{ "schemaVersion": 2, "eyebrow": "Nuclear Medicine", "title": "Gastrointestinal Bleeding Scan", "summary": "Technetium-99m–labeled red blood cell scintigraphy can document active or intermittent gastrointestinal bleeding when endoscopy is nondiagnostic or impractical, but its limited anatomic precision means results should guide—not independently determine—angiography, endoscopy, or surgery.", "seoDescription": "Clinical use, interpretation, pitfalls, and next steps after technetium-99m red blood cell scintigraphy for overt gastrointestinal bleeding.", "clinicalQuestion": "When should technetium-99m red blood cell scintigraphy be used to localize gastrointestinal bleeding and direct intervention?", "specialty": "Gastroenterology and Nuclear Medicine", "audience": "U.S. physicians and medical trainees", "tags": [ "GI bleeding scan", "99mTc-labeled red blood cell scan", "RBC scintigraphy", "acute lower gastrointestinal bleeding", "obscure overt gastrointestinal bleeding", "SPECT/CT" ], "keyTakeaways": [ "Do not use a GI bleeding scan to delay resuscitation or CT angiography in hemodynamically unstable patients with suspected ongoing lower GI bleeding; CTA is recommended before endoscopic or radiologic treatment in that setting.[10]", "Use 99mTc-labeled RBC scintigraphy primarily to detect active or intermittent overt mid- or lower-GI bleeding and provide gross localization when a noninvasive study is needed.[11][20]", "A positive scan should not be the sole basis for segmental bowel resection because localization can be inaccurate; surgery directed exclusively by scintigraphy produced an undesirable result in at least 42% of patients in one retrospective series.[16]", "After a positive CTA with active extravasation, proceed promptly to transcatheter angiography with embolization or endoscopic hemostasis in an experienced center rather than obtaining RBC scintigraphy.[8]", "Add SPECT/CT when planar scintigraphy is equivocal or when better anatomic assignment would alter downstream angiographic, endoscopic, or surgical planning.[12][18]" ], "sections": [ { "id": "select-the-right-patient", "eyebrow": "Patient Selection", "heading": "When a GI bleeding scan changes management", "intro": "Choose the study according to bleeding tempo, hemodynamics, and the next potentially therapeutic procedure.", "paragraphs": [ "Order 99mTc-labeled red blood cell (RBC) scintigraphy for overt suspected gastrointestinal bleeding—especially mid- or lower-tract bleeding—when bleeding may be intermittent and a noninvasive demonstration of active hemorrhage or gross regional localization would determine whether to pursue angiography, repeat endoscopy, or subsequent small-bowel evaluation.[11][20] The test can assess whether bleeding is active or intermittent, but it is not a definitive anatomic localization study.[11][16]", "Do not select RBC scintigraphy as the first localization test for hemodynamic instability with suspected ongoing lower GI bleeding. In this branch, obtain CT angiography (CTA) before endoscopic or radiologic therapy; CTA can identify active extravasation and direct prompt catheter angiography with embolization or endoscopic hemostasis.[10][8] CTA also has better positive correlation with catheter angiography than RBC scintigraphy in a retrospective lower-GI bleeding cohort.[4]", "If hematochezia occurs with hemodynamic instability, evaluate for an upper-GI source with upper endoscopy rather than presuming a colonic source.[3] A bleeding scan neither excludes upper-GI hemorrhage nor substitutes for source-directed endoscopy when clinical features indicate an upper source.[3][20]" ], "bullets": [ "Use after stabilization when active or intermittent overt bleeding remains unlocalized and a positive result would trigger a specific next procedure.[11][22]", "Avoid using the scan to justify blind surgical resection; confirm a bleeding site by endoscopy, angiography, operative assessment, or other definitive localization.[16][5]", "Consider recurrent or persistent bleeding after negative bidirectional endoscopy as a small-bowel bleeding pathway; repeat endoscopy may be appropriate first, followed by video capsule endoscopy if no source is found.[8]" ], "subsections": [], "table": { "caption": "Imaging selection for suspected active gastrointestinal bleeding.[8][10][11][16]", "columns": [ "Clinical branch", "Preferred next test", "Role of RBC scintigraphy", "Action after a positive result" ], "rows": [ [ "Hemodynamic instability with suspected ongoing lower-GI bleeding", "CTA before endoscopic or radiologic treatment.[10]", "Do not delay CTA for scintigraphy.