Real time high resolution magnetic resonance imaging for the assessment of gastric motility disorders

Ajaj, Waleed

doi:10.1136/gut.2003.038588

Cited by 110 publications

(83 citation statements)

References 32 publications

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“…Several research groups have reported that fluid motions in the stomach promote the emulsification of oil components and drug release from matrix tablets (Schwizer et al, 2006;Abrahamsson et al, 2005). Ajaj et al (2004) reported unusual peristaltic motions in gastroparesis patients having a decreased ACW speed or different degrees of ACW contractions, which were monitored by magnetic resonance imaging (MRI). However, the physical effects of gastric peristalsis on gastric digestion are not yet fully understood.…”

Section: Introductionmentioning

confidence: 99%

Development of a Human Gastric Digestion Simulator Equipped with Peristalsis Function for the Direct Observation and Analysis of the Food Digestion Process

Kozu

Nakata

Nakajima

et al. 2014

FSTR

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A novel in vitro gastric device, the Gastric Digestion Simulator (GDS), was developed for the direct observation and quantitative analysis of the food digestion process in the human stomach. In addition to simulating the chemical digestion environment, this device provides a physical digestion environment comparable to that found in the stomach by simulating peristalsis, which is assumed to contribute to solid food disintegration. The GDS was successfully used to directly observe the disintegration process of Tofu (bean curd) as a typical solid food containing protein. The size distribution and protein content of Tofu particles during the digestion experiments were investigated. The results demonstrated the difference in particle disintegration between GDS and flask shaking experiments, which may be due to the lack of peristalsis in the latter case. Moreover, the size distribution of Tofu particles after the GDS experiments was affected by the physical properties of Tofu, thus revealing the usefulness of GDS for food digestion analysis.Keywords: GI tract, gastric digestion, in vitro gastric device, peristalsis, direct observation, solid food IntroductionIn the human gastrointestinal (GI) tract, foods are digested by a combination of physical and chemical processes. Chemical digestive processes are catalyzed by digestive enzymes secreted in the stomach and small intestine, and disintegrate foods down to the molecular scale. However, physical digestive processes, which are induced mainly by peristalsis, mix and empty gastric and intestinal contents, and thus play an important role in promoting food digestion in the GI tract. Peristalsis in the GI tract is caused by peristaltic wall motion (e.g., antral contraction waves (ACWs)) in the stomach. Periodically generated ACWs induce the motion of the gastric contents, mix the gastric contents, and grind bulk solid foods to reduce their particle size (Kong and Singh, 2008) Food digestion in the human GI tract has been studied using in vivo, in vitro, and in silico approaches. MRI has been used for in vivo studies on gastric peristaltic motion and the physical properties of gastric contents. The speed of ACWs and the ACW amplitude in the human stomach were calculated using data obtained by real-*To whom correspondence should be addressed. time MRI (King et al., 1984;Pallotta et al., 1998). The timedependent change of the viscosity of the gastric contents was measured using echo planar MRI (Marciani et al., 2000). This study seeks to develop a new in vitro gastric digestion device that focuses mainly on the physical digestion environment of the human stomach, and to assess the device's performance. The gastric digestion simulator (GDS) that we developed here can simulate peristaltic motion in the human stomach and enables direct observation of the digestion process in real time. In this study, two different types of Tofu were used as model solid foods.We investigated food digestion characteristics using GDS to quantitatively understand the dynamic digestion processes in t...

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Section: Introductionmentioning

confidence: 99%

Development of a Human Gastric Digestion Simulator Equipped with Peristalsis Function for the Direct Observation and Analysis of the Food Digestion Process

Kozu

Nakata

Nakajima

et al. 2014

FSTR

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“…In previous studies, magnetic resonance imaging (Ajaj et al, 2004), three-dimensional computed tomography, and single-photon emission computed tomography (SPECT) (Bouras et al, 2002) were used to assess the gastric accommodation reflex of the proximal stomach. However, no simple and useful method exists for the clinical evaluation of this phenomenon.…”

Section: Introductionmentioning

confidence: 99%

Simple and non-invasive assessment of the accommodation reflex of the proximal stomach

Kusunoki

Haruma

Hara

et al. 2010

J Smooth Muscle Res

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Background: Impaired gastric accommodation of the proximal stomach is one of the major pathophysiological mechanisms in functional dyspepsia (FD). However, no useful method exists for the clinical evaluation of this phenomenon. Aim: The aim of the present study was to establish a simple and non-invasive method for evaluating the accommodation reflex of the proximal stomach. Methods: Nine healthy subjects received up to 1,700 mL water (stepwise administration in 100-mL increments) using a nasogastric tube while they were in a supine position. To assess the meal-induced gastric accommodation reflex, we measured the cross-sectional area of the proximal stomach via ultrasonography (US) at 3-min intervals after administration of water. We also measured the pressure of the water column using the same tube. Then, we administrated up to 400 mL of water in 100-mL increments and measured the area of the proximal stomach in 44 FD patients with early satiation (the measurements were performed at intervals of 3-min), and we compared the results with those for 44 healthy subjects. Results: The incremental changes in the area of the proximal stomach corresponded well with the amount of water administered. The area of the proximal stomach increased, but the antral area and the intragastric pressure remained relatively stable. After administration of more than 100 ml water, the area of the proximal stomach in healthy subjects was significantly greater than that in FD patients.

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“…Moreover, image analysis of MRI bowel data is a complicated, high workload process, which requires dedicated readers and sound statistical analysis (7)(8)(9)(10). The motion encoding technique known as tagged imaging or SPAMM (spatial modulation of the magnetization) was originally developed for cardiac motion (11,12) but has been increasingly used in the abdominal area for measurements of deformation of the liver, distension of the stomach, and gastric activity (13)(14)(15). In SPAMM, a short prepulse sequence periodically saturates the magnetization that will eventually appear as a line or tag pattern in the image.…”

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confidence: 99%

Use of continuously MR tagged imaging for automated motion assessment in the abdomen: A feasibility study

Sprengers

Paardt

Zijta

et al. 2012

Magnetic Resonance Imaging

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Purpose: To investigate the feasibility of measuring motion in the abdomen using a continuously tagged magnetic resonance imaging sequence. Materials and Methods:To assess (nonperiodic) motion in the abdomen, a nontriggered, continuously tagged transient field echo (TFE) sequence was implemented that acquires one complete 3D dataset per prepulse after a fixed delay. In postprocessing, a frequency analysis approach was developed for compact reviewing of the data and noise suppression. For proof of principle, a simulation was made and one free-breathing dynamic in vivo scan was acquired in a healthy volunteer. During the dynamic scan the volunteer received glucagon intravenously. Results:The simulation showed that this frequency analysis enables the extraction of motion at low signal-tonoise ratio levels. Motion information was successfully gathered from the in vivo scan. The decline in bowel motion caused by the administration of glucagon could be quantitatively measured using the continuously tagged sequence. Conclusion:Continuously tagged imaging in the abdomen for the purpose of automated gathering of motion information is feasible and could aid the study of bowel motion.

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Real time high resolution magnetic resonance imaging for the assessment of gastric motility disorders

Cited by 110 publications

References 32 publications

Development of a Human Gastric Digestion Simulator Equipped with Peristalsis Function for the Direct Observation and Analysis of the Food Digestion Process

Development of a Human Gastric Digestion Simulator Equipped with Peristalsis Function for the Direct Observation and Analysis of the Food Digestion Process

Simple and non-invasive assessment of the accommodation reflex of the proximal stomach

Use of continuously MR tagged imaging for automated motion assessment in the abdomen: A feasibility study

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