Pitfalls in detection of acute gastrointestinal bleeding with multi-detector row helical CT

Clinical outcomes of acute upper gastrointestinal bleeding according to the risk indicated by Glasgow-Blatchford risk score-computed tomography score in the emergency room

BACKGROUND/AIMS

Acute upper gastrointestinal (UGI) bleeding is a significant emergency situation with a mortality rate of 2% to 10%. Therefore, initial risk stratification is important for proper management. We aimed to evaluate the role of contrast-enhanced multidetector computed tomography (MDCT) for risk stratification in patients with acute UGI bleeding in the emergency room (ER).

METHODS

This retrospective study included patients with UGI bleeding in the ER. Glasgow-Blatchford risk score-computed tomography (GBS-CT) was assessed using a combination of GBS and the MDCT scan scoring system.

RESULTS

Of the 297 patients with UGI bleeding, 124 (41.8%) underwent abdominal MDCT. Among them, 90.3% were classified as high-risk by GBS, and five patients died (4.0%). Rebleeding occurred in nine patients (7.3%). The high-risk GBS-CT group had significantly higher in-hospital mortality (10.5% in high-risk vs. 1.4% in moderate risk vs. 0% in low-risk, p = 0.049), transfusion amount (p < 0.001), and endoscopic hemostasis (p < 0.001) compared to the moderate- and low-risk groups.

CONCLUSION

Adding MDCT scans to the existing validated prognosis model when predicting the risk of UGI bleeding in patients in the ER plays a significant role in determining in-hospital mortality, transfusions, and the need for endoscopic hemostasis.

The Role of CT-Angiography in the Acute Gastrointestinal Bleeding: A Pictorial Essay of Active and Obscure Findings

Gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalisation. Although 80–85% of cases of gastrointestinal bleeding resolve spontaneously, it can result in massive haemorrhage and death. The presentation of gastrointestinal bleeding can range from asymptomatic or mildly ill patients requiring only conservative treatments to severely ill patients requiring immediate intervention. Identifying the source of the bleeding can be difficult due to the wide range of potential causes, the length of the gastrointestinal tract and the intermittent nature of the bleeding. The diagnostic and therapeutic approach is fully dependent on the nature of the bleeding and the patient’s haemodynamic status. Radiologists should be aware of the appropriate uses of computed tomography angiography and other imaging modalities in patients with acute gastrointestinal bleeding, as well as the semiotics of bleeding and diagnostic pitfalls in order to appropriately diagnose and manage these patients. The learning objective of this review is to illustrate the computed tomography angiography technique, including the potential role of dual-energy computed tomography angiography, also highlighting the tips and tricks to identify the most common and uncommon features of acute gastrointestinal bleeding and its obscure form.

Adding non-contrast and delayed phases increases the diagnostic performance of arterial CTA for suspected active lower gastrointestinal bleeding

OBJECTIVES

When assessing for lower gastrointestinal bleed (LGIB) using CTA, many advocate for acquiring non-contrast and delayed phases in addition to an arterial phase to improve diagnostic performance though the potential benefit of this approach has not been fully characterized. We evaluate diagnostic accuracy among radiologists when using single-phase, biphasic, and triphasic CTA in active LGIB detection.

METHOD AND MATERIALS

A random experimental block design was used where 3 blinded radiologists specialty trained in interventional radiology retrospectively interpreted 96 CTA examinations completed between Oct 2012 and Oct 2017 using (1) arterial only, (2) arterial/non-contrast, and (3) arterial/non-contrast/delayed phase configurations. Confirmed positive and negative LGIB studies were matched, balanced, and randomly ordered. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive and negative predictive values, and time to identify the presence/absence of active bleeding were examined using generalized estimating equations (GEE) with sandwich estimation assuming a binary distribution to estimate relative benefit of diagnostic performance between phase configurations.

