99Tcm-RBC显像诊断小肠出血

目的　探讨99Tcm RBC显像诊断小肠出血的临床价值。方法　对 6 4例小肠出血患者行99Tcm RBC显像并与病理检查结果进行比较。结果　99Tcm RBC显像诊断小肠出血阳性率 95 .3% ,定位诊断率 84.4% ,特异性 88.5 %。结论　增加捕捉时机是提高99Tcm RBC显像定位诊断小肠出血的有效方法。     

改良99Tcm-RBC显像对下消化道出血的定位诊断价值

目的探讨改良99Tcm-RBC显像对下消化道出血的定位诊断价值.方法常规静脉注射示踪剂,矩形探头取全腹部视野.待腹部出现异常放射性浓聚后,用核素在体表标记出血区,结合口服99TcmO-4 液,密切观察99TcmO-4 峰通过肠腔的情况和99TcmO-4 峰与异常放射性浓聚区的融合时间,必要时加侧位观察.结果 18例改良99Tcm-RBC显像中,5例小肠出血患者99TcmO-4 前峰迅速覆盖标记区内异常放射性浓聚灶,融合时间平均为(38.4±12.5) min;13例结肠出血患者可见顺次显示空回肠各部直至回盲部, 融合时间平均为(98.7±31.6) min.结论以99TcmO-4 峰融合时间60 min为参考标准,可区分大小肠出血,再结合观察回盲部显像位置初步确定出血位置.改良99Tcm-RBC显像较常规99Tcm-RBC显像对下消化道出血定位诊断有一定优势.     

Hawkeye VG型SPECT/CT融合显像在下消化道出血定位中的临床应用

目的 利用99Tcm体内标记RBC法,探讨Hawkeye VG型SPECT/CT融合显像在下消化道出血定位诊断中的临床应用价值.方法 回顾性分析56例确诊下消化道出血的患者资料,其中男42例,女14例,年龄10～ 76岁.采用体内标记法标记RBC,剖腹探查术前静脉注射99TcmO4-洗脱液370 MBq后即刻行下腹部平面显像,随后在同一床位行SPECT和CT扫描,并进行图像融合处理.分析图像,进行下消化道出血的定位诊断.x2检验分析平面显像与SPECT/CT融合显像的诊断灵敏度与定位准确性间的差异.结果 56例患者中,平面显像和融合显像示下腹部有放射性异常浓聚灶者分别为50例和52例.2种显像方法各有42例和52例完成出血定位诊断,其中平面显像有31例,融合显像有48例定位与手术探查出血点一致.2种显像方法诊断灵敏度分别为89.3％(50/56)和92.9％ (52/56),差异无统计学意义(x2=0.11,P＞0.05);定位准确性分别为73.8％ (31/42)和92.3％ (48/52),两者差异有统计学意义(x2=4.63,P＜0.05).结论 Hawkeye VG型SPECT/CT融合显像是一种灵敏、简便、准确的下消化道出血定位检查方法.     

99Tcm-RBC连续减影显像诊断消化道出血的临床价值

目的 评价^99Tc^m-RBC连续减影显像诊断消化道出血的临床价值。方法 对92例疑诊消化道出血患者行^99Tc^m体内标记RBC消化道出血显像。5min／帧，连续采集60min，得到12帧常规非减影图像(CNS)，用计算机以t 5min为时间轴对其作连续减影处理，得到11帧减影图像(SSS)。若早期显像结果为阴性或疑有再出血时行3，6或24h延迟显像。比较SSS和CNS的定性及定位诊断效能。结果图像以30，60min及24h内3个时间段进行分析。SSS的灵敏度分别为87．1％(30min)和91．9％(60min)，明显高于CNS的56．4％(30min)和62．9％(60min)。24h延迟显像CNS的灵敏度增至85．4％。两种方法的特异性无明显差异。SSS的定位诊断符合率为92．8％，明显高于CNS的73．8％。结论 ^99Tc^m-RBC连续减影显像较常规非减影显像能更早期、更准确地对微量消化道出血作出定性定位诊断。     

