Acute gastrointestinal bleeding: detection of source and etiology with multi-detector-row CT

Value of multidetector computed tomography angiography in severe non-variceal upper gastrointestinal bleeding: a retrospective study in a referral bleeding unit

BACKGROUND

Non-variceal upper gastrointestinal bleeding is a common gastroenterological emergency associated with significant morbidity and mortality. Upper gastrointestinal endoscopy is currently recommended as the gold standard modality for both diagnosis and treatment. As historically played a limited role in the diagnosis of acute non-variceal upper gastrointestinal bleeding, multidetector-row computed tomography angiography is emerging as a promising tool in the diagnosis of non-variceal upper gastrointestinal bleeding, especially for severe cases. However, to date, evidence concerning the role of multidetector-row computed tomography angiography in the non-variceal upper gastrointestinal bleeding diagnosis is still lacking.

AIM

The purpose of this study was to retrospectively investigate the diagnostic performance of emergent multidetector-row computed tomography angiography performed prior to any diagnostic modality or following urgent upper endoscopy to identify the status, the site, and the underlying etiology of severe non-variceal upper gastrointestinal bleeding.

METHODS

Institutional databases were reviewed in order to identify severe acute non-variceal upper gastrointestinal bleeding patients who were admitted to our bleeding unit and were referred for emergent multidetector-row computed tomography angiography prior to any hemostatic treatment (< 3 h) or following (< 3 h) endoscopy, between December 2019 and October 2022. The study aim was to evaluate the diagnostic performance of multidetector-row computed tomography angiography to detect the status, the site, and the etiology of severe non-variceal upper gastrointestinal bleeding with endoscopy, digital subtraction angiography, surgery, pathology, or a combination of them as reference standards.

RESULTS

A total of 68 patients (38 men, median age 69 years [range 25-96]) were enrolled. The overall multidetector-row computed tomography angiography sensitivity, specificity, and accuracy to diagnose bleeding status were 77.8% (95% CI: 65.5-87.3), 40% (95% CI: 5.3-85.3), and 75% (95% CI: 63.0-84.7), respectively. Finally, the overall multidetector-row computed tomography angiography sensitivity to identify the bleeding site and the bleeding etiology were 92.4% (95% CI: 83.2-97.5) and 79% (95% CI: 66.8-88.3), respectively.

CONCLUSION

Although esophagogastroduodenoscopy is the mainstay in the diagnosis and treatment of most non-variceal upper gastrointestinal bleeding cases, multidetector-row computed tomography angiography seems to be a feasible and effective modality in detecting the site, the status, and the etiology of severe acute non-variceal upper gastrointestinal bleeding. It may play a crucial role in the management of selected cases of non-variceal upper gastrointestinal bleeding, especially those clinically severe and/or secondary to rare and extraordinary rare sources, effectively guiding timing and type of treatment. However, further large prospective studies are needed to clarify the role of multidetector-row computed tomography angiography in the diagnostic process of acute non-variceal upper gastrointestinal bleeding.

Diagnostic utility of CT angiography compared with endoscopy in patients with acute GI hemorrhage

BACKGROUND AND AIMS

Because it is minimally invasive, CT angiography (CTA) has emerged as an attractive diagnostic tool for investigation of acute GI hemorrhage.

METHODS

This study examined patients with acute GI bleeding who underwent CTA.

RESULTS

CTA was the initial diagnostic examination in 177 patients, identifying upper and lower GI bleeding lesions in 16 and 27 patients, respectively. In 103 patients with an initial negative CTA, 78 had endoscopy (32 EGD and 46 colonoscopy/flexible sigmoidoscopy), of whom 52 (67%) had a bleeding lesion identified, including 23 with a high-risk bleeding lesion requiring therapy. Peptic ulcer disease and diverticular bleeding were the most commonly identified bleeding lesions. With endoscopy as a criterion standard, the sensitivity of CTA for the detection of a source of GI bleeding was 20%.

CONCLUSIONS

CTA has very poor sensitivity for identification of a GI bleeding source or lesion, suggesting that CTA should not be used as an initial diagnostic test.

Clinical Predictors of Gastrointestinal Bleeding Source before Computed Tomography Angiography

BACKGROUND

Acute gastrointestinal bleeding (GIB) is a commonly encountered medical emergency. In cases of negative endoscopic evaluations, computed tomography angiography (CTA) is usually the next diagnostic step. To date, data regarding positive CTA examinations are lacking. We aimed to assess the clinical and laboratory parameters that predict a positive CTA examination, as demonstrated by the extravasation of contrast material into the bowel lumen.

METHODS

We performed a single-center retrospective study, including all patients who were admitted with GIB and who underwent CTA. Analysis was performed to compare patients' characteristics, and logistic regression was used to explore parameters associated with a positive CTA.

