SMALL BOWEL IMAGING - STILL A RADIOLOGIC APPROACH?

Cross-sectional imaging: current status and future potential in adult celiac disease

Celiac disease (CD), triggered by exposure to gluten in genetically susceptible individuals, is an immune-mediated small bowel disease affecting about 1% of the population worldwide. But the prevalence of CD varies with age, sex, and location. A strict gluten-free diet remains the primary treatment for CD, currently. Most of patients with CD respond well to gluten-free diet with good prognosis, while some patients fail to get symptomatic relief or histological remission (e.g., nonresponsive or refractory CD). Because of heterogeneous clinical appearance, the diagnosis of CD is difficult. Moreover, malignant complications and poor outcomes accompanied with refractory CD present great challenges in disease management. Over the past three decades, cross-sectional imaging techniques (computed tomography [CT] and magnetic resonance imaging [MRI]) play an important role in small bowel inflammatory and neoplastic diseases. Compared with endoscopic techniques, cross-sectional imaging permits clearly presentation of both intraluminal and extraluminal abnormalities. It provides vascular and functional information, thus improving the possibility as diagnostic and follow-up tool. The value of cross-sectional imaging for patients with suspected or confirmed CD has been gradually demonstrated. Studies revealed that certain features suggested by cross-sectional imaging could help to establish the early diagnosis of CD. Besides, the potential contributions of cross-sectional imaging may lie in the evaluation of disease activity and severity, which helps guiding management strategies. The purpose of this review is to provide current overviews and future directions of cross-sectional imaging in adult CD, thus facilitating the understanding and application in clinical practice. CLINICAL RELEVANCE STATEMENT: In this review, we systematically summarized the existing knowledge of cross-sectional imaging in adult CD and analyzed their possible roles in clinical practice, including disease diagnosis, complication identification, treatment evaluation, and prognostic prediction. KEY POINTS: • Regarding a condition described as "celiac iceberg", celiac disease remains underdiagnosed and undertreated. • Cross-sectional imaging is helpful in clinical management of celiac disease, including disease diagnosis, complication identification, treatment evaluation, and prognostic prediction. • Cross-sectional imaging should be considered as the valuable examination in patients suspected from celiac disease.

Comparison of the Efficacy of Diluted Polyethylene Glycol and Low-Density (0.1% w/v) Barium Sulfate Suspension for CT Enterography

PURPOSE

To compare small bowel distension and side effects between a diluted polyethylene glycol (PEG) solution and a low-density (0.1% w/v) barium sulfate suspension (LDBSS) for CT enterography (CTE) preparation.

MATERIALS AND METHODS

Total 173 consecutive patients who underwent CTE were enrolled in this study. The LDBSS (1 L) was used in 50 patients, and the diluted iso-osmotic PEG solution (1 L) was used in 123 patients. Two blinded radiologists independently scored jejunal and ileal distensions on a 5-point scale. To compare side effects between the two groups, the patients reported whether they had immediate complications after the administration of the oral contrast media.

RESULTS

For ileal and jejunal distension, the diluted PEG solution showed no difference from the LDBSS for either reader (ileum: reader 1, median, 4; 4, interquartile range, 3-4; 3-4, p = 0.997; reader 2, median, 4; 4, interquartile range, 3.3-4.0; 3-4, p = 0.064; jejunum: reader 1, median, 2; 2, interquartile range, 2-3; 2-3, p = 0.560; reader 2, median, 3; 2, interquartile range, 2-3; 2-3, p = 0.192). None of the patients complained of immediate complications following administration of either of the oral contrast media.

CONCLUSION

The diluted PEG solution showed comparable bowel distension compared to LDBSS and no immediate side effects; thus, it can be a useful alternative.

Clinical impact of wireless capsule endoscopy for small bowel investigation (Review)

Wireless capsule endoscopy is currently considered the gold standard in the investigation of the small bowel. It is both practical for physicians and easily accepted by patients. Prior to its development, two types of imaging investigations of the small bowel were available: radiologic and endoscopic. The first category is less invasive and comfortable for patients; it presents the ensemble of the small bowel, but it may imply radiation exposure. Images are constructed based on signals emitted by various equipment and require special interpretation. Endoscopic techniques provide real-time colored images acquired by miniature cameras from inside the small bowel, require interpretation only from a medical point of view, may allow the possibility to perform biopsies, but the investigation only covers a part of the small bowel and are more difficult to accept by patients. Wireless capsule endoscopy is the current solution that overcomes a part of the previous drawbacks: it covers the entire small bowel, it provides real-time images acquired by cameras, it is painless for patients, and it represents an abundant source of information for physicians. Yet, it lacks motion control and the possibility to perform biopsies or administer drugs. However, significant effort has been oriented in these directions by technical and medical teams, and more advanced capsules will surely be available in the following years.