异位胃黏膜核素显像对小儿下消化道出血的诊断

目的研究放射性核素异位胃黏膜显像在小儿下消化道出血中的显像特征及临床诊断价值。方法应用99Tcm-高得酸盐(99TcmO4-)对57例患儿分别进行了多时相(动态、30min及60min静态)显像。结果57例患儿中异位胃黏膜显像阳性39例。44例进行了手术治疗,其中Meckel’s憩室29例,影像特征呈小圆形或类圆形异常核素浓聚灶,常位于右下腹或脐周围,位置固定;肠重复畸形8例,影像特征呈肠袢形或大团块状异常核素浓聚影,不规则。假阳性2例(4.55%),假阴性3例(6.82%)。结论放射性核素的特征性影像可为异位胃黏膜所致的下消化道出血患儿提供可靠的病因和定位诊断。     

^99Tc^m—RBC显像诊断小肠出血

目的：探讨^99Tc^m-RBC显像诊断小肠出血的临床价值。方法：对64例小肠出血患者行^99Tc^m-RBC显像并与病理检查结果进行比较。结果：^99Tc^m-RBC显像诊断小肠出血阳性率95．3％，定位诊断率84．4A％，特异性88．5％。结论增加捕捉时机是提高^99Tc^m-RBC显像定位诊断小肠出血的有效方法。     

美克尔憩室核素显像与临床特征相关性分析

目的：研究99mTc-高锝酸盐（99cmTcO4^-）异位胃黏膜显像特点与临床特征之间的相关性。方法：观察MD异位胃黏膜患者，行99cmTcO4^-显像与手术后病理诊断的符合率，核素扫描特征与临床特征，并用Pearson相关分析法进行分析。结果：MD异位胃黏膜患者消化道出血临床严重程度与病检中憩室合并溃疡、出血率密切相关（rp=0．68，P〈0．01），与核素扫描中异位胃黏膜最大直径显像时间明显负相关（rp=-0．57，P〈O．05），与核素扫描中异位胃黏膜显像的最大直径无明显相关（rp=0．32，P〉0．05）。结论：99cmTcO4^-显像诊断MD异位胃黏膜的敏感性高、阳性预测值强。憩室黏膜溃疡、出血可能是导致MD异位胃黏膜患者发生消化道出血的重要原因。     

SPECT显像诊断小儿Meckel''s憩室并出血

目的 :评价SPECT显像在美克耳憩室并出血诊断中的价值。材料和方法 :对 17例疑为美克耳憩室并出血的患儿进行了高锝酸盐 (99mTcO4- )腹部平面显像 ,2例作了断层显像。结果 :阴性显像 6例 ,5例经临床表现及相关检查排除美克耳憩室 ,1例经手术证实为美克耳憩室。阳性显像 11例 ,9例经手术及病理证实为美克耳憩室 ,1例为空肠及其系膜巨大海绵状血管瘤 ,1例为回肠管状重复畸形。SPECT显像对美克耳憩室诊断的敏感性、特异性和准确性分别为 90 .0 %、71.4%和 82 .4%。结论 :SPECT显像简单易行 ,是诊断美克耳憩室并出血的首选影像学方法 ,加采断层显像可以提高敏感性。     

胃肠出血核素显像的近况

大多数上消化道出血由内窥镜定位,而下消化道活动性出血,尤其是小肠出血,核素显像及血管造影具有重要诊断作用。本文主要介绍近年来核素显像在胃肠出血诊断方面的运用,包括出血原因、显像剂种类和检查方法的选择、显像表现、临床意义、敏感性、特异性、准确性、假阴性、假阳性,并与其它影像学手段作对比。     

99mTc-MIBI显像及CT对原发性甲状旁腺机能亢进症的诊断价值

目的:评价99mTc-甲氧基异丁基异腈(MIBI)显像及CT在原发性甲状旁腺机能亢进症(PHPT)的临床诊断价值。方法:38例拟诊PHPT患者进行了99mTc-MIBI显像,其中33例同期进行CT检查,并与临床诊断结果进行对比分析和评价。结果:38例中有31例确诊为PHPT,其中甲状旁腺腺瘤29例(包括异位瘤2例),甲状旁腺增生2例,99mTc-MIBI显像诊断敏感性为90.3%,特异性为100%,准确性为92.11%,CT诊断敏感性为57.17%,特异性100%,准确性为63.63%,99mTc-MIBI显像与CT比较差异有显著性意义(P<0.05)。结论:99mTc-MIBI显像作为功能显像在诊断PHPT方面优于CT,是术前定位的重要方法。     

Localization of small bowel bleeding by arterial injection of Tc-99m-labeled RBC

A 79-year-old man with melena was suspected of having small bowel bleeding because upper and lower endoscopic findings were negative. Technetium-99m-labeled red blood cell (Tc-99m-RBC) scintigraphy was performed by arterial injection of a radiotracer from the superior mesenteric artery (SMA) after angiography. Extravasation was seen in the ileum by scintigraphy although angiography was negative. Scintigram 2 minutes after arterial injection was consistent with the late capillary phase of balloon occluded angiography. This comparison provided a better anatomical distinction. Tc-99m-RBC scintigraphy by arterial injection through the SMA identified the bleeding site in the small bowel more accurately than conventional intravenous Tc-99m-RBC scintigraphy.     

Gastrointestinal bleeding from capillary hemangioma of the ileum detected by 99mTc-HSAD scintigraphy]

It has been well-known that technetium-99m-human serum albumin-diethylenetriaminepenta-acetic acid (99mTc-HSAD) scintigraphy is useful for diagnosis of the localization of the gastrointestinal arterial or venous bleeding. In this report, we describe a case of venous bleeding from capillary hemangioma of the ileum end detected by 99mTc-HSAD scintigraphy. This patient was a 9-year-old girl with severe anemia. Gastrointestinal bleeding was suspected from her clinical course and laboratory tests. Immediately after melena occurred, 99mTc-HSAD scintigraphy showed the extravasation of RI suggesting gastrointestinal bleeding in the ileum end. Abdominal angiography immediately after 99mTc-HSAD scintigraphy, however, could not show the extravasation of contrast agent. Because the condition of the patient became worse, laparotomy was performed on the basis of 99mTc-HSAD scintigraphy findings. At surgery, venous bleeding from capillary hemangioma in the ileum end was observed. It was suggested that 99mTc-HSAD scintigraphy was very useful for identifying the gastrointestinal venous bleeding.     

Glucagon in the scintigraphic diagnosis of small-bowel hemorrhage by Tc- 99m-labeled red blood cells

Twelve patients undergoing scintigraphy with Tc-99m-labeled red blood cells (RBC) exhibited abnormal small-bowel activity and were given glucagon to assess its role in detecting bleeding from the small bowel. Six demonstrated focal accumulation of activity which was not identified prior to glucagon. Endoscopy, barium studies, angiography, and colonoscopy located the small-bowel bleeding site in 4 patients; in the other 2, studies of the colon failed to show the bleeding site and the origin was presumed to be the small bowel. The authors suggest that intravenous glucagon can be beneficial as an adjuvant to Tc-99m-RBC when diagnosing bleeding from the small bowel.     

Scintigraphic diagnosis of gastrointestinal bleeding with 99mTc-labeled blood-pool agents

Abdominal scintigraphy with 99mTc-labeled albumin or red blood cells was used in 68 patients to localize gastrointestinal bleeding or confirm that it had stopped. Acute, active bleeding was identified in 33 patients; characteristic patterns of bleeding from the stomach, biliary passages, small intestine, and colon are shown. Sensitivity was 0.86 (95% confidence limits, 0.57-0.98) and specificity was 1.0 (95% confidence limits, 0.82-1.0) in 33 patients who had scintigraphy and endoscopy performed in succession. Abdominal scintigraphy appears to be a valuable supplement to conventional diagnostic methods. In upper gastrointestinal bleeding, scintigraphy should be considered when endoscopy fails. In lower intestinal bleeding, scintigraphy should be the method of choice.     

