technetium-tc-99m-pyrophosphate and Gastrointestinal-Hemorrhage

Massive lower gastrointestinal bleeding is described in two patients with Crohn's disease. In case 1, extravasation of contrast material from the ileal branch of the ileocolic artery was seen during selective angiography. In case 2, results of an in vitro labeled 99Tc pyrophosphate red blood cell scan localized bleeding to the ileum. In both cases, medical management was unsuccessful, and surgical resection of the affected bowel was required to stop the bleeding. Angiographic appearance of Crohn's disease is discussed, and a review of the literature of this unusual feature of Crohn's disease is presented.

Topics: Adult; Angiography; Cecum; Crohn Disease; Diphosphates; Extravasation of Diagnostic and Therapeutic Materials; Female; Gastrointestinal Hemorrhage; Humans; Ileitis; Ileum; Male; Radionuclide Imaging; Recurrence; Technetium; Technetium Tc 99m Pyrophosphate

Both in vivo and in vitro red cell labeling methods are available for performing gastrointestinal bleeding studies. While in vitro labeling has been shown to result in higher binding efficiency, no comparison of clinical image quality has been reported between those techniques. This study compares in vivo and in vitro methods using both subjective and objective measurements of image quality.. A consecutive series of gastrointestinal bleeding studies performed on 23 patients using in vivo labeling was compared to a series of 23 studies using in vitro labeling. Images at 30 min postinjection were randomized and analyzed by two observers. Subjective evaluation of image quality, as well as renal activity, was based on a comparison of femoral vein and inferior vena cava activity to adjacent background using numerical scores with a scale of 0-3. Image quality using the subjective scores was further classified as acceptable and poor. Target-to-background measurements of femoral vein to adjacent soft tissue in the thigh and inferior vena cava to adjacent abdominal background also were made.. In vitro label subjective image quality was acceptable in 87% and 91% of cases for vascular and renal activity, respectively, but only 35% and 52% for in vivo labeling. In vitro label target-to-background ratios were significantly better than in vivo label for the femoral vein and inferior vena cava, as well as for the subjective assessment of vascular image quality, but not for renal activity.. In vitro red cell labeling improves clinical image quality as compared with in vivo labeling. Both subjective and objective measurements of image quality are useful for comparing the results of labeling methods.

Topics: Abdomen; Erythrocytes; Femoral Vein; Gastrointestinal Hemorrhage; Humans; Image Enhancement; Information Storage and Retrieval; Kidney; Observer Variation; Radionuclide Imaging; Radiopharmaceuticals; Retrospective Studies; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pyrophosphate; Thigh; Vena Cava, Inferior

Topics: Aged; Diagnosis, Differential; Erythrocytes; Gastrointestinal Hemorrhage; Humans; Ileal Neoplasms; Ileum; Liver Neoplasms; Male; Neuroendocrine Tumors; Radionuclide Imaging; Technetium Tc 99m Pyrophosphate

Intravenously administered dextran is used clinically as a plasma expander. The aim of this study was to assess the use of 99Tcm-dextran in the diagnosis of gastrointestinal (GI) blood leaks. Twenty-one patients with GI blood loss underwent 99Tcm-dextran scintigraphy, 17 of whom were found to be positive. Pathologic or 99Tcm-RBC (red blood cell) blood pool correlation was possible in 15 cases, while 2 were unconfirmed. No case had a positive 99Tcm-RBC blood pool study and a negative 99Tcm-dextran study. Images obtained with 99Tcm-dextran were generally better than those with 99Tcm-RBC. This agent may have several other advantages over 99Tcm-RBC blood pool and 99Tcm-sulphur colloid scintigraphy for detecting GI blood loss.

Topics: Adult; Dextrans; Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Occult Blood; Organotechnetium Compounds; Radionuclide Imaging; Reference Values; Reproducibility of Results; Technetium Tc 99m Pyrophosphate; Technetium Tc 99m Sulfur Colloid

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

Both labeled RBC and Meckel's scans have been used to evaluate pediatric patients with gastrointestinal bleeding, sometimes sequentially in the same patient. Particularly in infants, from whom withdrawal of sufficient blood for in vitro RBC labeling is often not possible, in vivo labeling with stannous pyrophosphate is used. However, prior administration of stannous-containing agents is known to alter the in vivo distribution of Tc-99m pertechnetate and to interfere with the subsequent Meckel's scan. The authors report on a Meckel's scan performed on an infant 1 week after a GI bleeding study with Tc-99m and stannous pyrophosphate. The Meckel's scan shows abnormal tracer distribution with absent gastric uptake, rendering the scan uninterpretable. In pediatric patients with gastrointestinal bleeding, a Meckel's scan should be done before labeled RBC imaging.

