Background and Goals: Magnetic resonance (MR) enterography provides the
advantages of conventional enteroclysis and those of cross-sectional
imaging. Adequate luminal distension, combined with ultrafast sequences,
results in excellent delineation of mural and extramural manifestations
of Crohn's disease. Recent technical advances, including
ultra-high-field strength MR with its capability to provide fast
multiplanar images with excellent soft tissue contrast, are only rarely
included in abdominal studies.
Study: One
hundred four consecutive patients with a proved or suspected diagnosis
of ileitis terminalis were prospectively selected for MR imaging studies
and ileocolonoscopy. The final diagnosis was based on histopathological
findings or based on a combined endpoint of clinical, laboratory,
endoscopic, and imaging findings.
Results:
According to the endoscopic examination, stenosis was present in 26
patients (25%) and could be ruled out in 78 patients (75%). Total
agreement between MR and endoscopy could be reached in 74 patients
(71%). Histology indicated absence of inflammation in 50 patients (48%).
MR and endoscopic findings were concordant in 38 patients (76%) and 37
patients (74%), respectively. Corresponding results by ileocolonoscopy
were 37 true negative, 29 true positive, 4 false positive, and 12 false
negative (sensitivity, 70.7%; specificity, 74%).
Conclusions:
MR enterography with a 3.0-T scanner is a powerful tool in the
evaluation of ileal diseases, and has therefore made MR enterography the
first-line modality at our institution in patients with suspected
inflammatory bowel disease.
Purpose: To assess the impact of an additional rectal enema filling in small bowel hydro-MRI in patients with Crohn’s disease.
Materials and Methods: A total of 40 patients with known Crohn’s disease were analyzed retrospectively: 20 patients only ingested an oral contrast agent (group A), the other 20 subjects obtained an additional rectal water enema (group B). For small bowel distension, a solution containing 0.2% locust bean gum (LBG) and 2.5% mannitol was used. In all patients, a breathhold contrast-enhanced T1w three-dimensional volumetric interpolated breathhold examination (VIBE) sequence was acquired. Comparative analysis was based on image quality and bowel distension as well as signal-to-noise ratio (SNR) measurements. MR findings were compared with those of conventional colonoscopy, as available (N 25).
Results: The terminal ileum and rectum showed a significantly higher distension following the rectal administration of water. Furthermore, fewer artifacts were seen within group B. This resulted in a higher reader confidence for the diagnosis of bowel disease, not only in the colon, but also in the ileocecal region. Diagnostic accuracy in diagnosing inflammation of the terminal ileum was 100% in group B; in the nonenema group there were three false-negative diagnoses of terminal ileitis.
Conclusion: Our data show that the additional administration of a rectal enema is useful in small bowel MRI for the visualization of the terminal ileum. The additional time needed for the enema administration was minimal, and small and large bowel pathologies could be diagnosed with high accuracy. Thus, we suggest that a rectal enema in small bowel MR imaging be considered
MRI of the small bowel is a new method for the assessment of inflammatory bowel diseases. However, inflammatory bowel disease can affect both the small and large bowel. Therefore, our goal was to assess the feasibility of displaying the small bowel and colon simultaneously by MR imaging. Eighteen patients with inflammatory bowel disease were studied. For small bowel distension, patients ingested a solution containing mannitol and locust bean gum. Furthermore, the colon was rectally filled with water. MR examinations were performed on a 1.5-T system. Before and after intravenous gadolinium administration, a T1w data set was collected. All patients underwent conventional colonoscopy as a standard of reference. The oral ingestion and the rectal application of water allowed an assessment of the small bowel and colon in all patients. By means of MRI (endoscopy), 19 (13) inflamed bowel segments in the colon and terminal ileum were detected. Furthermore, eight additional inflammatory lesions in the jejunum and proximal ileum that had not been endoscopically accessible were found by MRI. The simultaneous display of the small and large bowel by MRI is feasible. Major advantages of the proposed MR concept are related to its non-invasive character as well as to the potential to visualize parts of the small bowel that cannot be reached by endoscopy.