Cine MR enterography grading of small bowel peristalsis: evaluation of the antiperistaltic effectiveness of sublingual hyoscyamine sulfate

Technical Feasibility of Quantitative Measurement of Various Degrees of Small Bowel Motility Using Cine Magnetic Resonance Imaging

OBJECTIVE

Cine magnetic resonance imaging (MRI) has emerged as a noninvasive method to quantitatively assess bowel motility. However, its accuracy in measuring various degrees of small bowel motility has not been extensively evaluated. We aimed to draw a quantitative small bowel motility score from cine MRI and evaluate its performance in a population with varying degrees of small bowel motility.

MATERIALS AND METHODS

A total of 174 participants (28.5 ± 7.6 years; 135 males) underwent a 22-second-long cine MRI sequence (2-dimensional balanced turbo-field echo; 0.5 seconds per image) approximately 5 minutes after being intravenously administered 10 mg of scopolamine-N-butyl bromide to deliberately create diverse degrees of small bowel motility. In a manually segmented area of the small bowel, motility was automatically quantified using a nonrigid registration and calculated as a quantitative motility score. The mean value (MV) of motility grades visually assessed by two radiologists was used as a reference standard. The quantitative motility score's correlation (Spearman's ρ) with the reference standard and performance (area under the receiver operating characteristics curve [AUROC], sensitivity, and specificity) for diagnosing adynamic small bowel (MV of 1) were evaluated.

RESULTS

For the MV of the quantitative motility scores at grades 1, 1.5, 2, 2.5, and 3, the mean ± standard deviation values were 0.019 ± 0.003, 0.027 ± 0.010, 0.033 ± 0.008, 0.032 ± 0.009, and 0.043 ± 0.013, respectively. There was a significant positive correlation between the quantitative motility score and the MV (ρ = 0.531, P < 0.001). The AUROC value for diagnosing a MV of 1 (i.e., adynamic small bowel) was 0.953 (95% confidence interval, 0.923-0.984). Moreover, the optimal cutoff for the quantitative motility score was 0.024, with a sensitivity of 100% (15/15) and specificity of 89.9% (143/159).

CONCLUSION

The quantitative motility score calculated from a cine MRI enables diagnosis of an adynamic small bowel, and potentially discerns various degrees of bowel motility.

State of the Art MR Enterography Technique

ABSTRACT

Magnetic resonance enterography (MRE) is a well-established imaging technique that is commonly used for evaluating a variety of bowel diseases, most commonly inflammatory bowel disease which is increasing in prevalence. Inflammatory bowel disease is composed of 2 related, but distinct disease entities: Crohn disease (CD) and ulcerative colitis. In ulcerative colitis, inflammation is generally limited to the mucosa and invariably involves the rectum, and often the more proximal colon. CD is typified by transmural inflammation with skip lesions occurring anywhere from the mouth to anus, but characteristically involves the terminal ileum. The transmural involvement of CD may lead to debilitating ulceration and, ultimately, development of sinus tracts, which can be associated with abscesses and fistulae as extraenteric manifestations of the disease. Because much of the small bowel and extraenteric disease cannot be adequately assessed with conventional endoscopy, imaging plays a crucial role in initial diagnosis and follow-up. MRE does not use ionizing radiation which is important for these patients, many of which present earlier in life and may require multiple imaging examinations. In this article, we review the clinical indications, patient preparation, and optimal technique for MRE. We also discuss the role and proper selection of intravenous gadolinium-based contrast material, oral contrast material, and antiperistaltic agents, including pediatric considerations. Finally, we review the recommended and optional pulse sequence selection, including discussion of a "time-efficient" protocol, reviewing their utility, advantages, and limitations. Our hope is to aid the radiologist seeking to develop a robust MRE imaging program for the evaluation of bowel disease.

Recommendations for MRI technique in the evaluation of pelvic endometriosis: consensus statement from the Society of Abdominal Radiology endometriosis disease-focused panel

Endometriosis is a common entity causing chronic pain and infertility in women. The gold standard method for diagnosis is diagnostic laparoscopy, which is invasive and costly. MRI has shown promise in its ability to diagnose endometriosis and its efficacy for preoperative planning. The Society of Abdominal Radiology established a Disease-Focused Panel (DFP) to improve patient care for patients with endometriosis. In this article, the DFP performs a literature review and uses its own experience to provide technical recommendations on optimizing MRI Pelvis for the evaluation of endometriosis.

A Systematic Review of Technical Parameters for MR of the Small Bowel in non-IBD Conditions over the Last Ten Years

Technical guidelines for magnetic resonance imaging (MRI) of the small bowel (SB) in the setting of inflammatory bowel diseases (IBDs) were detailed in a 2017 consensus issued by European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Pediatric Radiology (ESPR); however, MRI for non-IBD conditions was not addressed. Hence, we performed a systematic review collecting researches on SB MRI for non-IBDs. The literatures were then divided into morphologic group and functional group. Information about the MRI techniques, gastrointestinal preparation, and details of cine-MRI protocols was extracted. We found that a 1.5 T MRI system, prone positioning, and MR enterography were frequently utilized in clinical practice. Gadolinium contrast sequences were routinely implemented, while diffusion-weighted imaging (DWI) was much less performed. The gastrointestinal preparation varied throughout the studies. No uniform protocols for cine imaging could be established. SB MRI examinations for non-IBDs are far from standardized, especially for functional studies. Recommendations for standard parameters in cine-MRI sequences are difficult to make due to lack of evidentiary support. MRI investigations in non-IBD conditions are needed and the standardization of non-IBD imaging in clinical practice is required.