RESULTS

Specificity increased with additional contrast phases (arterial 72.2; arterial/non-contrast 86.1; arterial/non-contrast/delayed 95.1; p < 0.001) without changes in sensitivity (arterial 77.1; arterial/non-contrast 70.2; arterial/non-contrast/delayed 73.1; p = 0.11) or mean time required to identify bleeding per study (s, arterial 34.8; arterial/non-contrast 33.1; arterial/non-contrast/delayed 36.0; p = 0.99). Overall agreement among readers (Kappa) similarly increased (arterial 0.47; arterial/non-contrast 0.65; arterial/non-contrast/delayed 0.79).

CONCLUSION

The addition of non-contrast and delayed phases to arterial phase CTA increased specificity and inter-reader agreement for the detection of lower gastrointestinal bleeding without increasing reading times.

KEY POINTS

• A triphasic CTA including non-contrast, arterial, and delayed phase has higher specificity for the detection of lower gastrointestinal bleeding than arterial-phase-only protocols. • Inter-reader agreement increases with additional contrast phases relative to single-phase CTA. • Increasing the number of contrast phases did not increase reading times.

CT of acute abdominopelvic hemorrhage: protocols, pearls, and pitfalls

Abdominal and pelvic hemorrhage may be secondary to a number of causes and is often a medical emergency. Patient presentation ranges from obvious trauma with evidence of hemodynamic instability to vague symptoms. CT has become the imaging modality of choice for identifying abdominopelvic hemorrhage. Recognizing acute hemorrhage as well as identifying its location and severity are key to expediting management. In the Emergency Department, ultrasound often used in the initial evaluation of trauma patients, but is not sensitive for subtle bleeds or injuries. CT is the best first-line imaging tool to identify abdominal hemorrhage and, compared with angiography, has been shown to be superior in detecting intra-abdominal bleeding, especially when the bleeding rate is low. Depending on location and etiology, abdominopelvic hemorrhage may have a characteristic appearance, such as the "sentinel clot" sign associated with blunt trauma to the solid organs or the "triangle sign" of a mesenteric bleed. The following pictorial essay reviews CT technique, study interpretation, and interpretative pearls and pitfalls in the recognition of acute abdominopelvic hemorrhage.

Gastrointestinal Bleeding at CT Angiography and CT Enterography: Imaging Atlas and Glossary of Terms

Gastrointestinal (GI) bleeding is a common potentially life-threatening medical condition frequently requiring multidisciplinary collaboration to reach the proper diagnosis and guide management. GI bleeding can be overt (eg, visible hemorrhage such as hematemesis, hematochezia, or melena) or occult (eg, positive fecal occult blood test or iron deficiency anemia). 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. The purpose of this pictorial review by the Society of Abdominal Radiology GI Bleeding Disease-Focused Panel is to provide a practical resource for radiologists interpreting GI bleeding CT studies that reviews the proper GI bleeding terminology, the most common causes of GI bleeding, key patient history and risk factors, the optimal CT imaging technique, and guidelines for case interpretation and illustrates many common causes of GI bleeding. A CT reporting template is included to help generate radiology reports that can add value to patient care. An invited commentary by Al Hawary is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

Diagnosis of acute overt gastrointestinal bleeding with CT-angiography: Comparison of the diagnostic performance of individual acquisition phases

PURPOSE

To compare the respective values of arterial phase, portal venous phase and combination of phases using 64-section multidetector computed tomography (MDCT) for diagnosing acute overt gastrointestinal bleeding (AOGIB).

PATIENTS AND METHODS

Forty-nine patients with AOGIB were included. There were 30 men and 19 women, with a mean age of 65.4±15.6 (SD) years [range, 34-91years]. Two observers reviewed MDCT examinations in consensus for presence of active bleeding, location of bleeding site and nature of causative lesion. The different acquisition phases were reviewed independently.

