Quantitative assessment of terminal ileum motility on MR enterography in Crohn disease: a feasibility study in children

MRI-Based Characterization of Intestinal Motility in Children and Young Adults With Newly Diagnosed Ileal Crohn Disease Treated by Biologic Therapy: A Controlled Prospective Study

BACKGROUND. Changes in intestinal motility in patients with newly diagnosed Crohn disease have historically been evaluated primarily in a subjective manner. OBJECTIVE. The purpose of this study was to assess longitudinal changes in objective intestinal motility scores in children and young adults with newly diagnosed ileal Crohn disease treated with biologic (anti-tumor necrosis factor-α) medical therapy compared with those in control participants. METHODS. This prospective study included 20 children and young adults (eight female and 12 male patients; mean age, 14.6 ± 2.1 [SD] years) with newly diagnosed ileal Crohn disease who were recruited between December 2018 and October 2021 as well as 15 control participants without any known gastrointestinal conditions (eight female and seven male patients; mean age, 18.1 ± 4.4 years). All participants underwent research MRI examinations of the small bowel, including dynamic cine 2D SSFP sequences. Patients with Crohn disease underwent additional research MRI examinations performed at both 6 weeks and 6 months after initiation of biologic therapy. Two operators independently derived terminal ileal intestinal motility scores from the dynamic cine sequences by use of FDA-approved software (with higher scores indicating greater intestinal motility). Intestinal motility scores were compared between patient and control groups by use of t tests, whereas changes in intestinal motility scores after treatment were assessed using linear mixed models. Interoperator absolute agreement was assessed using the intra-class correlation coefficient (ICC). RESULTS. Mean terminal ileal intestinal motility scores were not significantly different between patients with newly diagnosed ileal Crohn disease and control participants (for operator 1, 180.9 ± 63.3 vs 229.7 ± 115.2, respectively [p = .12]; for operator 2, 175.0 ± 62.2 vs 236.4 ± 117.4, respectively [p = .05]). Mean intestinal motility scores changed over time compared with baseline in response to biologic therapy, for operator 1 (180.9 ± 63.3 at baseline, 248.1 ± 104.9 at 6 weeks after treatment initiation, and 249.1 ± 73.2 at 6 months after treatment initiation [p = .04]) and operator 2 (175.0 ± 62.2 at baseline, 247.8 ± 112.7 at 6 weeks after treatment initiation, and 239.6 ± 72.7 at 6 months after treatment initiation [p = .03]). Absolute agreement in intestinal motility scores was excellent between operators (ICC = 0.89). CONCLUSION. MRI measurements of intestinal motility are dynamic in children and adults with newly diagnosed small-bowel Crohn disease, showing early increases in response to biologic therapy. CLINICAL IMPACT. MRI-based intestinal motility scores may aid individualized assessment of disease activity and treatment response in patients with small-bowel Crohn disease.

Intestinal strictures in Crohn's disease: a 2021 update

Intestinal strictures remain one of the most intractable and common complications of Crohn's disease (CD). Approximately 70% of CD patients will develop fibrotic strictures after 10 years of CD diagnosis. Since specific antifibrotic therapies are unavailable, endoscopic balloon dilation and surgery remain the mainstay treatments despite a high recurrence rate. Besides, there are no reliable methods for accurately evaluating intestinal fibrosis. This is largely due to the fact that the mechanisms of initiation and propagation of intestinal fibrosis are poorly understood. There is growing evidence implying that the pathogenesis of stricturing CD involves the intricate interplay of factors including aberrant immune and nonimmune responses, host-microbiome dysbiosis, and genetic susceptibility. Currently, the progress on intestinal strictures has been fueled by the advent of novel techniques, such as single-cell sequencing, multi-omics, and artificial intelligence. Here, we perform a timely and comprehensive review of the substantial advances in intestinal strictures in 2021, aiming to provide prompt information regarding fibrosis and set the stage for the improvement of diagnosis, treatment, and prognosis of intestinal strictures.

