[Comparison of conventional enteroclysis, intestinal ultrasound and MRI-enteroclysis for determining changes in the small intestine and complications in patients with Crohn's disease]

Assessment of disease behavior in patients with Crohn's disease by MR enterography

BACKGROUND

Magnetic resonance imaging (MRI) of the bowel is an increasingly used modality to evaluate patients with Crohn's disease. The Montreal classification of the disease behavior is considered as an excellent prognostic and therapeutic parameter for these patients. In our study, we correlated the behavior assessment performed by a radiologist based on MRI with the surgeons' clinical assessment based on the assessment during abdominal surgery.

METHODS

We evaluated 76 patients with Crohn's disease, who underwent bowel resection and had an MRI within 4 weeks before surgery. Radiological behavior assessment was performed by 2 radiologists based on MRI. Behavior was classified into B1 (nonstricturing and nonpenetrating), B2, and B3 (penetrating) disease. Surgical assessment was done by the same surgeon, who performed all bowel resections, based on intraoperative findings and histologic results.

RESULTS

The surgical assessment identified 4 patients (5%) as B1, 16 patients (21%) as B2, and 56 patients (74%) as B3. In 97% (n = 74) of all patients, the intraoperative and radiological assessment were identical with interobserver agreement of 0.937. In one case, B2 was radiological considered as B1, and in another case, B3 was diagnosed as B2. The diagnosis of a stricture had the highest sensitivity of 96%, whereas the detection of inflammatory mass showed the lowest sensitivity of 81%. Abscesses had the lowest positive predictive value of 68% with a specificity of 88%. Best correlation was found for fistulae (0.895).

CONCLUSIONS

MRI represents an excellent imaging modality to correctly assess the Montreal classification-based disease behavior in patients scheduled for bowel resection with Crohn's disease.

Noninvasive imaging of the small bowel in Crohn's disease: the final frontier

The substantial morbidity and mortality associated with Crohn's disease underlines the importance of accurate assessment at presentation, during follow-up, when investigating complications, and when evaluating the response to therapeutic interventions. Accurate methods are required to quantify the severity and extent of disease.

Comparison of high-resolution ultrasound and MR-enterography in patients with inflammatory bowel disease

AIM: To compare the results of high-resolution ultrasound (HR-US) and magnetic resonance enterography (MRE) examinations in patients with inflammatory bowel disease (IBD).

METHODS: The reports of 250 consecutive cases with known IBD, who had an MRE and HR-US examination, were retrospectively analyzed. Using a patient-based approach we evaluated morphological disease features such as affected bowel wall, stenosis, abscess and fistula. The comparison between the two modalities was based on the hypothesis, that any pathological change described in any imaging modality was a true finding, as no further standard of reference was available for complete assessment.

RESULTS: Two hundred and fifty examinations representing 207 different patients were evaluated. Both modalities assessed similar bowel wall changes in 65% of the examinations, with more US findings in 11% and more MRE findings in 15%. When the reports were analyzed with regard to “bowel wall inflammation”, US reported more findings in 2%, while MRE reported more findings in 53%. Stenoses were assessed to be identical in 8%, while US found more in 3% and MRE in 29% (P < 0.01). For abscess detection, US showed more findings in 2% (n = 4) while MRE detected more in 6% (n = 16). US detected more fistulas in 1% (n = 2), while MRE detected more in 13% (n = 32) (P < 0.001). The most common reason for no detected pathology by US was a difficult to assess anatomical region (lesser pelvis, n = 72).

CONCLUSION: US can miss clinically relevant pathological changes in patients with IBD mostly due to difficulty in assessing certain anatomical regions.

Comparison of sonographically measured bowel wall vascularity, histology, and disease activity in Crohn's disease

The purposes of this study was to provide a retrospective comparison of semiquantitatively measured bowel wall vascularity by power Doppler sonography, endoscopic-histopathological biopsy findings, and disease activity in patients with confirmed Crohn's disease. Thirty-two out of 1,332 patients with histologically confirmed Crohn's disease (18 female, 14 male; mean age 38.8 years) met the inclusion criteria: ileocolonoscopy with biopsy and power Doppler sonographic determination of bowel wall vascularity with assessment of disease activity within a period of 5 days. Sonographic determination of bowel wall vascularity was based on a semiquantitative score. Endoscopic bowel wall biopsy specimens were assessed using a self-developed inflammation score and the disease activity was calculated using Crohn's disease activity index (CDAI). A significant association (p < 0.05) was shown for results of histology and bowel wall vascularity in the terminal ileum (kappa = 0.66; sensitivity 95%; specificity 69%). There was no observed association between CDAI and histology, although there was an association between CDAI and bowel wall vascularity (sensitivity 82%). Increased bowel wall vascularity in the terminal ileum measured by power Doppler ultrasound reflects inflammatory activity in histologically examined bowel wall. Power Doppler ultrasound may be able to monitor activity changes of the bowel wall determined by pharmaceutical treatment.