[10]", "Prompt catheter angiography with embolization or endoscopic hemostasis in an experienced center when CTA shows active extravasation.[8]" ], [ "Overt mid- or lower-GI bleeding with intermittent or uncertain activity after stabilization", "99mTc-labeled RBC scintigraphy can document active or intermittent bleeding and provide gross localization.[11][20]", "Appropriate when noninvasive detection/localization will direct subsequent intervention.[11]", "Use the result to target further evaluation; do not base surgical resection solely on scan localization.[16]" ], [ "Negative upper and lower endoscopy with persistent or recurrent bleeding", "Repeat endoscopy may be performed first; if no source is found, video capsule endoscopy is indicated.[8]", "May help localize active bleeding before angiography after stabilization.[8]", "Proceed according to the demonstrated site and bleeding activity; capsule endoscopy is contraindicated when bowel obstruction is suspected.[8]" ] ] } }, { "id": "stabilize-and-triage", "eyebrow": "Immediate Triage", "heading": "Stabilize before localization imaging", "intro": "A scan is a localization tool, not a resuscitation strategy.", "paragraphs": [ "At presentation, obtain hemodynamic parameters, medication exposure that promotes bleeding, physical examination including digital rectal examination, and laboratory markers as part of the acute lower-GI bleeding assessment.[10] A shock index greater than 1 (heart rate divided by systolic blood pressure) identifies patients more likely to be unstable or to have ongoing active bleeding, whereas a shock index below 1 supports relative stability.[7]", "For hemodynamically stable lower-GI bleeding without cardiovascular disease, use a restrictive red-cell transfusion threshold of hemoglobin 7 g/dL or less. In stable patients with acute or chronic cardiovascular disease, use a threshold of hemoglobin 8 g/dL or less.[10] These thresholds do not replace clinical judgment in active exsanguination or evolving shock.", "In self-limited lower-GI bleeding without adverse clinical features, an Oakland score of 8 points or less can guide discharge for outpatient investigation rather than inpatient imaging.[10] A GI bleeding scan is not a routine outpatient test for a resolved bleed; reserve it for a clinical question linked to active or intermittent overt hemorrhage.[11]" ], "bullets": [ "Document whether bleeding is ongoing at the time of imaging request; scan yield and procedural planning depend on active or intermittent blood loss.[11][20]", "Identify antiplatelet and anticoagulant exposure because these therapies can worsen hemorrhage or reveal an underlying lesion, including colonic malignancy.[7]", "Escalate unstable hematochezia toward upper endoscopy and CTA-based localization rather than a routine lower-GI-only pathway.[3][10]" ], "subsections": [], "table": { "caption": "Initial triage decisions that determine whether scintigraphy is appropriate.[3][7][10][11]", "columns": [ "Finding", "Interpretation", "Next action" ], "rows": [ [ "Shock index >1", "Suggests hemodynamic instability or ongoing active bleeding.[7]", "Resuscitate and use CTA for suspected ongoing lower-GI bleeding; assess for an upper-GI source if hematochezia is unstable.[3][10]" ], [ "Stable; hemoglobin ≤7 g/dL; no cardiovascular disease", "Restrictive transfusion threshold.[10]", "Transfuse red blood cells while pursuing source-directed evaluation.[10]" ], [ "Stable; hemoglobin ≤8 g/dL; acute or chronic cardiovascular disease", "More liberal transfusion threshold.[10]", "Transfuse red blood cells while pursuing source-directed evaluation.[10]" ], [ "Self-limited bleed; no adverse features; Oakland score ≤8", "Low-risk outpatient pathway may be appropriate.[10]", "Discharge for outpatient investigation rather than routine inpatient scintigraphy.[10]" ] ] } }, { "id": "interpret-the-study", "eyebrow": "Interpretation", "heading": "What a positive or negative RBC scan means", "intro": "Interpret scintigraphy as evidence of bleeding activity with approximate regional localization.", "paragraphs": [ "A GI bleeding scan uses 99mTc-labeled RBCs to identify overt GI bleeding, particularly from the mid or lower tract, and can distinguish active from intermittent bleeding during the acquisition period.[11] A positive result supports active blood loss but does not reliably establish the exact bowel segment, lesion type, or suitability for targeted resection.[16][19]", "Planar scan localization may be distorted by moving intraluminal blood and by activity outside the bowel. Reported mimics include vascular blood pooling, hemolysis after transfusion, abdominal varices, dilated abdominal aorta, ischemic bowel, hepatic hemangioma, diverticular abscess, uterine leiomyoma, pelvic kidney, and postoperative hyperemia.