Comparison between Transabdominal Ultrasound and Endoscopic Retrograde Cholangiopancreatography in the Detection of the Common Bile Duct Stone

The common bile duct stone (CBDS) is a common clinical problem that can cause serious complications, such as acute cholangitis and pancreatitis. It is important to have an accurate, safe and reliable method for the definitive diagnosis of CBDS before proceeding to therapeutic endoscopic retrograde cholangiopancreatography (ERCP). This study aimed to compare the accuracy of trans-abdominal ultrasound (TAUS) as a diagnostic tool at Al-Kindi teaching hospital in Baghdad/Iraq with invasive tool like ERCP in the diagnosis of bile duct stones, using specificity, sensitivity and positive and negative predictive values. After obtaining ethical committee approval& informed consent from every patient. This prospective study was conducted on 50 patients (15 male patients and 35 females patients) whose ages ranged between (5-80) years and suspected to have CBDS depending on history, clinical suspicion and blood tests. Both TAUS and ERCP were performed. Final diagnosis was confirmed depending on ERCP as it served as a diagnostic standard in the diagnosis of CBDS. Among the 50 patients suspected to have CBDS by TAUS, only 33 (66 %) patients had stone and 38 (76 %) patients had stone by ERCP. Our result also showed that sensitivity, specificity, positive predictive values and negative predictive values for TAUS were 79 %, 75 %, 91 % and 53 % respectively. TAUS can play an important role as an initial screening procedure for CBDS detection because of its different advantages like easy availability, cost effectiveness, no requirement of contrast material and lack of ionizing radiation but should be done with other imaging modality to avoid serious complications of ERCP.