Ileal pouch and related complications: spectrum of imaging findings with emphasis on MRI

Radiographic Evaluation of Ileal Pouch Disorders: A Systematic Review

BACKGROUND

Radiographic imaging of the abdomen and pelvis plays an important role in the diagnosis and management of ileal pouch disorders with modalities including CT, MRI, contrasted pouchography, and defecography.

OBJECTIVES

To perform a systematic review of the literature and describe applications of cross-sectional imaging, pouchography, defecography, and ultrasonography.

DATA SOURCES

PubMed, Google Scholar, and Cochrane database.

STUDY SELECTION

Relevant articles on endoscopy in ileal pouches published between January 2003 and June 2023 in English were included on the basis of Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

INTERVENTION

Main abdominal and pelvic imaging modalities and their applications in the diagnosis of ileal pouch disorders were included.

MAIN OUTCOME MEASURES

Accuracy in characterization of ileal pouch disorders.

RESULTS

CT is the test of choice for the evaluation of acute anastomotic leaks, perforation, and abscess(es). MRI of the pelvis is suitable for the assessment of chronic anastomotic leaks and their associated fistulas and sinus tracts, as well as for the penetrating phenotype of Crohn's disease of the pouch. CT enterography and magnetic resonance enterography are useful in assessing intraluminal, intramural, and extraluminal disease processes of the pouch and prepouch ileum. Water-soluble contrast pouchography is particularly useful for evaluating acute or chronic anastomotic leaks and outlines the shape and configuration of the pouch. Defecography is the key modality to evaluate structural and functional pouch inlet and outlet obstructions. Ultrasonography can be performed to assess the pouch in experienced IBD centers.

LIMITATIONS

This is a qualitative, not quantitative, review of mainly case series and case reports.

CONCLUSIONS

Abdominopelvic imaging, along with clinical and endoscopic evaluation, is imperative for accurately assessing structural, inflammatory, functional, and neoplastic disorders. See video from symposium .

ECCO-ESGAR Topical Review on Optimizing Reporting for Cross-Sectional Imaging in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The diagnosis and follow up of patients with inflammatory bowel disease [IBD] requires cross-sectional imaging modalities, such as intestinal ultrasound [IUS], magnetic resonance imaging [MRI] and computed tomography [CT]. The quality and homogeneity of medical reporting are crucial to ensure effective communication between specialists and to improve patient care. The current topical review addresses optimized reporting requirements for cross-sectional imaging in IBD.

METHODS

An expert consensus panel consisting of gastroenterologists, radiologists and surgeons convened by the ECCO in collaboration with ESGAR performed a systematic literature review covering the reporting aspects of MRI, CT, IUS, endoanal ultrasonography and transperineal ultrasonography in IBD. Practice position statements were developed utilizing a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥80% of the participants agreed on a recommendation.

RESULTS

Twenty-five practice positions were developed, establishing standard terminology for optimal reporting in cross-sectional imaging. Assessment of inflammation, complications and imaging of perianal CD are outlined. The minimum requirements of a standardized report, including a list of essential reporting items, have been defined.

CONCLUSIONS

This topical review offers practice recommendations to optimize and homogenize reporting in cross-sectional imaging in IBD.

The comparison of CT fistulography and MR imaging of perianal fistulae with surgical findings: a case-control study

PURPOSE

The purpose of this study was to evaluate the diagnostic efficacies of CT fistulography and MRI, in the diagnostic work-up of perianal fistula patients.

MATERIALS AND METHODS

All 41 patients who were included in the study (36 males and 5 females, with an average age of 41 years) underwent CT fistulography and MRI examinations prior to surgery. The fistula characteristics obtained from these examinations were compared with the surgical findings. The comparative results were evaluated by means of the Kappa analysis method.

