核素显像对小儿小肠出血的临床意义
作者：徐彰 陈桧平 卢华君 黄爱芬 胡伟国 徐辉。
【摘要】 目的 探讨放射性核素显像对小儿小肠出血定位及病因诊断的价值。 方法 回顾性分析本科经手术及病理明确病因的31例小肠出血患儿的临床资料。31例术前均经胃镜及肠镜检查未能明确病因而行核素显像检查。先行99mTcO4显像，阴性者再行99mTc—RBC 显像，腹部出现异常放射性核素浓聚为阳性。 结果 31例小肠出血患儿Meckel憩室15例(占48.39%)、小肠重复畸形7例(占22.58%)。31例患儿99mTcO—４显像阳性17例，其中病理发现异常胃黏膜16例；99mTcO—４阴性14例，99mTC—RBC显像阳性9例，其中4例Meckel中有1例病理发现异常胃黏膜。1例Meckcl憩室99mTcO—４显像对异位胃黏膜诊断的灵敏度、特异性分别为93.75%、86.67%，阳性结果时预期值71.43%；99mTcO—４显像对儿童小肠出血的检出率为54.84%，联合99mTc—RBC显像后检出率增至83.87%。 结论 核素显像对小儿小肠出血的定位、定性有重要的指导意义。
【Abstract】 Objective To evaluate the clinical value of radionuclide imaging in children with small intestinal bleeding. Methods 31 cases of small intestinal bleeding were retrospective analyzed, which were identified by operations and pathology. Before operations,99m?TcO4— abdomen dynamic imaging were performed on all patients, those had negativity results underwent farther 99m?Tc—RBC imaging. Results 15 of 31(48.39%)with positivity result cases in 99mTcO4— imaging were found having Meckel diverticulum; 7(22.58%)were found duplication of intestine.17 out of 31 of the patients were positive in 99mTcO4— imaging , 16 of whom were found having ectopic stomach musoca in pathology examination , the other 14 were negative in 99mTcO4— imaging . 9 cases were positive in 99mTc—RBC imaging ,among 4 of whom with Mekel diverticulum ,there was 1 case in which abnormal stomach musoca was found according to pathology examination . The sensitivity and specificity of radio nuclide 99mTcO4— imaging to ectopic stomach musoca were 93.75% and 86.67%, respectively, the expectation value was 71.4% when radio nuclide imaging were positive ;when combined with 99mTc—RBC imaging , the detecting rate improved from 54.84% to 83.87%, compared with using 99mTcO4 imaging alone . Conclusion radionuclide image is a noninvasive and reliable detective method in diagnosis of intestinal bleeding in children.
【Key words】 radionuclide image gastrointestinal bleeding children small intestine。
小肠出血约占整个消化道出血的3%～5%［１］，大量出血可危及患儿生命，需紧急外科手术，而慢性少量出血又常因难以及时准确找到出血部位而延误治疗。近年来，随着医学诊疗技术的飞跃发展，小肠出血的诊断水平不断提高。本文回顾性分析31例小肠出血病例，旨在探讨核素显像对小肠出血病因和定位诊断的意义。
1 资料和方法。
1.1 一般资料。
2000年6月至2005年6月，本院外科收住31例小肠出血患儿，术前均经胃镜及肠镜检查，未能明确病因，后行核素显像检查。31例中，男19例，女12例，年龄9个月～12岁，平均(5.29±3.39)岁。临床症状均有黑便，伴脐周疼痛7例、中上腹轻压痛11例、休克5例、贫血27例。Hb 45～116g/L，平均(72.05±14.19)g/L。重度贫血7例，中度贫血6例，轻度贫血14例。病程6h～3年。
1.2 方法。
核素显像用美国ADAC公司V60型SPECT设备，配置长孔型低能高分辨率准直器(VXGP)。禁食、禁水 6h以上，年龄小不合作的患儿予苯巴比妥肌注。先行异常胃黏膜显像：高锝酸盐（99mTcO—４ ）腹部显像，静脉注射99mTcO—４ ，剂量为9.25mBq/kg体重，立即动态显像，1min 1帧，连续采集30帧，1h行静态显像。99mTcO—４显像阴性者再行锝标记的红细胞(99mTc—RBC)腹部显像：取仰卧位，探头置于腹部，静脉注射焦磷酸盐(PYP) 30min后再注射99mTcO—４ 10mBq/kg体重体内标记红细胞，显像条件5s 1帧，连续采集16帧， 再 3min 1帧，连续采集16帧，1h行静态显像，若为阴性，于 2、4、8、24h分别行延迟显像。
1.3 显像结果判断标准。
2 结果。
2.1 99mTcO—４显像结果。
17例呈阳性，经手术后病理检查证实15例有异位胃黏膜，其中11例为Meckel憩室，4例为小肠重复畸形，未发现异位胃黏膜2例中，1例为血管瘤，另1例小肠套叠。
2.2 联合99mTc—RBC显像结果。
14例99mTcO—４显像为阴性患儿行99mTc—RBC显像，9例显像呈阳性(占64.29%，2h内显像阳性5例，延迟显像阳性4例)，其中Meckel憩室4例，小肠重复畸形3例。1例Meckel憩室发现有异位胃黏膜。显像位置与手术一致5例。
2.3 手术结果。
31手术病理结果：Meckel憩室15例(占48.39%)；小肠重复畸形7例(占22.58%)；血管发育不良4例(12.90%)，血管瘤3例(占9.7%)，小肠套叠、平滑肌瘤各1例(占3.22%)。
3 讨论。
小肠长约3～5 m，迂曲重叠，活动度大，各种传统的检查方法，如胃肠钡剂检查，敏感性、特异性均低。小肠疾病起病多隐匿，没有特异性，小肠出血常是多种小肠疾病的首发症状，定位和病因诊断是治疗的关键［２］。