Imaging Pearls ❯ Small Bowel ❯ GI Bleed: Causes and Detection
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- “GI bleeding can be characterized by the presumed location of origin. UGIB is defined as bleeding that originates from the esophagus, stomach, or duodenum. This accounts for approximately 80% of bleeding events. LGIB has previously been defined as bleeding that originates distal to the ligament of Treitz but more recently is defined as bleeding distal to the ileocecal valve and throughout the colon. LGIB, depending on its anatomic landmarks, accounts for approximately 15%–30% of all GI bleeding events. Finally, small bowel or midgut GI bleeding is defined as bleeding that occurs between the ligament of Treitz to the ileocecal valve and accounts for approximately 5%–10% of GI bleeding events.”
The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations.
Sengupta N,et al.
Radiology. 2024 Mar;310(3):e232298. doi: 10.1148/radiol.232298 
The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations.
Sengupta N,et al.
Radiology. 2024 Mar;310(3):e232298. doi: 10.1148/radiol.232298
The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations.
Sengupta N,et al.
Radiology. 2024 Mar;310(3):e232298. doi: 10.1148/radiol.232298- “Because of its noninvasive nature, short examination time, and widespread availability, CTA is well-suited to evaluate patients with overt GI bleeding, particularly in hemodynamically unstable patients. In patients with overt GI bleeding, CT is used to identify intraluminal blood products or active contrast material extravasation to localize the site of hemorrhage and can also detect etiologies outside of the GI tract. CT techniques such as digital subtraction and dual-energy acquisition have improved the ability of CT to detect subtle GI tract lesions . CTA also provides additional information regarding the patient’s vascular and enteric anatomy, which is often helpful for choosing and planning a subsequent interventional radiology, endoscopic, or surgical procedure.”
The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations.
Sengupta N,et al.
Radiology. 2024 Mar;310(3):e232298. doi: 10.1148/radiol.232298 - “The biggest limitation of 99mTc-RBC scans is that this study can only be performed on hemodynamically stable patients. The RBC labeling preparation time and long imaging times prevents performing this study on patients who are hemodynamically unstable because of hypotension or abnormal heart rate. The risk-benefit ratio of obtaining a 99mTc-RBC scan, which has a long imaging time, versus correctly identifying an active LGIB site has to be weighed in borderline hemodynamically ,unstable patients.”
The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations.
Sengupta N,et al.
Radiology. 2024 Mar;310(3):e232298. doi: 10.1148/radiol.232298 - “CTE may have several advantages over endoscopic techniques. CTE has greater sensitivity for detecting small bowel masses, particularly those that are mural-based, and can help direct targeted, deep enteroscopy procedures when a source is identified. Cross-sectional imaging techniques (CT and MRI) allow visualization of extraintestinal abdominopelvic structures such as malignancies that may involve bowel or changes in the mesentery, bowel wall, and bowel/mesenteric vessels as potential causes of GI bleeding even in the absence of active contrast material extravasation. In patients with occult small bowel bleeding and relative contraindications to capsule endoscopy such as radiation, prior surgery, Crohn disease, and/or small bowel stenosis, CTE maybe the first-line study to characterize the abnormality .”
The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations.
Sengupta N,et al.
Radiology. 2024 Mar;310(3):e232298. doi: 10.1148/radiol.232298
- “Upper GI bleeding, which originates proximal to the ligament of Treitz, is more common than lower GI bleeding, which arises distal to the ligament of Treitz. Small bowel bleeding accounts for 5–10% of GI bleeding cases commonly manifesting as obscure GI bleeding, where the source remains unknown after complete GI tract endoscopic and imaging evaluation. CT can aid in identifying the location and cause of bleeding and is an important complementary tool to endoscopy, nuclear medicine, and angiography in evaluating patients with GI bleeding. For radiologists, interpreting CT scans in patients with GI bleeding can be challenging owing to the large number of images and the diverse potential causes of bleeding.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - "Active GI bleeding is depicted by the accumulation of extrav- asated contrast material in the bowel lumen as a focus, jet, cloud, or blush of variable size, usually appearing during the arterial phase. Contrast extravasation generally changes in size, attenuation, shape, and location on later phase images usually moving downstream. An enhancing focus that changes in attenuation but not shape on later phase images may be a vascular lesion (eg, aneurysm, pseudoaneurysm, or angioectasia). The absence of hyperattenuating material on noncontrast images in the same location of possible contrast extravasation on postcontrast images helps to confirm active bleeding.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - "The most common CT pitfall that mimics active contrast extravasation is the presence of hyperattenuating material within bowel loops, most frequently hyperattenuating colonic fecal material, retained or inadvertently administered positive oral contrast material, or prior pill ingestion.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - "Upper GI bleeding is more common than lower GI bleeding, with an annual incidence of 100–200 per 100 000 compared with 20.5–27 per 100 000 for lower GI bleeding. Small bowel bleeding accounts for 5%–10% of GI bleeding cases and is considered its own bleeding category, often manifesting as obscure GI bleeding, where the source remains unknown after complete GI tract endoscopic and imaging evaluation.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - "Identifying intraluminal hyperattenuating hemorrhage on noncontrast images can direct the search of arterial and venous phase images for a bleeding site. Subsequently, the arterial phase images should be scrutinized for signs of contrast extravasation, which should be confirmed on venous phase images, if the intraluminal contrast extravasation changes in size, attenuation, and/ or shape. Venous phase images should also be reviewed to identify slower venous bleeds that may not appear during the arterial phase. Reviewing maximum intensity projection images can enhance delineation of vascular anatomy and pathology.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656- “Esophageal, gastric, and duodenal cancers can all ulcerate and cause GI bleeding. Esophageal cancers can show asymmetric or marked focal wall thickening, often with para-esophageal lymph nodes. Gastric cancer can produce focal or diffuse gastric wall thickening or manifest as an intraluminal polypoid lesion and can be associated with perigastric lymph nodes, liver and pulmonary metastases, and peritoneal disease. Gastric lymphoma can manifest as focal or diffuse wall thickening, an ulcerated mass, or polypoid or nodular fold thickening. Gastric metastatic disease can arise from melanoma, breast cancer, and lung cancer.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - Small Bowel Bleeding: Differential Dx
- Small Bowel Ulcers
- Crohns disease
- Nonsteroidal Anti-Inflammatory Drug Enteropathy.
