Tag Archives: CT enterography

Positioning Radiology Tests for GI Bleeding

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N Sengupta et al. Am J Gastroenterol 2024; 119: 438-449. Open Access! The Role of Imaging for Gastrointestinal Bleeding: Consensus Recommendations From the American College of Gastroenterology and Society of Abdominal Radiology. Thanks to Dr. Benjamin Gold for this reference.

This article was jointly published: Radiology 2024; 310(3):e232298

This article focuses on GI bleeding in adults; it has a lot of useful information about the advantages, disadvantages, techniques and performance date of numerous radiology tests which can help sort out GI bleeding.

CTE identification of a Dieulafoy’s lesion (from Figure 4)
CTE here shows a slowly bleeding angioectasia (arrow), most conspicuous on the delayed phase.

Some of the recommendations for Overt Lower GI Bleeding:

CT Angiography:

Catheter Angiography:

99mTc-RBC Scan

For Suspected Small Bowel Bleeding:

CT Enterography (uses oral contrast). Technique: CTE should be performed using multiphase technique in patients older than 40 years of age where vascular lesions are a common cause for bleeding.

Meckel’s Scan “A Meckel scan can be considered to identify the cause of unexplained intermittent GI bleeding in children and adolescents after negative endoscopic evaluation, including capsule endoscopy if available, and cross-sectional evaluation of the small bowel.”

Radiology compared to capsule endoscopy and balloon-assisted endoscopy The authors discuss the advantages and limitations of radiologic testing versus capsule endoscopy and balloon-assisted endoscopy for small bowel bleeding is provided in Appendix S5

My take: This article provides a good update/review on useful radiologic imaging for GI bleeding. For pediatric GI bleeding, the etiologies are much different and many patients should be evaluated with a Meckel’s scan prior to panendoscopy (depending on the clinical presentation).

Related blog posts:

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Radiomic Imaging in Crohn’s Disease

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X Li et al. Gastroenterol 2021; 160: 2303-2316. Development and Validation of a Novel Computed-Tomography Enterography Radiomic Approach for Characterization of Intestinal Fibrosis in Crohn’s Disease

Methods: This article describes the development a computed-tomography enterography (CTE)–based radiomic model (RM). This retrospective multicenter study included 167 CD patients who underwent preoperative CTE and bowel resection. 1454 radiomic features were extracted from venous-phase CTE and a machine learning–based RM was developed based on the reproducible features using logistic regression. The RM was validated in an independent external test cohort recruited from 3 centers.

Key findings:

  • In the training cohort, the area under the ROC curve (AUC) of RM for distinguishing moderate–severe from none–mild intestinal fibrosis was 0.888.
  • In the test cohort, the RM had an AUC of 0.816.
  • RM was more accurate than visual interpretations by either radiologist (radiologist 1, AUC = 0.554; radiologist 2, AUC = 0.598; both, P < .001) in the test cohort

My take: This CT approach with RM allowed for accurate characterization of intestinal fibrosis in CD. The images look pretty cool too.

More imaging needed?

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With new tools at our disposal in diagnosing inflammatory bowel disease, we need to decide how and when to use them.  Potential new modalities include stool inflammatory markers, video capsule endoscopy, CT enterography (CTE), and MR enterography (MRE).  Several studies have shown that the information that these studies yield may change management. The latest of these studies (Inflamm Bowel Dis 2012; 18: 219-25) looked at how the knowledge of CTE effected management and physician confidence with Crohn’s disease.

The authors prospectively assessed 273 patients with established or suspected Crohn’s disease.  In their analysis, 70 patients (48%) of established cases had altered management because of CTE and 69 (54%) of suspected cases.  These changes were considered to be  independent of clinical, serological or histologic findings.  Changes included medication modification in 45 (16.2%), excluding Crohn’s disease in 46 (16.8%), surgery referral in 10 (3.7%), alternate diagnosis established in 9 (3.2%), & canceling surgery in 7 (2.6%).  The authors considered excluding active small disease as an important management plan change; this occurred in 18 patients (6.6%).

The authors state that their current practice is to use MRE for serial imaging rather than CTE, to minimize risks from radiation; though CTE is often the initial imaging.

My take on this article is that information from imaging often increases the certainty about the diagnosis and gives a more complete picture of the severity.  It is likely that more information leads to more aggressive therapy.  At the same time, in pediatric gastroenterology, the trend towards using more effective therapy earlier in the course of the disease has developed even in the absence of extensive imaging (see previous: Only one chance to make first impression).  Whether more imaging in pediatric patients would be worthwhile is not known.

Additional references:

  • -JPGN 2008; 47: 31.  Capsule endoscopy may reclassify pediatric IBD
  • -NEJM 2010; 363: 1, 4. Safety of CT. Can have overdose of radiation and even standard doses could cause complications. Also, a big issue is downstream unnecessary testing due to incidental findings.
  • -Clin Gastro 2008; 6:283. Use of CT enterography.
  • -JPGN 2010; 51: 603.  MRE for suspected IBD.  Useful in Crohn’s disease.
  • -IBD 2004;10: 278-285.  WCE for Crohn’s (review)  Capsule can help differentiate UC from Crohn’s.