RESULTS

AOGIB was identified in 28/49 patients (57%) with the multiphasic set, in 26/49 patients (53%) with arterial phase and in 25/49 patients (51%) with portal venous phase. Multiphasic set helped locate the bleeding site in 40/49 patients (82%). The cause was elucidated in 23/49 patients (47%) with multiphasic set. The differences between set performances were not statistically significant. Sensitivity for depicting AOGIB with the multiphasic set was 92% and specificity was 76%.

CONCLUSION

Multiphasic 64-section MDCT has high diagnostic performances in patients with AOGIB. Further studies with a larger population are needed to reach statistical significance and demonstrate better diagnostic performance of multiphasic MDCT in comparison with the arterial or portal phase alone.

CT angiography for acute gastrointestinal bleeding: what the radiologist needs to know

Acute gastrointestinal (GI) bleeding is a common cause of both emergency department visits and hospitalizations in the USA and can have a high morbidity and mortality if not treated rapidly. Imaging is playing an increasing role in both the diagnosis and management of GI bleeding. In particular, CT angiography (CTA) is a promising initial test for acute GI bleeding as it is universally available, can be performed rapidly and may provide diagnostic information to guide management. The purpose of this review was to provide an overview of the uses of imaging in the diagnosis and management of acute GI bleeding, with a focus on CTA.

Gastrointestinal hemorrhage: evaluation with MDCT

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. 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.

Computed tomography angiography in patients with active gastrointestinal bleeding

Gastrointestinal bleeding represents a common medical emergency, with considerable morbidity and mortality rates, and a prompt diagnosis is essential for a better prognosis. In such a context, endoscopy is the main diagnostic tool; however, in cases where the gastrointestinal hemorrhage is massive, the exact bleeding site might go undetected. In addition, a trained professional is not always present to perform the procedure. In an emergency setting, optical colonoscopy presents limitations connected with the absence of bowel preparation, so most of the small bowel cannot be assessed. Scintigraphy cannot accurately demonstrate the anatomic location of the bleeding and is not available at emergency settings. The use of capsule endoscopy is inappropriate in the acute setting, particularly in the emergency department at night, and is a highly expensive method. Digital angiography, despite its high sensitivity, is invasive, presents catheterization-related risks, in addition to its low availability at emergency settings. On the other hand, computed tomography angiography is fast, widely available and minimally invasive, emerging as a promising method in the diagnostic algorithm of these patients, being capable of determining the location and cause of bleeding with high accuracy. Based on a critical literature review and on their own experience, the authors propose a computed tomography angiography protocol to assess the patient with gastrointestinal bleeding.

Gastrointestinal Bleeding Scintigraphy in the Early 21st Century

Gastrointestinal bleeding scintigraphy performed with (99m)Tc-labeled autologous erythrocytes or historically with (99m)Tc-sulfur colloid has been a clinically useful tool since the 1970s. This article reviews the history of the techniques, the different methods of radiolabeling erythrocytes, the procedure, useful indications, diagnostic accuracy, the use of SPECT/CT and CT angiography to evaluate gastrointestinal bleeding, and Meckel diverticulum imaging. The causes of pediatric bleeding are discussed by age.

Multidetector CT angiography for acute gastrointestinal bleeding: technique and findings

Acute gastrointestinal bleeding is a common reason for emergency department admissions and an important cause of morbidity and mortality. Factors that complicate its clinical management include patient debility due to comorbidities; intermittence of hemorrhage; and multiple sites of simultaneous bleeding. Its management, therefore, must be multidisciplinary and include emergency physicians, gastroenterologists, and surgeons, as well as radiologists for diagnostic imaging and interventional therapy. Upper gastrointestinal tract bleeding is usually managed endoscopically, with radiologic intervention reserved as an alternative to be used if endoscopic therapy fails. Endoscopy is often less successful in the management of acute lower gastrointestinal tract bleeding, where colonoscopy may be more effective. The merits of performing bowel cleansing before colonoscopy in such cases might be offset by the resultant increase in response time and should be weighed carefully against the deficits in visualization and diagnostic accuracy that would result from performing colonoscopy without bowel preparation. In recent years, multidetector computed tomographic (CT) angiography has gained acceptance as a first-line option for the diagnosis and management of lower gastrointestinal tract bleeding. In selected cases of upper gastrointestinal tract bleeding, CT angiography also provides accurate information about the presence or absence of active bleeding, its source, and its cause. This information helps shorten the total diagnostic time and minimizes or eliminates the need for more expensive and more invasive procedures.

