The Exploratory Development Of A Self-made Oral Gd-DTPA Solution For Low Field MRCP In Children

Objective: to study in vitro a solution labled with a minimal Gd-DTPA concentration working as a negative gastrointestinal contrast agent in heavrily T2-weighted imaging of low field MRI,and to evaluate the value of ingestion that solution for low field MRCP(0.35T) in children.Methods:Part one: empirical study in vitro. To control study the effect of defferent concentration Dd-DTPA solution working on the signal of fluid, to optimize the contrast concentration. Respectively, 0.2,0.5,1.0,1.5,2.0,2.5,3.0 ml of Omniscan (Dd-DTPA 0.5mmol/ml) were added to seven cups,each filled 250ml warm bolied water. Phantom experiments were performed to select the optimal concentration of Gd-DTPA to be used as an oral negative contrast agent in low field MRCP. Part two: clinical research in vivoTo control evaluate the quality of MRCP image before and after ingestion Gd-DTPA solution in 20 children.20 children suspected of celiac disease were performed with MRCP before and after ingestion Gd-DTPA solution. Signal intensity measurements of gastroduodenal lumens,pancreatobiliary ducts,and image quality scores were obtained systematically before and after contrast ingestion.Results:The in vitro selected Gd-DTPA concentration was 1.992mmol/L(250 ml labeled with 1ml ounaiyin).Ingestion of more than 80ml solution eliminated or suppressed efficiently the gastroduodenal signal intensity, improving the rates of complete visualization of common biliary ducts(P<0.005)and the MRCP image quality scores (P<0.01)significantly in children.All children easily ingested the solution and did not have any complains.Conclusions:1.992mmol/L self-made Gd-DTPA solution was convenient and efficient negative gastrointestinal contrast agent for low field MRCP in children. It can suppress or eliminate wate signals from gastrointestinal tract and improve the quality of low field MRCP image in children.