Peri-Cholecystic Lןver Enhancement Using Dual-Layer Spectral CT Imaging May Predict Positive Bile Cultures in The Sקtting of Acute Cholecystitis

Purpose: To determine the predictive utility of 50keV mono-energetic imaging features for microbial bile culture positivity and the need for cholecystostomy in patients with suspected acute cholecystitis.

Methods: 69 consecutive patients over a four-year period (2/2017–8/2021) with clinical and radiological signs of cholecystitis on contrast enhanced dual-layer spectral CT imaging were retrospectively identified. A ranked score Likert scale was created for 3 imaging criteria: gallbladder mucosal integrity, pericholecystic liver parenchyma enhancement, and fat stranding surrounding the gallbladder. 50keV low-monoenergetic images in the portal venous phase were reviewed by 6 radiologists on a PACS system at standardized windows (60HU width; 350HU center). Images were ranked and scores correlated with laboratory data (WBC, CRP), as well as conventional imaging criteria including gall bladder size and wall thickness. Correlation to cholecystostomy and bile culture positivity was performed via Chi-Square tests, followed by sensitivity, specificity and odds ratios calculations.

Results: Robust peri-cholecystic liver enhancement was predictive of positive bile cultures in patients undergoing cholecystostomy (P = 0.006; sensitivity 88.9%, specificity 66.7%; odds ratio 16.0 [CI 2.2-117.1]). By contrast, both laboratory markers and four imaging findings including mucosal integrity, peri-cholecystic fat stranding, GB length and wall thickness, showed lower sensitivities (79-82%), specificities (16-21%) and odds ratios (0.67-1.25). Higher scores for adjacent liver enhancement and poorer mucosal wall integrity correlated with cholecystostomy as well (P<0.021, P

Conclusions: The 50keV mono-energetic imaging feature of prominent pericholecystic liver enhancement may potentially predict bacterial infection in patients with cholecystitis. With further validation this tool might provide a useful clinical biomarker that can help guide patient treatment.