Three-dimensional computed tomography cholangiography: a new technique for biliary tract imaging

Abstract

Knowledge of the segmental anatomy and intersegmental biliary connections is an essential prerequisite to the effective management of patients with complex biliary strictures. Three dimensional (3D) imaging has the ability to demonstrate complex anatomical relationships that are difficult to appreciate on simple non-invasive two dimensional (2D) imaging. Our aim was to develop a technique for accurate, non-invasive 3D computed tomography (CT) cholangiography. Contiguous 4 mm CT sections were obtained through the liver during a dynamic bolus of 200 ml IV contrast. 3D surface reconstructions were then performed, the biliary system was isolated from surrounding hepatic parenchyma using segmentation and contrast threshold algorithms. 14 patients (six females, eight males, median age 68 years (range 48-82)) were studied. 13/14 had malignant biliary obstruction and one had obstruction secondary to a pancreatic pseudocyst. Obstruction was at the liver hilum in eight, the common bile duct in five and the common hepatic duct in one. Four patients had biliary endoprostheses but were symptomatic from inadequate drainage. There was good demonstration of the biliary anatomy, obstructed segments and intersegmental biliary connections in 13/14; irregular biliary dilatation secondary to primary sclerosing cholangitis rendered interpretation difficult in one. 3D cholangiography provided a useful adjunct to other imaging techniques. In particular, in patients with complex hilar strictures it aided implementation of appropriate interventional drainage procedures.

Multislice CT cholangiography without biliary contrast agent: technique and initial clinical results in the assessment of patients with biliary obstruction

“…The role of CT in the assessment of the biliary tract has been already discussed, with conventional [9,17,18,22,24] or single-slice helical scanners [10,11,12,13,14,15,16,20,25]. Unenhanced CT for detection of lithiasis has been tested in few papers [17,20,22,24,26], with reported sensitivities ranging from 25% [24] to 90% [22].…”

“…Contrast-enhanced CT cholangiography without cholangiographic contrast material has been described in only few papers [18,19,31,32]. Conventional CT was used by Gillams and coworkers in 14 patients with bile duct obstruction, with clear demonstration of the biliary system and the intersegmental biliary anatomy in 13 of 14 (93%) patients [18].…”

“…The role of CT in the assessment of the biliary tract has been discussed in the literature, with [9,10,11,12,13,14,15,16] or without [17,18,19,20,21] cholangiographic contrast agents; however, the use of cholangiographic contrast is problematic (in particular intravenous contrast) and the long acquisition time required by conventional or single-slice helical scanners affects image quality and patient compliance [11].…”

Helical CT cholangiography

“…Use of negative contrast does have a disadvantage because structures with attenuation values similar to bile were also isolated in the threshold algorithm. In their group of patients, this included intrahepatic metastasis, abscesses, and pancreatic pseudocysts [9].…”

Helical CT in the Examination of Bile Duct Obstruction

“…There are recent reports of the application of 3-D CT reformats in the imaging of the biliary ducts (3,7,14,15) while the value of 2-D reformats in biliary duct disorders has not received attention in the literature. This retrospective analysis was performed in order to evaluate the efficacy of helical CT with 2-D multiplanar reformats in detecting the cause of bile duct obstruction, especially as a supplement to ultrasonography (US).…”