This result is equivalent to the study of Pham Hong Lien, Nguyen Viet Thanh. * Right intrahepatic bile duct stone position The diagnosis of right intrahepatic bile duct stone position by MRCP had the sensitivity (Se) of 95.65%, the specificity (Sp) of 94.73%, the accuracy (Acc) of 95.23%, the positive predictive value (PPV) of 95.65%, the negative predictive value (NPV) of 94.73% (Table 3.14).