Multiple jejunal angiodysplasia detected by enema-helical CT

Multiphase CT enterography evaluation of small-bowel vascular lesions

OBJECTIVE

By use of multiphase CT enterography (CTE), small-bowel vascular lesions associated with gastrointestinal bleeding can be classified into three categories--angioectasias, arterial lesions, and venous abnormalities--on the basis of common morphology and enhancement patterns. This article will review the unique patterns of enhancement and lesion morphology seen on multiphase CTE and how those findings enable detection and characterization of specific lesions in many cases.

CONCLUSION

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 a 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.

Errors in the radiological evaluation of the alimentary tract: part II

Plain abdominal radiography and computed tomographic (CT) enteroclysis are 2 essential radiological investigations in the study of gastrointestinal tract. Errors in patient preparation, execution, and interpretation may lead to severe consequences in the diagnosis and thus in patient outcome. Abdominal radiography is one of the most frequently requested radiographic examinations, and has an established role in the assessment of the acute abdomen. CT enteroclysis has revolutionized the assessment of small-bowel pathology, especially in patients with inflammatory bowel. The purpose of this article is to describe the pitfalls in the execution and interpretation of plain abdominal film and CT enteroclysis.

In the workup of patients with obscure gastrointestinal bleed, does 64-slice MDCT have a role?

Purpose:

The purpose was to prospectively determine the sensitivity of 64-slice MDCT in detecting and diagnosing the cause of obscure gastrointestinal bleed (OGIB).

Materials and Methods:

Our study included 50 patients (male 30, female 20) in the age range of 3–82 years (average age: 58.52 years) who were referred to our radiology department as part of their workup for clinically evident gastrointestinal (GI) bleed or as part of workup for anemia (with and without positive fecal occult blood test). All patients underwent conventional upper endoscopy and colonoscopy before undergoing CT scan. Following a noncontrast scan, all patients underwent triple-phase contrast CT scan using a 64-slice CT scan system. The diagnostic performance of 64-slice MDCT was compared to the results of capsule endoscopy, 99m-technetium-labeled red blood cell scintigraphy (99mTc-RBC scintigraphy), digital subtraction angiography, and surgery whenever available.

Results:

CT scan showed positive findings in 32 of 50 patients. The sensitivity, specificity, positive predictive value, and negative predictive values of MDCT for detection of bleed were 72.2%, 42.8%, 81.2%, and 44.4%, respectively. Capsule endoscopy was done in 15 patients and was positive in 10 patients; it had a sensitivity of 71.4%. Eleven patients had undergone 99mTc-RBC scintigraphy prior to CT scan, and the result was positive in seven patients (sensitivity 70%). Digital subtraction angiography was performed in only eight patients and among them all except one patient showed findings consistent with the lesions detected on MDCT.

Conclusion:

MDCT is a sensitive and noninvasive tool that allows rapid detection and localization of OGIB. It can be used as the first-line investigation in patients with negative endoscopy and colonoscopy studies. MDCT and capsule endoscopy have complementary roles in the evaluation of OGIB.

[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.

Prospective blinded comparison of wireless capsule endoscopy and multiphase CT enterography in obscure gastrointestinal bleeding

PURPOSE

To compare the performance of multiphase computed tomographic (CT) enterography with that of capsule endoscopy in a group of patients with obscure gastrointestinal bleeding (OGIB).

MATERIALS AND METHODS

This prospective HIPAA-compliant study was approved by the institutional review board and the institutional conflict of interest committee. All patients provided written informed consent. Two radiologists, blinded to clinical data and results of capsule endoscopy, interpreted images from CT enterography independently, with discordant interpretations resolved by consensus. Results were compared with those from a reference standard (surgery or endoscopy) and clinical follow-up. Sensitivity and 95% confidence intervals were calculated for each modality.

RESULTS

Fifty-eight adult patients, referred for the evaluation of OGIB (occult, 25 patients [43%]; overt, 33 patients [57%]), underwent both tests. A small bowel bleeding source was identified in 16 of the 58 patients (28%). The sensitivity of CT enterography was significantly greater than that of capsule endoscopy (88% [14 of 16 patients] vs 38% [six of 16 patients], respectively; P = .008), largely because it depicted more small bowel masses (100% [nine of nine patients] vs 33% [three of nine patients], respectively; P = .03). No additional small bowel tumors were discovered during the follow-up period (range, 5.6-45.9 months; mean, 16.6 months).

CONCLUSION

In this referral population, the sensitivity of CT enterography for detecting small bowel bleeding sources and small bowel masses was significantly greater than that of capsule endoscopy. On the basis of these findings, the addition of multiphase CT enterography to the routine diagnostic work-up of patients with OGIB should be considered, particularly in patients with negative findings at capsule endoscopy.

