Objective To study the appropriate concentration of oral Gadovist solution for improving the image quality of three-dimensional sampling perfection with application optimized contrasts using different flip angle evolutions magnetic resonance cholangiopancreatography(3D-SPACE-MRCP).Methods In vitro experiments,0.05％,0.1％,0.15％and 0.2％Gadovist solution and direct drinking water were put into 100 mL plastic containers respectively for 3D-SPACE-MRCP scanning to measure the signal intensity(SI)of Gadovist solutions in each group.The concentration and the SI of Gadovist solution were analyzed with Spearman correlation,and one-way variance analysis was performed to compare the SI of different concentration Gadovist solutions.In clinical experiments,128 subjects were randomly divided into 4 groups,and then taken orally 300 mL of 0.05％,0.1％,0.15％and 0.2％Gadovist solutions respectively.The 3D-SPACE-MRCP scanning was performed,and the image quality was evaluated by two physicians and compared by one-way variance analysis.Results In vitro experiments,there was an extremely strong negative correlation between the concentration and the SI of Gadovist solution(r=-0.969,P＜0.05),and there were significant differences in the SI among different concentrations of Gadovist solution(P＜0.05).In clinical experiments,among the 26 cases with first-level images,24 cases were distributed in the 0.1％Gadovist solution group.There was a statistically significant difference in image quality of the 3D-SPACE-MRCP with different oral concentrations of Gadovist solution(F=89.57,P＜0.05),however,there was no statistically significant difference between the 0.15％and the 0.2％Gadovist solution groups using the Tukey test(P＞0.05).Conclusion Oral Gadovist solution can significantly improve the images quality of 3D-SPACE-MRCP,and 0.1％solution is the appropriate dilution concentration.

Objective To investigate the effect of magnetic resonance cholangiopancreatography(MRCP)after Gd-BOPTA enhancement to clearly show the pancreaticobiliary duct,and to explore the reasonable time of MRCP examination after enhance-ment.Methods The quality of MRCP images in 124 patients after Gd-BOPTA enhancement was retrospectively evaluated by two physicians.The interval time of MRCP examination from the beginning of arterial phase to MRCP acquisition was obtained from pic-ture archiving and communication system(PACS),and the relationship between the image quality grade of pancreaticobiliary duct and the interval time was analyzed by ANOVA.Then the reasonable examination time of MRCP was calculated.Results After Gd-BOPTA enhancement,there was a significant difference in the interval time between different grades of intrahepatic and extrahepatic bile ducts on MRCP images(P＜0.05).The image quality of bile duct decreased with the increasing interval time,however,there was no sig-nificant difference in the interval time between different grades of pancreatic duct(P＞0.05).The mean interval time of clear grade of intra-hepatic bile duct was(9.9±3.1)min,and the 95％confidence interval(CI)was 9.2-10.6 min.Conclusion The clarity of the bile ducts on MRCP is gradually decreased after Gd-BOPTA enhancement,while no change in that of the pancreatic duct.The MRCP examination should be completed within 10.6 min after the arterial phase beginning,which is of great significance for controlling image quality.