RESULTS

We included 154 patients. Of them, 25 patients (16.2%) had active GIB on CTA vs. 129 patients (83.8%) who did not. On univariate analysis, several parameters were positively associated with active GIB, including congestive heart failure (OR 2.47, 95% CI 1.04-5.86, p = 0.04), warfarin use (OR 4.76, 95% CI 1.49-15.21, p = 0.008), higher INR (OR 1.33, 1.04-1.69, p = 0.02), and low albumin level (OR 0.37, 95% CI 0.17-0.79, p = 0.01). On multivariate logistic regression analysis, only high INR (OR 1.34, 95% CI 1.02-1.76, p = 0.03) and low albumin (OR 0.3, 95% CI 0.12-0.7, p = 0.005) kept their positive association with active bleeding, while a high ASA score was negatively associated with an active GIB.

CONCLUSIONS

We could identify high INR and low albumin as strong predictors of active GIB, as demonstrated by positive CTA. On the other hand, comorbid patients classified by a high ASA score did not experience a higher rate of active GIB.

Diagnostic accuracy of RBC scintigraphy and CTA for detection of patients with suspected lower gastrointestinal bleeding: a systematic review and meta-analysis

OBJECTIVE

Detection of lower gastrointestinal bleeding (LGIB) through noninvasive modalities is very important in the successful management of LGIB. RBC scintigraphy and CT have a role in the detection of LGIB and guiding the management of patient by localization of the bleeding site. However, only a small number of studies have evaluated the role of RBC scintigraphy and CT in the diagnosis of LGIB. This systematic review was conducted to evaluate the diagnostic performance of RBC scintigraphy and CT in the detection of LGIB in patients with clinical or biochemical findings suspicious of LGIB.

METHODS

This systematic review followed PRISMA guidelines. Searches in PubMed, Scopus, and Embase were conducted using relevant keywords, and articles published through 30 April 2022, were included. Using endoscopy or surgical outcomes as the reference standard, the numbers of true and false positives and true and false negatives were extracted. Pooled estimates of diagnostic test accuracy - including sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and summary ROC (SROC) curve - were generated using bivariate random-effects meta-analysis.

RESULTS

Three studies comprising 171 patients were included in the systematic review and meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for the detection of LGIB using RBC scintigraphy were 0.787 (95% CI, 0.643-0.893), 0.289 (95% CI, 0.164-0.443), 1.214 (95% CI, 0.923-1.597) and 0.576 (95% CI, 0.296-1.121) respectively. The area under the SROC curve was 0.73. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio for the detection of LGIB using CT were 0.931 (95% CI, 0.772-0.992), 0.870 (95% CI, 0.737-0.951), 6.085 (95% CI, 0.840-44.097), 0.126 (95% CI, 0.006-2.509) respectively. The area under the SROC curve was 0.095.

CONCLUSION

RBC scintigraphy has overall good sensitivity and CTA has excellent sensitivity specificity, positive and negative likelihood ratio in the detection of LGIB in patients with clinical or biochemical findings suspicious for LGIB.CTA along with RBC scintigraphy can be used algorithmically to rule out patients who do not have a localization for the site of LGIB thereby helping these patients to avoid invasive procedures like endoscopy or surgical explorations.

The Accuracy of Computed Tomography Angiography Compared With Technetium-99m Labelled Red Blood Cell Scintigraphy for the Diagnosis and Localization of Acute Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis

Imaging tests are commonly used as an initial or early investigation for patients presenting with suspected acute gastrointestinal bleeding (AGIB). However, controversy remains regarding which of two frequently used modalities, computed tomography angiography (CTA) or technetium-99m labelled red blood cell scintigraphy (RBCS), is most accurate. This systematic review and meta-analysis was performed to compare the accuracy of CTA and RBCS for the detection and localization of AGIB. Five electronic databases were searched with additional manual searching of reference lists of relevant publications identified during the search. Two reviewers independently performed screening, data extraction and methodological assessments. Where appropriate, the bivariate model was used for meta-analysis of sensitivities and specificities for the detection of bleeding and Freeman-Tukey double-arcsine transformation used for meta-analysis of proportions of correctly localized bleeding sites. Forty-four unique primary studies were included: twenty-two investigating CTA, seventeen investigating RBCS and five investigating both modalities. Meta-analysis produced similar pooled sensitivities; 0.83 (95% CI 0.74-0.90) and 0.84 (0.68-0.92) for CTA and RBCS respectively. Pooled specificity for CTA was higher than RBCS; 0.90 (0.72-0.97) and 0.84 (0.71-0.91) respectively. However, differences were not statistically significant. CTA was superior to RBCS in correctly localizing bleeding; pooled proportions of 1.00 (0.98-1.00) and 0.90 (0.83-0.96) respectively (statistically significant difference, P < 0.001). There is no evidence that CTA and RBCS have different diagnostic performance with respect to the detection of AGIB. However, CTA is superior to RBCS in terms of correctly localising the bleeding site, supporting usage of CTA over RBCS as the first line imaging investigation.

