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Magnetic resonance elastography (MRE) can estimate liver stiffness (LS) noninvasively. We prospectively assessed whether motion-encoding gradient (MEG) direction, slice position, or high-caloric food intake affects the repeatability of MRE measurements of LS.Twenty healthy volunteers (8 women, 12 men; age, 48 ± 12 years) were imaged in a 3.0T scanner at four timepoints: twice after overnight fasting (B1 , B2 ) and twice after consuming a 1050-calorie standardized meal (A1 , A2 ; after 30 and 60 min, respectively). Each session comprised sequential MRE acquisitions in which MEG was applied in three orthogonal directions with three slices positioned over the liver for each. Between sessions, the participants were repositioned to assess test-retest reproducibility.The LS measurements before/after food intake were 3.36 ± 1.31 kPa/3.22 ± 1.03 kPa, 2.04 ± 0.33 kPa/2.27 ± 0.38 kPa, and 2.47 ± 0.50 kPa/2.64 ± 0.76 kPa for MEG superimposed along the anterior-posterior (AP), foot-head (FH), and right-left (RL) directions, respectively. Before and after food intake, LS estimates were lower and more reproducible (

The conventional test for measurement of gastric emptying is scintigraphy (1,2). Using a solid-phase meal is recommended, as it quantifies the emptying of a physiologic caloric meal. Most centers use a 99mTc sulfur colloid-labeled egg-containing meal with standard imaging at 0, 1, 2, and 4 hours. In fact, a 4-hour gastric emptying test, using radiolabeled EggBeaters® with jam, toast, and water and measured by external scintigraphy, is advocated by the Society of Nuclear Medicine and The American Neurogastroenterology and Motility Society as the recommended standard (2). Assessment of gastric emptying over 4 hours is necessary, as extrapolation to measure T½ may be erroneous (3). Some regard the gastric retention of solids at 4 hours as the most reliable parameter for identifying gastroparesis. Gastric emptying T½ (GE T½) is also acceptable if imaging has been performed to 4 hours or at least to 50% emptying. However, it is also important to assess emptying at least 1 and 2 hours after radiolabeled meal ingestion, since prolongation of the early phases of emptying may also be associated with symptoms of gastroparesis, even though the gastric retention at 4 hours is normal or mildly delayed. Pharmacological studies have traditionally used GE T½ as an endpoint of significant interest. Traditionally, estimation of GE T½ has utilized detailed imaging over the 4-hour period or a power exponential analysis (4,5) which increases the cost of the procedure through the need for repeated imaging and special calculations. In the past, we have championed the use of hourly imaging for estimation of gastric emptying (6). The emptying phase of solids is generally linear after the initial lag phase, and gastroparesis due to neuropathic or myopathic motility disorders retards GE T½ (5,7,8). Therefore, measurement of GE T½ is a relevant clinical and pharmacodynamic measurement and, given the approximately linear post-lag phase, it is conceivable that imaging may be spaced out in time and still give accurate measurements of GE T½. We aimed to examine the validity of the use of hourly imaging (0-4 hours) as a measurement of GE T½ compared to T½ estimates obtained from more detailed imaging, every 15 minutes for the first 2 hours and every 30 minutes for the subsequent 2 hours.

Aims/Introduction: Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the major incretins; their secretion after various nutrient loads are well-evaluated in Caucasians. However, little is known of the relationship between incretin secretion and differing nutritional loading in Japanese subjects. In the present study, we evaluated GIP and GLP-1 secretion in Japanese subjects with normal glucose tolerance (NGT) after glucose loading (75 g glucose and 17 g glucose) and meal ingestion. Materials and Methods: A total of 10 Japanese NGT subjects participated in 75 g oral glucose tolerance test (OGTT), 17 g OGTT and meal tolerance test (MTT). Plasma glucose (PG), serum insulin (IRI), serum C-peptide (CPR), plasma total GIP, and plasma total GLP-1 levels during OGTT and MTT were determined. Results: Area under the curve (AUC)-GIP was increased in proportion to the amount of glucose, and was highest in MTT, showing that GIP secretion is also stimulated by nutrients other than glucose, such as lipid. In contrast, although the larger glucose load tended to induce a larger GLP-1 release, AUC-GLP-1 was not significantly different among the three loading tests (75 g OGTT, 17 g OGTT, MTT) irrespective of the kind or amount of nutrition load. Conclusions: Our results suggest that nutritional composition might have a greater effect on GIP secretion than that on GLP-1 secretion in Japanese NGT subjects. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00143.x, 2012)

