关键词: 造影剂, 消化道出血, CT

Abstract: Objective A new type of low density gastrointestinal tract contrast agent is prepared by using simple and easily available materials, so as to realize accurate display and positioning of gastrointestinal bleeding. Methods Using edible whipped cream and xanthan gum as materials, a low density contrast agent was prepared after stirring with a mixer at 160-260 r/min for about 5 minutes at a temperature of about 7 ℃. Then test its stability at different temperatures, observe its uniformity on the CT scan image and measure the CT value, compare its density with the blood clot, and finally use the pig's small intestine, saline bag and plasma mixed with heparin to simulate gastrointestinal bleeding, to compare its display and positioning effect on hemorrhage foci with water, so as to explore the application value of this low-density contrast agent in gastrointestinal hemorrhage. Results The low density contrast agent showed good stability at room temperature （25 ℃） and refrigerator temperature （2 ℃~4 ℃）; the CT scan image showed that its uniformity was relatively high, and the measured CT value ranges -500 to -700 Hu, which is obviously different from the density of blood clot; compared with water, this low density contrast agent has obvious advantages in the display and positioning of hemorrhage foci. Conclusion The gastrointestinal lowdensity contrast agent made of edible whipped cream and xanthan gum has good stability and high uniformity, it can display and locate the hemorrhage foci accurately, so it has an important clinical value for the diagnosis of gastrointestinal bleeding.

Key words: contrast agents, gastrointestinal bleeding, computed tomography