Obscure and occult gastrointestinal bleeding: comparison of different imaging modalities

Patients with persistent, recurrent, or intermittent bleeding from the gastrointestinal (GI) tract for which no definite cause has been identified by initial esophagogastroduodenoscopy, colonoscopy, or conventional radiologic evaluation are considered to have an obscure GI bleeding (OGIB). The diagnosis and management of patients with OGIB is challenging, often requiring extensive and expensive workups. The main objective is the identification of the etiology and site of bleeding, which should be as rapidly accomplished as possible, in order to establish the most appropriate therapy. The introduction of capsule endoscopy and double balloon enteroscopy and the recent improvements in CT and MRI techniques have revolutionized the approach to patients with OGIB, allowing the visualization of the entire GI tract, particularly the small bowel, until now considered as the "dark continent" . In this article we review and compare the radiologic and endoscopic examinations currently used in occult and OGIB, focusing on diagnostic patterns, pitfalls, strengths, weaknesses, and value in patients' management.

Detection and localization of active gastrointestinal bleeding with multidetector row computed tomography angiography: a 5-year prospective study in one medical center

GOAL

To prospectively assess the utility of multidetector row computed tomography angiography (MDCTA) in the diagnosis of active gastrointestinal bleeding (GIB).

BACKGROUND

MDCTA is a relatively recent advance in CT scanning technology enabling excellent vascular visualization and detection of various vascular abnormalities. However, there is no prospective study with a large population evaluating the role of MDCTA in the diagnosis of active GIB.

STUDY

From January 2006 to January 2011, 113 consecutive patients with clinical signs of active GIB underwent MDCTA (16-slice, 64-slice, or dual-source). The criteria for positive CT findings included active extravasation of contrast material within bowel lumen, abnormal bowel mucosal enhancement, vascular malformation, abnormally enhancing polyp or diverticulum, or tumor. Two radiologists reviewed the images and assessed CT findings in consensus. The standards of reference included digital subtraction angiography, endoscopy, surgery, or final pathology reports. Sensitivity, specificity, positive and negative predictive values, and accuracy of MDCTA for detection of active GIB were evaluated.

RESULTS

Positive CT findings for active GIB were identified in 80 of 113 patients (70.8%), all of which were confirmed by 1 or more reference standard. Negative MDCTA results were obtained in 33 patients (29.2%). Of these, 27 patients did not require any further intervention and were discharged without incident. The overall sensitivity, specificity, positive and negative predictive values, and accuracy of MDCTA was 86.0%, 100%, 100%, 60.6%, and 88.5%, respectively.

CONCLUSIONS

MDCTA is an accurate first-line screening method for detection and localization of GIB and can guide triage in patients with active GIB.

Multidetector CT angiography in acute gastrointestinal bleeding: why, when, and how

Acute gastrointestinal (GI) bleeding remains an important cause of emergency hospital admissions, with substantial related morbidity and mortality. Bleeding may relate to the upper or lower GI tract, with the dividing anatomic landmark between these two regions being the ligament of Treitz. The widespread availability of endoscopic equipment has had an important effect on the rapid identification and treatment of the bleeding source. However, the choice of upper or lower GI endoscopy is largely dictated by the clinical presentation, which in many cases proves misleading. Furthermore, there remains a large group of patients with negative endoscopic results or failed endoscopy, in whom additional techniques are required to identify the source of GI bleeding. Multidetector computed tomography (CT) with its speed, resolution, multiplanar techniques, and angiographic capabilities allows excellent visualization of both the small and large bowel. Multiphasic multidetector CT allows direct demonstration of bleeding into the bowel and is helpful in the acute setting for visualization of the bleeding source and its characterization. Thus, multidetector CT angiography provides a time-efficient method for directing and planning therapy for patients with acute GI bleeding. The additional information provided by multidetector CT angiography before attempts at therapeutic angiographic procedures leads to faster selective catheterization of bleeding vessels, thereby facilitating embolization. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.313105206/-/DC1.