Impact on Blood Product Utilization with Thromboelastography Guided Resuscitation for Gastrointestinal Hemorrhage

BACKGROUND

Thromboelastography (TEG) can guide transfusion therapy in trauma and has been associated with decreased transfusion requirements. This population differs from the medical population where the most common bleeding source is gastrointestinal hemorrhage (GIB). The utility of TEG in patients with acute GIB is not well described. We sought to assess whether the use of TEG impacts blood product utilization in patients with medical GIB.

METHODS

A retrospective study looking at all adult patients admitted with a primary diagnosis of GIB to the George Washington University Intensive Care Unit (ICU) between 01/01/2017 to 12/31/2019. The primary intervention was the use of TEG to guide blood product resuscitation in addition to standard of care (TEG arm) versus standard of care alone (non-TEG arm).

RESULTS

The primary outcome was the total number of blood products utilized. Patients in the TEG arm used more blood products compared to the non-TEG arm (9.10 vs 3.60, p < 0.001). There was no difference in secondary endpoints except for an increased requirement for mechanical ventilation within the TEG arm (26.2% vs 13.4%, p  =  0.018).

CONCLUSIONS

The use of TEG to guide resuscitation in patients with acute GIB may be associated with increased blood product utilization without any clinical benefit to patient-centered outcomes.

Role of multidetector computed tomography angiography in non-variceal upper gastrointestinal bleeding: A comprehensive review

Non-variceal upper gastrointestinal bleeding (NVUGIB) is a common gastroenterological emergency associated with significant morbidity and mortality. Upper gastrointestinal endoscopy is currently recommended as the gold standard modality for both diagnosis and treatment, with computed tomography traditionally playing a limited role in the diagnosis of acute NVUGIB. Following the introduction of multidetector computed tomography (MDCT), this modality is emerging as a promising tool in the diagnosis of NVUGIB. However, to date, evidence concerning the role of MDCT in the NVUGIB diagnosis is still lacking. The aim of our study was to review the current evidence concerning the role of MDCT in the diagnosis of acute NVUGIB.

Immediate coiling of a gastroduodenal arterial bleeding in a case of haemorrhagic shock without haematemesis, a case report

Introduction

and importance: Upper gastrointestinal (GI) bleeding is common in the clinic. In combination with haemorrhagic shock, morbidity is high. Rapid diagnosis and treatment can save lives. With the introduction of precision imaging several treatment options are feasible. Up-to-date diagnosis and treatment requires expertise from interventional radiology, gastroenterology and surgery to form a dedicated intervention team. This is illustrated by a typical case.

Case presentation

We report a 78-year-old otherwise healthy male with a severe diverticulum bleeding. He was initially diagnosed with acute pancreatitis. Approximately 60 minutes after CT scanning, he became haemodynamically instable. He also vomited coffee-like fluid but no clear blood or clots. A repeated CT scan showed active bleeding in the retroperitoneal space highly suspicious for a diverticular bleeding just outside the lumen of the duodenum. An acute multidisciplinary intervention team immediately decided not to perform endoscopy (according to the upper GI bleeding guidelines) but to extend the imaging procedure with digital subtraction angiography (DSA). By this time, active bleeding from a side branch of the gastroduodenal artery was noted and successfully coiled.

Clinical discussion

Guidelines determine day-to-day management in clinical medicine. Still, there is an exception to every rule. The case presented here was typical of upper GI bleeding with haemodynamic instability and signs of shock, but without haematemesis. This combination indicated a bleeding from somewhere outside the lumen of the GI tract. Instead of endoscopy, the acute intervention team decided to perform CT angiography (CTa) with subsequent DSA. On imaging, the bleeding focus was immediately identified and treated by coiling.

Conclusion

Performance of CTa immediately followed by DSA and no endoscopy was decided by an acute intervention team in a patient with upper GI bleeding and haemorrhagic shock. Swift coiling of the bleeding artery outside the GI tract lumen was successful. The team in charge relied on a hybrid multifunctional unit fully equipped to perform interventional radiologic as well as GI procedures.

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Direct computed tomography angiography could be an option in case the patient vomits no pure blood.

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Multidisciplinary revaluation is essential in an unstable patient with an upper GI bleeding until the situation is stabilized.

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The role of coiling is growing, with this important technic a laparotomy could be avoid.