[18][19] Correlate equivocal activity with anatomic imaging and procedural findings before committing to embolization or surgery.", "SPECT/CT improves anatomic correlation beyond planar imaging and can reduce equivocal interpretations caused by the two-dimensional appearance of planar studies.[12][18] Request SPECT/CT when distinguishing bowel from vascular, urinary, pelvic, or postoperative activity would change the choice or target of angiography, endoscopy, or operative exploration." ], "bullets": [ "A positive study is most useful when it changes the target or urgency of a planned therapeutic procedure, not when it merely confirms that the patient has bled.[11][16]", "A negative scan does not establish that bleeding has stopped permanently; intermittent hemorrhage may not occur during imaging.[11][20]", "Do not use a scan result alone to assign a precise surgical segment; retrospective data demonstrate limited localization accuracy and clinically unacceptable results when surgery relies exclusively on scintigraphy.[16]" ], "subsections": [ { "heading": "Communicate an actionable report", "paragraphs": [ "For a positive examination, communicate whether activity is convincing versus equivocal, the earliest apparent abdominal region, whether subsequent activity migrates in a pattern compatible with intraluminal transit, and whether SPECT/CT changed the anatomic assignment. This framing helps the receiving gastroenterologist, interventional radiologist, or surgeon avoid treating a false regional localization as a definitive bleeding point.[18][19][16]" ], "bullets": [ "State important confounders, including recent transfusion, postoperative state, abnormal vascular structures, and pelvic or urinary activity.[18][19]", "Recommend correlation with CTA, endoscopy, catheter angiography, or operative findings when definitive localization is required.[5][16]" ] } ], "table": { "caption": "Interpretive limitations and practical responses for 99mTc-labeled RBC scintigraphy.[12][16][18][19]", "columns": [ "Scan finding or concern", "Clinical implication", "Next step" ], "rows": [ [ "Definite new activity consistent with active bleeding", "Supports active GI hemorrhage but provides only gross localization.[11][16]", "Use the regional information to direct source-confirming endoscopy or angiographic evaluation when intervention is needed.[11][16]" ], [ "Equivocal planar abdominal or pelvic activity", "Two-dimensional imaging and nonbowel blood-pool activity can create false localization.[18][19]", "Add SPECT/CT when anatomic assignment will alter management.[12][18]" ], [ "Negative scan during ongoing clinical concern", "Bleeding may be intermittent or absent during acquisition; a negative study does not provide definitive exclusion.[11][20]", "Reassess hemodynamics and bleeding tempo; use CTA for suspected ongoing unstable lower-GI bleeding or proceed through endoscopic/small-bowel pathways as indicated.[8][10]" ], [ "Positive scan proposed as basis for resection", "Localization may be inaccurate; scintigraphy-only surgical targeting has produced undesirable outcomes.[16]", "Obtain definitive localization before segmental resection.[5][16]" ] ] } }, { "id": "act-on-results", "eyebrow": "Next Procedures", "heading": "Convert localization into hemostasis", "intro": "The therapeutic pathway depends on stability, CTA findings, endoscopic access, and localization certainty.", "paragraphs": [ "For major acute lower-GI bleeding, colonoscopy should occur during the hospitalization, but evidence does not show that early colonoscopy improves patient outcomes.[10] This permits bowel preparation and endoscopic diagnosis or treatment once the patient is stable enough for the procedure; it should not delay CTA in suspected ongoing unstable bleeding.[10]", "When CTA demonstrates active contrast extravasation, use prompt transcatheter angiography with embolization or endoscopic hemostasis at an experienced center.[8] Catheter angiography is particularly relevant for high-risk active lower-GI bleeding when endoscopy cannot be performed because of hemodynamic instability or when endoscopic therapy has failed.[8]", "If upper and lower endoscopy are negative, repeat endoscopy may be used to exclude a missed lesion before proceeding to video capsule endoscopy for persistent unexplained bleeding.[8] Capsule endoscopy evaluates intraluminal small-bowel lesions but is contraindicated when bowel obstruction is suspected because of capsule retention risk; reported overall complication rates are 1% to 3%.