Analysis of surface geometry of the human stomach using real‐time 3‐D ultrasonography <i>in vivo</i>

Liao, Donghua; Gregersen, Hans; Hausken, Trygve; Gilja, Odd Helge; Mundt, Marco W.; Kassab, Ghassan S.

doi:10.1111/j.1365-2982.2004.00522.x

Cited by 61 publications

(53 citation statements)

References 18 publications

(27 reference statements)

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“…For 3D positioning and orientation measurement (POM), a transmitter was placed close to the subject, and a snap-on sensor was attached to a 3.5C broad spectrum 2.5-to 4-MHz convex transducer (12,49). As the transmitter produces a spatially varying magnetic field, and ferrous and conductive metals distort the magnetic field, all metal objects were removed from the subject and from the area directly between the POM transmitter and sensor (32). The POM transmitter was placed behind (ϳ10 cm) the subject (16), at the level of the stomach, so that the subject was positioned between the ultrasonography scanner and the transmitter.…”

Section: Measurementsmentioning

confidence: 99%

Comparative effects of oral and intraduodenal glucose on blood pressure, heart rate, and splanchnic blood flow in healthy older subjects

Gentilcore

Nair²,

Vanis³

et al. 2009

American Journal of Physiology-Regulatory, Integrative and Comp

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Gentilcore D, Nair NS, Vanis L, Rayner CK, Meyer JH, Hausken T, Horowitz M, Jones KL. Comparative effects of oral and intraduodenal glucose on blood pressure, heart rate, and splanchnic blood flow in healthy older subjects. Am J Physiol Regul Integr Comp Physiol 297: R716 -R722, 2009. First published June 24, 2009 doi:10.1152/ajpregu.00215.2009.-Postprandial hypotension occurs frequently, particularly in the elderly. The magnitude of the fall in blood pressure (BP) and rise in heart rate (HR) in response to enteral glucose are greater when gastric emptying (GE) or small intestinal infusion are more rapid. Meal ingestion is associated with an increase in splanchnic blood flow. In contrast, gastric distension may attenuate the postprandial fall in BP. The aims of this study were to evaluate, in older subjects, the comparative effects of intraduodenal glucose infusion, at a rate similar to GE of oral glucose, on BP, HR, superior mesenteric artery (SMA) flow, and blood glucose. Eight healthy subjects (5 men, 3 women, age 66 -75 yr) were studied on two occasions. On day 1, each subject ingested 300 ml of water containing 75 g glucose. GE was quantified by three-dimensional ultrasonography between time t ϭ 0 -120 min, and the rate of emptying (kcal/min) was calculated. On day 2, glucose was infused intraduodenally at the same rate as that on day 1. On both days, BP, HR, SMA flow, and blood glucose were measured. The mean GE of oral glucose was 1.3 Ϯ 0.1 kcal/min. Systolic BP (P Ͻ 0.01), SMA flow (P Ͻ 0.05), and blood glucose (P Ͻ 0.01) were greater and HR less (P Ͻ 0.01) after oral, compared with intraduodenal, glucose. There were comparable falls in diastolic BP during the study days (P Ͻ 0.01 for both). We conclude that the magnitude of the fall in systolic BP and rise in HR are less after oral, compared with intraduodenal, glucose, presumably reflecting the "protective" effect of gastric distension. postprandial hypotension; gastric emptying; three-dimensional and Doppler ultrasound POSTPRANDIAL HYPOTENSION, defined as a decrease in systolic blood pressure Ն20 mmHg, occurring within 2 h of the end of a meal (23,25,38,39), is an important clinical problem, most commonly affecting the elderly and patients with autonomic dysfunction, the latter often secondary to diabetes (23,25,38,39). Postprandial hypotension is associated with significant complications, including syncope and falls (25) and, in some cases, stroke and angina (1,25,51).The stomach is likely to modulate the hypotensive response to a high-carbohydrate meal in two ways, first, by controlling the rate at which glucose enters the small intestine. Our laboratory's studies in healthy older subjects (26, 42) and patients with type 2 diabetes (28, 46) have established that there is a direct relationship between the magnitude of the fall in systolic blood pressure with the rate of small intestinal delivery of glucose (26,28,41,42), a response that depends on the total load of glucose entering the duodenum independent of glucose concentration (11,27). When glu...