Duodenal angiodysplasia: a case report

Background

Angiodysplasia (AD) is an abnormal, ectatic dilated, tortuous blood vessel that is found in the mucosa and the submucosa of the gastro-intestinal tract (GIT). While colonic angiodysplasia is a recognized finding of the lower intestinal tract in the elderly, small intestinal angiodysplasia is rare. However, it is an important reason of GIT bleeding so its detection and proper management can be a challenge. It should be considered among the differential diagnosis in the scenario of mild or intermittent GIT bleedings of obscure cause.

Case presentation

A 71-year-old woman was presented to our emergency department with hypovolemic shock due to lower GIT bleeding, and she was suffering of melena and severe anemia. The revision of past medical history revealed a history of hypertension, diabetes mellitus, and chronic renal disease. After stabilization, she underwent abdominal computed tomography (CT) which revealed a small abnormal vascular lesion along the anterior and posterior wall of the 2nd part of the duodenum. It appeared as blush of contrast in the arterial phase (representing dilated mucosal capillaries draining into tortuous submucosal vein) suggestive of vascular lesion (duodenal angiodysplasia). The patient was transferred to undergo an angiogram which confirmed the diagnosis of duodenal angiodysplasia. Super selective cannulation of the feeding artery was performed followed by post coiling angiogram which revealed successful embolization. No acute complications were encountered during or immediately after procedure.

Conclusion

AD is a rare but important cause that should be considered in the differential diagnosis of GIT bleeding especially in the older patients. It should be looked for in CT angiography done in such a clinical situation. Superselective coil embolization is a safe and effective technique to manage bowel AD.

The utility of a dual-phase, dual-energy CT protocol in patients presenting with overt gastrointestinal bleeding

Background

Due to their easy accessibility, CT scans have been increasingly used for investigation of gastrointestinal (GI) bleeding.

Purpose

To estimate the performance of a dual-phase, dual-energy (DE) GI bleed CT protocol in patients with overt GI bleeding in clinical practice and examine the added value of portal phase and DE images.

Materials and Methods

Consecutive patients with GI bleeding underwent a two-phase DE GI bleed CT protocol. Two gastroenterologists established the reference standard. Performance was estimated using clinical CT reports. Three GI radiologists rated confidence in GI bleeding in a subset of 62 examinations, evaluating first mixed kV arterial images, then after examining additional portal venous phase images, and finally after additional DE images (virtual non-contrast and virtual monoenergetic 50 keV images).

Results

52 of 176 patients (29.5%) had GI bleeding by the reference standard. The overall sensitivity, specificity, and positive and negative predictive values of the CT GI bleed protocol for detecting GI bleeding were 65.4%, 89.5%, 72.3%, and 86.0%, respectively. In patients with GI bleeding, diagnostic confidence of readers increased after adding portal phase images to arterial phase images (p = 0.002), without additional benefit from dual energy images. In patients without GI bleeding, confidence in luminal extravasation appropriately decreased after adding portal phase, and subsequently DE images (p = 0.006, p = 0.018).

Conclusion

A two-phase DE GI bleed CT protocol had high specificity and negative predictive value in clinical practice. Portal venous phase images improved diagnostic confidence in comparison to arterial phase images alone. Dual-energy images further improved radiologist confidence in the absence of bleeding.

Extravasation Volume at Computed Tomography Angiography Correlates With Bleeding Rate and Prognosis in Patients With Overt Gastrointestinal Bleeding

OBJECTIVE

Despite the identification of active extravasation on computed tomography angiography (CTA) in patients with overt gastrointestinal bleeding (GIB), a large proportion do not have active bleeding or require hemostatic therapy at endoscopy, catheter angiography, or surgery. The objective of our proof-of-concept study was to improve triage of patients with GIB by correlating extravasation volume of first-pass CTA with bleeding rate and clinical outcomes.

MATERIALS AND METHODS

All patients who presented with overt GIB and active extravasation on CTA from January 2014 to July 2019 were reviewed in this retrospective, institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study. Extravasation volume was assessed using 3-dimensional software and correlated with hemostatic therapy (primary endpoint) and with intraprocedural bleeding, blood transfusions, and mortality as secondary endpoints using logistic regression models (P < 0.0125 indicating statistical significance). Odds ratios were used to determine the effect size of a threshold extravasation volume. Quantitative data (extravasation volume, aorta attenuation, extravasation attenuation and time) were input into a mathematical model to calculate bleeding rate.

