sodium-pertechnetate-tc-99m and Colonic-Diseases

Previous studies have demonstrated low yield and conflicting results as to the ability of technetium-99m labeled red blood cell (TRBC) scintigraphy to accurately localize the site of bleeding in acute lower gastrointestinal hemorrhage. Our objective was to evaluate the accuracy of TRBC scintigraphy in clinical day-to-day practice at our institution and to determine predictors of a positive test.. A retrospective medical records review of all patients who underwent TRBC scintigraphy over a 5-year period was conducted at a single academic medical center. The site of bleeding found on TRBC scintigraphy was correlated with the endoscopic, angiographic, surgical, and pathologic findings in each patient.. A total of 127 scans were performed in 115 patients. Forty-nine scans were positive (39%) and 78 were negative (61%). Forty-two patients had further evaluation after a positive scan, and the bleeding site was confirmed to be accurate in 20 of 42 patients (48%). A contradictory bleeding site was found in 5 of 49 positive scans (10%). Patients transfused greater than 2 units of packed red blood cells within 24 hours preceding the TRBC scan were twice as likely to have a positive scan (64%) than those transfused 2 units or less (32%) (P = 0.002). Multivariate analysis demonstrated that the number of units of blood transfused within 24 hours prior to the TRBC scan and the lowest recorded hematocrit were significantly different between patients with positive and negative scans. There was no difference in the rate of endoscopy between patients with a positive or negative scan result.. TRBC scintigraphy has a relatively low yield in the evaluation of acute lower gastrointestinal bleeding. Objective selection criteria such as number of units of packed red blood cells transfused prior to obtaining the scan may increase the overall yield.

Topics: Acute Disease; Colonic Diseases; Erythrocytes; Gastrointestinal Hemorrhage; Humans; Multivariate Analysis; Predictive Value of Tests; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Retrospective Studies; Sodium Pertechnetate Tc 99m

Endoscopy and, occasionally, X-ray studies are used to discover the focus of a gastrointestinal bleeding.. We describe a case of severe gastrointestinal bleeding where these methods failed. Scintigraphy after labelling of erythrocytes with 99m technetium was performed in a continuous manner for 60 minutes. Scintigrams were also taken three, ten and 23 hours after the injection.. No bleeding was revealed after 60 minutes, but two hours later a slight radioactivity was encountered in the right part of the abdomen and the later images localised the bleeding to the right colon. The bleeding ceased after right-sided hemicolectomy.. Scintigraphy is of value in localisation of gastrointestinal bleeding and should be performed in a continuous manner until the bleeding focus is localised. Secretion of unbound technetium through the mucosa of the stomach and its presence in the urinary tract should be taken in account.

Topics: Aged; Colonic Diseases; Female; Gastrointestinal Hemorrhage; Humans; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

99mTc red blood cell scintigraphy is a non invasive diagnostic method for low flow gastrointestinal bleeding.. To assess the diagnostic yield of this method in patients admitted with gastrointestinal bleeding in whom upper gastrointestinal endoscopy was negative.. The clinical records of 59 patients, aged 6 to 90 years old (35 male), with active gastrointestinal bleeding subjected to a 99mTc red blood cell scintigraphy were reviewed. All had non diagnostic upper gastrointestinal endoscopic studies, and in 20 a selective arteriography was performed.. In 40 patients the scintigraphy was positive for gastrointestinal bleeding, and in 57% of these the exam was positive during the first hour. Fifteen of the 19 patients with a negative scintigraphy did not have an active clinical bleeding at the moment of the examination. In 24 patients, a final etiological diagnosis was reached. In 93% of these patients scintigraphy correctly identified the bleeding site. In one patient with a negative scintigraphy, angiography disclosed a pseudo aneurysm of the splenic artery that was not bleeding actively.. In these patients with negative upper gastrointestinal endoscopy 99mTc red blood cell scintigraphy had a 91% sensitivity for the diagnosis of active gastrointestinal bleeding.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Colonic Diseases; Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Intestine, Small; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Retrospective Studies; Sodium Pertechnetate Tc 99m

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.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Algorithms; Angiography; Colonic Diseases; Colonoscopy; Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Time Factors

Radionuclide scintigraphy is commonly utilized as a screening examination before performing more invasive procedures in the work-up of patients with lower gastrointestinal (GI) bleeding. We reviewed our institutional experience with technetium-labelled red blood cell scintigraphy (TRCS) in detecting and localising acute lower GI bleeding. The study group included 72 patients who had 80 red cells scans over a five year period. Thirty-eight scans were positive (47.5%), and 42 were negative (52.5%). Sites of lower GI bleeding were confirmed by endoscopy, arteriography, surgery and/or pathology in 22 of the 38 positive scans. There were four false-negative scans (9.5%). The overall sensitivity and specificity of TRCS in detecting lower GI bleeding was 84.6% (22/26) and 70.4% (38/54), respectively. The accuracy of localization of bleeding sites in the patients with confirmed positive scans was 72.7% (16/22). Thirty mesenteric arteriograms were performed on patients in this series. Eleven arteriograms were performed after negative TRCS; one was positive. Technetium-labelled red blood cell scintigraphy appears to be a useful screening examination for patients with lower GI bleeding who are hemodynamically stable. This may avoid the potential morbidity of arteriography in patients who are not actively bleeding.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Colonic Diseases; Erythrocytes; False Negative Reactions; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Radionuclide Imaging; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pyrophosphate; Time Factors; Tin Polyphosphates