Acceleration of small bowel motility after oral administration of dai-kenchu-to (TJ-100) assessed by cine magnetic resonance imaging

Dai-kenchu-to (TJ-100) is an herbal medicine used to shorten the duration of intestinal transit by accelerating intestinal movement. However, intestinal movement in itself has not been evaluated in healthy volunteers using radiography, fluoroscopy, and radioisotopes because of exposure to ionizing radiation. The purpose of this study was to evaluate the effect of TJ-100 on intestinal motility using cinematic magnetic resonance imaging (cine MRI) with a steady-state free precession sequence. Ten healthy male volunteers received 5 g of either TJ-100 or lactose without disclosure of the identity of the substance. Each volunteer underwent two MRI examinations after taking the substances (TJ-100 and lactose) on separate days. They drank 1200 mL of tap water and underwent cine MRI after 10 min. A steady-state free precession sequence was used for imaging, which was performed thrice at 0, 10, 20, 30, 40, and 50 min. The bowel contraction frequency and distention score were assessed. Wilcoxon signed-rank test was used, and differences were considered significant at a P-value <0.05. The bowel contraction frequency tended to be greater in the TJ-100 group and was significantly different in the ileum at 20 (TJ-100, 8.95 ± 2.88; lactose, 4.80 ± 2.92; P < 0.05) and 50 min (TJ-100, 9.45 ± 4.49; lactose, 4.45 ± 2.65; P < 0.05) between the groups. No significant differences were observed in the bowel distention scores. Cine MRI demonstrated that TJ-100 activated intestinal motility without dependence on ileum distention.

Evaluation of gastrointestinal motility with MRI: Advances, challenges and opportunities

Dynamic magnetic resonance imaging (MRI) of gastrointestinal motility has developed rapidly over the past few years. The non-invasive and non-ionizing character of MRI is an important advantage together with the fact that it is fast and can visualize the entire gastrointestinal tract. Advances in imaging and quantification techniques have facilitated assessment of gastric, small intestinal, and colonic motility in a clinical setting. Automated quantitative motility assessment using dynamic MRI meets the need for non-invasive techniques. Recently, studies have begun to examine this technique in patients, including those with IBD, pseudo-obstruction and functional bowel disorders. Remaining challenges for clinical implementation are processing the large amount of data, standardization and validation of the numerous MRI metrics and subsequently assessment of the potential role of dynamic MRI. This review examines the methods, advances, and remaining challenges of evaluation of gastrointestinal motility with MRI. It accompanies an article by Khalaf et al. in this journal that describes a new protocol for assessment of pan-intestinal motility in fasted and fed state in a single MRI session.

Identifying decreased peristalsis of abnormal small bowel segments in Crohn's disease using cine MR enterography: the frozen bowel sign

PURPOSE

The purpose of this study was to evaluate whether affected bowel in Crohn's disease patients can be identified by observing decreased peristalsis (frozen bowel sign) using cine balanced steady-state free precession (cine BSSFP) images.

MATERIALS AND METHODS

5 radiologists independently reviewed cine BSSFP sequences from randomized MR Enterography (MRE) exams for 30 normal and 30 Crohn's disease patients, graded overall small bowel peristalsis from slowest to fastest, and graded peristalsis for the most abnormal small bowel segment. Sensitivity and specificity of the frozen bowel sign for diagnosing Crohn's disease were calculated. T tests of the peristalsis difference between abnormal segments and overall small bowel were conducted.

RESULTS

For 5 readers, the sensitivity and specificity of cine BSSFP of the frozen bowel sign for diagnosing Crohn's disease ranged from 70% to 100% and 87% to 100%, respectively. There were significant differences in peristalsis between abnormal small bowel segments and the overall small bowel for Crohn's patients, but not in the overall small bowel between normal-MRE patients and Crohn's disease patients.

CONCLUSION

Abnormal Crohn's small bowel segments have significantly decreased peristalsis compared to normal small bowel, which can be identified using cine BSSFP sequences as the frozen bowel sign.

Magnetic resonance imaging biomarkers of gastrointestinal motor function and fluid distribution

Magnetic resonance imaging (MRI) is a well established technique that has revolutionized diagnostic radiology. Until recently, the impact that MRI has had in the assessment of gastrointestinal motor function and bowel fluid distribution in health and in disease has been more limited, despite the novel insights that MRI can provide along the entire gastrointestinal tract. MRI biomarkers include intestinal motility indices, small bowel water content and whole gut transit time. The present review discusses new developments and applications of MRI in the upper gastrointestinal tract, the small bowel and the colon reported in the literature in the last 5 years.

Magnetic resonance enterography in evaluation and management of children with Crohn's disease

The role of radiologic evaluation in Crohn's disease (CD) has undergone a recent paradigm shift in which the radiologist adds value to the multidisciplinary team by longitudinally assessing therapeutic response and identifying treatment-modifying subtypes, such as fibrostenotic or fistulizing disease. Magnetic resonance enterography (MRE) has become the primary imaging modality used. The combination of multiplanar, multiparametric, and multiphasic contrast-enhanced imaging with the high spatial resolution and very high tissue contrast of MR imaging allows for detailed evaluation of intra-abdominal pathology, without the risk of cumulative radiation exposure. MRE provides the benefit of a complete evaluation of mural, extramural, and even extraintestinal manifestations and complications of CD in a single examination. Cine motility sequences and diffusion-weighted imaging may further increase sensitivity and specificity. MRE represents an ideal imaging modality for initial evaluation, assessment of therapeutic response, and evaluation of complications in patients with CD.