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Section: Measurementsmentioning

confidence: 99%

Comparative effects of oral and intraduodenal glucose on blood pressure, heart rate, and splanchnic blood flow in healthy older subjects

Gentilcore

Nair²,

Vanis³

et al. 2009

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Imaging-based volume methods include analysis of surface geometry of human stomach by real-time, 3D ultrasonography or, most recently, by 3D reconstruction of images acquired by ordinary ultrasonography assisted by magnetic scan-head tracking (53,78). In the most recent application of ultrasonography (54), an outline of the total stomach volume is visualized after ingestion of a liquid meal that serves as a contrast medium.…”

Section: Ultrasonographymentioning

confidence: 99%

Methods for measurement of gastric motility

Szarka¹,

Camilleri²

2009

American Journal of Physiology-Gastrointestinal and Liver Physi

102

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Szarka LA, Camilleri M. Methods for measurement of gastric motility. Am J Physiol Gastrointest Liver Physiol 296: G461-G475, 2009. First published January 15, 2009 doi:10.1152/ajpgi.90467.2008There is an array of tests available to measure gastric motility. Some tests measure end points, such as gastric emptying, that result from several different functions, whereas other tests are more specific and test only a single parameter, such as contractility. This article reviews the tests most commonly available in practice and research to evaluate in vivo the gastric functions of emptying, accommodation, contractility, and myoelectrical activity. The rationale for testing, the relative strengths and weaknesses of each test, and technical details are summarized. We also briefly indicate the applications and validations of the tests for use in experimental animal studies. contractility; emptying; accommodation; gastroparesis; dyspepsia ASSESSMENT OF THE MOTOR FUNCTIONS (motility) of the stomach is important in studies of gastric physiology and pathophysiology. Although not generally applied in gastroenterological practice, there is increasing use of tests to evaluate gastric function, particularly less invasive tests in clinical settings.There is an array of tests available to measure gastric motility. Some tests measure end points, such as gastric emptying, that result from several different functions, whereas other tests are more specific and test only a single parameter, such as contractility. This article reviews the tests most commonly available in practice and research to evaluate in vivo the gastric functions of emptying, accommodation, contractility, and myoelectrical activity. The rationale for testing, the relative strengths and weaknesses of each test, and technical details are summarized. A brief discussion is also provided for methods that have been used in animals to study motor functions of the stomach in animals. Tests to Evaluate Gastric Emptying of SolidsGastric emptying is a composite end point reflecting a variety of functions including gastric accommodation, the pressure gradient between the proximal and distal stomach, and antropyloroduodenal contractility and coordination. The trituration of solids and emptying of solid and liquid food from the stomach are arguably the most important physiological functions of the stomach. Abnormal gastric emptying, either accelerated at 1 h or delayed at 4 h, is among the factors that contribute to reporting of dyspepsia or the development of postprandial symptoms after meal challenge (35). For all tests of gastric motility and emptying, there are standard precautions (1): 1) Drugs affecting gastric motility (e.g., anticholinergics, narcotics, and prokinetics) are stopped for 48 h prior to the test, and the study is performed in the morning after an overnight fast. 2) Diabetic subjects should have a glucose level Ͻ275 mg/dl. 3) At the time the meal is ingested, Type 1 diabetic patients should receive half of their normal insulin dose. Gastric Emptying Scintigrap...

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“…Advances in imaging are being introduced initially as research tools and subsequently as clinical diagnostic tests. Medical imaging-based three-dimensional models of in vivo GI organs have characterized the oesophagus, stomach, small intestine, sigmoid colon and rectum using ultrasonography, computed tomography (CT) or MRI (Li et al 1994;Liao et al 2004a;Frokjaer et al 2005Frokjaer et al , 2007Jeays et al 2007a,b;Pal et al 2007). Figure 2 shows an example of reconstruction of the stomach shape obtained by three-dimensional ultrasonography.…”

Section: (B ) Geometric Modellingmentioning

confidence: 99%

“…The main methods we used for the three-dimensional GI geometric modelling establishment are briefly described below. More detailed description of the methods can be found in our previous literature in Liao et al (2004aLiao et al ( , 2005 and Frokjaer et al (2005Frokjaer et al ( , 2007. (i) Medical imaging-based three-dimensional model reconstruction…”

Section: (B ) