99mTc-labelled Red Blood Cell Scintigraphy Research Articles

Intérêt de l’exploration de l’intestin grêle dans les hémorragies digestives

In France, upper gastrointestinal haemorrhages have an estimated annual incidence of 143cases per 100,000inhabitants. Classically, two types of digestive hemorrhage are described: acute and chronic digestive hemorrhages. Upper endoscopy is carried out in case of hematemesis or melena. It requires that the patient has been fasting for at least 6hours for solids and 3hours for liquids. The main etiologies of hemorrhagic hemorrhage of the origin are the vascular abnormalities, inflammatory or drug-induced ulcerations, intestinal tumors, Meckel's diverticulum, and Dieulafoy ulcer. The modalities of exploration of the small intestine before digestive hemorrhage are the wireless capsule, a reference examination for the exploration of the small intestine, enteroscopy, therapeutic examination, entero-CT or MRI, and 99mTc-labeled red blood cell scintigraphy. In this review, we will discuss the different etiologies of the digestive haemorrhage of intestinal origin and propose a management algorithm.

Watch and wait: Conservative management of lower gastrointestinal bleeding

BackgroundAlthough indications for surgery in lower gastrointestinal bleeding (LGIB) are widely described, practice varies. This study was designed to assess outcomes of patients allowed to exceed traditional triggers for surgery because of LGIB. MethodsThis is a retrospective review of patients at an urban tertiary hospital over a 3-y period that had LGIB necessitating 99mTc-labeled red blood cell scintigraphy. Traditional indications for operative treatment of LGIB were defined as transfusion of >6U of packed red blood cells, hemodynamic instability, bleeding lasting >72h, and rebleeding after cessation of bleeding for >24h. ResultsOne hundred ninety-four LGIB patients had scintigraphy during the period of study with 180 meeting inclusion criteria. Fifty-six (31%) patients had at least one operative indication, and 32 (60%) were managed nonoperatively without a mortality. There were two (8.3%) mortalities in those who had operative management, one of which was because of exsanguination. Eighteen (32%) patients who met operative criteria were unlocalized. ConclusionsPatients with LGIB can be safely managed nonoperatively, even when the bleed is unlocalized and traditional indications for surgery are met. Exsanguinations because of LGIB treated nonoperatively are rare except in patients deemed not to be surgical candidates.

Huge Varicose Inferior Mesenteric Vein: an Unanticipated (99m) Tc-labeled Red Blood Cell Scintigraphy Finding.

Ectopic varices (EcV) are enlarged portosystemic venous collaterals, which usually develop secondary to portal hypertension (PHT). Mesocaval collateral vessels are unusual pathways to decompress the portal system. Here we report the case of a huge varicose inferior mesenteric vein (IMV) that drained into perirectal collateral veins, demonstrated by (99m)Tc-labeled red blood cell (RBC) scintigraphy performed for lower gastrointestinal (GI) bleeding in a 14-year-old girl. This case illustrates the crucial role of (99m)Tc-labeled RBC scintigraphy for the diagnosis of rare ectopic lower GI varices.

Utilidad de la gammagrafía con hematíes marcados en el síndrome de Blue Rubber Bleb Nevus

Blue Rubber Bleb Nevus syndrome is a rare disorder characterized by distinctive cutaneous and gastrointestinal venous malformations that usually cause episodes of occult gastrointestinal haemorrhage and iron deficiency anaemia. We describe an 8-year-old girl who had multiple cutaneous venous malformations since birth. She also suffered from several episodes of severe chronic iron deficiency anaemia and required blood transfusions. To evaluate the presence of gastrointestinal bleeding secondary to intestinal angiomatosis, we decided to perform 99mTc-labelled red blood cell scintigraphy, which confirmed cutaneous venous malformations and also showed gastrointestinal vascular lesions that suggested the diagnosis of Blue Rubber Bleb Nevus Syndrome.

