胃肠道出血显像
原理 胃 肠 道 不 显 影 正常 出血 显像
显像剂 99Tcm-SC 肝、脾、骨髓网状内皮摄取 15m后血管中大部分清除 99Tcm-RBC 停留血管中 从胃肠出血部位流入肠腔
显像方法 检查前口服过氯酸钾、胰高血糖素 视野 整个腹腔、盆腔 99Tcm-SC 10mCi 1F/2s，60s。1F/2m，20~30m。延迟 99Tcm-RBC 20~25mCi 1F/2s，60s。1F/5m，30~60m。延迟
图像分析 99Tcm-RBC 正常图像 腹部大血管显影清晰，呈倒Ｙ字形 肝、脾轻度显影，肾脏一过性显影，晚期膀胱显影 异常图像 出血者，病灶区出现局灶性浓集
Case 1 anterior images of the abdomen and pelvis through 50 minutes.
Further anterior images though 90 minutes
Gastric bleed Full history: This is a 70 year old woman, two weeks status post myocardial infarction and LAD stent placement. She was anticoagulated, but the Coumadin was discontinued 4 days ago due to a drop in her hematocrit level. She presents now with blood per rectum and a decreasing hematocrit requiring blood transfusion. Findings: As early as 5 minutes into the study, an abnormal focus of activity is seen in the left upper quadrant. This subsequently increases in both size and intensity, and eventually defines the stomach. Followup: The patient underwent upper endoscopy, where a venous site of hemmorhage was identified in the gastric fundus.
Case 2
胃内应急性溃疡出血 急诊显像: 病史: 男，53岁。左输尿管结石术后10天，出现发热、黑便，呕吐黑色血伴血凝块 急诊手术: 胃体部点状浓聚影并很快扩大到整个胃腔，肠道出现“肠形”，诊断胃内大出血 急诊手术: 胃体部出血灶，胃前壁、后壁浆膜下大面积淤瘢（8cm×10cm） 病史: 男，53岁。左输尿管结石术后10天，出现发热、黑便，呕吐黑色血伴血凝块
临床意义 确定出血部位(灵敏度85~90%) 最低可探测0.1ml/min的出血量 急性出血用99Tcm-SC显像 间歇性出血则用99Tcm-RBC显像 具有无创、简便的特点，常做急诊检查 下消化道出血用放射性核素显像 上消化道出血用内窥镜、选择性动脉造影