Hounsfield unit density in the characterisation of bile duct lesions

PURPOSE: To study the density of lesions in the lumens of extrahepatic bile ducts through computed tomography examinations, and to compare their characterisations with the results of pathology and/or endoscopic retrograde cholangiopancreatography (ERCP). METHODS: The density of lesions along extrahepatic bile ducts were measured and compared with pathology and/or ERCP. The lesions were evaluated in two main groups: benign or malignant. The bile duct wall enhancement, intrahepatic bile ducts, and gallbladder were also evaluated. RESULTS: The study was conducted with computed tomography scans of 197 cases (93 females, 104 males) who had optimal imaging. The results regarding density of extrahepatic intraductal lesions that were studied at BT were compared with pathology and magnetic resonance cholangiopancreatography results. Of 197 lesions, 125 (63.5%) were reported as benign and 72 (36.5%) were reported as malignant. The results for benign lesions showed an average density of 66.67 ± 17.30 Hounsfield units (HU), and for malignant lesions the average density was 82.38 ± 13.67 HU. CONCLUSION: Lesion density level (HU) gives valuable information for the differentiation between benign and malign lesions in intraluminal extrahepatic bile ducts.