目的　研究小儿消化道出血99Tcm 高锝酸盐异位胃黏膜的显像特征 ,建立美克尔憩室和小肠重复畸形影像学的诊断标准。方法　对 14 1例消化道出血患儿作了99Tcm 高锝酸盐异位胃黏膜显像 ,按 7.4MBq/kg静脉注射99Tcm 高锝酸盐 ,以脐为中心进行动态 17min和静态 30min或 1h的采集。结果　 14 1例患儿中 5 9例显像阳性 ,阳性检出率为 41.84%。 14 1例消化道出血中 ,经手术和病理证实了 48例。其中美克尔憩室 18例 ,形态呈小圆形或近似小圆形 1～ 3cm的异常浓集区。小肠重复畸形 2 2例 ,其中呈条索肠袢状 12例 ,团块状 5例 ,4cm以上大圆形异常浓集区 4例。食管、胃重复畸形 3例。在 48例患儿中 ,假阴性率为 2 .0 8% (小肠重复畸形 1例 ) ,假阳性 5例 ,为 10 .42 %。结论　美克尔憩室与小肠重复畸形在 99Tcm 高锝酸盐异位胃黏膜显像中 ,有特征性影像学表现 Objective To study the imaging characteristics of ectopic gastric mucosa of 99Tcm pertechnetate in children with gastrointestinal hemorrhage and to establish the diagnostic criteria of meikell diverticulum and small intestine deformity. Methods A total of 14 1 cases of gastrointestinal bleeding in children with 99Tcm ectopic gastric mucosa imaging, according to 7.4MBq / kg intravenous 99Tcm pertechnetate, umbilicus dynamic 17min and static 30min or 1h collection. Results In 14 1 cases, 59 cases were positive and the positive rate was 41.84%. Among the 14 cases of gastrointestinal bleeding, 48 cases were confirmed by operation and pathology. Meckel diverticulum in which 18 cases, the shape of a small round or similar small circular 1 ~ 3cm of the abnormal concentration area. There were 22 cases of small intestine deformity, including 12 cases of clavicle shape, 5 cases of clumps and 4 cases of large circular anomalous concentration area. Esophageal and gastric deformities in 3 cases. Among 48 children, the false negative rate was 2.08% (1 case of small bowel deformity) and 5 cases of false positives (10.42%). Conclusions Meckel’s diverticulum and intestinal small intestine deformity in 99Tcm pertechnetate ectopic gastric mucosa imaging, there are characteristic imaging findings