Topics: Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Infant, Newborn; Meckel Diverticulum; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates

Topics: Female; Gastrointestinal Hemorrhage; Humans; Middle Aged; Omentum; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates; Varicose Veins

A technetium-99m labelled red blood cell scintigraphy was performed in 51 patients with an unexplained gastro intestinal bleeding. Static images were acquired on the injection day then at 24 hours. Forty one patients had a positive scintigraphy. In 13 patients with a positive scintigraphy, on the injection day (5 cases) and later (8 cases), no intestinal bleeding was identified in spite of further investigations guided by scintigraphy. In 24 patients, with a positive scintigraphy on the injection day (20 cases) and later (4 cases), an intestinal lesion was identified and treated; data were confirmed in 19 cases: there were 15 colon lesions, localized on caecum in 10 cases and 4 small bowel lesions. Clinical value and limitations of the investigation are discussed. The scintigraphic localization is usually accurate if the abnormal focus activity is noticed on the injection day. It helps to guide further investigations of the bleeding site. This non invasive method should be performed more quickly to help to localize intestinal bleeding which poses a diagnostic problem.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anemia, Hypochromic; Child; Child, Preschool; Diverticulum, Colon; Duodenal Ulcer; Gastrointestinal Hemorrhage; Humans; Infant; Intestinal Diseases; Intestinal Neoplasms; Intestinal Polyps; Middle Aged; Peptic Ulcer Hemorrhage; Radionuclide Imaging; Technetium Tc 99m Pyrophosphate; Ulcer

Radionuclide imaging for the detection and localization of gastrointestinal bleeding is a highly sensitive and well-established clinical tool. 99Tcm-labelled erythrocytes have permitted the recognition of intermittent bleeding up to 24 h following injection. However, free pertechnetate is actively secreted by gastric mucosa and can result in confounding gut activity. The possibility that pertechnetate may elute from the radiolabelled erythrocytes was investigated in an in vitro model. Blood samples from five subjects undergoing gated cardiac studies were labelled by modified in vivo, modified in vitro and pure in vitro methods and then incubated in serum for 24 h. Automated cell counts and instant thin layer chromatography were used to measure the physical and radiochemical stability of the labelled erythrocytes. No detectable haemolysis occurred and no free pertechnetate was released from the cells. However, an unexpected hydrophilic 99Tcm species became detectable in the supernatant with a quantitative index which increased from an initial value of 0.016 +/- 0.004 to 0.079 +/- 0.012 at 24 h (P less than 0.00001). This index did not differ among the three labelling methods. A chromatographically similar material was identified in the urine of a patient undergoing a gastrointestinal bleed study. The possibility of gut and/or hepatobiliary secretion of this material needs further clarification before delayed positive studies can be relied upon to indicate gastrointestinal bleeding.

Topics: Erythrocytes; Gastrointestinal Hemorrhage; Humans; In Vitro Techniques; Isotope Labeling; Radionuclide Imaging; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates

Topics: Adult; Colonic Diseases; Diphosphates; Erythrocytes; Factitious Disorders; Female; Gastrointestinal Hemorrhage; Humans; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

We report on three cases of intestinal bleeding detected by nuclear imaging using 99mTc pyrophosphate in vivo-labelled red blood cells.

Topics: Aged; Aged, 80 and over; Diagnosis, Differential; Diagnostic Imaging; Diphosphates; Female; Gastrointestinal Hemorrhage; Hemangioma; Humans; Ileal Neoplasms; Meckel Diverticulum; Mesenteric Arteries; Radiography; Sigmoid Neoplasms; Subtraction Technique; Technetium; Technetium Tc 99m Pyrophosphate

Nearly three-quarters of patients on long-term treatment with non-steroidal anti-inflammatory drugs (NSAIDs) have small-intestinal inflammation, the consequences of which are largely unknown. Two potentially important complications, blood and protein loss from the small intestine, have been studied. 49 patients on NSAIDs underwent study with an indium-111 labelled leucocyte technique which localises and measures intestinal inflammation. 32 patients underwent simultaneous study with technetium-99m labelled red blood cells (RBC), which showed identical sites of localisation to 111In-leucocytes in 19. Intestinal blood loss was measured in 8 patients by use of chromium-51 labelled RBC, and a significant correlation between blood loss and intestinal inflammation was found. Intestinal protein loss was assessed in 9 patients with 51Cr-labelled proteins; patients with NSAID-induced small-intestinal inflammation were found to have a protein-losing enteropathy. These studies show that small intestinal inflammation caused by NSAIDs is associated with blood and protein loss, both of which may contribute to the general ill-health of rheumatic patients.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Rheumatoid; Chromium Radioisotopes; Enteritis; Erythrocytes; Feces; Gastrointestinal Hemorrhage; Humans; Indium Radioisotopes; Intestine, Small; Leukocytes; Proteins; Technetium; Technetium Tc 99m Pyrophosphate; Tin Polyphosphates

Topics: Adult; Aged; Diphosphates; Erythrocytes; Female; Gastrointestinal Hemorrhage; Humans; Male; Middle Aged; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate

Topics: Aged; Diphosphates; Gastrointestinal Hemorrhage; Humans; Ileal Neoplasms; Leiomyoma; Male; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate