Computerized tomography enterography and its role in small-bowel imaging

Impact of CT enterography on the diagnosis of small bowel gastrointestinal stromal tumors

OBJECTIVE

Our purpose is to determine the impact of CT enterography on small bowel gastrointestinal stromal tumor (GIST) detection and biologic aggressiveness, and to identify any imaging findings that correlate with biologic aggressiveness.

METHODS

Records of patients with histologically confirmed small bowel GISTs who underwent CT imaging were reviewed. Biologic aggressiveness was based on initial histologic grading (very low, low, intermediate, high grade; or malignant), with upgrade to malignant category if local or distant metastases developed during clinical follow-up. Imaging indications, findings, and type of CT exam were compared with the biologic aggressiveness.

RESULTS

111 small bowel GISTs were identified, with suspected small bowel bleeding being the most common indication (45/111; 40.5%). While the number of malignant GISTs diagnosed by CT remained relatively constant (2-3 per year), the number of non-malignant GISTs increased substantially (mean 1.5/year, 1998-2005; 8.4/year, 2006-2013). In patients with suspected small bowel bleeding, CT enterography identified 33 GISTs (7/33, 21% malignant) compared to 12 GISTs by abdominopelvic CT (6/12, 50% malignant; p < 0.03). Tumor size (p < 0.0001), internal necrosis (p = 0.005), internal air or enteric contrast (p ≤ 0.021), and ulceration (p ≤ 0.021) were significantly associated with high-grade and malignant tumors, and irregular or invasive tumor borders (p < 0.01) was associated with malignant tumors.

CONCLUSION

The detection of small bowel GISTs can increase due to the use of CT enterography in patients with suspected small bowel bleeding. The large majority of small bowel GISTs detected by CT enterography are not malignant.

Protein C deficiency related obscure gastrointestinal bleeding treated by enteroscopy and anticoagulant therapy

Obscure gastrointestinal bleeding is an uncommonly encountered and difficult-to-treat clinical problem in gastroenterology, but advancements in endoscopic and radiologic imaging modalities allow for greater accuracy in diagnosing obscure gastrointestinal bleeding. Ectopic varices account for less than 5% of all variceal bleeding cases, and jejunal variceal bleeding due to extrahepatic portal hypertension is rare. We present a 47-year-old man suffering from obscure gastrointestinal bleeding. Computed tomography of the abdomen revealed multiple vascular tufts around the proximal jejunum but no evidence of cirrhosis, and a visible hypodense filling defect suggestive of thrombus was visible in the superior mesenteric vein. Enteroscopy revealed several serpiginous varices in the proximal jejunum. Serologic data disclosed protein C deficiency (33.6%). The patient was successfully treated by therapeutic balloon-assisted enteroscopy and long-term anticoagulant therapy, which is normally contraindicated in patients with gastrointestinal bleeding. Diagnostic modalities for obscure gastrointestinal bleeding, such as capsule endoscopy, computed tomography enterography, magnetic resonance enterography, and enteroscopy, were also reviewed in this article.

Endoscopic and radiographic evaluation of the small bowel in 2012

Traditionally, the diagnosis of small bowel disorders has been challenging secondary to the small intestine's length, tortuosity, and anatomic location. Recent technologic advancements in the field of enteroscopy and radiographic imaging have facilitated a more thorough endoscopic evaluation of patients with small bowel disease ranging from obscure gastrointestinal bleeding to inflammatory bowel disease and small bowel tumors. Such developments have made it possible to avoid invasive surgical procedures in certain clinical scenarios where they were previously the gold standard. In this review, we report an update on the diagnostic and management approach to patients with small bowel disease, emphasizing the advantages and limitations of the latest modalities now available to primary care physicians and gastroenterologists for evaluating patients with presumed disease of the small intestine.

Endoscopic skipping of the distal terminal ileum in Crohn's disease can lead to negative results from ileocolonoscopy

BACKGROUND & AIMS

Crohn's disease often involves the terminal ileum (TI), but skipping of the distal TI can occur. This can lead to negative results from ileocolonoscopy. We analyzed advanced cross-sectional images to determine how frequently this occurs.

METHODS

We analyzed data from 189 consecutive patients (55% women) with Crohn's disease, evaluated in 2009 by computed tomography enterography (CTE) and ileocolonoscopy. The discharge impression of the gastroenterologist who treated the patients was used as the reference standard for Crohn's disease activity.

RESULTS

Of the patients evaluated, 153 underwent TI intubation during endoscopy; 67 of these (43.8%) had normal results from ileoscopy, based on endoscopic appearance. Despite their normal results from ileoscopy, 36 of these patients (53.7%) had active, small-bowel Crohn's disease. The ileum appeared normal at ileoscopy because the disease had skipped the distal ileum of 11 patients (30.6%), developed only in the intramural and mesenteric distal ileum of 23 patients (63.9%), and appeared only in the upper gastrointestinal region of 2 patients (5.6%). These patients had a shorter duration of disease (61.1% for less than 5 years) compared with those found to have Crohn's disease based on ileoscopy (41.1% for less than 5 years; P < .05). CTE detected extracolonic Crohn's disease in 26% of patients; 14% of patients were found to have disorders unrelated to inflammatory bowel disease that warranted further investigation or consultation (including 4 cancers).

CONCLUSIONS

Ileoscopy examination can miss Crohn's disease of the TI because the disease can skip the distal ileum or is confined to the intramural portion of the bowel wall and the mesentery. CTE complements ileocolonoscopy in assessing disease activity in patients with Crohn's disease.

New concepts in intestinal imaging for inflammatory bowel diseases

In the last decade, multiple imaging technologies have been developed that improve visualization of the mucosal, mural, and perienteric inflammation associated with inflammatory bowel diseases. Whereas these technologies have traditionally been used to detect and stage suspected enteric inflammation, we review new, emerging roles in detecting clinically occult inflammation (in asymptomatic patients) and inflammatory complications, predicting response prior to therapy, assessing response after therapy, and enteric healing. We compare the relative performance of these technologies in detecting inflammation, focusing on their advantages and disadvantages and how they might complement each other. We also discuss their potential benefits for patients and clinical trials, reviewing technologic developments and areas of research that could provide important insights into the pathophysiology of inflammatory bowel diseases-related enteric inflammation.

CT enterography: principles, technique and utility in Crohn's disease

CT enterography is a modification of conventional CT technique optimized for the evaluation of small bowel. This technique utilizes multidetector scanners with high spatial and temporal resolution; multiplanar reconstructions; and large volumes of enteric contrast to provide bowel distension. This article discusses the essential principles of the exam and its use in the evaluation of Crohn's disease of the small bowel.