RESULTS

Fifty consecutive patients including 6 (12%) upper, 18 (36%) small bowel, and 26 (52%) lower GIB met inclusion criteria. Forty-two underwent catheter angiography, endoscopy, or surgery; 16 had intraprocedural active bleeding, and 24 required hemostatic therapy. Higher extravasation volumes correlated with hemostatic therapy (P = 0.007), intraprocedural active bleeding (P = 0.003), and massive transfusion (P = 0.0001), but not mortality (P = 0.936). Using a threshold volume of 0.80 mL or greater, the odds ratio of hemostatic therapy was 8.1 (95% confidence interval, 2.1-26), active bleeding was 11.8 (2.6-45), and massive transfusion was 18 (2.3-65). With mathematical modeling, extravasation volume had a direct and linear relationship with bleeding rate, and the lowest calculated detectable bleeding rate with CTA was less than 0.1 mL/min.

CONCLUSIONS

Larger extravasation volumes correlate with higher bleeding rates and may identify patients who require hemostatic therapy, have intraprocedural bleeding, and require blood transfusions. Current CTAs can detect bleeding rates less than 0.1 mL/min.

Computed tomography versus lower endoscopy as initial diagnostic method for evaluating patients with hematochezia at emergency room

For acute lower gastrointestinal bleeding (LGIB), lower gastrointestinal endoscopy is the preferred initial diagnostic test. However, it is difficult to perform urgently. Computed tomography (CT) is a convenient alternative.This study aimed to determine the diagnostic performance of CT compared to lower endoscopy as an initial test for evaluating acute LGIB.The medical records of 382 patients who visited our emergency department with hematochezia between January 2012 and January 2017 were retrospectively analyzed. Of them, 112 underwent CT, 65 underwent colonoscopy, and 205 underwent sigmoidoscopy as an initial test. For each method, sensitivity, specificity, positive predictive value, and negative predictive value were calculated upon active bleeding site detection and LGIB etiology diagnosis.The sensitivity, specificity, positive predictive value, and negative predictive value of CT for active bleeding site detection were 85.7%, 100%, 100%, and 96.9%, respectively, while those for identifying the etiology of LGIB were 87.4%, 40.0%, 83.5, and 47.6%, respectively.CT was not inferior to lower endoscopy for active bleeding site detection. Early localization and the exclusion of active bleeding were possible with CT. Etiology was diagnosed with high sensitivity and PPV by CT. Thus, CT can be an alternative initial diagnostic tool for evaluating acute LGIB.

CTA measurements of acute lower gastrointestinal bleeding size predict subsequent positive catheter angiography

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

This was a single-institution retrospective study consisting of 32 patients with computed tomography angiography (CTA) positive for gastrointestinal bleeding who went on to receive catheter angiography. 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.

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.

Impact of Computed Tomography Evaluation Before Colonoscopy for the Management of Colonic Diverticular Hemorrhage

GOALS

The purpose of this study was to investigate and summarize our experience of a standardized strategy using computed tomography (CT) followed by colonoscopy for the assessment of colonic diverticular hemorrhage with focus on a comparison of CT and colonoscopy findings in patients with colonic diverticular hemorrhage.

BACKGROUND

Colonic diverticular hemorrhage is usually diagnosed by colonoscopy, but it is difficult to identify the responsible bleeding point among many diverticula.

STUDY

We retrospectively included 257 consecutive patients with colonic diverticular hemorrhage. All patients underwent a CT examination before colonoscopy. All-cause mortality and rebleeding-free rate after discharge were analyzed by Kaplan-Meier analysis and compared using the log-rank test.

RESULTS

In CT examinations, 184 patients (71.6%) had definite diverticular hemorrhage with 31.9% showing intraluminal high-density fluid on plain CT, 39.7% showing extravasation, and 31.1% showing arteriovenous increase of extravasation on enhanced CT. In colonoscopy, 130 patients (50.6%) showed endoscopic stigmata of bleeding with 12.1% showing active bleeding, 17.1% showing a nonbleeding visible vessel, and 21.4% showing an adherent clot. A comparison of the locations of bleeding in CT and colonoscopy showed that the agreement rate was 67.3%, and the disagreement rate was 0.8% when the lesion was identified by both modalities patients with definite diverticular hemorrhage identified by CT had a longer hospital stay, higher incidences of hemodynamic instability and rebleeding events than did patients with presumptive diverticular hemorrhage.

CONCLUSION

CT evaluation before colonoscopy can be a good option for managing patients with colonic diverticular hemorrhage.

Management of Diverticular Hemorrhage: Catching That Culprit Diverticulum Red-Handed!

Background/Summary

Acute colonic diverticular hemorrhage (CDH) represents a significant challenge for gastroenterologists. There are some clinical problems in the diagnosis, treatment, and prevention of CDH. CDH is the most common cause of overt lower gastrointestinal bleeding in adults in Eastern and Western countries. Moreover, CDH imposes significant economic and clinical burdens on the health care system. Colonoscopy is recommended as a useful diagnostic tool for CDH after bowel preparation. Colonoscopy can be used to identify the culprit diverticulum and to provide endoscopic therapy. In most cases, however, the bleeding stops spontaneously. For this reason, it is still controversial whether urgent colonoscopy or elective colonoscopy is "preferable."