- Angioectasia
- Varices
- Small bowel tumors (GIST)
- Meckels diverticulum - "Metastases to the small bowel are the most common small bowel malignancy, representing approximately 50% of all small bowel neoplasms. A metastasis should be the primary consideration when identifying a new small bowel mass in a patient with a known malignancy. Hematogenous metastasis to the small bowel may arise from melanoma or lung or breast tumors, while direct peritoneal spread can occur from ovarian, gastric, or colonic tumors. Metastases may manifest as a single mass or multiple discrete masses or with peritoneal in- volvement.The appearance can range from small polypoid nodules to large lesions with aggressive features.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - "Adenocarcinoma is the second most common primary small bowel malignancy. Adenocarcinomas usually arise in the proximal small bowel, most commonly in the duodenum, followed by the jejunum, and thus, they are commonly identified with advanced endoscopic techniques such as video capsule endoscopy and push (extended) enteroscopy . However, in patients with Crohn disease, adenocarcinoma more commonly arises in the ileum. On CT im- ages, adenocarcinoma commonly forms a single poorly enhancing mass that may grow with a circumferential or nodular pattern.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - “Neuroendocrine tumors (NETs) represent the most common primary small bowel malignancy and most commonly occur in the distal ileum. At cross-sectional imaging, small NETs have a characteristic flat, or plaque-like appearance. As the tumor enlarges, a desmoplastic reaction typically forms in the adjacent mesentery, resulting in the mass assuming a U-shaped or horseshoe appearance. NETs are characteristically hyperenhancing on arterial or enteric phase images. The tumors are frequently multiple, with two or more lesions identified in the same bowel segment.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656 - "While diverticulosis is the most common cause of lower GI bleeding, angioectasia is the most common vascular lesion causing lower GI bleeding and has an increased incidence with age. In the colon, angioectasia is more common in the cecum and ascending colon. On CT images, colonic angioectasia can appear as punctate or discoid foci of enhancement in the colon wall. As in the small bowel, angioectasias may be incidental findings unrelated to the cause of bleeding.”
Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms
Flavius F. Guglielmo et al.
RadioGraphics 2021; 41:1632–1656
- “Acute gastrointestinal tract bleeding (GIB) remains an important cause of morbidity and mortality. In the United States, >750,000 patients visit the emergency department each year with GIB, and in nearly half of those visits, the source of GIB is in the lower gastrointestinal tract. Despite advances in management, the mortality rate for patients with GIB remains at approximately 10% but increases to 40% in cases of massive bleeding associated with hemodynamic instability or the requirement for transfusion of >4 units of blood. Acute lower GIB is defined as bleeding into the large bowel or bleeding into the small-bowel distal to the ligament of Treitz.”
ACR Appropriateness Criteria Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - "Acute lower GIB is defined as bleeding into the large bowel or bleeding into the small-bowel distal to the ligament of Treitz. This condition may present as either melena or hematochezia, depending on the site and severity of bleeding. Causes of lower GIB include inflammatory bowel disease, neoplasms, stress ulcers, surgical anastomoses, vascular lesions such as angiodysplasia, and diverticulosis, with diverticulosis ac- counting for 30% of cases. In a subgroup of patients, portal hypertension can cause lower GIB as a result of clinically obvious anorectal varices or obscure ectopic varices in the small or large bowel.”
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - "Approximately 75% of episodes of acute lower GIB due to diverticulosis stop spontaneously, especially in patients requiring transfusions of <4 units of blood over a 24-hour period. Hence, in a substantial number of patients with acute lower GIB, conservative management is likely to be sufficient. For these patients, no immediate interventions are required, and diagnostic tests to identify the source of lower GIB can be arranged electively.”
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - “The arterial phase of CTA can be used to identify the beginning of intraluminal extravasation of intravascular contrast and to locate the culprit arterial branch; this information allows for more focused transcatheter arteriography and embolization. Along with the arterial phase, the portal venous phase of CTA can be used to further evaluate the nature of the culprit pathology. Noncontrast CT has no role in patients with acute GIB, whereas multiphase CTA can be completed within minutes and can be conducted even in hemody- namically precarious patients.”
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - "In one prospective study, multiphase CTA was able to identify active bleeding or a potential bleeding lesion in 92% of cases versus the 29% of cases identified with transcatheter arteriography. In 5 of 19 patients with active bleeding after CTA, transcatheter arteriography results were negative in spite of a short interval between CTA and transcatheter arteriography (median, 33 minutes); these results highlight the extremely intermittent nature of GIB. Individual studies have shown that the sensitivity of CTA ranges from 79% to 100%.”
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - “In another retrospective review, transcatheter arteriography was negative in all 14 patients with lower GIB who had negative CTA results [38], highlighting the lack of evidence to support transcatheter arteriography when CTA is negative. Another study demonstrated that no intervention was needed in any patient who was hemodynamically stable at the time of negative CTA .”
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - Variant 1: CTA of the abdomen and pelvis without and with intravenous (IV) contrast, diagnostic/ therapeutic colonoscopy, or RBC scan abdomen and pelvis is usually appropriate as the next step for a hemodynamically stable patient with lower GIB and active bleeding clinically observed as hematochezia or melena. These procedures are equivalent alternatives (ie, only one procedure will be ordered to provide the clinical information to effectively manage the patient’s care).
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - Variant 2: CTA of the abdomen and pelvis without and with IV contrast or transcatheter arteriography/ embolization is usually appropriate as the next step for a hemodynamically unstable patient with active lower GIB or a patient who has required >5 units of blood within 24 hours. These procedures are equivalent alternatives (ie, only one procedure will be ordered to provide the clinical information to effectively manage the patient’s care). Diagnostic/ therapeutic colonoscopy may be appropriate for this clinical scenario, but the experts could not agree on the exact appropriateness category.
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - Variant 3: Transcatheter arteriography/embolization is usually appropriate as the next intervention for a patient with ongoing or recurrent lower GIB where colonoscopy has localized the bleeding site and treatment was attempted. CTA of the abdomen and pelvis without and with IV contrast or repeat diagnostic/therapeutic colonoscopy may be appropriate for this clinical scenario, but the experts could not agree on the exact appropriateness category.
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - Variant 4: Diagnostic/therapeutic colonoscopy is usually appropriate as the next intervention for a patient with ongoing or recurrent lower GIB where transcatheter arteriography has localized the bleeding site and treatment was attempted. The patient has no prior radiological or endoscopic investigations.
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 - Variant 5: CE or CTE of the abdomen and pelvis with IV contrast is usually appropriate as the next procedure or intervention in a hemodynamically stable patient with obscure (nonlocalized) recurrent lower GIB, assuming a prior negative adequate colonoscopy and upper gastrointestinal endoscopy. These procedures are equivalent alternatives (ie, only one procedure will be ordered to provide the clinical information to effectively manage the patient’s care). Transcatheter arteriography/embolization may be appropriate for this clinical scenario, but the experts could not agree on the exact appropriateness category.
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152 
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152
ACR Appropriateness Criteria Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update
Karuppasamy K et al.
J Am Coll Radiol 2021;18:S139-S152
- Purpose The purpose of this study was to determine whether the measured size of active gastrointestinal hemorrhage was useful in predicting subsequent positive findings at catheter angiography.
Materials and methods. Each CTA was reviewed, with axial measurements of the anterior–posterior and transverse dimensions of the largest foci of hemorrhage recorded. Volumetric analysis was used to measure the volume of hemorrhage. These measurements were performed for both the arterial and portal venous phases. Additionally, the interval growth between the arterial and portal venous phase was also calculated.
CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
Hsu M et al.
