Abstract:Motility quantitation revealed a significant difference in motility of terminal ileum in patients with small bowel CD compared with healthy subjects, concording with visible dysmotility and inflammatory changes. J. Magn. Reson. Imaging 2016;44:277-287.
“…MRI is non‐invasive, safe and widely available and, coupled with advances in post‐processing technologies, enables rapid and repeatable quantification . Encouragingly, the first steps toward clinical implementation have been taken with dynamic motility imaging now being routine in various centers and with several prospective clinical studies being published …”
Section: Introductionmentioning
confidence: 99%
“…[3][4][5][6][7][8][9][10][11] Encouragingly, the first steps toward clinical implementation have been taken with dynamic motility imaging now being routine in various centers and with several prospective clinical studies being published. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] The gastrointestinal tract is complex, undergoing fasted and fed contractile cycles that take place over hours, such as the migrating motor complex. 20 It is not practical to perform prolonged MRI imaging of the intestine in a clinical setting.…”
Objective
MRI is increasingly used to evaluate small bowel contractility. The objective of this study was to validate a clinically practical stimulation test (300‐kcal meal) for small bowel motility.
Methods
Thirty‐one healthy subjects underwent dynamic MRI to capture global small bowel motility after ±10h fasting, of which 15 underwent bowel preparation consisting of 1 L 2.5% mannitol solution and 16 did not. Each subject underwent (1) a baseline motility scan (2) a food challenge (3) a post‐challenge scan, and (4) second post‐challenge scan (after ±20 minutes). This protocol was repeated within 2 weeks. Motility was quantified using a validated motility assessment technique.
Key Results
Motility in prepared subjects at baseline was significantly higher than motility in unprepared subjects (0.36 AU vs 0.18 AU, P < 0.001). In the prepared group, the food challenge produced an 8% increase in motility (P = 0.33) while in the unprepared subjects a significant increase of 30% was observed (P < 0.001). Responses to food remained insignificant (P = 0.21) and significant (P = 0.003), for the prepared and unprepared subjects, respectively, ±20 minutes post food challenge. These results were confirmed in the repeated scan session.
Conclusion & Inferences
A significant response to a 300‐kcal meal was measured within 10 minutes in unprepared bowel, supporting the clinical use of this challenge to provoke and assess motility changes. A caloric challenge did not produce an observable increase in motility in mannitol prepared subjects.
“…MRI is non‐invasive, safe and widely available and, coupled with advances in post‐processing technologies, enables rapid and repeatable quantification . Encouragingly, the first steps toward clinical implementation have been taken with dynamic motility imaging now being routine in various centers and with several prospective clinical studies being published …”
Section: Introductionmentioning
confidence: 99%
“…[3][4][5][6][7][8][9][10][11] Encouragingly, the first steps toward clinical implementation have been taken with dynamic motility imaging now being routine in various centers and with several prospective clinical studies being published. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] The gastrointestinal tract is complex, undergoing fasted and fed contractile cycles that take place over hours, such as the migrating motor complex. 20 It is not practical to perform prolonged MRI imaging of the intestine in a clinical setting.…”
Objective
MRI is increasingly used to evaluate small bowel contractility. The objective of this study was to validate a clinically practical stimulation test (300‐kcal meal) for small bowel motility.
Methods
Thirty‐one healthy subjects underwent dynamic MRI to capture global small bowel motility after ±10h fasting, of which 15 underwent bowel preparation consisting of 1 L 2.5% mannitol solution and 16 did not. Each subject underwent (1) a baseline motility scan (2) a food challenge (3) a post‐challenge scan, and (4) second post‐challenge scan (after ±20 minutes). This protocol was repeated within 2 weeks. Motility was quantified using a validated motility assessment technique.
Key Results
Motility in prepared subjects at baseline was significantly higher than motility in unprepared subjects (0.36 AU vs 0.18 AU, P < 0.001). In the prepared group, the food challenge produced an 8% increase in motility (P = 0.33) while in the unprepared subjects a significant increase of 30% was observed (P < 0.001). Responses to food remained insignificant (P = 0.21) and significant (P = 0.003), for the prepared and unprepared subjects, respectively, ±20 minutes post food challenge. These results were confirmed in the repeated scan session.