Key Messages

This review aims to highlight the various clinical problems (purge, timing of colonoscopy, CT angiography, and endoscopy) encountered in the attempt to identify and treat the culprit diverticulum red-handed.

CT for Evaluation of Acute Gastrointestinal Bleeding

Acute gastrointestinal (GI) bleeding is common and necessitates rapid diagnosis and treatment. Bleeding can occur anywhere throughout the GI tract and may be caused by many types of disease. The variety of enteric diseases that cause bleeding and the tendency for bleeding to be intermittent may make it difficult to render a diagnosis. The workup of GI bleeding is frequently prolonged and expensive, with examinations commonly needing to be repeated. The use of computed tomography (CT) for evaluation of acute GI bleeding is gaining popularity because it can be used to rapidly diagnose active bleeding and nonbleeding bowel disease. The CT examinations used to evaluate acute GI bleeding include CT angiography and multiphase CT enterography. Understanding the clinical evaluation of acute GI bleeding, including the advantages and limitations of endoscopic evaluation, is necessary for the appropriate selection of patients who may benefit from CT. Multiphase CT enterography is used primarily to evaluate stable patients who have undergone upper and lower endoscopy without identification of a bleeding source. CT angiography is used to examine stable and unstable patients who respond to resuscitation, are believed to be actively bleeding, and are considered unlikely to have an upper GI source of hemorrhage. In the emergent setting, CT may yield critical 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. ^©RSNA, 2018.

Multidetector-Row Computed Tomography and Colonoscopy for Detecting a Rectal Dieulafoy Lesion as a Source of Lower Gastrointestinal Hemorrhage

A Dieulafoy lesion of the rectum is a very rare entity that can cause massive lower gastrointestinal (GI) hemorrhage. Identifying the bleeding point is sometimes difficult because these lesions are very small. We herein describe an 82-year-old man with active hemorrhage due to a rectal Dieulafoy lesion. He was referred to our hospital because of persistent hematochezia from the morning of that day. He had a history of atrial fibrillation, chronic heart failure, diabetes mellitus, and hyperuricemia. Prompt multidetector-row computed tomography (MDCT) enabled us to detect active bleeding from the lower rectum. Subsequently, colonoscopy revealed an exposed vessel in the lower rectum without surrounding ulceration, and hemostasis was successfully achieved using a hemostatic forceps with soft coagulation. After hemostasis had been achieved, the patient recovered and was discharged without complications and rebleeding. He is doing well 6 months after discharge from the hospital. Sequential examination by MDCT and colonoscopy is considered an efficient treatment strategy for patients with active lower GI bleeding.

Correlation Between Findings of Multislice Helical Computed Tomography (CT), Endoscopic Examinations, Endovascular Procedures, and Surgery in Patients with Symptoms of Acute Gastrointestinal Bleeding

Background

Endoscopic methods (gastroscopy and colonoscopy) are considered fundamental for the diagnosis of gastrointestinal bleeding. In recent years, multidetector computed tomography (MDCT) has also gained importance in diagnosing gastrointestinal bleeding, particularly in hemodynamically unstable patients and in cases with suspected lower gastrointestinal tract bleeding. CT can detect both the source and the cause of active gastrointestinal bleeding, thereby expediting treatment initiation.

Material/Methods

The study group consisted of 16 patients with clinical symptoms of gastrointestinal bleeding in whom features of active bleeding were observed on CT. In all patients, bleeding was verified by means of other methods such as endoscopic examinations, endovascular procedures, or surgery.

Results

The bleeding source was identified on CT in all 16 patients. In 14 cases (87.5%), bleeding was confirmed by other methods.

Conclusions

CT is an efficient, fast, and readily available tool for detecting the location of acute gastrointestinal bleeding.

Diagnostic and therapeutic treatment modalities for acute lower gastrointestinal bleeding: a systematic review

BACKGROUND AND STUDY AIMS

 Investigations for lower gastrointestinal bleeding (LGIB) include flexible sigmoidoscopy, colonoscopy, computed tomographic angiography (CTA), and angiography. All may be used to direct endoscopic, radiological or surgical treatment, although their optimal use is unknown. The aims of this study were to determine the diagnostic and therapeutic yields of endoscopy, CTA, and angiography for managing LGIB, and their influence on rebleeding, transfusion, and hospital stay.

PATIENTS AND METHODS

 A systematic search of MEDLINE, PubMed, EMBASE, and CENTRAL was undertaken to identify randomized controlled trials (RCTs) and nonrandomized studies of intervention (NRSIs) published between 2000 and 12 November 2015 in patients hospitalized with LGIB. Separate meta-analyses were conducted, presented as pooled odds (ORs) or risk ratios (RR) with 95 % confidence intervals (CIs).

