Direct Visualization of Pancreatic Juice Flow Using Unenhanced MRI With Spin Labeling Can Be Aid in Diagnosing Chronic Pancreatitis

OBJECTIVE. The purpose of this study is to prospectively assess whether direct visualization of pancreatic juice flow using an unenhanced MRI technique with spin labeling can aid in the diagnosis of chronic pancreatitis. SUBJECTS AND METHODS. Ten healthy volunteers and 50 patients who were categorized as having no chronic pancreatitis (n = 11), early chronic pancreatitis (n = 7), or established chronic pancreatitis (n = 32) underwent MRI, including direct pancreatic juice visualization using a flow-out technique with a time-spatial labeling inversion pulse, comprising a nonselective inversion recovery pulse immediately followed by a spatially selective inversion labeling pulse. The mean velocities and volumes of pancreatic juice excretion were also obtained. Variance tests were used to evaluate the clinical groups with respect to the appearance rate and mean velocity; the Kruskal-Wallis test was used for volume. RESULTS. There were no significant differences between healthy volunteers and patients with no chronic pancreatitis. The appearance rate, mean velocity, and volume of pancreatic juice excretion tended to decrease with the degree of chronic pancreatitis. Although the difference in these values was statistically significant between the healthy group and the established chronic pancreatitis group, the values of the early group and other groups were not statistically significant. There was a significant correlation between the appearance rate of pancreatic juice and the clinical groups (tau = -0.4376, p = 0.0015). CONCLUSION. The measurement of directly visualized pancreatic juice flow may aid in establishing the diagnosis of chronic pancreatitis.