Conclusion & Inferences
A significant response to a 300‐kcal meal was measured within 10 minutes in unprepared bowel, supporting the clinical use of this challenge to provoke and assess motility changes. A caloric challenge did not produce an observable increase in motility in mannitol prepared subjects.
“…20,26,31,42,48 The motility in the terminal ileum was lower in Crohn's patients in comparison to healthy subjects. 42 It has been shown that the lesion detection rate is increased when static and dynamic MRI is combined. 25,49 The motility patterns in Crohn's disease revealed reduced contraction-wave frequencies, amplitudes, and decreased luminal occlusion rates.…”
Section: Crohn's Diseasementioning
confidence: 95%
“…Several studies show that small bowel motility quantified with dynamic MRI can be used as a biomarker of inflammatory activity in Crohn's disease and to differentiate healthy from diseased bowel . The motility in the terminal ileum was lower in Crohn's patients in comparison to healthy subjects . It has been shown that the lesion detection rate is increased when static and dynamic MRI is combined .…”
Section: Clinical Implementationmentioning
confidence: 99%
“…It has been automated for more repeatable and standardized results and it produces very easily readable color maps. The software has been used and validated in several studies 4,7,9,10,13,18,20,22,23,[25][26][27][39][40][41][42] and one software version is commercially available. 43 F I G U R E 1 This figure visualizes the described quantification techniques.…”
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. Dynamic MRI is used in the stomach to measure frequency and amplitude of antral contractions. [3][4][5] It is used for the small bowel to look at segmental and global motility using frequency measures and surrogate measures. [6][7][8][9][10][11][12] In the colon it has been applied to assess motion and velocity of contents, wall motion and to study motility using surrogate measures. 13-17 So far there has been a paucity of validation studies. To our knowledge there is only one study in which dynamic MRI findings were compared to manometry, demonstrating 100% correlation between visualized colonic movements and intraluminal pressure changes. 17 The clinical value of dynamic MRI is under evaluation for pathologies like inflammatory bowel disease (IBD), chronic intestinal pseudo-obstruction (CIPO) and constipation. they quantified small bowel motility using dynamic MRI. 18 In this review we discuss the challenges and opportunities in evaluating gastrointestinal motility with dynamic MRI. The first part of this review summarizes the technical aspects of the dynamic MRI technique; the second part discusses the observations made by applying the described
BackgroundCurrently available tools for noninvasive motility quantification of the small intestine are limited to dynamic 2D MRI scans, which are limited in their ability to differentiate between types of intestinal motility.PurposeTo develop a method for quantification and characterization of small intestinal motility in 3D, capable of differentiating motile, non‐motile and peristaltic motion patterns.Study TypeProspective.SubjectsFourteen healthy volunteers (127 small intestinal segments) and 10 patients with Crohn's disease (87 small intestinal segments).Field Strength/Sequence3.0 T, 3D balanced fast field echo sequence, 1 volume per second.AssessmentUsing deformable image registration between subsequent volumes, the local velocity within the intestinal lumen was quantified. Average velocity and average absolute velocity along intestinal segments were used with linear classifiers to differentiate motile from non‐motile intestines, as well as erratic motility from peristalsis. The mean absolute velocity of small intestinal content was compared between healthy volunteers and Crohn's disease patients, and the discriminative power of the proposed motility metrics for detecting motility and peristalsis was determined. The consensus of two observers was used as referenced standard.Statistical TestsStudent's t‐test to assess differences between groups; area under the receiver operating characteristic curve (AUC) to assess discriminative ability. P < 0.001 was considered significant.ResultsA significant difference in the absolute velocity of intestinal content between Crohn's patients and healthy volunteers was observed (median [IQR] 1.06 [0.61, 1.56] mm/s vs. 1.84 [1.37, 2.43] mm/s), which was consistent with manual reference annotations of motile activity. The proposed method had a strong discriminative performance for detecting non‐motile intestines (AUC 0.97) and discernible peristalsis (AUC 0.81).Data ConclusionAnalysis of 3D cine‐MRI using centerline‐aware motion estimation has the potential to allow noninvasive characterization of small intestinal motility and peristaltic motion in 3D.Evidence Level3Technical EfficacyStage 2
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