Diagnostic efficacy of double-balloon enteroscopy in patients with suspected isolated small bowel Crohn's disease

BACKGROUND

Owing to the development of double-balloon enteroscopy (DBE) and video capsule endoscopy (VCE) in recent years, direct visualization of the entire small intestinal mucosa has become possible. Because of the nonspecific symptoms and the anatomic location of the small bowel, diagnosis of isolated small bowel Crohn's disease (CD) remains a challenge. The aim of this research was to explore the value of DBE for isolated small bowel CD in situations where routine tests cannot confirm the diagnosis.

METHODS

This study included patients with suspected isolated small bowel CD who were hospitalized in Shengjing Hospital from April 2014 to June 2018. We included patients presenting with chronic diarrhea, abdominal pain, abdominal mass, perianal lesions, and systemic symptoms including weight loss, fever, and anemia after excluding infection factors. Patients with purely colonic CD were excluded from this cohort. Patients with suspected isolated small bowel CD underwent DBE.

RESULTS

In 16/18 patients, pathological findings were detected by DBE. In 12 of the cases, small bowel CD was confirmed. The remaining four patients were diagnosed with small bowel inflammation, duodenal carcinoma, ileum inflammation and small bowel ulcers. However, the diagnosis of CD was confirmed in 14/18 (78%) patients by taking into account the clinical presentation, endoscopic and histological results as well as the experimental treatment. DBE assisted in the diagnosis in 86% (12/14) of the patients.

CONCLUSIONS

In the diagnosis of small bowel CD, DBE is a helpful tool. Before assessment with DBE, clinical features, colonoscopy, and CT were used to initially assess the intestine. According to the lesions indicated by CT, we chose the most appropriate endoscope insertion route, and combined the endoscopic characteristics and pathological results of DBE to confirm the diagnosis.

The efficacy of new oral contrast mixture for computed tomography enterography

Purpose

To show the reliabilities of the new mixture (composed of water, methylcellulose, lactulose, locust bean gum, and sorbitol) and to compare the luminal distension and radiological confidence scores of this solution with water-lactulose mixture.

Material and methods

Computed tomography enterography (CTE) images in a three-year period were included randomly in our institutional review board-approved and retrospective study. Ninety-one patients drank a lactulose and water mixture (Group 1), and 54 patients drank the new mixture (Group 2). Patients who drank the oral contrast agent were taken to a 64-detector row multiple detector computed tomography machine. Coronal and sagittal reformatted images were also formed. The gastrointestinal tract was divided into 11 segments for scoring. Each segment was graded for distensional and radiological confidence. CTE images were evaluated by two radiologists.

Results

Inter- and intra-reader reliabilities were good or excellent for all gastrointestinal segments in both groups (p < 0.001). The best κ values were obtained in sigmoid colon assessments. Lower agreement values were detected in duodenum and jejunum scores. The new mixture group (Group 2) showed better results than Group 1 for ileum and colonic segments according to distension and confidence scorings.

Conclusions

Inter- and intra-reader reliabilities of the new mixture were good or excellent for CTE. The new mixture seems to be more efficient and reliable for ileum and colon. The new mixture can increase bowel distention, radiological confidence, and quality in CTE evaluations.

Gastrointestinal tract involvement in acute pancreatitis: initial findings and follow-up by magnetic resonance imaging

Background

To study the initial and follow up patterns of gastrointestinal tract involvement in acute pancreatitis (AP) using magnetic resonance imaging (MRI).

Methods

A total of 209 patients with AP undergoing abdominal MRI on 1.5 T MRI were compared to 100 control patients selected from our daily clinical caseload who underwent MRI over the same recruitment period and had no other disease which can cause abnormality of gastrointestinal tract. Initial and follow up MRI examinations of gastrointestinal tract abnormalities were noted for AP patients. The severity of AP was graded by the MRSI and APACHE II. Spearman correlation of gastrointestinal tract involvement with MRSI and APACHE II was analyzed.