Feasibility of evaluating Crohn's disease activity at 3.0 Tesla

PURPOSE

To determine whether abdominal 3.0T MRI can be used for evaluation of Crohn's disease (CD) compared with ileocolonoscopy (CS), and to determine patient preference for MRI as opposed to CS.

MATERIALS AND METHODS

Twenty patients scheduled for CS underwent MRI. At CS, disease severity was graded and the Crohn's Disease Endoscopic Index of Severity (CDEIS) was determined. Radiological grading (by two observers) was compared with endoscopic grading and CDEIS. Patient experience and preference were determined.

RESULTS

In respectively 10 (observer 1) and 13 patients (observer 2) exact agreement between radiological and endoscopic grading was found. In respectively 10 and 7 patients radiological and endoscopic grading differed one level. No statistically significant correlation was found between radiological grading and CDEIS. Between bowel wall thickness and CDEIS weak to moderate correlations were found, and between bowel wall enhancement and CDEIS weak correlations were found. All patients preferred MRI over CS.

CONCLUSION

It is feasible to perform abdominal 3.0T MRI using orally administered contrast medium for evaluation of CD, and this method can be considered a patient-friendly alternative to CS.

Contrast-enhanced wideband harmonic imaging ultrasound (SonoVue): a new technique for quantifying bowel wall vascularity in Crohn's disease

OBJECTIVE

To assess the possibility of quantitative determination of bowel wall vascularity using contrast-enhanced (SonoVue) wideband harmonic imaging ultrasound and the HDI-Lab software in patients with Crohn's disease.

MATERIAL AND METHODS

Twenty-one patients (13 F, 8 M, average age 33.8+/-12.7 years, range 21-60 years) with histologically confirmed Crohn's disease and bowel wall thickness > or -5 mm were recruited for the study. All ultrasound examinations were performed using a Philips HDI 5000 scanner. Bowel wall vascularity was determined at the site of maximum bowel wall thickness at baseline and at 30, 60, 90 and 120 s following application of the contrast enhancer SonoVue (1.2 ml) using the HDI-Lab software.

RESULTS

The mean length of bowel segments exhibiting increased wall thickness was 122.3 mm (range: 23-350+/-74.7 mm), with a mean wall thickness of 7.6+/-1.2 mm. Onset of echo enhancement secondary to contrast medium application was observed after an average 13.4 s (range 7-19+/-4.2 s). Echo intensity corresponding to maximum vascularity was measured 30 s after application of contrast medium. Maximum average contrast medium uptake was 217.5% (range 118-466+/-100.1%).

CONCLUSIONS

It is possible to quantify bowel wall vascularity accurately in patients with Crohn's disease using contrast-enhanced pulse inversion ultrasound (low-MI).

Ultrasound and magnetic resonance imaging assessmentof active bowel segments in Crohn's disease

AIM

Determining bowel disease activity in Crohn's patients can be difficult on clinical and laboratory assessment. Endoscopy is invasive and barium studies use ionising radiation. The aim of this study was to compare ultrasound and magnetic resonance imaging (MRI) in detecting Crohn's disease activity in the small or large bowel.

MATERIALS AND METHODS

Thirty patients, previously diagnosed with Crohn's disease, had bowel ultrasound and MR imaging, and were deemed active or inactive on each test. The 'gold standard' was based on clinical assessment and one or more of the following: endoscopy, barium studies or surgery.

RESULTS

For determining Crohn's disease activity, the sensitivities and specificities of bowel ultrasound and MRI were 87 percent and 100 percent, and 87 percent and 71 percent, respectively. Significant parameters that defined disease activity were bowel wall thickening on ultrasound and MRI, and contrast enhancement of the bowel wall and mesenteric vascularity/stranding on MRI.

CONCLUSION

Ultrasound and MRI were both sensitive for determining Crohn's disease activity in the bowel, but MRI with gadolinium enhancement was less specific.

Dynamic studies of gadolinium uptake in brain tumors using inversion-recovery echo-planar imaging

Echo-planar imaging has been used to observe the dynamics of Gd-DTPA uptake in brain tumors. It has been possible to examine both vascular uptake and diffusion across the blood-brain barrier in a single experiment, by using the IR-MBEST echo-planar sequence which combines a high temporal resolution (approximately 3 s) with strong T1 weighting. To model the uptake it is necessary to know the arterial concentration of Gd-DTPA; in this study the signal in the sagittal sinus was measured to avoid the need to take repeated blood samples. The time constant for transfer across the blood-brain barrier was measured to be between 20 and 1050 s for different tumors. The results of the modeling correlated with the results of other assessments of tumor vascularity.