[Gastrointestinal bleeding: the role of radiology]

Gastrointestinal bleeding represents a diagnostic challenge both in its acute presentation, which requires the point of bleeding to be located quickly, and in its chronic presentation, which requires repeated examinations to determine its etiology. Although the diagnosis and treatment of gastrointestinal bleeding is based on endoscopic examinations, radiological studies like computed tomography (CT) angiography for acute bleeding or CT enterography for chronic bleeding are becoming more and more common in clinical practice, even though they have not yet been included in the clinical guidelines for gastrointestinal bleeding. CT can replace angiography as the diagnostic test of choice in acute massive gastrointestinal bleeding, and CT can complement the endoscopic capsule and scintigraphy in chronic or recurrent bleeding suspected to originate in the small bowel. Angiography is currently used to complement endoscopy for the treatment of gastrointestinal bleeding.

Small intestinal vascular malformation bleeding: diagnosis by double-balloon enteroscopy combined with abdominal contrast-enhanced CT examination

Aim

The purpose of this study was to explore the value of double-balloon enteroscopy combined with abdominal vascular-enhanced CT examination for the diagnosis of intestinal vascular malformation bleeding, to explore a simple and effective method for the diagnosis of small intestinal vascular malformation bleeding.

Methods

Ten patients with intestinal bleeding were first examined with double-balloon enteroscopy. If active bleeding considered as vascular malformation was observed, the patient underwent abdominal vascular-enhanced CT examination. If no active bleeding was observed with double-balloon enteroscopy, the patient also underwent abdominal vascular-enhanced CT examination. When intestinal vascular malformation bleeding was diagnosed with double-balloon enteroscopy and/or abdominal vascular-enhanced CT examination, the patient underwent surgical operation and vascular malformation was confirmed with pathologic diagnosis.

Results

In ten patients who underwent double-balloon enteroscopy examination, active intestinal bleeding was observed in seven patients and no active bleeding was observed in three patients. All ten patients underwent abdominal vascular-enhanced CT examination and vascular malformation was detected in all the patients with confirmation by pathologic diagnosis.

Conclusion

Double-balloon enteroscopy combined with abdominal vascular enhanced CT examination is a simple and effective method for the diagnosis of intestinal vascular malformation bleeding.

Multi-detector row CT of patients with acute intestinal bleeding: a new perspective using multiplanar and MIP reformations from submillimeter isotropic voxels

Acute intestinal bleeding is a severe condition, with a mortality rate of up to 40% in case of associated hemodynamic instability. The diagnosis of acute intestinal bleeding is often challenging and to date, there is no definite consensus upon the most appropriate technique for this specific diagnosis. This pictorial essay illustrates our preliminary use of multiplanar (MPR) and maximum intensity projection (MIP) reformations using MDCT scanner with submillimeter and isotropic voxels as an adjunct to axial images in patients with acute intestinal bleeding. MDCT examinations were routinely performed with 64-slice helical CT scanner and images were reconstructed 0.6-mm thickness at 0.5-mm intervals. Multiplanar reconstructions and MIP views were created with a commercially available workstation. Reformatted images from submillimeter isotropic voxels enhanced the depiction of subtle vascular abnormalities and served as a useful adjunct to the axial plane images to improve diagnostic capabilities. Although we are aware that reformatted images should not replace careful analysis of the axial images in patients with acute gastrointestinal bleeding, reformatted images from submillimeter isotropic voxels may clarify the cause of the bleeding, add confidence to image analysis and help interventional radiologists or surgeons improving planning approach.