[8]", "Reserve surgery for bleeding that remains uncontrolled after appropriate localization and endoscopic or radiologic approaches. Avoid blind bowel resection, which carries substantial morbidity and mortality, and do not treat a scintigraphic regional signal as sufficient localization for operative segment selection.[5][16]" ], "bullets": [ "Positive CTA: expedite therapeutic angiography/embolization or endoscopic hemostasis.[8]", "Positive RBC scan without definitive lesion localization: use it to prioritize targeted confirmatory evaluation rather than proceeding directly to resection.[11][16]", "Negative bidirectional endoscopy with recurrent bleeding: reassess for a missed upper or lower lesion, then evaluate the small bowel with capsule endoscopy when no obstruction is suspected.[8]" ], "subsections": [], "table": { "caption": "Procedure escalation after imaging or endoscopic evaluation.[5][8][10][16]", "columns": [ "Clinical state", "Definitive next step", "Key limitation or exception" ], "rows": [ [ "Major lower-GI bleed after stabilization", "Perform colonoscopy during the hospital stay.[10]", "Early colonoscopy has not been shown to improve outcomes; do not delay CTA in unstable ongoing bleeding.[10]" ], [ "CTA with active extravasation", "Prompt transcatheter angiography with embolization or endoscopic hemostasis in an experienced center.[8]", "Therapeutic choice depends on local expertise and clinical access to the bleeding site.[8]" ], [ "Active bleeding with endoscopy infeasible because of instability or failed endoscopic therapy", "Catheter angiography is an important therapeutic option.[8]", "Use prior CTA or other localization to improve procedural targeting when available.[8][5]" ], [ "Persistent/recurrent bleeding after negative bidirectional endoscopy", "Repeat endoscopy may be performed first, then video capsule endoscopy if no source is found.[8]", "Do not use capsule endoscopy when bowel obstruction is suspected.[8]" ], [ "Considering surgery after positive RBC scan", "Confirm site by a definitive modality before segmental resection.[5][16]", "Scintigraphy alone has limited localization accuracy.[16]" ] ] } }, { "id": "monitor-and-reassess", "eyebrow": "Monitoring", "heading": "Reassess bleeding activity after a nondiagnostic study", "intro": "A nondiagnostic scan requires renewed clinical triage rather than automatic repeat imaging.", "paragraphs": [ "Monitor recurrent hematochezia or melena, serial hemodynamics, and hemoglobin trajectory after a negative or equivocal scan. A new shock index above 1 should move the patient back to an active-bleeding pathway, with CTA favored for suspected ongoing unstable lower-GI hemorrhage.[7][10]", "If bleeding becomes self-limited and the patient has no adverse clinical features, use risk stratification rather than continued inpatient localization testing; an Oakland score of 8 or less can support discharge for outpatient investigation.[10] If bleeding persists or recurs after negative upper and lower endoscopy, reassess for a missed lesion and proceed to small-bowel evaluation when appropriate.[8]", "For recurrent obscure bleeding after prior endoscopic evaluation, repeat endoscopy, video capsule endoscopy, or intraoperative endoscopy may be required depending on the clinical course and prior localization results.[8] Recurrent bleeding after a negative study is a reason to re-evaluate the diagnostic branch, not proof that the prior study was falsely negative." ], "bullets": [ "Escalate immediately if bleeding recurs with instability; do not wait for elective scintigraphy.[7][10]", "Use the prior scan as contextual regional information, but obtain contemporaneous CTA or endoscopic evidence before urgent targeted intervention when possible.[8][16]", "Document obstruction risk before selecting video capsule endoscopy.[8]" ], "subsections": [], "table": { "caption": "Reassessment after a negative or equivocal GI bleeding scan.[7][8][10]", "columns": [ "Post-scan course", "Interpretation", "Next action" ], "rows": [ [ "No further overt bleeding; low-risk features; Oakland score ≤8", "Self-limited lower-GI bleeding may be suitable for outpatient investigation.[10]", "Consider discharge with outpatient evaluation.[10]" ], [ "Recurrent bleeding with shock index >1", "Suggests active or hemodynamically significant bleeding.[7]", "Resuscitate and obtain CTA for suspected ongoing lower-GI bleeding; assess for upper-GI bleeding in unstable hematochezia.[3][10]" ], [ "Persistent or recurrent bleeding after negative upper and lower endoscopy", "Raises concern for missed lesions or small-bowel bleeding.[8]", "Consider repeat endoscopy first, then video capsule endoscopy if no obstruction is suspected.[8]" ] ] } } ], "faq": [], "references": [ { "number": 1, "title": "Managing Acute Lower Gastrointestinal Bleeding | NEJM Clinician", "detail": "clinician.nejm.org", "url": "https://clinician.nejm.org/managing-acute-lower-gastrointestinal-bleeding-nejm-jw.NA55870", "authors": "clinician.nejm.org", "host": "clinician.nejm.org" }, { "number": 2, "title": "Management of acute gastrointestinal blood loss: summary of SIGN guidelines | The BMJ", "detail": "www.bmj.com", "url": "https://www.bmj.com/content/337/bmj.a1832/rapid-responses", "authors": "www.bmj.com", "host": "www.bmj.com" }, { "number": 3, "title": "Management of Acute Lower Gastrointestinal Bleeding | NEJM Clinician", "detail": "clinician.nejm.org", "url": "https://clinician.nejm.org/management-acute-lower-gastrointestinal-bleeding-nejm-jw.NA41492", "authors": "clinician.nejm.org", "host": "clinician.nejm.org" }, { "number": 4, "title": "Correlation of CT Angiography and 99mTechnetium-Labeled Red Blood Cell Scintigraphy to Catheter Angiography for Lower Gastrointestinal Bleeding: A Single-Institution Experience - 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Chua - 2008 - Journal of Medical Imaging and Radiation Oncology - Wiley Online Library", "detail": "onlinelibrary.wiley.com", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-1673.2008.01964.x", "authors": "onlinelibrary.wiley.com", "host": "onlinelibrary.wiley.com" }, { "number": 10, "title": "Diagnosis and management of acute lower gastrointestinal bleeding: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - PubMed", "detail": "www.ncbi.nlm.nih.gov", "url": "http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=34062566", "authors": "www.ncbi.nlm.nih.gov", "host": "www.ncbi.nlm.nih.gov" }, { "number": 11, "title": "Gastrointestinal Bleeding Scan - StatPearls - NCBI Bookshelf", "detail": "www.ncbi.nlm.nih.gov", "url": "https://www.ncbi.nlm.nih.gov/books/NBK544317", "authors": "www.ncbi.nlm.nih.gov", "host": "www.ncbi.nlm.nih.gov" }, { "number": 12, "title": "Diagnostic ability of (99m)Tc-HSA-DTPA scintigraphy in combination with SPECT/CT for gastrointestinal bleeding - 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ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/pii/S0001299886800289", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com" }, { "number": 20, "title": "Detection of gastrointestinal bleeding with 99mTc-labeled red blood cells - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0001299882800056", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com" }, { "number": 21, "title": "Colonoscopy Versus Catheter Angiography for Lower Gastrointestinal Bleeding After Localization on CT Angiography - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S1546144022001223", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com" }, { "number": 22, "title": "Colon Hemorrhage - an overview", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/topics/medicine-and-dentistry/colon-hemorrhage", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com" }, { "number": 23, "title": "Predictors of positive angiography and evaluation of the outcome of transcatheter control of non variceal upper gastrointestinal hemorrhage - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/pii/S0378603X15002181#!", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com" }, { "number": 24, "title": "No catheter angiography is needed in patients with an obscure acute gastrointestinal bleed and negative CTA - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0899707117300311", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com" } ], "editorialNote": "Prepared from cited clinical literature using Astra's research workflow. Verify recommendations against current guidance and patient-specific factors.", "citations": [ { "number": 1, "title": "Managing Acute Lower Gastrointestinal Bleeding | NEJM Clinician", "detail": "clinician.nejm.org", "url": "https://clinician.nejm.org/managing-acute-lower-gastrointestinal-bleeding-nejm-jw.NA55870", "authors": "clinician.nejm.org", "host": "clinician.nejm.org", "snippet": "Copyright © 2026\n\nMassachusetts Medical Society.\n\nAll rights reserved, including those for text and data mining, AI training, and similar technologies.\n\nElectronic ISSN 3067-1876\n\nThe content of this site is intended for health care professionals.\n\n# Managing Acute Lower Gastrointestinal Bleeding\n\n#", "score": 0.5274388 }, { "number": 2, "title": "Management of acute gastrointestinal blood loss: summary of SIGN guidelines | The BMJ", "detail": "www.bmj.com", "url": "https://www.bmj.com/content/337/bmj.a1832/rapid-responses", "authors": "www.bmj.com", "host": "www.bmj.com", "snippet": "Title: Management of acute gastrointestinal blood loss: summary of SIGN guidelines | The BMJ\n3. Management of acute gastrointestinal blood loss: summary of SIGN guidelines. # Management of acute gastrointestinal blood loss: summary of SIGN guidelines. In Palmer et al guideline on acute non variceal ", "score": 0.5021246 }, { "number": 3, "title": "Management of Acute Lower Gastrointestinal Bleeding | NEJM Clinician", "detail": "clinician.nejm.org", "url": "https://clinician.nejm.org/management-acute-lower-gastrointestinal-bleeding-nejm-jw.NA41492", "authors": "clinician.nejm.org", "host": "clinician.nejm.org", "snippet": "### Background and Objective\n\nIn a new ACG clinical guideline on management of acute overt lower gastrointestinal (GI) bleeding, researchers developed evidence-based recommendations based on a systematic literature review. They defined lower GI bleeding as colorectal bleeding and not small-bowel ble", "score": 0.45464227 }, { "number": 4, "title": "Correlation of CT Angiography and 99mTechnetium-Labeled Red Blood Cell Scintigraphy to Catheter Angiography for Lower Gastrointestinal Bleeding: A Single-Institution Experience - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S1051044319304105", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: Correlation of CT Angiography and 99mTechnetium-Labeled Red Blood Cell Scintigraphy to Catheter Angiography for Lower Gastrointestinal Bleeding: A Single-Institution Experience - ScienceDirect\n# Clinical Study Correlation of CT Angiography and 99mTechnetium-Labeled Red Blood Cell Scintigraphy", "score": 0.7043437 }, { "number": 5, "title": "The Accuracy of Computed Tomography Angiography Compared With Technetium-99m Labelled Red Blood Cell Scintigraphy for the Diagnosis and Localization of Acute Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/pii/S0363018823000828", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: The Accuracy of Computed Tomography Angiography Compared With Technetium-99m Labelled Red Blood Cell Scintigraphy for the Diagnosis and Localization of Acute Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis - ScienceDirect\n# The Accuracy of Computed Tomography Angiography Comp", "score": 0.6793707 }, { "number": 6, "title": "Imaging of Gastrointestinal Bleeding: An Update - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S000129982300048X", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: Imaging of Gastrointestinal Bleeding: An Update - ScienceDirect\nThis article discusses about the use of gastrointestinal bleeding scintigraphy in its current practice with emphasis on radiopharmaceutical, imaging techniques, interpretation and pitfalls. Prior to interpretation of the gastroin", "score": 0.5760895 }, { "number": 7, "title": "Acute lower gastrointestinal bleeding - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S1357303923002803", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: Acute lower gastrointestinal bleeding - ScienceDirect\n# Gastrointestinal emergencies Acute lower gastrointestinal bleeding. Acute lower gastrointestinal bleeding often presents a challenging clinical situation. Although bleeding can be severe and associated with significant haemodynamic compr", "score": 0.5608546 }, { "number": 8, "title": "Gastrointestinal Bleeding: A Comprehensive Imaging Review... : Journal of Radiological Science", "detail": "journals.lww.com", "url": "https://journals.lww.com/jrs/fulltext/9900/gastrointestinal_bleeding__a_comprehensive_imaging.37.aspx", "authors": "journals.lww.com", "host": "journals.lww.com", "snippet": "This section explores the important role of radiologic evaluation, including advanced computed tomography (CT) techniques, angiography, and nuclear imaging in detecting and localizing GI bleeding. While CTA offers a valuable noninvasive screening tool, catheter angiography remains a crucial modality", "score": 0.6912478 }, { "number": 9, "title": "Diagnostic accuracy of CT angiography in acute gastrointestinal bleeding - Chua - 2008 - Journal of Medical Imaging and Radiation Oncology - Wiley Online Library", "detail": "onlinelibrary.wiley.com", "url": "https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-1673.2008.01964.x", "authors": "onlinelibrary.wiley.com", "host": "onlinelibrary.wiley.com", "snippet": "# Diagnostic accuracy of CT angiography in acute gastrointestinal bleeding. The aim of the study was to carry out a systematic review determining the accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding. Studies were included if they compared CT angiography to a reference s", "score": 0.78214747 }, { "number": 10, "title": "Diagnosis and management of acute lower gastrointestinal bleeding: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - PubMed", "detail": "www.ncbi.nlm.nih.gov", "url": "http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=34062566", "authors": "www.ncbi.nlm.nih.gov", "host": "www.ncbi.nlm.nih.gov", "snippet": "Title: Diagnosis and management of acute lower gastrointestinal bleeding: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - PubMed\n## Save citation to file. 1: ESGE recommends that the initial assessment of patients presenting with acute lower gastrointestinal bleeding should include", "score": 0.49157855 }, { "number": 11, "title": "Gastrointestinal Bleeding Scan - StatPearls - NCBI Bookshelf", "detail": "www.ncbi.nlm.nih.gov", "url": "https://www.ncbi.nlm.nih.gov/books/NBK544317", "authors": "www.ncbi.nlm.nih.gov", "host": "www.ncbi.nlm.nih.gov", "snippet": "Last Update: August 14, 2023.\n\n## Introduction\n\nGastrointestinal bleeding scan (GIBS) is a non-invasive diagnostic radionuclide imaging study to evaluate patients with a suspected overt GI bleed, especially involving mid and lower gastrointestinal (GI) tract. It is performed with 99mTc-RBCs and help", "score": 0.45522344 }, { "number": 12, "title": "Diagnostic ability of (99m)Tc-HSA-DTPA scintigraphy in combination with SPECT/CT for gastrointestinal bleeding - PubMed", "detail": "www.ncbi.nlm.nih.gov", "url": "https://www.ncbi.nlm.nih.gov/pubmed/24599405", "authors": "www.ncbi.nlm.nih.gov", "host": "www.ncbi.nlm.nih.gov", "snippet": "Skip to main page content. An official website of the United States government. **The .gov means it’s official.**. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site. The ** ensures that you are connecting to the", "score": 0.8646883 }, { "number": 13, "title": "An Evaluation of 99mTc-Labeled Red Blood Cell Scintigraphy for the Detection and Localization of Gastrointestinal Bleeding Sites - Gastroenterology", "detail": "www.gastrojournal.org", "url": "https://www.gastrojournal.org/article/S0016-5085(82)80334-X/fulltext", "authors": "www.gastrojournal.org", "host": "www.gastrojournal.org", "snippet": "# An Evaluation of 99mTc-Labeled Red Blood Cell Scintigraphy for the Detection and Localization of Gastrointestinal Bleeding Sites. DOI: 10.1016/S0016-5085(82)80334-X External Link80334-X)Also available on ScienceDirect External Link. 99mTechnetium-labeled red blood cell scintigraphy was performed u", "score": 0.7135319 }, { "number": 14, "title": "Provocative mesenteric angiography for occult gastrointestinal bleeding: a systematic review - PMC", "detail": "www.ncbi.nlm.nih.gov", "url": "http://www.ncbi.nlm.nih.gov/pmc/articles/10435437?term=", "authors": "www.ncbi.nlm.nih.gov", "host": "www.ncbi.nlm.nih.gov", "snippet": "Title: Provocative mesenteric angiography for occult gastrointestinal bleeding: a systematic review - PMC\nEligible studies included primary research studies with patients undergoing provocative mesenteric angiography (PMA) for diagnosis or localization of occult GIB. The following outcome data were ", "score": 0.5769478 }, { "number": 15, "title": "Acute Massive Gastrointestinal Bleeding: Detection and Localization with Arterial Phase Multi–Detector Row Helical CTRadiology", "detail": "pubs.rsna.org", "url": "https://pubs.rsna.org/doi/abs/10.1148/radiol.2383050175", "authors": "pubs.rsna.org", "host": "pubs.rsna.org", "snippet": "# Acute Massive Gastrointestinal Bleeding: Detection and Localization with Arterial Phase Multi–Detector Row Helical CT1. **Purpose:** To prospectively evaluate accuracy of arterial phase multi–detector row helical computed tomography (CT) for detection and localization of acute massive gastrointest", "score": 0.629889 }, { "number": 16, "title": "Limited value of technetium 99m-labeled red cell scintigraphy in localization of lower gastrointestinal bleeding - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/pii/S0002961005812565", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: Limited value of technetium 99m-labeled red cell scintigraphy in localization of lower gastrointestinal bleeding - ScienceDirect\n# Limited value of technetium 99m-labeled red cell scintigraphy in localization of lower gastrointestinal bleeding\\*. The aim of this study was to assess the accura", "score": 0.5501488 }, { "number": 17, "title": "An Evaluation of 99mTc-Labeled Red Blood Cell Scintigraphy for the Detection and Localization of Gastrointestinal Bleeding Sites - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S001650858280334X", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: An Evaluation of 99mTc-Labeled Red Blood Cell Scintigraphy for the Detection and Localization of Gastrointestinal Bleeding Sites - ScienceDirect\n# An Evaluation of 99mTc-Labeled Red Blood Cell Scintigraphy for the Detection and Localization of Gastrointestinal Bleeding Sites. 99mTechnetium-la", "score": 0.48264915 }, { "number": 18, "title": "Case series review illustrating the utility of SPECT/CT in enhancing reader confidence and avoiding pitfalls in interpreting 99mTc-labeled red blood cell scans - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/pii/S1930043324013773", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: Case series review illustrating the utility of SPECT/CT in enhancing reader confidence and avoiding pitfalls in interpreting 99mTc-labeled red blood cell scans - ScienceDirect\n## Radiology Case Reports. Volume 20, Issue 4, April 2025, Pages 2080-2086. # Case Report Case series review illustra", "score": 0.7489592 }, { "number": 19, "title": "Pitfalls of gastrointestinal bleeding studies with 99mTc-labeled RBCs - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/pii/S0001299886800289", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "# Pitfalls of gastrointestinal bleeding studies with 99mTc-labeled RBCs. Author links open overlay panel,. ### An evaluation of 99mTc-labeled red blood cell scintigraphy for the detection and localization of gastrointestinal bleeding sites. ### Detection of gastrointestinal blood loss with Tc-99m-la", "score": 0.725824 }, { "number": 20, "title": "Detection of gastrointestinal bleeding with 99mTc-labeled red blood cells - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0001299882800056", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: Detection of gastrointestinal bleeding with 99mTc-labeled red blood cells - ScienceDirect\n# Detection of gastrointestinal bleeding with 99mTc-labeled red blood cells. Author links open overlay panel, , , ,. https://doi.org/10.1016/S0001-2998(82)80005-680005-6 \"Persistent link using digital ob", "score": 0.71137124 }, { "number": 21, "title": "Colonoscopy Versus Catheter Angiography for Lower Gastrointestinal Bleeding After Localization on CT Angiography - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S1546144022001223", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "Title: Colonoscopy Versus Catheter Angiography for Lower Gastrointestinal Bleeding After Localization on CT Angiography - ScienceDirect\n# Original Article Health Services Research and Policy Colonoscopy Versus Catheter Angiography for Lower Gastrointestinal Bleeding After Localization on CT Angiogra", "score": 0.644248 }, { "number": 22, "title": "Colon Hemorrhage - an overview", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/topics/medicine-and-dentistry/colon-hemorrhage", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "#### Management\n\nInitial resuscitation with blood products is imperative. In an unstable patient with a massive gastrointestinal bleed O-negative blood can be transfused whilst the type specific blood is cross-matched. Coagulopathies should be corrected. [...] The management of these problems requir", "score": 0.53881395 }, { "number": 23, "title": "Predictors of positive angiography and evaluation of the outcome of transcatheter control of non variceal upper gastrointestinal hemorrhage - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/pii/S0378603X15002181#!", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "## The Egyptian Journal of Radiology and Nuclear Medicine. Volume 47, Issue 1, March 2016, Pages 161-168. # Original Article Predictors of positive angiography and evaluation of the outcome of transcatheter control of non variceal upper gastrointestinal hemorrhage. Author links open overlay panel, ,", "score": 0.5054935 }, { "number": 24, "title": "No catheter angiography is needed in patients with an obscure acute gastrointestinal bleed and negative CTA - ScienceDirect", "detail": "www.sciencedirect.com", "url": "https://www.sciencedirect.com/science/article/abs/pii/S0899707117300311", "authors": "www.sciencedirect.com", "host": "www.sciencedirect.com", "snippet": "# Original Article No catheter angiography is needed in patients with an obscure acute gastrointestinal bleed and negative CTA. To evaluate the negative predictive power of computed tomography angiography (CTA) for the identification of obscure acute gastrointestinal (GI) bleeding (GI bleeding not v", "score": 0.4689128 } ], "publishedAt": "2026-08-24T16:09:52.369206+00:00", "updatedAt": "2026-08-24T16:09:52.369206+00:00", "readingMinutes": 6, "slug": "gastrointestinal-bleeding-scan" }