ABSTRACT
PurposeGas is rarely studied or reported to be used as a contrast agent of stomach MRI examination because it might lead to susceptibility artifacts, the purpose of this study is to evaluate the application value of gas as a contrast agent of stomach MRI examination.Materials and Methods Sixty patients who were supposed to have upper abdominal MRI examination were enrolled, all patients were given intramuscular injection of 654-2, gas from oral ingestion of aerogenic powder was used as contrast agent, MRI examinations were then executed and images quality of MRI were analyzed and classified. Results All 60 patients felt it acceptable for the taste of aerogenic powder, only 5 cases felt uncomfortable during swallowing; no adverse reactions were observed in all the 60 cases. Excellent gas contrast medium filling of the stomach cavity were confirmed with CT scanning in 57 cases (95%). Gas acted as a negative contrast agent in the stomach cavity with good continuity and uniform signal; and the proximal part of the stomach and duodenum was well displayed. There were 21 cases (35.0%) classified as grade 0 about their image quality; 25 cases (41.7%) as grade 1; 6 cases (10.0%) as grade 2; 8 cases (13.3%) as grade 3, with total 52 cases (86.7%) with image quality which could meet the requirement of clinical diagnosis. Cases of grade 0-2 showed coronary T2WI images with vivid stomach contour and clear stomach wall with no artifacts; axial FS-T2WI images with few artifacts, relative clear stomach contour and good display of stomach wall; less artifact could be found in axial TIWI image with good display of stomach wall; axial T2WI images showed more artifacts and gastric wall was displayed not clear enough. Cases classified as grade 3 showed coronal T2WI, FS-T2WI, T1WI and T2WI axial images with significant artifacts, vague outline, distortions or ghosting of the contour of stomach and tumor.Conclusion As contrast agent for gastric MRI examination, gas is safe, homogeneously distributed with stable signal characteristic and is easy for patients to tolerate.