Abdominal Radiology (2020) 45:615–622 - Results There was a statistically significant difference in the absolute size of the maximum transverse dimension on portal venous phase imaging (mean = 19.8 mm, p < 0.001), as well as an interval increase in transverse (mean = 8.5 mm, p < 0.001) and anteriorposterior (mean = 5.4 mm, p = 0.027) size between arterial and portal venous phases in patients with positive catheter angiography versus negative catheter angiography. There was a statistically significant difference in the volume of hemorrhage on arterial (mean = 1.72 cm3, p = 0.020) and portal venous phases (mean = 5.89 cm3, p = 0.016), as well as an interval change in the size of hemorrhage between the two phases (mean = 4.17 cm3, p = 0.020) in patients with positive catheter angiography versus patients in the negative catheter angiography group.
Conclusions The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.
CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
Hsu M et al.
Abdominal Radiology (2020) 45:615–622 - Results There was a statistically significant difference in the volume of hemorrhage on arterial (mean = 1.72 cm3, p = 0.020) and portal venous phases (mean = 5.89 cm3, p = 0.016), as well as an interval change in the size of hemorrhage between the two phases (mean = 4.17 cm3, p = 0.020) in patients with positive catheter angiography versus patients in the negative catheter angiography group.
Conclusions The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.
CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
Hsu M et al.
Abdominal Radiology (2020) 45:615–622 - “The average maximum anterior–posterior size of hem- orrhage on the portal venous phase was 14.0 mm (range 2–64 mm) for the positive catheter angiography group as compared to 8.0 mm (range 1–34 mm) for the negative catheter angiography group. These were not statistically significantly different (p = 0.057). The average increase in maximum transverse size of hemorrhage between the arterial and portal venous phases was 8.5 mm (range 0–24 mm) for the positive catheter angiography group as compared to 1.2 mm (range 0–9 mm) for the negative angiography group. This was statistically significantly different (p < 0.001).”
CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
Hsu M et al.
Abdominal Radiology (2020) 45:615–622 
CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
Hsu M et al.
Abdominal Radiology (2020) 45:615–622- "The absolute axial size and volume of hemorrhage, as well as the interval change between the arterial and portal venous phases of CTA imaging is predictive of subsequent positive catheter angiography.”
CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography
Hsu M et al.
Abdominal Radiology (2020) 45:615–622
- Duodenal Perforation: Causes
- peptic ulcer disease
- diverticulitis
- trauma
- secondary to malignancy
- procedural complication. - "Risk factors for gastroduodenal artery pseudoaneurysm include acute pancreatitis and pancreaticoduodenectomy with pancreaticojejunal leak, ulcers, or iatrogenic causes (surgery, endoscopy with biopsy). In cases of ongoing hemorrhage, visualization of bleeding is dependent on the rate and duration of bleeding as well as CT technique. In patients with suspected gastrointestinal hemorrhage, IV contrast should be administered, and positive oral contrast must be avoided as it obscures visualization of active bleeding.”
Duodenal emergencies: utility of multidetector CT with 2D multiplanar reconstructions for challenging but critical diagnoses
Polotsky M, Vadvala HV, Fishman EK, Johnson PT
Emergency Radiology https://doi.org/10.1007/s10140-019-01735-7 - “The most common symptomatic benign neoplasm of the duodenum is a benign gastro- intestinal stromal tumor (GIST). GIST appears as a heterogeneous mass, with varying degrees of enhancement based on the size, and can be exophytic or cause narrowing of the bowel lumen. An important differential for GIST is carcinoid tumor. Duodenal carcinoids (8% of GI carcinoids) are hyperenhancing lesions on arterial and portal venous phase appearing as intraluminal polyps or masses or circumferential wall thickening.”
Duodenal emergencies: utility of multidetector CT with 2D multiplanar reconstructions for challenging but critical diagnoses
Polotsky M, Vadvala HV, Fishman EK, Johnson PT
Emergency Radiology https://doi.org/10.1007/s10140-019-01735-7
- Results Intratumoral hemorrhage was seen in 15.4% and 25.6% of GISTs and in 0% and 0% of non-GISTs (p=0.079 and 0.010), with good interobserver agreement (κ = 0.715). The drainage vein diameter correlated well with the maximum diam- eter of the tumor (r = 0.744, p < 0.001). The CT value of the solid tumor part in the arterial and venous phases (p < 0.01) and the CT value of the drainage vein in the arterial phase (p < 0.05) were higher for GISTs than for non-GISTs (p < 0.01).
Conclusions Strong parenchymal enhancement with the peak in the arterial phase and the CT value of the drainage vein in the arterial phase was characteristics findings of GIST compared with non-GISTs. The diameter of the drainage vein was proportional to the maximum diameter of GISTs.
Comparison of characteristic computed tomographic findings of gastrointestinal and non‐gastrointestinal stromal tumors in the small intestine
Inoue A et al.
Abdominal Radiology (2019) 44:1237–1245 - Results Intratumoral hemorrhage was seen in 15.4% and 25.6% of GISTs and in 0% and 0% of non-GISTs (p=0.079 and 0.010), with good interobserver agreement (κ = 0.715). The drainage vein diameter correlated well with the maximum diameter of the tumor (r = 0.744, p < 0.001). The CT value of the solid tumor part in the arterial and venous phases (p < 0.01) and the CT value of the drainage vein in the arterial phase (p < 0.05) were higher for GISTs than for non-GISTs (p < 0.01).
Comparison of characteristic computed tomographic findings of gastrointestinal and non‐gastrointestinal stromal tumors in the small intestine
Inoue A et al.