Meckel’s Diverticulum With Recurrent Bleeding Diagnosed by Double-Balloon Enteroscopy

a p w a c n D o 19-year-old woman presented with intermittent rectal bleeding for 6 months. There were 2 episodes of gastrontestinal bleeding associated with syncope 2 months before urrent admission. Physical examination was unremarkable exept for pale conjunctivae. The hemoglobin level was 9.8 g/dL normal range, 12–16 g/dL). Multiple modalities including uper gastrointestinal endoscopy, colonoscopy, enterolysis, aniography, 99mTc-labeled red blood cell scintigraphy, multislice omputerized tomographic scans, and capsule endoscopy were erformed during the previous 6-month period, but no definite leeding lesion was identified. Subsequently, double-balloon nteroscopy was performed and only revealed a wide-mouth iverticulum in the ileum with a polypoid lesion in the blind nd (Figure A). Focal hyperemic mucosa coating with blood on he polypoid lesion indicating recent bleeding also was noted. t laparotomy, a 6.0-cm Meckel’s diverticulum was found in the leum, 65 cm proximal to the ileocecal valve (Figure B). The iverticulum was resected surgically and proven pathologically o have ectopic gastric mucosa in the blind end (Figure C). The atient then was discharged on the 10th day of hospitalization. here was no further episode of bleeding after 1-year of folow-up evaluation. Meckel’s diverticulum is the most common congenital anomly of the gastrointestinal tract and occurs in 1%–3% of the opulation. Approximately half of Meckel’s diverticula is lined ith ectopic gastric mucosa.1 Lower gastrointestinal bleeding is common presentation of Meckel’s diverticulum, especially in hildren. Diagnosis of Meckel’s diverticulum can be made by uclear scan, small-bowel series, or rarely by barium enema. ouble-balloon enteroscopy rarely is used as a diagnostic tool f Meckel’s diverticulum. Our patient, with a 6-month history

Implications of negative technetium 99m–labeled red blood cell scintigraphy in patients presenting with lower gastrointestinal bleeding

Background Lower gastrointestinal (GI) bleeding frequently recurs after negative technetium 99m–labeled red blood cell (RBC) scintigraphy. Methods Between July 1, 1999 and July 31, 2005, 84 negative 99mTc-labeled RBC scintigrams were obtained for acute lower GI bleeding. Medical records were abstracted for age, gender, prior history of lower GI hemorrhage, length of hospitalization, initial hematocrit (Hct) and Hct nadir, transfusion requirements, cause of bleeding, use of anticoagulants and/or antiplatelet medications, and rebleeding episodes. Results The overall rate of rebleeding was 27% (n = 23). There were no significant associations between any of the patient variables investigated and rebleeding. Conclusions Despite negative 99mTc-labeled RBC scintigraphy, more than 25% of patients experience recurrent lower GI bleeding. Patient age, bleeding source, use of anticoagulant/antiplatelet medications, length of stay, admission Hct, Hct nadir, transfusion requirements, and gender are not predictive of the patients who will rebleed.

Enteroscopy as a Tool for Diagnosing Gastrointestinal Bleeding Requiring Blood Transfusion

Iron-deficiency anemia secondary to gastrointestinal blood loss is a common cause of hospitalization. In many cases, the bleeding site cannot be defined despite thorough routine examination of the gastrointestinal tract. The aim of this study was to evaluate push enteroscopy as a diagnostic tool in patients with severe anemia, secondary to recurrent gastrointestinal bleeding, that required management by transfusion. Thirty-five consecutive push enteroscopy investigations were performed in 1998 and 1999 on 25 patients (15 men, 10 women). Mean age was 57 +/- 16 years (range, 33-83). All patients had received blood transfusions because of pronounced anemia secondary to gastrointestinal bleeding. Before push enteroscopy, all patients had been investigated with esophagogastroduodenoscopy, colonoscopy, and small-bowel radiography using the double contrast technique; no bleeding site was found. In addition, 10 of 25 patients had been investigated beforehand with 99mTc-labelled red blood cell scintigraphy, and 5 of 25 with scintigraphy for Meckel diverticulum. Two patients were also investigated with angiography before the push enteroscopy, and in six patients an additional total intraoperative enteroscopy was performed, preceded by a new colonoscopy, esophagogastroduodenoscopy, and push enteroscopy. A bleeding site was disclosed in 15 of 25 (60%) patients. In 7 of 25 patients (28%) the bleeding site was found in the stomach or esophagus. even though the patients had undergone one or two esophagogastroduodenoscopies earlier with normal findings. Total intraoperative enteroscopy identified a bleeding site in four of six (67%) patients studied. Two patients had bleeding hemangiomas that were resected surgically. Two patients had small intestinal adenomas, one with adenocarcinoma in situ. Push enteroscopy performed with an overtube inserted under fluoroscopic guidance is an important diagnostic tool in patients in whom conventional examinations do not disclose bleeding sites. Interestingly, 28% of patients had bleeding within reach of the gastroscope, indicating that a new upper endoscopy should be recommended before push enteroscopy is performed. When no positive findings are seen on push enteroscopy and the patient is affected by severe, recurrent iron-deficiency anemia, total intraoperative enteroscopy should be considered.