RESULTS

 Two RCTs and 13 NRSIs were included, none of which examined flexible sigmoidoscopy, or compared endotherapy with embolization, or investigated the timing of CTA or angiography. Two NRSIs (57 - 223 participants) comparing colonoscopy and CTA were of insufficient quality for synthesis but showed no difference in diagnostic yields between the two interventions. One RCT and 4 NRSIs (779 participants) compared early colonoscopy (< 24 hours) with colonoscopy performed later; meta-analysis of the NRSIs demonstrated higher diagnostic and therapeutic yields with early colonoscopy (OR 1.86, 95 %CI 1.12 to 2.86, P  = 0.004 and OR 3.08, 95 %CI 1.93 to 4.90, P  < 0.001, respectively) and reduced length of stay (mean difference 2.64 days, 95 %CI 1.54 to 3.73), but no difference in transfusion or rebleeding.

CONCLUSIONS

 In LGIB there is a paucity of high-quality evidence, although the limited studies on the timing of colonoscopy suggest increased rates of diagnosis and therapy with early colonoscopy.

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.

ACR Appropriateness Criteria® Nonvariceal Upper Gastrointestinal Bleeding

Upper gastrointestinal bleeding (UGIB) remains a significant cause of morbidity and mortality with mortality rates as high as 14%. This document addresses the indications for imaging UGIB that is nonvariceal and unrelated to portal hypertension. The four variants are derived with respect to upper endoscopy. For the first three, it is presumed that upper endoscopy has been performed, with three potential initial outcomes: endoscopy reveals arterial bleeding source, endoscopy confirms UGIB without a clear source, and negative endoscopy. The fourth variant, "postsurgical and traumatic causes of UGIB; endoscopy contraindicated" is considered separately because upper endoscopy is not performed. When endoscopy identifies the presence and location of bleeding but bleeding cannot be controlled endoscopically, catheter-based arteriography with treatment is an appropriate next study. CT angiography (CTA) is comparable with angiography as a diagnostic next step. If endoscopy demonstrates a bleed but the endoscopist cannot identify the bleeding source, angiography or CTA can be typically performed and both are considered appropriate. In the event of an obscure UGIB, angiography and CTA have been shown to be equivalent in identifying the bleeding source; CT enterography may be an alternative to CTA to find an intermittent bleeding source. In the postoperative or traumatic setting when endoscopy is contraindicated, primary angiography, CTA, and CT with intravenous contrast are considered appropriate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

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.

Localizing Acute Lower Gastrointestinal Hemorrhage: CT Angiography Versus Tagged RBC Scintigraphy

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.

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.

RESULTS

In total, 45 CTA and 90 RBC scintigraphic examinations were performed during the study period. 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). There were no significant differences between the two groups in average hospital length of stay, blood transfusion requirement, incidence of acute kidney injury, or in-hospital mortality.

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.

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.

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.

Role of enhanced multi-detector-row computed tomography before urgent endoscopy in acute upper gastrointestinal bleeding

BACKGROUND AND AIM

Multi-detector-row computed tomography (MDCT) has been reported to be a potentially useful modality for detection of the bleeding origin in patients with acute upper massive gastrointestinal (GI) bleeding. The purpose of this study is to investigate the efficacy of MDCT as a routine method for detecting the origin of acute upper GI bleeding prior to urgent endoscopy.

METHODS

Five hundred seventy-seven patients with acute upper GI bleeding (514 nonvariceal patients, 63 variceal patients) who underwent urgent upper GI endoscopy were retrospectively analyzed. Patients were divided into three groups: enhanced MDCT, unenhanced MDCT, and no MDCT before endoscopy. The diagnostic accuracy of MDCT for detection of the bleeding origin was evaluated, and the average procedure times needed to endoscopically identify the bleeding origin were compared between groups.

RESULTS

Diagnostic accuracy among endoscopists was 55.3% and 14.7% for the enhanced MDCT and unenhanced MDCT groups, respectively. Among nonvariceal patients, accuracy was 50.2% in the enhanced MDCT group, which was significantly better than that in the unenhanced MDCT group (16.5%). In variceal patients, accuracy was significantly better in the enhanced MDCT group (96.4%) than in the unenhanced MDCT group (0.0%). These accuracies were similar to those achieved by expert radiologists. The average procedure time to endoscopic detection of the bleeding origin in the enhanced MDCT group was significantly faster than that in the unenhanced MDCT and no-MDCT groups.

CONCLUSIONS

Enhanced MDCT preceding urgent endoscopy may be an effective modality for the detection of bleeding origin in patients with acute upper GI bleeding.

