Diagnostic value of dynamic contrast-enhanced magnetic resonance imaging in the evaluation of the biliary obstruction

Abstract

Purpose: In this study, our purpose was to investigate the diagnostic efficacy of the dynamic contrast-enhanced magnetic resonance imaging (MRI) method in the patients with bile duct obstruction.

Materials and methods: 108 consecutive patients (53 men, 55 women, mean age; 55.77 ± 14.62, range 18-86 years) were included in this study. All the patients underwent conventional upper abdomen MRI using intravenous contrast material (Gd-DTPA) and MRCP in 1.5 Tesla MRI scanner. MRCP images were evaluated together with the T1 and T2w images, and both biliary ducts and surrounding tissues were examined for possible pathologies that may cause obstruction.

Results: MRI/MRCP findings compared with final diagnoses, MRI/MRCP in the demonstration of bile duct obstruction sensitivity 96%, the specificity 100%, and accuracy 96.3%, in the detection of presence and level of obstruction, the sensitivity 96.7%, specificity 100%, and accuracy 97.2%, in the diagnosis of choledocholithiasis, the sensitivity 82.3%, specificity 96%, and accuracy 91.7%, and in the determination of the character of the stenosis, sensitivity 95.6%, specificity 91.3%, and accuracy 94.5% were found.

Conclusion: The combination of dynamic contrast-enhanced MRI and MRCP techniques in patients with suspected biliary obstruction gives the detailed information about the presence of obstruction, location, and causes and is a highly specific and sensitive method.

Figure 1

This figure demonstrates a mass lesion located in the left lobe of the liver close to hilus (a) hypointense on T1-weighted MR image, (b) heterogenous hyperintense on T2-weighted image, and (c) heterogenous contrast enhancement on contrast-enhanced fat-saturated T1-weighted image. (d) MRCP image demonstrates the mass that originated from left main bile duct and causes significant bile duct dilatation at the periphery of the liver (arrows). The lesion was considered to be a cholangiocarcinoma with MRI and MRCP findings and also confirmed surgically.

Figure 2

MRCP image demonstrates (a) a calculus (white arrow) located in the distal common bile that does not cause bile duct dilatation. This calculus was not detected during the MRI examination and received a false negative diagnosis. (b) ERCP image demonstrates the calculus (black arrow). This calculus was extracted during the procedure.

Figure 3

MRCP image demonstrates an irregular heterogenous hypointense region in the distal common bile duct (arrow). On MRI, this region evaluated as benign pathology such as calculus and sludge. ERCP image demonstrates a filling defect in this region (arrow). This filling defect was determined as Fasciola hepatica and extracted during the procedure.

Figure 4

T2-weighted (a), contrast-enhanced T1-weighted MRI (b), and MRCP slices demonstrate significant stenosis in the common bile duct at the level of pancreas head (white arrow) and bile duct dilatation proximal to the stenosis. Any mass lesion is not seen at the stenosis level. On MRI and MRCP, the cause of stenosis considered as chronic pancreatitis because of pseudocysts located in corpus and tail of the pancreas (asterisk). (d) ERCP demonstrates the malignant character of stricture (black arrow), and the result of biopsy was adenocarcinoma of the pancreas.

Figure 5

In a case who had undergone laparoscopic cholecystectomy operation 3 years ago, MRCP image demonstrates (a) stricture at hilar level (arrows) and mild dilatation of left main hepatic duct. Although this case had received false positive diagnosis as malignant stricture with MRI and MRCP findings, during ERCP, benign stricture developed secondary to cholecystectomy was diagnosed (arrows). Balloon dilatation and stent replacement was performed during ERCP procedure, and the result of biopsy was benign.