This study clarifies normal values and ranges for bile duct and gallbladder measurements, adjusted for demographic data, and evaluates these measurements in a variety of common pathologic states.