Intravenous cholangiography: optimum dosage and methodology

Computed tomographic cholangiography in living liver transplant donors: factors determining the degree of contrast enhancement

OBJECTIVE

To determine factors affecting liver and bile duct contrast enhancement during computed tomographic cholangiography (CTC) in living-donor transplant candidates.

METHODS

Forty-four candidates underwent preoperative triphasic CT followed by intravenous infusion of 20 mL of iodipamide for CTC. Body size indices and liver volume were correlated to parenchymal and biliary enhancement. Bile duct visibility was compared to duct enhancement.

RESULTS

Poorly visualized first- and second-order bile ducts demonstrated diminished enhancement (P < 0.015). Both CTC parenchymal and biliary enhancement correlated inversely with body surface area, height, and weight (P < 0.001); inverse correlation was also seen between liver volume and parenchymal enhancement (P < 0.001). A moderately positive correlation was noted between CTC biliary and parenchymal portal venous enhancement (r = 0.421; P = 0.004).

CONCLUSIONS

Computed tomographic cholangiography parenchymal and biliary enhancement diminishes with increased body size and liver volume, supporting a need for adjustable contrast dosing. Portal venous parenchymal enhancement may serve as a preinfusion indicator.

Intravenous 64-multi-detector row CT-cholangiography of porcine livers: a feasibility study with definition of the temporal window for optimal bile duct delineation

BACKGROUND/PURPOSE

To assess the feasibility of intravenous 64-multi-detector row computed tomography (CT)-cholangiography of porcine livers with definition of the temporal window for optimal bile duct delineation.

METHODS

Six healthy Landrace pigs, each weighing 28.97 +/- 2.99 kg, underwent 64-multi-detector row CT-cholangiography. Each pig was infused with 50 ml of meglumine iotroxate continuously over a period of 20 min and, starting with the initiation of the infusion, 18 consecutive CT scans of the abdomen at 2-min intervals were acquired. All series were evaluated for bile duct visualization scores and maximum bile duct diameters as primary study goals and bile duct attenuation and liver enhancement as secondary study goals.

RESULTS

Of the 16 analyzed biliary tract segments, maximum bile duct visualization scores ranged between 4.00 +/- 0.00 and 2.83 +/- 1.47. Time to maximum bile duct visualization scores ranged between 10 and 34 min. Average bile duct visualization scores for the 10- to 34-min interval ranged between 3.99 +/- 0.05 and 2.78 +/- 0.10. Maximum bile duct diameters ranged between 6.47 +/- 1.05 and 2.65 +/- 2.23 mm. Time to maximum bile duct diameters ranged between 24 and 34 min. Average bile duct diameters for the 10- to 34-min interval ranged between 6.00 +/- 0.38 and 2.40 +/- 0.13 mm.

CONCLUSIONS

Intravenous 64-multi-detector row CT-cholangiography of non-diseased porcine liver is feasible, with the best bile duct delineation acquired between 10 and 34 min after initiation of the contrast agent infusion.

Assessment of the optimal temporal window for intravenous CT cholangiography

The optimal temporal window of intravenous (IV) computed tomography (CT) cholangiography was prospectively determined. Fifteen volunteers (eight women, seven men; mean age, 38 years) underwent dynamic CT cholangiography. Two unenhanced images were acquired at the porta hepatis. Starting 5 min after initiation of IV contrast infusion (20 ml iodipamide meglumine 52%), 15 pairs of images at 5-min intervals were obtained. Attenuation of the extrahepatic bile duct (EBD) and the liver parenchyma was measured. Two readers graded visualization of the higher-order biliary branches. The first biliary opacification in the EBD occurred between 15 and 25 min (mean, 22.3 min +/- 3.2) after initiation of the contrast agent. Biliary attenuation plateaued between the 35- and the 75-min time points. Maximum hepatic parenchymal enhancement was 18.5 HU +/- 2.7. Twelve subjects demonstrated poor or non-visualization of higher-order biliary branches; three showed good or excellent visualization. Body weight and both biliary attenuation and visualization of the higher-order biliary branches correlated significantly (P<0.05). For peak enhancement of the biliary tree, CT cholangiography should be performed no earlier than 35 min after initiation of IV infusion. For a fixed contrast dose, superior visualization of the biliary system is achieved in subjects with lower body weight.