Prospective evaluation of contrast-enhanced computed tomography for the detection of colonic diverticular bleeding

BACKGROUND AND AIMS

To prospectively evaluate the role of contrast-enhanced computed tomography (CE-CT) in the detection of colonic diverticular bleeding (CDB).

PATIENTS AND METHODS

Consecutive patients who presented with hematochezia and were clinically suspected of CDB were prospectively enrolled. Those who could undergo both CE-CT and total colonoscopy, and who were finally diagnosed as CDB, were included in the analysis.

RESULTS

Fifty-two cases were finally included in the analysis. The detection rate of CDB by CT was 15.4 % (8/52). Univariate analysis showed that the interval from the latest episode of hematochezia to the performance of CT and the presence of a past history of CDB were contributing factors for detection. The interval was 1.6 ± 4.6 h (mean ± SD) in patients detected by CT, and 3.4 ± 3.2 h in those without detection. The detection rate of CDB by total colonoscopy was 38.5 % (20/52). The overall detection rate was 46.2 % (24/52), which was superior to what CT or colonoscopy alone achieved.

CONCLUSIONS

CE-CT may play a complementary role to colonoscopy in patients with suspected CDB, but is not recommended for all cases due to its low detection rate. Patients who can be examined within 2 h of last hematochezia would be candidates for urgent CT.

Splenic duplication: a rare cause of acute upper gastrointestinal bleeding

Acute gastrointestinal bleeding represents a common medical emergency. We report the rare case of acute upper gastrointestinal bleeding caused by varices in the gastric fundus secondary to splenic duplication. Splenic duplication has been only rarely reported in the literature, and no case so far has described the associated complication of gastrointestinal bleeding, caused by venous drainage of the upper spleen via varices in the gastric fundus. We describe the imaging findings from endoscopy, endosonography, computed tomography (CT), flat-panel CT, and angiography in this rare condition and illustrate the effective role of intra-arterial embolization.

Accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding: systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic accuracy of computed tomography (CT) angiography in the evaluation of patients with an episode of acute gastrointestinal haemorrhage.

METHODS

Systematic review and meta-analysis to estimate pooled accuracy indices. A bivariate random effects model was adjusted to obtain a summary receiver-operating characteristic (sROC) curve and the corresponding area under the curve (AUC).

RESULTS

Twenty-two studies were included and provided data on 672 patients (range of age 5-74) with a mean age of 65 years. The overall sensitivity of CT angiography for detecting active acute GI haemorrhage was 85.2 % (95 % CI 75.5 % to 91.5 %). The overall specificity of CT angiography was 92.1 % (95 % CI 76.7 % to 97.7 %). The likelihood ratios for positive and negative test results were 10.8 (95 % CI 3.4 to 34.4) and 0.16 (95 % CI 0.1 to 0.27) respectively, with an AUC of 0.935 (95 % CI 0.693 to 0.989). The sources of heterogeneity explored had no significant impact on diagnostic performance.

CONCLUSIONS

CT shows high diagnostic accuracy and is an excellent diagnostic tool for detection and localising of intestinal bleeding sites. It is highly available, provides fast detection and localisation of the bleeding site, and is minimally invasive.

KEY POINTS

• CT angiography is increasingly used for investigating severe gastrointestinal bleeding. • This systematic review and meta-analysis updates previous ones. • In patients with massive gastrointestinal bleeding, CT angiography/MDCT detects bleeding accurately. • CT angiography is useful in locating the bleeding site and determining appropriate treatment.

A Blood Flow Measurement Robotic System: Ultrasound Visual Servoing Algorithms Under Pulsation and Displacement of an Artery

The purpose of this paper is to propose blood flow measurement algorithms during nonperiodic displacement of an artery by controlling an ultrasound (US) probe. Detecting the position and speed of the bleeding source is required as the first step in treating internal bleeding in emergency medicine. Current methods for detecting a bleeding source, however, involve an invasive approach and cannot quantitatively estimate bleeding speed. Current emergencymedical care therefore requires an alternative system for addressing these problems. In this study, we aim to develop a blood flow measurement system for detecting a bleeding source by using a noninvasive modality, such as a US imaging device. Some problems related to the measurement error still need to be addressed before we can create this system. Specifically, blood flow measurement error in the abdominal area is typically large because the displacement of the artery is large and nonperiodic to adequately control the probe. As the first step in solving these problems, we focused on the displacement of the artery toward the out-ofplane state of the US image and developed measurement algorithms to control the probe, based on respiratory information, during artery displacement. We conducted experimentsmeasuring cross-sectional area and flow rate using an ultrasound phantom containing an artery model and a manipulator equipped with a US probe, BASIS-1. As of this writing, results represent the first experimental validation of the proposed algorithms.

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.