Neurophysiological Effects of the Anterior Cingulate Cortex on the Exacerbation of Crohn’s Disease: A Combined fMRI-MRS Study

Background

Crohn’s disease (CD) is characterized by repetitive phases of remission and exacerbation, the quality of life of patients with CD is strongly influenced by disease activity, as patients in the active phase experience significantly worse symptoms. To investigate the underlying mechanism of how the course of CD is exacerbated based on the bi-directionality of the brain-gut axis (BGA), we conducted a multi-modality neuroimaging study that combined resting-state functional magnetic resonance imaging (rs-fMRI) with proton magnetic resonance spectroscopy (MRS) to detect abnormalities in the anterior cingulate cortex (ACC).

Materials and Methods

Clinical scales including Visual Analog Scale (VAS) and Hospital Anxiety and Depression Scale (HADS) were used to evaluate the degree of abdominal pain and mood state of participants. We made a comparison between CD patients in the active phase, the remission phase and healthy controls (HCs), not only employed the innovative wavelet-transform to analyze the amplitude of low frequency fluctuation (ALFF) but also compared the sensitivity of wavelet-transform and the traditional fast Fourier transform (FFT). Brain metabolites such as glutamate (Glu), myo-inositol (mIns) and gamma-aminobutyric acid (GABA) were also detected. Then correlation analysis was made to see whether changes in the ACC correlated with CD’s clinical symptoms.

Results

CD patients in the active phase showed higher VAS scores (p = 0.025), the scores of anxiety and depression were also higher (all p < 0.05). Wavelet-transform is slightly more sensitive in the current research. Patients in the active phase exhibited higher ALFF in the left ACC and the left superior frontal gyrus, medial (SFGmed). Patients in the active phase showed increased Glu levels in the ACC than patients in the remission phase or HCs (p = 0.039 and 0.034 respectively) and lower levels of mIns than HCs (p = 0.036). There was a positive correlation between mWavelet-ALFF values of the ACC and HADS-depression scores in CD patients (r = 0.462, p = 0.006). Besides, concentrations of Glu positively correlated with mWavelet-ALFF in the ACC in all participants (r = 0.367, p = 0.006).

Conclusion

Abnormal spontaneous activity and metabolic levels in the ACC were detected in CD patients in the active phase along with severer abdominal pain and worse mood state, these may contribute to the exacerbation of CD. Therefore, the ACC might be a potential neural alternative for managing the exacerbation of CD.

Impact of bowel dilation on small bowel motility measurements with cine-MRI: assessment of two quantification techniques

Objectives

To evaluate the effect of bowel dilation on cine-MRI small bowel motility measurements, by comparing a conventional motility score (including bowel wall and lumen) with a bowel wall-specific motility score in healthy and diseased populations.

Methods

Four populations were included: 10 Crohn's patients with a stricture and prestricture dilation for segmental motility analysis, and 14 mannitol-prepared healthy subjects, 15 fasted healthy subjects and eight chronic intestinal pseudo-obstruction (CIPO) patients (characterized by dilated bowel loops) for global small bowel motility analysis. All subjects underwent a cine-MRI scan from which two motility scores were calculated: a conventional score (including bowel wall and lumen) and a bowel wall-specific score. The difference between the two scores was calculated per population and compared between groups with a one-way ANOVA and Tukey-Kramer analysis.

Results

In Crohn's patients, the median (IQR) change between the conventional and wall-specific motility score was 0% (-2 to +4%) within the stricture and 0% (-1 to +7%) in the prestricture dilation. For the global small bowel, this was -1% (-5 to 0%) in mannitol-prepared healthy subjects, -2% (-6 to +2%) in fasted healthy subjects and +14% (+6 to+20%) in CIPO patients. The difference between the two motility scores in CIPO patients differed significantly from the four other groups (p = 0.002 to p < 0.001).

Conclusions

The conventional small bowel motility score seems robust in Crohn's disease patients and healthy subjects. In patients with globally and grossly dilated bowel loops, a bowel-wall specific motility score may give a better representation of small bowel motility.

Advances in knowledge

These findings support researchers and clinicians with making informed choices for using cine-MRI motility analysis in different populations.