消化道出血的病灶检出和准确定位对于及时治疗具有重要意义，核素显像作为一种无创、安全、有效的检查方法，可以灵敏地检测出消化道出血病灶，尤其对于纤维胃镜和结肠镜不能到达的小肠、慢性间歇性出血、其他检查未能发现病灶的隐匿性出血具有较大价值和优势。连续减影、动态采集等方法的改进，在一定程度上弥补了核素显像定位精度的不足，而将高分辨率的CT解剖影像与高灵敏度的单光子发射计算机断层成像（SPECT）功能显像融合的SPECT/CT的临床应用，大大提高了核素显像对消化道出血定位的准确性，降低了假阴性及假阳性率。

Radionuclide diagnosis of gastrointestinal hemorrhage  WANG Shao-yan, ZUO Chang-jing. Department of Nuclear Medicine, Changhai Hospital, the Second Military Medical University, Shanghai 200433,China
Corresponding author: ZUO Chang-jing, E-mail：changjing.zuo@gmail.com
Abstract    Sensitive detection and accurate location of the hemorrhagic lesions are very important for the timely treatment of gastrointestinal hemorrhage. As a non-invasive, safe and effective technique, radionuclide imaging can detect gastrointestinal hemorrhage lesions sensitively. It is very useful for the examination of small intestine where gastrofiberscope and colonoscopy can not reach, and the chronic intermittent bleeding or occult bleeding with lesions which other methods failed to detect. Improvement on the methods, such as sequential subtraction scintigraphy and dynamic imaging, has made up for deficiency of  location accuracy of radionuclide imaging to a certain extent. SPECT / CT, with high-resolution anatomical imaging and high-sensitivity function imaging fusion, greatly increased the location accuracy of gastrointestinal hemorrhage and reduced false-negative and false-positive of radionuclide imaging.