Abdominal Radiology (2019) 44:1237–1245
- “In the emergent setting, CT may yield criti- cal information regarding the presence, location, and cause of active bleeding—data that can guide the choice of subsequent therapy. Recent developments in the use of and techniques for performing CT angiography have made it a potential first-line tool for evaluating acute GI bleeding.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Acute gastrointestinal (GI) bleeding is a common problem, occurring in the upper GI tract of 100–200 per 100000 persons annually and in the lower GI tract of 20.5–27.0 per 100000 persons annually. Although 80%–85% of cases of GI bleeding resolve spontaneously, it can result in massive hemorrhage and death. Most causes of acute GI bleeding are identifiable and treatable.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “In the current nomenclature, upper GI bleeding (UGIB) is defined as bleeding originating proximal to the Treitz ligament, and lower GI bleeding (LGIB) is defined as bleeding originating from the colon or rectum. The term suspected small-bowel bleeding is used when the upper and lower GI tracts have been evaluated (typically with endoscopy) and no bleeding site has been identified. The term obscure GI bleeding is used when no bleeding source is found after the entire GI tract has been examined with advanced techniques.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Endoscopy is highly useful for diagnosing the cause of UGIB, with 92%–98% sensitivity and 3%–100% specificity, and enables effective treatment of bleeding in the majority of cases.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “CT angiography is an accurate examination for identifying the source of acute GI bleeding. A meta-analysis of data from 672 patients with moderate to severe UGIB and/or LGIB revealed an overall sensitivity of 85% and a specificity of 92% for detection of the bleeding site.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Most complications of GI hemorrhage result from hypotension; therefore, the patient must be stabilized and his or her blood volume must be restored before a diagnostic workup is initiated (6,7). Reversal of anticoagulant medication and correction of the coagulation abnormality may be performed. However, before these measures are implemented, a risk-versus- bene t analysis in which the severity of bleed- ing, severity of coagulation abnormalities, and risk associated with discontinuing prophylactic medications are taken into account must be performed.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Radiologic methods have a role in assessing UGIB only when upper endoscopy is not feasible or yields inconclusive results. Upper GI endoscopy may be contraindicated in the setting of shock, substantial comorbidity, or massive hemorrhage. Adequate endoscopic evaluation of the bleeding source may not be possible when extensive luminal blood obscures visualization or the bleeding originates from a difficult anatomic location such as the distal duodenum.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Colonoscopy has several limitations. Patients must have undergone adequate colon preparation before proceeding to colonoscopy. Colonoscopy without colon preparation is not recommended by the American College of Gastroenterology. In emergent situations, a rapid colon preparation involving the administration of 4–6 L of a polyethylene glycol–based solution for 3–4 hours may be attempted. However, this procedure is frequently difficult to perform, and it may result in an incomplete or nondiagnostic endoscopic evaluation.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Detecting extraluminal disease in a bleeding patient maybe helpful in influencing treatment and goals of care—for example, in a case of a bleeding small- bowel neoplasm with metastatic disease. CT may also be used to identify complications of hypoperfusion (eg, signs of bowel ischemia or infarction) or the risk of organ disease exacerbation due to hypoperfusion (eg, findings of heart failure, arterial stenosis or coronary atherosclerosis, or renal parenchymal disease).”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Dual-energy CT techniques offer potential bene ts for evaluation of GI bleeding. Acquiring both high- and low-energy datasets through a volume of tissue enables one to estimate the radiation attenuation caused by iodine in each pixel of the image by using material-decomposition algorithms. Attenuation due to iodine can be subtracted from an image by means of VNC image reconstruction. A VNC image set can be used in place of a traditional nonenhanced image series to lower the radiation dose
of an examination.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “Optimal sensitivity for identification of active extravasation is achieved by evaluating the arterial phase and portal venous phase images together. The finding of intraluminal enhancement that changes in attenuation and shape between the arterial and portal venous phases is specific for active extravasation.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “A positive result at CT angiography is predictive of a positive result at subsequently performed fluoroscopic angiography. Sun et al found that among 26 patients with positive CT angiography results who subsequently underwent fluoroscopic angiography, the fluoroscopic findings were positive in 85% of cases. Compared with RBC scintigraphy, CT angiography has similar capability in the prediction of positive fluoroscopic angiography results but is better for localizing the site of bleeding.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “CT angiography and multiphase CT enterography yield a large volume of images that must be reviewed efficiently in the emergent setting. A consistent approach to these examinations facilitates effective interpretation of imaging findings. In addition to the routine scan pattern, the radiologist must add specific attention to the bowel and its vasculature for sources of GI hemorrhage. Thin-section reconstructions in the coronal plane are typically preferred for primary image review because more bowel is displayed at a given time. Additional planes are used for further evaluation of any suspicious findings. Review of coronal MIP images is helpful for identifying subtle enhancement associated with active extravasation, vascular anomalies, and tumors.” CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press)
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press)
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press)- “Anatomic locations where abnormalities are commonly seen are initially reviewed. Beginning with the arterial phase images, the ileocolic vessels are examined from their origin to the cecum. The ileocolic vein is examined for appropriate caliber and early filling; the findings of this evaluation may indicate a shunt through a vascular malformation or mass. The cecum is then reviewed for the presence of a mass or vascular malformation. Similarly, the inferior mesenteric artery is followed through the superior rectal artery and superior rectal vein to the rectum. The anus and rectum are examined for vascular malformations or masses.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) - “The causes of acute GI bleeding and the ex- pected associated imaging findings vary according to the segment of the GI tract.The most common causes of acute GI bleeding are categorized according to bowel segment in Tables 4 and 5 (3,59,60). Important points regarding the sources of bleed- ing in the upper GI tract, lower GI tract, and small bowel are reviewed in the following sections.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) 
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:000–0000 (in press)
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:000–0000 (in press)
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:000–0000 (in press)
- “Many common causes of bleeding in the esophagus and upper GI tract, such as peptic ulcer disease, cannot be optimally evaluated with CT. When the cause of UGIB is not found, identification of a high-attenuating hematoma or active hemorrhage is still clinically helpful and may lead to repeat endoscopy .Ulcers can be identified by carefully searching for defects in the enhancing gastric and duodenal mucosa.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:000–0000 (in press)
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“In younger patients, the most common cause of small-bowel bleeding is Crohn disease. Although mild GI bleeding is very common in patients with Crohn disease, severe GI hemorrhage is relatively rare, with a prevalence of 0.6%–4.0%.The bleeding associated with Crohn disease is most commonly attributed to diffuse areas of inflammation, but it can be due to a focal con- dition such as a bleeding ulcer or pseudopolyp. Inflammatory findings of Crohn disease include subtle wall thickening, mural enhancement, and ulcerations, which are best detected at CT enterography.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:000–0000 (in press)
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“Acute GI bleeding is a common problem that warrants expert clinical decision making and advanced diagnostic testing.The urgency of the diagnostic workup and the type of examination chosen are dependent on many factors, including suspected rate of bleeding, level of hemodynamic stability, and risk factors for complications. Endoscopy is currently the method of
choice for initial diagnostic evaluation and therapeutic intervention in patients with UGIB and LGIB. Rapid and comprehensive CT assessment enables fast detection of GI bleeding and abnormalities
of extraenteric structures, which can affect clinical decision making.”
CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:0000–0000 (in press) CT for Evaluation of Acute Gastrointestinal Bleeding Michael L.Wells et al. RadioGraphics 2018; 38:000–0000 (in press) - “Diverticulosis is the most common cause of acute LGIB, and the endoscopic evaluation of this condition can be particularly problematic. Attempts to locate a bleeding diverticulum among dozens or hundreds of diverticula and suboptimal bowel preparation can lead to hours of tedious endoscopic evaluation and nondiagnostic examinations. Preoperative localization of the bleeding source with CT may be invaluable for enabling targeted endoscopy.”
- CTA Abdomen for GI Bleeding: Facts
• Can detect bleeding rates as slow as 0.3 mL/min, compared with 0.5 to 1.0 mL/min for conventional angiography and 0.2 mL/min for Tc-99m-labeled RBC scintigraphy
• CTA may be positive when other techniques are negative including endoscopy and GI Bleeding studies
• Pooled sensitivity of 85% in diagnosing GI in the GI tract and may see intraluminal blood even if bleeding site is not seen - Upper GI Bleeding (UGIB): Facts
• Occurs proximal to the ligament of Treitz, originating from the esophagus, stomach, or duodenum
• UGIB will present with hematemesis or melena, but UGIB can also result in hematochezia
• Overt GI bleeding (GIB) refers to patients who present with melena or hematochezia with a source of bleeding that is identified.
