Influence of cholecystectomy on the flow dynamic pattern of bile in the extrahepatic bile duct: Assessment by cine-dynamic MRCP with spatially-selective IR pulse

Bile Flow Dynamics in Patients with Cholelithiasis: An Evaluation with Cine-Dynamic Magnetic Resonance Cholangiopancreatography Using a Spatially Selective Inversion-Recovery Pulse

Background: A variety of pathophysiological changes in the biliary system occur in patients with cholelithiasis, but the changes in the bile flow dynamics in those patients remain unclear. The purpose of this study was to elucidate the changes in the bile flow dynamics in patients with cholelithiasis using cine-dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatially selective inversion-recovery (IR) pulse. Methods: We retrospectively examined 25 patients with gallstones (gallstone group) and 69 patients without gallstones (non-gallstone group) who underwent abdominal MRI, including in- and opposed-phase T1-weighted images and cine-dynamic MRCP with a spatially selective IR pulse. The frequency and secretion grade of the antegrade and reverse flow of the bile on the cine dynamic MRCP images and the signal intensity ratio (SIR) of the gallbladder in the in- and opposed-phase T1-weighted images were evaluated. Results: The frequency and mean secretion grade of the antegrade bile flow were significantly higher in the gallstone group than in the non-gallstone group (p = 0.011 and p = 0.003), while no significant differences in those values of the reverse bile flow were found between the two groups. The SIR of the gallbladder in the T1-weighted gradient-echo in-phase images was significantly lower in the gallstone group than in the non-gallstone group (p = 0.004). Conclusions: Cine-dynamic MRCP with a spatially selective IR pulse can noninvasively visualize changes in the bile flow dynamics of patients with gallstones.

Association of Cholecystectomy With Liver Fibrosis and Cirrhosis Among Adults in the USA: A Population-Based Propensity Score-Matched Study

Background and Aims: Cholecystectomy is the “gold standard” for treating diseases of the gallbladder. In addition, non-alcoholic fatty liver disease (NAFLD), liver fibrosis or cirrhosis, are major causes of morbidity and mortality across the world. However, the association between cholecystectomy and these diseases is still unclear. We assessed the association among US adults and examined the possible risk factors.

Methods: This cross-sectional study used data from 2017 to 2018 National Health and Nutrition Examination Survey, a population-based nationally representative sample of US. Liver fibrosis and cirrhosis were defined by median stiffness, which was assessed by transient elastography. Furthermore, patients who had undergone cholecystectomy were identified based on the questionnaire. In addition, Propensity Score Matching (PSM, 1:1) was performed based on gender, age, body mass index (BMI) and diabetes.

Results: Of the 4,497 included participants, cholecystectomy was associated with 60.0% higher risk of liver fibrosis (OR:1.600;95% CI:1.278–2.002), and 73.3% higher risk of liver cirrhosis (OR:1.733, 95% CI:1.076–2.792). After PSM based on age, gender, BMI group and history of diabetes, cholecystectomy was associated with 139.3% higher risk of liver fibrosis (OR: 2.393;95% CI: 1.738–3.297), and 228.7% higher risk of liver cirrhosis (OR: 3.287, 95% CI: 1.496–7.218).

Conclusions: The present study showed that cholecystectomy is positively associated with liver fibrosis and cirrhosis in US adults. The discovery of these risk factors therefore provides new insights on the prevention of NAFLD, liver fibrosis, and cirrhosis.

Pancreatobiliary Flow Dynamics: Association Between Bile and Pancreatic Juice Evaluated With Cine-Dynamic Magnetic Resonance Cholangiopancreatography Using Spatially Selective Inversion Recovery Pulse

BACKGROUND

The physiological flow patterns and the reciprocal relationship between pancreatic juice and bile excretion dynamics have not been clearly elucidated by imaging.

PURPOSE

To assess the physiological flow patterns of bile and pancreatic juice simultaneously in order to clarify the pancreatobiliary flow dynamics using cine-dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatial selective inversion recovery (IR) pulse.

STUDY TYPE

Retrospective.

POPULATION

A total of 85 patients with physiologically normal pancreatobiliary flow without ductal dilatation (normal group) and 19 patients with dilated pancreatic duct.

FIELD STRENGTH/SEQUENCE

A 3 T, fast spin echo sequence with IR pulse to nullify the signal of static pancreatic juice and bile.

ASSESSMENT

The frequency and secretion grade of the antegrade and reverse flow of the pancreatic juice and bile on cine-dynamic MRCP were visually evaluated. Additionally, the reciprocal relationship between pancreatic juice and bile flow was evaluated based on its flow patterns.

STATISTICAL TESTS

Spearman's rank correlation coefficient analysis and the Kruskal-Wallis and Mann-Whitney U tests were used. P values of <0.05 were considered to indicate statistical significance.

RESULTS

In the normal group, the antegrade pancreatic juice flow and no bile flow pattern was most frequently observed (29%), followed by the no pancreatic juice flow and no bile flow pattern (23%), the antegrade pancreatic juice flow and antegrade bile flow pattern (22%), and the no pancreatic juice flow and reverse bile flow pattern (9%). The flow of the pancreatic juice and bile were synchronized with each other in 47%, while they were not in 53%. In the dilated pancreatic duct group, the mean secretion grade of the antegrade bile and pancreatic juice flow was significantly lower than in the normal group.

DATA CONCLUSION

Cine-dynamic MRCP with a spatially selective IR pulse can visualize the variations of the physiological flow patterns of bile and pancreatic juice including 53% of unsynchronized patterns.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 5.