Nuclear medicine diagnosis of the liver

Four types of radionuclide investigations are described here: 99mTc-labeled red blood cell scintigraphy, colloid liver scintigraphy, hepatobiliary scintigraphy, and positron emission tomography with [18F]fluorodeoxyglucose. The role of nuclear imaging techniques in the diagnosis of liver diseases has changed in recent years and now compliments morphological imaging modalities by offering the unique ability to visualize function and metabolism. The studies described here are therefore rarely performed now by themselves for the delineation of secondary liver tumors. These radionuclide investigations are used principally to narrow the differential diagnosis of focal liver disease.

Predictive value of technetium Tc 99m-labeled red blood cell scintigraphy for positive angiogram in massive lower gastrointestinal hemorrhage

This study was performed to evaluate whether the time interval from injection of technetium Tc 99m (99mTc)-labeled red blood cells to the time of a radionuclide "blush" (positive scan) can be used to improve the efficacy in predicting a positive angiogram. A retrospective review revealed 160 patients who received 99mTc-labeled red blood cell scintigraphy for evaluation of massive lower gastrointestinal hemorrhage between 1989 and 1994. Patients were included who demonstrated signs of shock on admission, had an initial decrease in hematocrit of > or = 6 percent, or required a minimum transfusion of two units of packed red blood cells. Scanning duration was 90 minutes, with imaging every 2 minutes. Time interval from injection to a positive scan was analyzed to determine predictability of a positive angiography. Of 160 patients, 86 demonstrated positive scans, of whom 47 underwent angiography. These 47 patients were divided into two groups according to scan results. Group 1 (n = 33) had immediate appearance of blush; Group 2 (n = 14) had blush after two minutes. In Group 1, 20 of 33 patients had a positive angiogram, yielding a positive predictive value of 60 percent (P = 0.033). Of the 14 patients with negative angiograms (13 from Group 1, and 1 with a negative scan), 6 had radiographic occlusion of the inferior mesenteric artery and 1 had spasm of the right colic artery, with scans that blushed in the respective distributions. Excluding these seven patients yielded a positive predictive value of 75 percent (P = 0.0072) for angiography. In patients with a delayed blush (Group 2), 13 of 14 had negative angiograms, yielding a negative predictive value of 93 percent (92 percent excluding those with nonvisualization of the inferior mesenteric artery). Twenty of 21 (95 percent) positive angiograms occurred in Group 1 patients. Of the 27 patients with negative angiograms, 13 were Group 2 patients. Patients with immediate blush on 99mTc-labeled red blood cell scintigraphy required urgent angiography. Patients with delayed blush have low angiographic yields. These data suggest that patients with delayed blush or negative scans may be observed and evaluated with colonoscopy.

Technetium-99m-labeled red blood cell imaging

Red blood cells labeled with 99mTc constitute a suitable intravascular agent for imaging of vascular abnormalities. Hemangiomas are characterized by low perfusion and a high blood pool. This "perfusion blood-pool mismatch," not encountered in other lesions, may help in the specific diagnosis of this tumor. This is particularly so in cavernous hemangiomas of the liver where three-phase 99mTc-labeled red blood cell scintigraphy should precede liver biopsy. Red cell scintigraphy also is useful for establishing the vascular nature of hemangiomas of the head and neck and the skin and for diagnosis of venous occlusion. Heat-damaged red blood cells provide a specific spleen imaging agent. This should be used when patients with suspected splenic pathology have equivocal colloid scintigraphy.