• Occult GIB is defined as patients who present with iron-deficiency anemia with or without guaiac-positive stools who are found to have a source of bleeding. - Upper GI Bleeding (UGIB): Etiology
• The most common etiologies are;
• duodenal ulcer
• gastric erosions
• gastric ulcer
• varices
• Mallory-Weiss tears
• esophagitis,
• duodenitis
• neoplasm - ACR Appropriateness Criteria®Nonvariceal Upper Gastrointestinal Bleeding
- ACR Appropriateness Criteria®Nonvariceal Upper Gastrointestinal Bleeding
- ACR Appropriateness Criteria®Nonvariceal Upper Gastrointestinal Bleeding
- ACR Appropriateness Criteria®Nonvariceal Upper Gastrointestinal Bleeding
- PURPOSE: To evaluate the negative predictive power of computed tomography angiography (CTA) for the identification of obscure acute gastrointestinal (GI) bleeding (GI bleeding not visualized/treated by endoscopy) on subsequent mesenteric angiography (MA) with the intention to treat.
CONCLUSIONS: The high NPV of CTA for the evaluation of GI bleeding suggests utility for excluding patients that are unlikely to benefit from MA and subsequent endovascular therapy. CTA may be considered for the first line diagnostic study for the evaluation of obscure GI bleeding. No catheter angiography is needed in patients with an obscure acute gastrointestinal bleed and negative CTA.
Shukla PA et al. Clin Imaging. 2017 May - Jun;43:106-109 - PURPOSE: The diagnostic yield of computed tomography angiography (CTA) compared to digital subtraction angiography (DSA) for major obscure gastrointestinal bleeding (OGIB) is not known. Aim of the study was to prospectively evaluate the diagnostic yield of CTA versus DSA for the diagnosis of major OGIB.
CONCLUSION: Due to the lower invasiveness and higher diagnostic yield CTA should be favored over DSA for the diagnosis of major OGIB. Computed tomography versus digital subtraction angiography for the diagnosis of obscure gastrointestinal bleeding
Wildgruber M, Wrede CE, Zorger N, et al. Eur J Radiol. 2017 Mar;88:8-14. - OBJECTIVE: Lower gastrointestinal hemorrhage is a common cause of hospitalization and has substantial associated morbidity and financial cost. CT angiography (CTA) is emerging as an alternative to (99m)Tc-labeled RBC scintigraphy (RBC scintigraphy) for the localization of acute lower gastrointestinal bleeding (LGIB); however, data on comparative efficacy are scant. The aim of this study was to assess the utility of CTA compared with RBC scintigraphy in the overall evaluation and management of acute LGIB.
CONCLUSION: Both CTA and RBC scintigraphy can be used to identify active bleeding in 38% of cases. However, the site of bleeding is localized with CTA in a significantly higher proportion of studies. Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - “Several studies have shown high sensitivity of CTA in detecting the source and localizing the site of LGIB , including identification of nonbleeding intestinal and vascular lesions , and the results suggest an advantage over RBC scintigraphy.”
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - RESULTS: 24 consecutive patients (11 men; median age 64 years) were included. CTA and DSA identified an active bleeding or a potential bleeding lesion in 92% (22 of 24 patients; 95% CI 72%-99%) and 29% (7 of 24 patients; 95% CI 12%-49%) of patients, respectively (p<0.001). CTA and DSA identified an active bleeding in 42% (10 of 24; 95% CI 22%-63%) and 21% (5 of 24; 95% CI 7%-42%) of patients, respectively (p=0.06)
Computed tomography versus digital subtraction angiography for the diagnosis of obscure gastrointestinal bleeding
Wildgruber M, Wrede CE, Zorger N, et al. Eur J Radiol. 2017 Mar;88:8-14. - “The high NPV (negative predictive value) of CTA for the evaluation of GI bleeding suggests utility for excluding patients that are unlikely to benefit from MA (mesenteric angiography) and subsequent endovascular therapy. CTA may be considered for the first line diagnostic study for the evaluation of obscure GI bleeding.”
No catheter angiography is needed in patients with an obscure acute gastrointestinal bleed and negative CTA. Shukla PA et al. Clin Imaging. 2017 May - Jun;43:106-109. - Lower GI Bleeding (LGIB): Causes
• diverticular in origin (30–65%)
• angiodysplasia (4–15%)
• hemorrhoids (4–12%)
• ischemic colitis (4–11%)
• other colitis (3–15%)
• neoplasia (2–11%)
• post-polypectomy (2–7%)
• rectal ulcer (0–8%)
• rarer causes like Deulafoy lesions and rectal varices - “On MDCTA, the extravasation of contrast material may demonstrate a linear, jet like, swirled or a pooled configuration. MDCTA provides a validated road map for ongoing invasive intervention for hemostasis in patients with positive blush, however a negative first CTA is a good predictor that patients presenting with LGIB will settle spontaneously not necessitating further intervention.”
Making decisions using radiology in lower GI hemorrhage Zahid A, Young CJ International Journal of Surgery Volume 31, July 2016, Pages 100–103 - “Multidetector CT Angiography (MDCTA) provides a first line diagnostic tool in the detection of the site of lower GI hemorrhage. As opposed to nuclear imaging techniques, MDCT allows for greater anatomical assessment of LGIB, allowing for planning of more invasive treatment. In the setting of acute LGIB, its sensitivity has been reported at 91–92%.”
Making decisions using radiology in lower GI hemorrhage Zahid A, Young CJ International Journal of Surgery Volume 31, July 2016, Pages 100–103 - “Comparison was performed between patients who had positive and negative invasive MA (mesenteric angiogram) after a positive CTMA (CT mesenteric angiogram). Results Forty-eight invasive MA scans were performed in patients with LGIB following a positive CTMA scan. Twenty-three (47.9 %) were due to diverticular disease while 20 (41.7 %) bled from the small bowel. The median delay from a positive CTMA to invasive MAwas 144 (32–587)min. Of the 48 invasive MA, 25 demonstrated active extravasation. Invasive MA scans that was performed within 90 min after a positive CTMA scan were 8.56 (95 % CI 0.96–76.1, p=0.05) times more likely to detect a positive extravasation.”
Does the timing of an invasive mesenteric angiography following a positive CT mesenteric angiography make a difference? Koh FH et al. Int. J. Colorectal Dis., 30 (1) (2014 Nov 4), pp. 57–61 - “Preceding VA with a diagnostic study improves positive localization of the site of lower gastrointestinal hemorrhage compared with VA alone. Increasing the use of CTA for pre-angiography imaging may reduce overall imaging studies while appearing to increase positive yield at VA. Computed tomographic angiography can be used as part of a lower intestinal hemorrhage management algorithm and does not appear to worsen renal function despite the additional contrast load.”
Arteriography for Lower Gastrointestinal Hemorrhage: Role of Preceding Abdominal ComputedTomographic Angiogram in Diagnosis and Localization. Jacovides CL et al. JAMA Surg 2015 Jul;150(7):650-6. - “Although nuclear scintigraphy and CTA had similar sensitivity and specificity, localization of hemorrhage site by CTA was more precise and consistent with angiography findings. As a pre-angiography test, compared with nuclear scintigraphy, CTA reduced overall the number of imaging studies required (mean [SD] number per patient admission, 2.1 [0.3] vs 2.5 [0.8]; P = .005) and resulted in administration of more overall contrast (mean [SD], 220 [80] vs 130 [70] mL; P < .001) without worsening renal function.”