Multi-phase CT enterography in obscure GI bleeding

Multiphase CT enterography is a modification of conventional abdominal CT designed to optimize detection of abnormalities responsible for obscure GI bleeding. This imaging test appears to be complimentary to wireless capsule endoscopy in the evaluation of this difficult group of patients. A description of exam technique, findings, and discussion of results will be presented in this article.

The potential role of spiral computed tomography in acute gastrointestinal bleeding

We present four cases of profuse gastrointestinal (GI) bleeding where the site of haemorrhage was demonstrated using multi-slice computed tomography (MSCT), with concordant findings at laparotomy and pathological examination. A review of the current literature is undertaken and the role of spiral computed tomography as a method of sourcing the bleeding point is discussed in relation to other management modalities.

Obscure gastrointestinal bleeding and small bowel pathology: comparison between wireless capsule endoscopy and multidetector-row CT enteroclysis

Obscure gastrointestinal bleeding is defined as bleeding of unknown origin, that persists or recurs after negative conventional barium contrast studies and upper and lower tract endoscopy. The causes of such a bleeding frequently arise in the small bowel, and they are represented by mucosal vascular abnormalities, neoplasms and other conditions such as Crohn's disease, Meckel's diverticulum, and vasculitis. Conventional barium contrast studies and push enteroscopy allow only a limited small bowel examination; moreover, intraoperative endoscopy may be inconclusive, since the small bowel is difficult to evaluate given its length and tortuous course. In the same way, angiographic diagnosis is stricktly related to the activity rate of hemorrhage. Wireless capsule endoscopy and multidetector-row CT enteroclysis are two recently developed minimally invasive techniques that may provide a complete small bowel examination, the first offering a direct visualization of the mucosal aspect, the second allowing evaluation of mural and extramural pathologies. This review is an update of the technique and clinical application of capsule endoscopy and multidetector-row CT enteroclysis in patients suffering from obscure small bowel bleeding.

Obscure gastrointestinal bleeding: evaluation with 64-section multiphase CT enterography--initial experience

This retrospective HIPAA-compliant study was approved by the institutional review board and institutional conflict of interest committee. Patients gave informed consent for use of medical records. The purpose of the study was to retrospectively evaluate the findings depicted at computed tomographic (CT) enterography performed with a 64-section CT system and by using neutral enteric contrast material and a three-phase acquisition in patients with obscure gastrointestinal bleeding (OGIB). Twenty-two outpatients (11 men, 11 women; age range, 37-83 years) with OGIB underwent CT enterography. Findings were compared with capsule and traditional endoscopic, surgical, and angiographic findings. CT enterographic findings were positive for a bleeding source in 10 (45%) of 22 patients. Eight of 10 positive findings at CT enterography were also positive at capsule endoscopy or subsequent clinical diagnosis. CT enterography helped correctly identify three lesions undetected at capsule endoscopy. Study results suggest that multiphase, multiplanar CT enterography may have a role in the evaluation of OGIB.

American Gastroenterological Association (AGA) Institute technical review on obscure gastrointestinal bleeding

This literature review and the recommendations therein were prepared for the AGA Institute Clinical Practice and Economics Committee. The paper was approved by the Committee on March 12, 2007, and by the AGA Institute Governing Board on May 19, 2007.

Capsule endoscopy versus computed tomographic or standard angiography for the diagnosis of obscure gastrointestinal bleeding

BACKGROUND AND AIMS

Capsule endoscopy (CE) is superior to push enteroscopy and small bowel barium radiography in detecting the source of obscure GI bleeding. We now compared whether CE has a superior diagnostic yield than CT angiography (CTA) or standard mesenteric angiography (ANGIO) in patients with obscure GI bleeding.

METHODS

From June 2004 to October 2005, consecutive patients admitted for OGIB underwent both CTA and ANGIO, followed by CE, performed blindly by independent examiners within the next 7 days. The primary end point of the study was the diagnostic yield for each technique, defined as the frequency of detection of lesions with a high probability of bleeding.

RESULTS

Twenty-eight patients (16 men and 12 women, mean age 74 +/- 2 yr) with OGIB (overt bleeding in 20 cases and chronic occult in 8) were prospectively evaluated. CTA or standard angiography could be performed in 25 of 28 patients (applicability 86%), because of contrast allergy (1 patient) and chronic renal failure (2 patients). A source of bleeding was detected by CE in a greater proportion of patients, 72% (18 of 25, 95% CI 50.6-87.9%), than CTA, 24% (6 of 25, 95% CI 9.4-45.1%, P= 0.005 vs CE), or ANGIO, 56% (14 of 25, 95% CI 34.9-75.6%, P= NS). Similarly, CE was able to diagnose 100% of patients diagnosed by CTA and 86% of patients diagnosed by ANGIO. Moreover, CE was positive in 12 of 19 (63%) negative cases on CTA and in 6 of 11 (55%) negative cases on ANGIO. As a result of the CE findings, therapeutic intervention was undertaken in 9 of 19 (47%) patients with positive results.