Results

In 209 patients with AP, 63% of the AP patients on their initial MRI exams and 5% of control subjects had at least one gastrointestinal tract abnormality (P<0.05). In the control group, thirty-seven patients were normal on MRI, 24 patients with renal cysts, eighteen patients with liver cysts, eleven patients with liver hemangiomas, and ten patients with splenomegaly. The abnormalities of gastrointestinal tract observed in AP patients included thickened stomach wall (20%), thickened duodenum wall (27%), thickened ascending colon wall (11%), thickened transverse colon wall (15%), and thickened descending colon wall (26%), among others. Gastrointestinal tract abnormalities were correlated with the MRSI score (r=0.46, P<0.05) and APACHE II score (r=0.19, P<0.05). Among 62 patients who had follow up examinations, 26% of patients had gastrointestinal tract abnormality, which was significantly lower than that in the initial exams (P<0.05). Resolution of gastrointestinal tract abnormal MRI findings coincided with symptom alleviation in AP patients.

Conclusions

Gastrointestinal tract abnormalities on MRI are common in AP and they are positively correlated with the severity of AP. It may add value for determining the severity of AP.

Evaluation of bowel distension and bowel wall visualization according to patient positions during administration of oral contrast media for CT enterography

OBJECTIVE

To compare small bowel distension and bowel wall visualization among three different patients' positions (supine, sitting and right decubitus) during administration of oral contrast media in preparation for CT enterography (CTE).

METHODS

A total of 150 consecutive patients (104 males and 46 females; mean age 34.6 years, range 15-78 years) who were scheduled to undergo CTE were recruited. Patients were randomly allocated into the three position groups during oral contrast media administration, and there were 50 patients in each group. Two blinded radiologists independently scored the luminal distension and visualization of the bowel wall using a continuous 5-point scale (1: worst and 5: best) at the jejunum and ileum. The Mann-Whitney U test was used to evaluate differences between any two groups among the three positions for bowel distension and wall visualization.

RESULTS

For ileal distension, the supine and sitting positions performed better than the right decubitus position [for reader 1, mean: 3.4/3.2/2.9 (hereafter, supine/sitting/right decubitus in order), p = 0.002/0.033; for reader 2, 3.3/3.0/2.6, p < 0.001/0.027]. However, there was no significant difference among the three groups for jejunal distension (for reader 1, 2.4/2.3/2.2; for reader 2, 2.4/2.4/2.2, p > 0.05, respectively). For bowel wall visualization, the supine and sitting positions were superior to the right decubitus position for the ileum when scored by one reader (4.0/3.8/3.4, p = 0.001/0.015).

CONCLUSION

Supine and sitting positions during the administration of oral contrast media provided better ileal distension than the right decubitus position in obtaining CTE. Advances in knowledge: The performance of CTE largely depends on adequate luminal distension and wall visualization. As the terminal ileum is the predominant site of small bowel pathology for inflammatory bowel disease, the supine or sitting position would be preferable for patients who are suspected of having small bowel pathology.

The effect of without using anisodamine during CT enterography on image quality, diagnostic performance and latent side effects

OBJECTIVE

To examine whether no anisodamine injection before CTE was feasible without impairing image quality and diagnostic performance.

MATERIALS

The change of mural thickness and luminal diameter were compared between using and no using anisodamine. The diagnostic performance of small-bowel disease was analyzed and compared.

RESULTS

No motion artifact was detected in two groups. There was no significant difference regarding the change of luminal diameter and mural thickness (all P>0.05). The diagnostic accuracy of small-bowel disease was no significant difference (P=0.63).

CONCLUSION

Lack of anisodamine injection before CTE did not impair image quality and diagnostic performance compared with CTEs performed with anisodamine injection.

Comparison of patients' tolerance between computed tomography enterography and double-balloon enteroscopy

BACKGROUND

Computed tomography enterography (CTE) and double-balloon enteroscopy (DBE) are widely used in diagnosis of small bowel diseases. Both of these examinations bring discomfort to patients. The aim of this study was to compare patients' tolerance and preference between CTE and DBE.

