Advantages and disadvantages of magnetic resonance cholangiography for patients with cholelithiasis with reference to those patients associated with dilatation of the common bile duct

Magnetic resonance cholangiography (MRC) was performed on patients with cholelithiasis with dilatation of the common bile duct (more than 10 mm in diameter) before surgery, and the advantages and disadvantages were investigated based on laparotomy findings. Subjects were 27 patients with cholelithiasis associated with common bile duct dilatation who were operated on at the department since June 1996. There were 13 men and 14 women. A mean age of them was 68.2±11.2 years, ranging from 43 to 90 years. As preoperative imagings, abdominal ultrasonography (US) and abdominal CT scan were performed in all cases; either of intravenous cholangiography (IVC), endoscopic retrograde cholangiography (ERCP), or percutaneous transhepatic cholangiography (PTC) was conducted in them; and MRC was performed in 22 cases except incompatible cases. Patients were imaged in the coronal planes by 0.5-T MR scanner employing a body surface coil at 10 second catch at a single breath-hold without injection of contrast medium. Twenty-one (21) out of 27 patients were proven to have common bile duct stones. The overall diagnostic accuracies in US, CT, IVC, and MRC were 40.7%, 62.9%, 68.4% and 86.3%, respectively. The diameters of common bile duct were ranged from 10 mm to 45 mm (mean 15.9±7.9 mm). MRC allows to assess microstones in the common bile duct, and moreover it is useful for postoperative or allergic patients. However, MRC can necessarily reveal peripapillary diverticulum, and it may overestimate the gallbladder in case of negative cholecystogram. MRC can noninvasively and rapidly reveal the presence of stones in the common bile duct, but further studies are required for a better evaluation of the potential disadvantages of this technique. (author)