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.

Symptoms that are associated with decreased pancreatic enzyme flow: MRCP assessment

BACKGROUND

Pancreatic exocrine insufficiency is one of the causes of malabsorption syndrome. In many cases of malabsorption syndrome, pancreatic exocrine insufficiency can be treated with pancreatic enzyme replacement therapy. Therefore, it is important to detect pancreatic endocrine insufficiency as early and accurately as possible. Recent studies have shown that cine-dynamic MR cholangiopancreatography (MRCP) may be useful to evaluate pancreatic exocrine function PURPOSE: To identify abdominal symptoms that suggest decreased flow of pancreatic enzyme secretion for which cine-dynamic MRCP should be performed to diagnose pancreatic exocrine insufficiency.

STUDY TYPE

Prospective.

POPULATION

In all, 111 patients with various types of abdominal symptoms.

FIELD STRENGTH/SEQUENCE

5 T or 3 T, MRCP with spatially selective inversion recovery pulse (cine-dynamic MRCP).

ASSESSMENT

Cine-dynamic MRCP was performed and an 18-question clinical questionnaire on abdominal symptoms was administered. The secretion grade derived from cine-dynamic MRCP was compared between those answering "yes" and "no" for all 18 items STATISTICAL TESTS: Univariate analysis and further analyzed using multiple regression analysis. The associations between the secretion grade and the items in the clinical questionnaire were analyzed by univariate analysis and further analyzed using multiple regression analysis.

RESULTS

The following three items showed significantly negative correlations with secretion grade: Q9, Does your rectal gas smell foul? (β = -0.44, P = 0.001); Q13, Is stool quantity large? (β = -0.41, P = 0.001); and Q18, Are your stools soft? (β = -0.53, P < 0.001). No significant correlations with exocrine pancreatic function measured by cine-dynamic MRCP were seen for the remaining 15 abdominal symptom items.

DATA CONCLUSION

Abdominal symptoms that suggest decreased flow of pancreatic enzyme secretion were foul rectal gas, large stool, and soft stool. Pancreatic exocrine insufficiency due to decreased pancreatic enzyme flow may be suspected in patients with these abdominal symptoms.

LEVEL OF EVIDENCE

1 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;50:417-423.