Topics: Aged; Aged, 80 and over; Angiodysplasia; Colon; Colonic Diseases; Diagnosis, Differential; Erythrocytes; Gastrointestinal Hemorrhage; Humans; Male; Radiography; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

To evaluate the success of technetium-99m-labeled red blood cell scintigraphy in localizing the site of gastrointestinal bleeding, and to identify the clinical and technical factors that contribute to scan accuracy.. A retrospective review was conducted of all patients who underwent a tagged red blood cell scan for the evaluation of gastrointestinal bleeding at our institution from 1981 to 1991.. Of a total of 153 patients, 90 (59%) had positive scans, whereas, in 63 (41%), they were negative. Of the 90 patients who had positive scans, it was possible to assess scan accuracy in 44 who had corrective surgery or an additional diagnostic procedure which definitively localized the site of bleeding. Of those 44 patients, the correct bleeding site was identified by red blood cell scanning in 33 patients (75%) overall and in all six patients with a left colon bleeding site. In this group of 44 patients, 22 scans were positive within 2 h, and of these the scan was accurate in localizing the bleeding site in 19 of 22 (86%). When the three subjects with upper gastrointestinal bleeding were excluded, the scan was positive in 100% of the remaining 19 patients.. The technetium-labeled red blood cell scan is a reliable tool for the assessment of unexplained lower gastrointestinal bleeding when the scan is positive within the first 2 h, and an upper gastrointestinal source has already been excluded.

Topics: Aged; Colonic Diseases; Erythrocytes; Evaluation Studies as Topic; Female; Gastrointestinal Hemorrhage; Humans; Intestine, Small; Male; Radionuclide Imaging; Retrospective Studies; Sodium Pertechnetate Tc 99m

In cases of severe colon bleeding, it is more important to know the site than the cause, in case surgery is required. Technetium-labeled red-cell scan (TLRCS) is known to identify the site of bleeding at the rate of 0.1 ml per minute or more. The aim of this retrospective study was to see whether TLRCS was a reliable indicator of the site of severe colon bleeding. A retrospective study was made of patients investigated in this way for acute, severe colon bleeding at St. Vincent's Hospital, Melbourne, from 1984 to 1988 (five years). TLRCS identified the site of bleeding in less than half of the cases but correctly identified the site in all nine patients in whom bleeding was so severe as to require emergency surgery, avoiding total colectomy in eight cases.

Topics: Aged; Aged, 80 and over; Colonic Diseases; Emergencies; Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Radionuclide Imaging; Retrospective Studies; Sodium Pertechnetate Tc 99m

99mTechnetium-labelled red blood cell scintigraphy (99mTc RBC scintigraphy) was used as the second-line investigation to localise bleeding in 23 patients (11 male, 12 female; mean age 67 years) presenting with active bleeding per rectum. Scintigraphy was available on a 24 h basis. A total of 18 patients had positive scans (78%). Surgery was performed urgently in 11 patients and the site of bleeding, as predicted by scintigraphy, was confirmed in 9 (82%). 99mTc RBC scintigraphy was less useful in patients who were not bleeding actively or who were being investigated for chronic anaemia. This study suggests that 99mTc RBC scintigraphy can play a useful role in the preoperative localisation of unexplained gastrointestinal bleeding in hospitals with nuclear medicine facilities, but confirms it has little place in the management of patients unless they are bleeding actively.

Topics: Adult; Aged; Aged, 80 and over; Anemia, Hypochromic; Cecal Diseases; Colonic Diseases; Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The use of perchlorate to block gastric uptake of free 99Tcm-pertechnetate after in vivo labelling of red cells was investigated. In 19 out of 20 cases there was no evidence that previous administration of perchlorate adversely affected red cell labelling using commercial stannous agents. Adequate scintigraphic images of the vascular system could be obtained for up to 24 h after the cells were labelled. The technique was found to be of value in the investigation of sites of gastrointestinal bleeding.

Topics: Colon; Colonic Diseases; Erythrocytes; Esophageal and Gastric Varices; Female; Gastrointestinal Hemorrhage; Humans; Male; Perchlorates; Radionuclide Imaging; Sodium Compounds; Sodium Pertechnetate Tc 99m; Stomach

Localization of colorectal bleeding using a gamma camera was attempted in a prospective study of 24 patients after in-vivo labelling of their erythrocytes with 99mTc-pertechnetate. In 7 of 8 patients with bright-red rectal bleeding a correct localization was given by scintiphotos, thus helping the surgeon to plan the operative procedure. Of 11 patients with recently acute colorectal bleeding but no signs of actual haemorrhage, 8 had no scintigraphic bleeding. Five investigations had to be excluded due to technical errors. The scintigraphic classification was correct in a significant number of patients (p less than 0.02). It is concluded that bleeding can be identified in colorectum at brisk-haemorrhagic stools and be correctly localized to the right or left side of the colon. This non-invasive scintigraphic procedure should therefore be undertaken before an abdominal 2-3 vessel arteriography is performed.

Topics: Colonic Diseases; Erythrocytes; Gastrointestinal Hemorrhage; Humans; Prospective Studies; Radionuclide Imaging; Rectal Diseases; Sodium Pertechnetate Tc 99m; Technetium