CONCLUSION

CE detects more lesions than CTA or standard mesenteric angiography in patients with obscure GI bleeding and has a therapeutic impact in almost half of the patients with positive findings.

CT enteroclysis: technique and clinical applications

CT enteroclysis (CTE) has been gradually evolving with technical developments of spiral and multidetector row CT technology. It has nowadays become a well-defined imaging modality for the evaluation of various small bowel disorders. Volume challenge of 2L of enteral contrast agent administrated to the small bowel via a nasojejunal catheter ensures luminal distension, the prerequisite for the detection of mural abnormalities, also facilitating the accurate visualization of intraluminal lesions. CT acquisition is centered on small bowel loops, reconstructed in thin axial slices and completed by multiplanar views. Image analysis is essentially done in cine-mode on work-stations. CTE is of particular diagnostic value in intermediate or advanced stages of Cohn's disease, including the depiction of extraintestinal complications. It has become the imaging modality of choice for the localization and characterization of small bowel tumors. The cause and degree of low-grade small bowel obstruction is more readily analyzed with the technique of CTE than conventional CT. Limitations of CTE concern the assessment of pure intestinal motility disorders, superficial mucosal lesions and arteriovenous malformations of the small bowel, which are not consistently visualized. CTE should be selectively used to answer specific questions of the small bowel. It essentially contributes to the diagnostic quality of modern small bowel imaging, and therefore deserves an established, well-defined place among the other available techniques.

Multidetector computed tomography enteroclysis (MDCT-E) with neutral enteral and IV contrast enhancement in tumor detection

The aim of our study was to evaluate the reliability of MDCT-enteroclysis (MDCT-E), an emerging technique of small bowel examination that combines the advantages of MDCT examination of the abdomen and the enteral volume challenge of enteroclysis, in evaluation of small bowel neoplasms. In our institutions, MDCT-E was used to study 456 patients (age range 21-84 years, mean 53 years) admitted for suspicion of small bowel disease. All examinations were done on multichannel CT units, 129 on a 16-slice scanner and 327 on a four-slice scanner. Post-processing and multiplanar reformatting and interpretation were performed on dedicated workstations. After adequate gastrointestinal preparation and naso-enteric intubation, small bowel was distended by methylcellulose infused by a peristaltic pump. One volumetric MDCT acquisition was obtained after 120-130 ml of intravenous contrast medium. Multiplanar reformatting was based on the image reconstruction parameters from 3 to 4 mm. Forty-five small bowel neoplasms were found; in the remaining cases, 223 Crohn's diseases and 149 other abnormalities were detected. All findings were confirmed by surgery, endoscopy or clinical follow-up. In our experience, MDCT-E with neutral enteral and IV contrast seems to be a reliable method in the diagnosis of small bowel neoplasms.

Radiology of small bowel obstruction: contemporary approach and controversies

The radiologic workup of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this complex situation have undergone considerable changes over the past two decades. The diagnosis and treatment of small bowel obstruction, a common clinical condition often associated with signs and symptoms similar to those seen in other acute abdominal disorders, continue to evolve. This article examines the changes related to the use of imaging in the diagnosis and management of patients with this potentially dangerous problem and revisits pertinent controversies.

An initial experience: using helical CT imaging to detect obscure gastrointestinal bleeding

Obscure gastrointestinal (GI) bleeding is a common but frustrating disease for clinicians because of its elusive nature despite extensive work-up. We evaluate the role of helical computed tomography (CT) imaging using rapid infusion of intravenous contrast and water as oral contrast in the work-up of patients who are actively bleeding. Helical CT may be a useful noninvasive, alternative study to consider when routine work-up fails to determine the cause of active GI bleeding. Our preliminary study shows that helical CT was able to identify a wide variety of causes of obscure GI bleeding.

Duodenal angiodysplasia: MR angiographic evaluation

We describe a patient in whom endoscopy failed to determine the origin of gastrointestinal bleeding, and magnetic resonance angiography showed dilated inferior pancreaticoduodenal veins that were considered indirect signs of the duodenal angiodysplasia. Incidentally, a connection between the inferior vena cava and the inferior pancreaticoduodenal veins were also noted. Repeat endoscopy and catheter angiography confirmed the presence of the angiodysplasias.

Unusual feature of jejunal leiomyosarcoma studied with US and CT-enteroclysis: a case report

Leiomyosarcoma is a mesodermal malignant neoplasm affecting the small intestine. Usually, the clinical signs are not specific and most commonly related to intestinal bleeding or obstruction. We report the case of a 71-year-old woman presenting anemia and melena: there was no evidence of abdominal palpable mass and endoscopic examinations were negative for pathologic findings. We performed sonography and CT-enterclysis. We detected a small jejunal mass presenting a heterogeneous density and echogenicity pattern, with some large peripheral calcifications. Histologic examination after surgery revealed the lesion to be a small bowel leiomyosarcoma.