PURPOSE: This study aims to evaluate the advantages of administering 200 ml of 5% dextrose water in improving pre-examination training efficiency, examination efficiency, success rate, and image quality of MRI scans in patients with gastric cancer. METHOD: This study included 122 gastric cancer patients who underwent upper abdominal MRI from March 2022 to March 2024. These patients were divided into two groups: a study group of which patients had 200 ml of 5% dextrose water before MRI scan (n = 59) and a control group with only routine preparations (n = 63). Group differences in the pre-examination training efficiency, examination efficiency, examination success rate and image quality of MRI scan were performed using chi-square test and T-test. RESULTS: We found there were statistically significant group differences in the success rate of MRI examination (96.6% in the study group and 85.7% in the control group, P = 0.036), the average time of pre-examination training before MRI examination (7.73 ± 6.35 min in the study group and 12.03 ± 5.39 min in the control group, P = 0.001), the average completion time of MRI examination (45.22 ± 5.85 min in the study group and 50.25 ± 8.45 min in the control group, P = 0.001), the rate of excellent image quality (66.1% in the study group and 44.4% in the control group, P = 0.038), the scores of image quality (3.92 ± 0.96 in the study group and 3.13 ± 1.33 in the control group, P = 0.0006). CONCLUSION: Our findings demonstrated that administering 200 ml of 5% glucose water before MRI examination in gastric cancer patients improved the pre-examination training efficiency, the efficiency and success rate of MRI examination and image quality, highlighting its potential to optimize the patient care in radiological examinations.