Intravenous cholangiography in the CT era

With the availability of computed tomography (CT), ultrasonography (US), percutaneous transhepatic cholangiography (PTC), and endoscopic retrograde cholangiopancreatography (ERCP), the use of intravenous cholangiography (IVC) has waned. A retrospective study of 69 intravenous cholangiograms performed from 1979 through 1982 assessed the utility of intravenous cholangiography, as well as its effect on patient management, at an institution where CT was highly developed. In no case after normal findings on CT and/or ultrasound examination did IVC make a positive pathologic diagnosis. After abnormal results on CT and/or US examinations, in no case did IVC add to the diagnosis. Finally, after technically suboptimal results of CT and/or US examinations, IVC made only 1 positive pathologic diagnosis. Overall, IVC correctly demonstrated only 5 of 9 cases of common duct stones or strictures. Of the 26 cases with anatomical correlation there were a total of 7 false-positive and -negative IVC examinations. In this series, IVC was rarely useful in the diagnosis of biliary tract disease. Given the high inaccuracy rate of IVC in this study, its use for the exclusion of biliary tract disease is discouraged.

Iotroxamide studies in man--biliary iodine levels following bolus injection and slow infusion. Comparison with ioglycamide

The concentration of iodine in the bile of patients with indwelling T-tubes has been measured following administration of the new cholangiographic agent Iotroxamide. Studies have been performed after administration of the contrast agent by both 10 min bolus injection and 1 h drip infusion techniques. Comparison has been made with the iodine concentrations obtained after administration of equimolar amounts of Ioglycamide. There was no significant difference in the biliary iodine levels obtained with the two methods of administration when Iotroxamide was the contrast agent employed. However, with Ioglycamide the slow infusion technique produced higher iodine levels than the bolus injection method (P less than 0.05). Comparison between the two agents reveals that, whichever administration technique is used, Iotroxamide provides higher iodine levels than Ioglycamide. After bolus injection the superiority for Iotroxamide is in the region of 20% and after slow infusion is of the order of 10--15%. It is concluded that Iotroxamide is likely to prove superior to Ioglycamide as a cholangiographic agent. In terms of opacification of the biliary tree there is little to choose between bolus injection and slow infusion techniques when using Iotroxamide and the relative toxicity of the two techniques should be the major factor in determining which method is employed in clinical practice.

Intravenous cholangiography in childhood

Intravenous cholangiography (IVC) was performed on 102 children aged between one and 13 years. Eighty of the patients who were non-icteric were divided into four groups and received contrast medium containing either 53, 75, 106 or 150 mg iodine/kg body weight by intravenous injection over ten minutes. Complete demonstration of the common bile duct (CBD) was achieved in 85% of patients and in a similar proportion of all age groups. There was some delay in opacification of the CBD in young children but this was not of practical significance. The two higher dosage regimen gave significantly better results than the two lower dosages (p less than 0.001) and this improvement was evident in the young and older age groups. Nausea and vomiting occurred as side effects in 6%. In eight patients in whom there was inadequate demonstration by the standard IVC, an infusion technique over 3--8 hours was carried out. This improved the demonstration in three children with diagnostic results in two.

Percutaneous transhepatic cholangiography using the "Chiba" needle--80 cases

Using the Chiba needle for percutaneous transhepatic cholangiography, bile ducts have been visualized radiographically in 80% of 80 patients with cholestatic jaundice. The success rate was 94.4% in the 54 patients with dilated bile ducts due to an extrahepatic bilary obstruction, and 50% of the 20 patients with undilated ducts. Four patients developed ascending cholangitis with septicaemia on the same day as the procedure, and early surgery after visualization of obstructed bile ducts is recommended. The technique was successful in three of five patients with sclerosing cholangitis. Percutaneous cholangiography using the Chiba needle is a convenient method of opacifying the biliary system in patients with severe large bile duct obstruction.