Meckel's diverticulum findings on Tc-99m red blood cell scintigraphy in a bleeding leukemic patient confirmed by Tc-99m pertechnetate scintigraphy

A 25-year-old Caucasian woman with a medical history of acute promyelocytic leukemia presented to the emergency department with massive gastrointestinal bleeding. A bone marrow biopsy excluded hemorrhagic leukemia. Esophagogastroduodenoscopy, colonoscopy, emergency abdominal angiography, abdominal CT scan, and wireless capsule endoscopy were performed but no source of bleeding could be detected. Tc-99m RBC scintigraphy was consistent with a small bowel bleeding focus. The persistent and focal images in the right abdomen were suggestive of Tc-99m RBC trapping in the lumen of a Meckel diverticulum (MD). In accordance with this suspicion, successive Tc-99m pertechnetate scintigraphy was performed after 3 days, consistent with the diagnostic hypothesis. Due to the persisting severe bleeding (with a drop in baseline hemoglobin from 10.4 to 7.1 g/dL), despite 8 units of blood transfusion, emergency surgery was performed. Through a minilaparotomy a segmental small bowel resection, including Meckel diverticulum, was performed. The postoperative course was uneventful.     

A case of cavernous hemangioma of the small intestine diagnosed by scintigraphy with Tc-99m-labeled red blood cells

Hemangioma of the small intestine is rare, and the preoperative diagnosis of it is difficult. We report a patient with gastrointestinal bleeding for whom Tc-99m-labeled red blood cell scintigraphy was useful in diagnosing cavernous hemangioma of the small intestine. A 25-year-old man was referred to our hospital for recurrent iron deficiency anemia. Because of the patient's severe anemia, imaging was performed to locate the bleeding lesion in the gastrointestinal tract. Scintigraphy with Tc-99m-labeled red blood cells revealed pooling indicating a tumor and extravasation of blood from the tumor. Scintigraphy with Tc-99m pertechnetate revealed no abnormal accumulation. Partial resection of the small intestine was done, and cavernous hemangioma of the small intestine was diagnosed by using the specimen of resected tissue.     

MRI versus scintigraphy with 99mTc-HMPAO-labelled granulocytes in the diagnosis of bone infection

PURPOSE: To assess the reliability of MRI and scintigraphy with 99mTc-HMPAO-labelled granulocytes in the diagnosis of bone infection. MATERIALS AND METHODS: Between November 2001 and November 2003, 25 patients (16 men and 9 women; age range 22-72 years; mean age 48 years) with suspected bone infection were evaluated. The lower limbs were more frequently involved (20/25 cases). MRI (T1 and T2-w sequences, both with and without fat suppression; T1-w fat-suppressed sequence after Gadolinium administration) and scintigraphy with 99mTc-HMPAO-labelled granulocytes were performed in all patients; the study was performed 30 min, 150 min and 24 h after the injection of 99mTc labelled autologous granulocytes. The maximum interval between MRI and scintigraphy was 15 days. The diagnosis was confirmed surgically (18/25 cases) or by clinical follow-up (7/25 cases). RESULTS: In 10/25 cases the clinical suspicion of bone infection was confirmed by MRI, scintigraphy and surgery. In 12/25 cases the clinical suspicion of bone infection was not confirmed either by imaging, surgery (5/12 cases) or follow-up (7/12 cases). In 3/25 cases the results were discordant: in 1/3 cases with chronic osteomyelitis confirmed by MRI and surgery, a false-negative diagnosis was made by scintigraphy. In 2/3 cases with negative MRI diagnoses confirmed by surgery, a false-positive diagnosis was made by scintigraphy owing to the infection of adjacent soft tissues. CONCLUSIONS: MRI is more reliable for the detection and evaluation of the local spread of bone infection. Conversely, when metallic devices causing artefacts on MR images are present, scintigraphy is the preferred alternative modality.     

Small bowel metastases from primary carcinoma of the lung: Presenting with gastrointestinal hemorrhage

Upper gastrointestinal system bleeding should be first taken into account when a patient complains of melena. On rare occasions, gastrointestinal bleeding may be due to primary or metastatic tumors of the gastrointestinal system. Here, we present a case in which the localization of bleeding was demonstrated by Tc-99m red blood cell labeled scintigraphy with the final diagnosis of metastases of non-small cell lung cancer to the small bowel.