Arteriography for Lower Gastrointestinal Hemorrhage: Role of Preceding Abdominal ComputedTomographic Angiogram in Diagnosis and Localization. Jacovides CL et al. JAMA Surg 2015 Jul;150(7):650-6.
- Small Bowel Angiodysplasia: Facts
• Most common cause of small bowel bleeding
• Associated with end-stage renal disease and aortic stenosis
• Most common in the right colon but can occur throughout the small bowel
• Tuft -like hypervascular enhancing focus less than 5 mm which fades on delayed phases.
• Multifocal in 40% to 75% cases
• Composed of abnormally dilated thin-walled vessels with high propensity for bleeding
- OBJECTIVE: Lower gastrointestinal hemorrhage is a common cause of hospitalization and has substantial associated morbidity and financial cost. CT angiography (CTA) is emerging as an alternative to (99m)Tc-labeled RBC scintigraphy (RBC scintigraphy) for the localization of acute lower gastrointestinal bleeding (LGIB); however, data on comparative efficacy are scant. The aim of this study was to assess the utility of CTA compared with RBC scintigraphy in the overall evaluation and management of acute LGIB.
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - CONCLUSION:
Both CTA and RBC scintigraphy can be used to identify active bleeding in 38% of cases. However, the site of bleeding is localized with CTA in a significantly higher proportion of studies.
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - MATERIALS AND METHODS: We retrospectively reviewed images from all CTA examinations performed for suspected acute LGIB at our tertiary care hospital from January 2010 through November 2011. The comparison group was determined by retrospective review of twice the number of RBC scintigraphic scans consecutively obtained from June 2008 to November 2011 for the same indication. All CTA and RBC scintigraphic scans were reviewed for accurate localization of the site and source of suspected active LGIB.
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - “Seventeen (38%) CTA scans showed active gastrointestinal bleeding compared with 34 (38%) RBC scintigraphic scans (p = 1.000). However, the site of bleeding was accurately localized on 24 (53%) CTA scans. This proportion was significantly greater than the proportion localized on RBC scintigraphic scans (27 [30%]) (p = 0.008).”
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - “Our data strongly support CTA as a valuable addition to the current modalities for the evaluation and management of acute LGIB. We expect that future studies with a larger sample size and a prospective design will con- firm our findings and help establish CTA as the preferred imaging modality in the overall algorithm for the management of acute LGIB.”
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - PURPOSE: To evaluate the negative predictive power of computed tomography angiography (CTA) for the identification of obscure acute gastrointestinal (GI) bleeding (GI bleeding not visualized/treated by endoscopy) on subsequent mesenteric angiography (MA) with the intention to treat.
CONCLUSIONS: The high NPV of CTA for the evaluation of GI bleeding suggests utility for excluding patients that are unlikely to benefit from MA and subsequent endovascular therapy. CTA may be considered for the first line diagnostic study for the evaluation of obscure GI bleeding.
Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy. Feuerstein JD et al. AJR Am J Roentgenol. 2016 Sep;207(3):578-84 - Lower GI Bleeding: Facts
• lower gastrointestinal bleeding (LGIB) accounts for approximately 24% of cases of gastrointestinal hemorrhage
• The disease spectrum varies from chronic and intermittent blood loss to severe acute hemorrhage.
• Overall mortality ranges from 4% to 5% but can be as high as 23% depending on age, comorbid conditions, and severity of hemorrhage
- “Gastrointestinal (GI) bleeding is a common medical problem, with high associated morbidity and mortality. The clinical presentation of gastrointestinal hemorrhage varies with the location of the bleeding source, the intensity of the bleed, and the presence of comorbidities that affect the ability to tolerate blood loss.”
Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009 - “Conventional endoscopic examinations are usually the initial diagnostic tests in patients presenting with overt gastrointestinal hemorrhage. However, implementation of upper tract endoscopy and colonoscopy in the emergency setting can be challenging due to inconsistent availability of the service and difficulties in achieving adequate colonic cleansing in emergent situations. Thus, imaging tests are often relied upon to establish the location and the cause of bleeding, either for initial diagnosis or after non-revealing upper and lower tract endoscopies ("obscure" bleeding). This article discusses the imaging evaluation of patients with gastrointestinal bleeding and reviews the imaging appearance of the most common causes, taking into account the two most relevant clinical presentations: overt bleeding and obscure bleeding.
“
Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009 - “The anatomic landmark traditionally used to classify the source of GI bleeding is the ligament of Treitz, with upper GI bleeding originating proximal to the ligament and lower GI bleeding distal to it.”
Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009 - “ The most common causes of upper tract bleeds are esophageal or gastric varices, gastritis or duodenitis, gastric cancer, and peptic ulcer disease. Causes of acute lower gastrointestinal tract hemorrhage include colonic diverticula, angioectasia, colonic or small bowel neoplasms, Meckel’s diverticulum, rectal ulcers, and hemorrhoids.” Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009
- “A careful evaluation is necessary to differentiate clot from non-hemorrhagic hyperattenuating contents, such as retained enteric contrast material, foreign bodies, and suture material. The attenuation coefficient of extraluminal blood typically is higher than usual intestinal contents: 30–45 Hounsfield units (HU) for unclotted blood and 40–70 HU for clotted blood.”
Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009 - “In addition, low intensity bleeds may be difficult to detect when extravasated contrast material dilutes with pre-existent intraluminal fluid or clot. Hyperenhancement of the bowel and hypervascular masses can simulate or mask true extravasated contrast material. Ingested or retained hyperattenuating foci in the bowel lumen can easily be characterized as such by comparing the unenhanced with the two enhanced series.”
Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009 - “Angioectasia is the most common vascular abnormality and consists of thin tortuous veins usually 2–10 mm in size with an arborizing pattern. Angioectasias are common in the general population. They are frequently multiple and most do not bleed. Therefore, the detection of angioectasia does not necessarily indicate that this is the source of bleeding.”
Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009 - “Based on the clinical presentation, GI bleeding can be ‘‘overt’’ (visible evidence of bleeding such as hematemesis or melena) or ‘‘occult’’ (iron deficiency anemia and positive fecal blood test). Bleeding is ‘‘obscure’’ when evaluation with conventional upper and lower tract endoscopy does not reveal the source.”
Gastrointestinal hemorrhage: evaluation with MDCT. Soto JA et al. Abdom Imaging. 2015 Jun;40(5):993-1009
- “ Because of the high prevalence in nonbleeding patients and frequent multiplicity of angioectasias, determining the clinical benefit from their detection by multiphase CTE and endoscopy is problematic. Although arterial lesions are less commonly encountered clinically, their detection is critically important because of high risk of life threatening bleeding. Along with wireless capsule endoscopy and balloon-assisted endoscopy, multiphase CTE is a useful tool for the evaluation of patients with obscure gastrointestinal bleeding due to small-bowel vascular lesions”
Multiphase CT Enterography Evaluation of Small Bowel Vascular Lesions
Huprich JE et al.
AJR 2013; 201:65-72 - “ Because of the high prevalence in nonbleeding patients and frequent multiplicity of angioectasias, determining the clinical benefit from their detection by multiphase CTE and endoscopy is problematic. Although arterial lesions are less commonly encountered clinically, their detection is critically important because of high risk of life threatening bleeding.”
