Sonographic Assessment of Acute Versus Chronic Cholecystitis: An Ultrasound Probability Stratification Model

Abstract

Objectives: What sonographic variables are most predictive for acute cholecystitis? What variables differentiate acute and chronic cholecystitis?

Methods: The surgical pathology database was reviewed to identify adult patients who underwent cholecystectomy for cholecystitis and had a preceding ultrasound of the right upper quadrant within 7 days. A total of 236 patients were included in the study. A comprehensive imaging review was performed to assess for gallstones, gallbladder wall thickening, gallbladder distension, pericholecystic fluid, gallstone mobility, the sonographic Murphy's sign, mural hyperemia, and the common hepatic artery peak systolic velocity.

Results: Of 236 patients with a cholecystectomy, 119 had acute cholecystitis and 117 had chronic cholecystitis on surgical pathology. Statistical models were created for prediction. The simple model consists of three sonographic variables and has a sensitivity of 60% and specificity of 83% in predicting acute versus chronic cholecystitis. The most predictive variables for acute cholecystitis were elevated common hepatic artery peak systolic velocity, gallbladder distension, and gallbladder mural abnormalities. If a patient had all three of these findings on their preoperative ultrasound, the patient had a 96% chance of having acute cholecystitis. Two of these variables gave a 73-93% chance of having acute cholecystitis. One of the three variables gave a 40-76% chance of having acute cholecystitis. If the patient had 0 of 3 of the predictor variables, there was a 29% chance of having acute cholecystitis.

Conclusions: Gallbladder distension, gallbladder mural abnormalities, and elevated common hepatic artery peak systolic velocity are the most important sonographic variables in predicting acute versus chronic cholecystitis.

Keywords: acute; cholecystitis; ultrasound.

Figure 1.

ROC curves of different models for acute versus chronic cholecystitis using all patients.

Figure 2:

Transabdominal sagittal ultrasound of the gallbladder showing marked wall thickening (calipers). This gallbladder wall measures at 12 mm and normal is less than 3mm. In addition, this gallbladder demonstrates mural abnormalities (arrow), demonstrated by an irregular, striated appearance of the gallbladder wall.

Figure 3a:

Transabdominal sagittal ultrasound of the gallbladder (arrow) shows marked luminal distension, with long axis measurement of 10 cm.

Figure 3b:

Transabdominal transverse ultrasound of the gallbladder shows a thin gallbladder wall (arrow), but with luminal distension to 5.1 cm measured on the short axis.

Figure 4:

Transabdominal sagittal spectral Doppler ultrasound image at the porta hepatis showing the common hepatic artery being appropriately measured, with angle correction and measured parallel to the portal vein (red vessel). This hepatic velocity artery is elevated at 234.8 cm/second.