RESULTS

CT fistulography predicted the correct perianal fistula classification in 30 (73.1%) of the 41 patients, whereas MRI correctly defined fistula classification in 38 (92.7%) of these patients (the K values were 0.621 and 0.896, respectively; with p < 0.001). CT fistulography depicted 29 secondary extensions in 16 patients, whereas MR imaging revealed 28 secondary extensions in 15 patients. A substantial agreement was found between surgical findings and two modalities (K value was 0.789 and 0.793 for CT fistulography and MRI, respectively, with a p value < 0.001). In terms of locations of internal openings, CT fistulography was able to detect the locations in 28 patients (68.2%), whereas MRI was more successful in this aspect, with a number of 35 patients (85.3%). Granulation tissues, inflammation and edema around the fistula, abscesses, and fistular wall fibrosis were also evaluated.

CONCLUSION

CT fistulography and MRI have different advantages in the diagnosis of perianal fistulas. A good command of knowledge concerning the issue may be a key factor in modality decision.

Ileal pouch functional outlet obstruction

Small bowel obstructions (SBOs) are common in patients who have undergone Ileal J-pouch-anal anastomosis (IPAA) surgery. SBO may be caused by stenosis of the diverting ileostomy, volvulus, internal hernia, adhesive bands, anastomotic stricture or intra-abdominal adhesions. Functional outlet obstruction is an important alternative diagnosis to consider in a patient post-IPAA presenting with obstructive symptoms. Recognition of this condition can prevent unnecessary surgery and save the patient from presenting repeatedly with obstructive symptoms.

Magnetic resonance enterography in post-operative inflammatory bowel disease

OBJECTIVE

To describe the role of magnetic resonance enterography (MRE) in patients with inflammatory bowel disease (IBD), and to review the expected post-operative appearance, as well as, potential surgical complications in this unique patient population.

CONCLUSION

MRE compares favorably to CT Enterography (CTE) in terms of overall diagnostic accuracy and may provide better functional assessment of the small bowel through cine-MRI, diffusion-weighted imaging and dynamic contrast-enhancement. In the post-operative population, MRE provides critical information including: normal post-surgical anatomy, chronic strictures vs. active inflammation and disease/treatment-related complications. The post-operative IBD patient undergoes frequent repeated imaging and MRE may significantly reduce cumulative radiation dose while providing similar or improved diagnostic accuracy compared to CTE. MRE should be considered as an alternative imaging modality in this population.

Radiographical evaluation of ulcerative colitis

Radiographical modalities have become important diagnostic tools in cases of ulcerative colitis (UC). Imaging can be used non-invasively to determine the extent of involvement, severity of disease and to detect disease-related complications and extra-intestinal inflammatory bowel disease (IBD) manifestations. While abdominal X-rays and barium enemas still retain their relevance in specific clinical settings, the use of computed tomography enterography (CTE) or magnetic resonance enterography (MRE) are now used as first-line investigations to exclude active small bowel disease in IBD patients and can be utilized to detect active colonic inflammation. Additionally, CT colonography and MR colonography are emerging techniques with potential applications in UC. Ultrasonography, leukocyte scintigraphy and positron emission tomography are novel abdominal imaging modalities currently being explored for IBD interrogations. This plethora of radiological imaging options has become a vital component of UC assessments.

Imaging techniques for assessment of inflammatory bowel disease: joint ECCO and ESGAR evidence-based consensus guidelines

The management of patients with IBD requires evaluation with objective tools, both at the time of diagnosis and throughout the course of the disease, to determine the location, extension, activity and severity of inflammatory lesions, as well as, the potential existence of complications. Whereas endoscopy is a well-established and uniformly performed diagnostic examination, the implementation of radiologic techniques for assessment of IBD is still heterogeneous; variations in technical aspects and the degrees of experience and preferences exist across countries in Europe. ECCO and ESGAR scientific societies jointly elaborated a consensus to establish standards for imaging in IBD using magnetic resonance imaging, computed tomography, ultrasonography, and including also other radiologic procedures such as conventional radiology or nuclear medicine examinations for different clinical situations that include general principles, upper GI tract, colon and rectum, perineum, liver and biliary tract, emergency situation, and the postoperative setting. The statements and general recommendations of this consensus are based on the highest level of evidence available, but significant gaps remain in certain areas such as the comparison of diagnostic accuracy between different techniques, the value for therapeutic monitoring, and the prognostic implications of particular findings.