METHODS

From August 1, 2014 to December 31, 2016, patients with suspected or known small bowel diseases who underwent both CTE and DBE were prospectively enrolled in our study. They were asked to fill out a questionnaire evaluating discomfort of the procedure after each examination.

RESULTS

One hundred and seven patients completed our study. Abdominal distension, painfulness, tenesmus, general discomfort, prolonged duration, difficulty in completing the test, and discomfort after the examination were significantly lower with CTE than with DBE (P<0.001, respectively). Mannitol intake (47.7%), bowel preparation (31.9%), and radiation exposure (15.0%) were regarded as the three most intolerable burdens in CTE. Painfulness (38.3%), bowel preparation (26.2%), and invasiveness (16.8%) were considered as the three most unacceptable parts of DBE. More patients (61.7%) preferred to repeat CTE rather than DBE (P<0.001).

CONCLUSION

Compared to DBE, CTE was a more tolerable and less burdensome examination and enjoyed higher preference by most patients.

CT enterography: Mannitol versus VoLumen

INTRODUCTION

Several different neutral oral contrast agents have been trialled in magnetic resonance and CT enterography (CTE). In the Auckland region, Mannitol 2.5% and VoLumen are both used in CTE. This study compares the performance of these two neutral oral contrast agents in CTE.

METHODS

Computed tomography enterography data were collected from 25 consecutive studies that used either Mannitol or VoLumen in 2014. All images were reviewed by three radiologists blinded to the type of oral contrast. Each quadrant was assessed for maximum distension, proportion of bowel loops distended, presence of inhomogeneous content and bowel wall visibility. Assessment also included whether the contrast agent reached the caecum and an overall subjective quality assessment. Patients were invited to answer a questionnaire regarding tolerability of the preparations.

RESULTS

Mannitol achieves better wall visibility in the right upper quadrant, left upper quadrant and left lower quadrant (P < 0.01). Overall differences in study quality favours Mannitol (P < 0.01) with 48% of the Mannitol studies being considered excellent compared with 4% of the VoLumen studies. There was no difference in maximal distension or proportion of loops distended.

CONCLUSION

Mannitol in CTE achieves studies of a better quality than and is a viable alternative to VoLumen.

Enteroscopy and radiology for the management of celiac disease complications: Time for a pragmatic roadmap

Celiac disease is the most common autoimmune enteropathy in Western countries, and is usually associated with a good response to the gluten free diet and an excellent prognosis. However, a minority of patients develop complications of the disease, such as refractory celiac disease, ulcerative jejunoileitis and neoplastic complications such as adenocarcinoma of the small bowel and enteropathy associated T cell lymphoma. Neoplastic complications described in association with celiac disease have a high mortality rate, due to their aggressive behavior and to the usual advanced stage at the time of diagnosis. In recent years, the detection of small bowel lesions has dramatically improved thank to the availability of highly performing radiologic and endoscopic techniques. The diagnostic delay of malignant complications in patients with celiac disease may be improved by establishing a pragmatic flowchart for the identification and follow up of "at risk" patients. We performed a comprehensive review of the articles published on this issue in order to promote a roadmap to be applied when facing with celiac patients with suspected small bowel complications.

Performance of two neutral oral contrast agents in CT enterography

INTRODUCTION

This study compares the performance of two neutral oral contrast agents in CT enterography (CTE). Mannitol 2.5%, an oral osmotic agent, is compared with psyllium fibre (Metamucil). Both these agents are commonly used, but to our knowledge, they have not been compared in CTE.

METHODS

CTE data were collected from 25 consecutive studies for both mannitol and psyllium fibre between 2011 and 2013. All images were reviewed by two radiologists and one registrar blinded to the oral contrast used. Each quadrant was assessed for maximum distension, proportion of bowel loops distended, presence of inhomogeneous content and bowel wall visibility. Overall subjective quality and whether the contrast agent reached the caecum were also assessed. Patients were invited to answer a questionnaire regarding tolerability of the preparations.

RESULTS

Wall visibility was rated good in 100% of the mannitol studies, compared with 71% of the psyllium fibre studies, in the right lower quadrant (P = 0.01). No statistically significant difference between groups was observed in either maximal distension or proportion of loops distended in any quadrant. Inhomogeneous material was observed in 12% of the mannitol cases and 86% of the psyllium fibre cases (P < 0.0001). In all mannitol cases, the contrast reached the caecum, compared with 50% of psyllium fibre cases (P < 0.0001), and 36% of the mannitol studies were considered excellent, compared with 20% of the psyllium fibre studies (P = 0.03).