This study was designed to clarify whether a part of the variability in gastric emptying could be ascribed to a relationship between meal ingestion and phase activity of the migrating motor complex and whether reproducibility is increased when meal ingestion takes place in relation to preselected characteristics of the migrating motor complex. We examined 12 healthy males, and the design included three examinations, twice with meal ingestion in a duodenal Phase I, and once in a Phase II. The meal consisted of an omelette labelled with 99mTc followed by 150 ml water labelled with 111In. The results showed that liquid lag phase (min) and was significantly shorter in Phase II than in Phase I (1 vs. 4, P = 0.007). The half emptying time of solid linear phase (min) was reproduced with nearly identical median and range values in the three series (I[1]: 67[51–87]; I[2]: 63[47–80]; 61[47–76]). With meal ingestion in Phase I a significant difference between inter- and intra-individual variance could not be demonstrated. With meal ingestion in Phase I a second examination in Phase I did not increase reproducibility of any of the variables compared to a second examination in Phase II. In conclusion, scientific investigations on gastric emptying have to be performed with phase related meal ingestion and a double-radionuclide technique.

Functional dyspepsia (FD) is characterized by upper gastrointestinal symptoms, which are frequently exacerbated by meal ingestion. While subgroups of FD patients exhibit a range of disturbances in upper gastrointestinal motor function, including delayed gastric emptying and abnormal intragastric meal distribution, which may reflect impaired proximal gastric relaxation and/or antral dysmotility, the association between symptoms and abnormalities in motor function appears to be relatively weak. More recently, the concept of visceral hypersensitivity to mechanical and chemical/nutrient stimuli has been promoted as important in the aetiology of dyspeptic symptoms. Somewhat surprisingly, the role of ‘dietary’ factors, that is, those factors, related directly to food ingestion, including patterns of nutrient intake, potential intolerance to specific foods or macronutrients, as well as cognitive factors, have been largely ignored. Moreover, presently available treatments fail to take into account the fact that symptoms are frequently induced by eating. This review focuses on the relevance of ‘dietary’ factors to FD.

Flow has been assessed in the gastric antrum using a velocity-sensitive version of the high-speed magnetic resonance imaging technique, echo planar imaging (EPI). Eight healthy volunteers attended fasted on three separate days and consumed 800 mL of either a 5% glucose (0.2 kcal mL-1), 10% glucose (0.4 kcal mL-1) or an isotonic mixed nutrient meal, Fresubin (1 kcal mL-1, 27.2 g fat). Gastric volumes were obtained at 10-min intervals for 1 h. Flow measurements were performed on a single slice through the antropyloric region 5 and 35 min after meal ingestion. Gastric volumes at 45 min were inversely proportional to the calorie density of the meal with (mean +/- SEM) 89 +/- 10%* of the Fresubin, 64 +/- 5%* of the 10% glucose and 41 +/- 5% of the 5% glucose remaining (*P0.005 vs 5% glucose). Substantial forward and backward antral flow was observed after all three meals in the initial 5-min imaging period. AT 35 min flow activity was significantly greater after both the high-calorie meals relative to the 5% meal (total number of flow events: Fresubin = 6.6 +/- 1.7,[symbol: see text] 10% glucose = 9.9 +/- 2.2, [symbol: see text] 5% glucose = 2.5 +/- 0.9,[symbol: see text] P0.03,[symbol: see text] P0.007 vs 5% glucose, n = 8). Peak forward velocities for the initial phase of emptying tended to be greater for the rapidly emptying 5% meal (5.9 +/- 0.8 cm-1) compared with the Fresubin (3.3 +/- 0.6 cm-1, P0.069, n = 8) and the 10% glucose (2.9 +/- 1.0 cm-1, P0.068, n = 8) meals. In spite of delayed gastric emptying, high-calorie meals were associated with substantial to and fro movements which may be important for meal tritruration and fat emulsification.

Background Using an experimental model of colonic gas infusion, we previously showed that the abdominal walls adapt to its content by an active phenomenon of abdominal accommodation. We now hypothesized that abdominal accommodation is a physiological phenomenon, and aimed to confirm that it can be induced by ingestion of a meal; a secondary aim was to determine whether the response to gut filling is region-specific. Methods In healthy subjects (n = 24) a nutrient test meal was administered until tolerated at a rate of 50 mL min−1. Electromyographic (EMG) activity of the anterior wall (upper and lower rectus, external and internal oblique) was measured via four pairs of surface electrodes, and EMG activity of the diaphragm via intraluminal electrodes on an esophageal tube. To address the secondary aim, the response to gastric filling was compared with that induced by colonic filling (1440 mL 30 min−1 anal gas infusion; n = 8). Key Results Participants tolerated 927 ± 66 mL of meal (450–1500 mL). Meal ingestion induced progressive diaphragmatic relaxation (EMG reduction by 16 ± 2%; P