Multiphase CT Enterography Evaluation of Small Bowel Vascular Lesions
Huprich JE et al.
AJR 2013; 201:65-72 - “ Along with wireless capsule endoscopy and balloon-assisted endoscopy, multiphase CTE is a useful tool for the evaluation of patients with obscure gastrointestinal bleeding due to small-bowel vascular lesions.”
Multiphase CT Enterography Evaluation of Small Bowel Vascular Lesions
Huprich JE et al.
AJR 2013; 201:65-72 - “ Although relatively noninvasive, capsule endoscopy can be associated with a 30% rate of false positive findings, up to a 20% rate of incomplete small bowel evaluation, and a small risk of capsule retention, sometimes necessitating endoscopic or surgical removal.”
Multiphase CT Enterography Evaluation of Small Bowel Vascular Lesions
Huprich JE et al.
AJR 2013; 201:65-72
- “ CT angiography performed in the emergency setting in patients with acute lower intestinal bleeding is feasible and correctly depicts the presence and location of active or recent hemorrhage, as well as the potential cause, in the majority of patients.”
Acute Lower Intestinal Bleeding: Feasibility and Diagnostic Performance of CT Angiography
Marti M et al.
Radiology 2012; 262:109-116 - “ CT angiography depicted or helped exclude active or recent bleeding with an accuracy of 98% (46 of 47 patients).”
Acute Lower Intestinal Bleeding: Feasibility and Diagnostic Performance of CT Angiography
Marti M et al.
Radiology 2012; 262:109-116 - “ CT angiography correctly helped identify the cause of bleeding in 93% (39 of 42) of patients in whom a source of hemorrhage was ultimately established.”
Acute Lower Intestinal Bleeding: Feasibility and Diagnostic Performance of CT Angiography
Marti M et al.
Radiology 2012; 262:109-116 - “ Findings of CT angiography and the standard of reference (angiography, colonoscopy, or surgical findings) were concordant for determining definitive or potential cause of bleeding in 44 of 47 patients (93% accuracy).”
Acute Lower Intestinal Bleeding: Feasibility and Diagnostic Performance of CT Angiography
Marti M et al.
Radiology 2012; 262:109-116 - “ Rather than restricting it to cases where colonoscopy fails initially, in the majority of cases, we propose CT angiography as the first step in diagnostic evaluation of patients with substantial bleeding for confirmation of active or recent hemorrhage and correct identification of the site and cause of bleeding.”
Acute Lower Intestinal Bleeding: Feasibility and Diagnostic Performance of CT Angiography
Marti M et al.
Radiology 2012; 262:109-116 - GI Bleed Scan protocol
- Non contrast
- Arterial phase (trigger at 150 HU)
- Venous phase (at 70 sec post start of injection)
- Acute Lower Intestinal Bleeding: Feasibility and Diagnostic Performance of CT Angiography
Marti M et al.
Radiology 2012; 262:109-116 - Why do a non-contrast CT for GI Bleeding studies?
- Prevent confusion of high density material in or near bowel with hemorrhage
- High density material in bowel is considered 60 HU or greater
- “ CTA is reported as demonstrating bleeding up to 0.3 mL/min and DSA up to 0.5 mL/min.”
Acute Gastrointestinal bleeding: CT Angiography with Multi-planar Reformatting
Steiner K et al.
Abdom Imaging (2011) 36:115-125 - “ CTA is a valuable tool for the interventional radiologist as, by demonstrating the site of bleeding, it allows planning of possible endovascular treatment options prior to angiography.”
Acute Gastrointestinal bleeding: CT Angiography with Multi-planar Reformatting
Steiner K et al.
Abdom Imaging (2011) 36:115-125 - “ CT angiography is an important non-invasive diagnostic tool in the management of gastrointestinal hemorrhage. A systematic and meticulous approach to image interpretation using multiplanar reformatting in conjunction with maximum intensity projections should be used, in particular to detect focal sites of extravasation of contrast and small pseudoaneurysms.”
Acute Gastrointestinal bleeding: CT Angiography with Multi-planar Reformatting
Steiner K et al.
Abdom Imaging (2011) 36:115-125 - “Although CT enterography has limited sensitivity (55.2%; 16 of 29 patients) in identifying the source of obscure gastrointestinal bleeding, positive CT enterography findings can reliably indicate the true cause of of obscure GI bleeding with a high positive predictive value (100%; 16 of 16 patients).”
Obscure Gastrointestinal Bleeding: Diagnostic Performance of Multidetector CT Enterography
Lee SS et al.
Radiology 2011; 259:739-748 - “ CT enterography has a potential role in the evaluation of obscure gastrointestinal bleeding. Despite the limited sensitivity of CT enterography, positive CT enterographic findings can reliably indicate the true source of obscure gastrointestinal bleeding. CT enterography is particularly effective in helping identify the source of bleeding in patients with a history of massive bleeding.”
Obscure Gastrointestinal Bleeding: Diagnostic Performance of Multidetector CT Enterogrphy
Lee SS et al.
Radiology 2011; 259:739-748 CONCLUSION: CT angiography is an accurate, cost effective tool in the diagnosis of acute GI bleeding and can show the precise location of bleeding, thereby directing further management.
Usefulness of CT angiography in diagnosing acute gastrointestinal bleeding: A meta-analysis
Lian-Ming Wu, Jian-Rong Xu, Yan Yin, Xin-Hua Qu
World J Gastroenterol 2010 August 21:16(31):3957-3963- Meckels Diverticulum: Facts
- Use of pharmacologic interventions can increase positive rate of Meckels scan. Drugs used include Pentagastrin,cimetidine and glucagon
- Current use of MDCT/CTA may be important - Meckels Diverticulum: Facts
- Detection by Tc-99m pertechnetate scan has a 90% detection rate in children but lower in adults
- False positive tests can occur with intussuception, crohns disease, AV malformations, GIST tumors, small bowel duplication with ectopic mucosa
- False negative tests occur when lack of adequate gastric mucosa in Meckels, or when decreased blood supply to region, or with brisk bleeding so tracer does not accumulate in the region - Meckels Diverticulum: Facts
- Most common congenital anomaly of GI tract and occurs in up to 2% of the population
- Occurs within 60 cm of ileocecal valve and is 6 cm in length
- Up to 57% of these contain ectopic gastric mucosa which is responsible for clinical symptoms
- Detection by Tc-99m pertechnetate scan which is actively accumulated and secreted by mucoid cells of gastric mucosa - ACR Appropriateness Criteria on Upper Gastrointestinal Bleeding
- Technetium-99m labeled erythocyte scans are of limited value in diagnosing UGIB but remain useful in certain cases of obscure UGIB
- Variceal UGIB refractory to endoscopic management should be treated with TIPS insertion. Primary and secondary TIPS patency rates have impoved dramatically with the use of stent grafts rather than bare metal stents
ACR Appropriateness Criteria on Upper Gastrointestinal Bleeding
Schenker MP et al.