CONCLUSION

Mannitol achieves studies of better quality and is now the preferred oral contrast for CTE studies at Auckland City Hospital.

Double-balloon enteroscopy in the diagnosis of suspected isolated Crohn's disease of the small bowel

BACKGROUND AND AIM

Diagnosis of Crohn's disease (CD) with isolated involvement of the small bowel remains a major challenge. Diagnostic procedures allowing direct insight into the midgut have become available with the introduction of double-balloon enteroscopy (DBE) and video-capsule endoscopy (VCE). The aim of the present study was to evaluate the role of DBE in the diagnosis of isolated CD of the small bowel.

METHODS

Sixteen patients (seven males) with suspected CD of the small bowel after exclusion of abnormal changes in the upper gastrointestinal tract and colon by esophagogastroduodenoscopy and colonoscopy including histology underwent DBE and high-resolution transabdominal ultrasound.

RESULTS

In seven of 16 (44%) patients, abnormal macroscopic findings were detected by DBE (e.g. ileitis terminalis, inflammatory stenosis, aphthous lesions or jejunal ulcers). In one of thecases, histology confirmed pathognomonic findings consistent with CD. However, the diagnosis of CD was confirmed in 11/16 (69%) patients taking into account the clinical presentation and course of the disease as well as the endoscopic and imaging results.

CONCLUSIONS

In cases of CD with clinical expression limited to the small bowel, DBE is a helpful tool. Nevertheless, in these patients, the combination of clinical findings and additional imaging modalities is required for confirmation of the diagnosis. A suggestive medical history, high-resolution ultrasound, EGD and colonoscopy lead the algorithm before the assessment with DBE.

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.

Magnetic Resonance Enterography Findings in Crohn's disease in the Pediatric Population and Correlation with Fluoroscopic and Multidetector Computed Tomographic Techniques

Traditionally, fluoroscopic examinations such as enteroclysis, upper GI studies, and small bowel follow through exams have been the procedures of choice in evaluating inflammatory bowel disease (IBD) in pediatric populations. With the advent of multidetector computed tomography (MDCT), it has subsequently become a complementary examination in imaging inflammatory bowel disease. A major advantage of MDCT over fluoroscopic examination is its ability to directly visualize bowel mucosa, as well as demonstrate extra-enteric complications of IBD such as abscesses, fistulae, and sinus tracts. The major disadvantage of CT however is exposure to ionizing radiation, especially in IBD patients of the pediatric age group who maybe repeatedly imaged due to exacerbations. As a result, magnetic resonance enterography (MRE) is becoming increasingly important in the evaluation and follow-up of pediatric patients with IBD. This pictorial essay will summarize the multi-modality imaging findings of IBD with emphasis on MRE including the imaging protocol and procedure. For the purposes of this article, patients less than 17 years of age have been considered to represent the pediatric population.

Diagnosis of small-bowel disease: comparison of magnetic resonance enteroclysis and conventional enteroclysis

In this prospective study, 32 patients with symptoms suggestive of small-bowel disease underwent conventional enteroclysis and magnetic resonance (MR) enteroclysis. Image quality, luminal distension, wall thickening, homogeneity of luminal opacification, the presence of artefacts and extraluminal changes were assessed. Small-bowel pathologies were subsequently proved surgically and by follow-up examinations in 19 (59.4%) of the patients. Abnormal findings were detected by MR enteroclysis in 11 of these 19 patients (57.9%). Normal findings on MR enteroclysis were found in eight of the 19 patients (42.1%) whereas conventional enteroclysis detected abnormal findings in these patients. Abdominal lesions outside the small bowel, comprised renal cysts, cholelithiasis, ovarian cysts and horseshoe kidney, and were detected by MR enteroclysis in two, one, four and one, respectively, of these normal patients but not by conventional enteroclysis. Excluding lesions outside of the small bowel, a higher rate of false-negative results and the missing of superficial lesions occurred with MR enteroclysis. It is, therefore, suggested that MR enteroclysis should not be used as a primary way of evaluating small-bowel disease and its use should be restricted to follow-up examinations of known disease.