J Am Coll radiol 2010;7:845-853 - ACR Appropriateness Criteria on Upper Gastrointestinal Bleeding
- All patients with presumed UGIB should first be examined by upper endoscopy
- Angiography and embolization should be considered for all patients with a known source of arterial UGIB refractory to endoscopic management for those with brisk, active bleeding and negative results on endoscopy
- CT is particularly useful for the localizing of obscure UGIB and in the workup of a patient with UGIB and a history of aortic reconstruction or pancreaticobiliary procedure - Upper GI Bleed: Common Causes per Endoscopy
- Duodenal ulcer (24.3%)
- Gastric erosions (23.4%)
- Gastic ulcer (21.3%)
- Varices (10.3%)
- Mallory-Weiss tear (7.2%)
- Esophagitis (6.3%)
- Duodenitis (5.8%)
- Neoplasms (2.9%) - Upper GI Bleed: Facts
- Definition: bleeding source is proximal to the ligament of Treitz so originates from the esophagus, stomach or duodenum
- Incidence in USA is between 36 and 48 per 100,000 persons annually
- Most common etiology is a duodenal ulcer (24.3%) - GI Bleeding: Classification
- Upper GI Bleed: proximal to the ligament of Trietz and accounts for 70% of bleeds. Mortality rate up to 10%
- Lower GI Bleed: distal to the ligament of Trietz and accounts for 30% of cases of GI bleed. Mortality rate up to 3.6% "In patients presenting with acute upper and lower GI bleeding, 64 MDCT has the potential of detecting the source of bleeding. This is a relatively new application for CT, which cannot only detect the site of hemorrhage but can also map out the relevant vascular anatomy, which can be crucial for either interventional embolization or surgical resection."
Acute Gastrointestinal Bleeding: The Potential Role of 64 MDCT and 3D Imaging in the Diagnosis
Horton KM, Jeffrey RB, Federle MP, Fishman EK
Emerg Radiol (2009) 16:349-356- Obscure GI Bleeding: Causes
Lower GI lesions
- Angiectasia
- Neoplasms - Obscure GI Bleeding: Causes
Middle GI lesions (over age 40)
- Angiectasia
- NSAID enteropathy
- Celiac disease - Obscure GI Bleeding: Causes
Middle GI lesions (under age 40)
- Tumors
- Meckel diverticulum
- Crohn disease
- Celiac disease - Obscure GI Bleeding: Causes
Upper GI lesions
- Varices
- Peptic ulcer
- Angiectasia
- Gastric antral vascular ectasia "Obscure GI bleeding (OGIB) is defined as loss of blood with no source identified after upper endoscopy and colonoscopy."
Gastroenterologic and Radiologic Approach to Obscure Gastrointestinal Bleeding: How, Why and When?
Graca BM et al.
RadioGraphics 2010; 30:235-252"Obscure GI bleeding (OGIB) refers to bleeding from the GI tract that persists or recurs without an obvious cause after esophagogastroduodenoscopy and colonoscopy."
Gastroenterologic and Radiologic Approach to Obscure Gastrointestinal Bleeding: How, Why and When?
Graca BM et al.
RadioGraphics 2010; 30: 235-252- Aortoenteric Fistulas: CT Findings
- Fistulae between native aorta and the adjacent bowel
- Hematoma may seen in the periaortic aorta
- Penetrating ulcer of the aorta is seen
- 80% of the fistulae involve the duodenum - Aortoenteric Fistulas: Clinical Findings Gastrointestinal bleeding80%Sepsis44%Abdominal pain30%Back pain15%Groin mass12%Abdominal pulsatile mass6%
- Aortoenteric Fistulas: Facts
- Without surgical intervention mortality approaches 100%
- Primary fistula are rare and most cases are secondary and a result of aortic reconstructive surgery
- Secondary fistulae may occur between 2 weeks and 10 years post surgery "Although the CT features of aortoenteric fistula and perigraft infection often are similar, ectopic gas, loss of fat plane, extravasation of aortic contrast material into the enteric lumen, and leakage of enteric contrast material into the paraprosthetic space are highly suggestive of aortoenteric fistula in a patient with gastrointestinal bleeding."
Aortoenteric Fistulas: CT Features and Potential Mimics
Vu QDM et al.
RadioGraphics 2009; 29: 197-209- Aortoenteric Fistulas: Differential Dx
- Retroperitoneal fibrosis
- Infected aortic aneurysm
- Infectious aortitis
- Perigraft infection without fistulization "This study found that triphasic CT enterography has the potential to identify the source of gastrointestinal bleeding in up to half of the patients if reader errors are eliminated."
Preliminary Estimate of Triphasic CT Enterography Performance in Hemodynamically Stable Patients with Suspected Gastointestinal Bleeding
Hara A et al.
AJR 2009; 193:1252-1260- Spontaneous Abdominal Hemorrhage: Ob/Gyn
- Rupture of an ectopic pregnancy (ring enhancing cystic adnexal mass surrounded by blood)
- Rupture of an ovarian cyst
- HELLP syndrome - Spontaneous Abdominal Hemorrhage: Adrenal
- Anticoagulation therapy
- Severe stress
- Sepsis
- Occult adrenal tumor (primary or metastatic) - Spontaneous Abdominal Hemorrhage: Kidney - Rupture of a tumor like an angiomyolipoma or renal cell carcinoma
- Splenic Artery Pseudoaneurysms: Presentation
- abdominal pain
- melana or hematochezia
- hematemasis
- fact: pseudoaneurysms rupture in up to 37% of cases with mortality then approaching 90% - Splenic Artery Aneurysm: Associated Conditions
- Atherosclerosis
- Hypertension
- Portal hypertension
- Cirrhosis
- Pregnancy
- Liver transplantation - Splenic Artery Aneurysm: Facts
- 3rd most common intra-abdominal aneurysm
- Frequency of 0.2% to 10.4%
- 4x more common in woman
- 3x more likely to rupture in men
- Splenic Vascular Pathology
- Aneurysm
- Pseudoaneurysm
- Fact: Aneurysms usually are incidental findings while pseudoaneurysms usually present with symptoms
- Spontaneous Abdominal Hemorrhage: Spleen
- Marked splenomegaly in malignancies like acute leukemia and lymphoma
- Marked splenomegaly in infectious causes like mononucleosis or CMV infection
- Prior trauma or history of repeated episodes of pancreatitis Spontaneous Abdominal Hemorrhage: Liver
- Rupture of an underlying tumor
----Hepatic adenoma
----Hepatoma
- Lymphoma
- HELLP syndrome (HELLP- hemilysis, elevated liver enzymes, low platelet count)Spontaneous Abdominal Hemorrhage: Causes
- Visceral (liver, spleen, renal and adrenal) - Gynecologic
- Coagulopathy related
- VascularWhat is spontaneous abdominal hemorrhage?
"Spontaneous abdominal hemorrhage is defined as the presence of intraabdominal hemorrhage from a nontraumatic and noniatrogenic cause."
- "MDCT is proposed as an alternative first line investigation to locate lower gastrointestinal bleeding before placing the patients under observation or performing embolization or surgery."
MDCT of Acute Lower Gastrointestinal Bleeding
Tew K et al.
AJR 2004; 182:427-430
- Coagulopathy or vasculitis ( polyarteritis nodosa and Wegener’s granulomatosis)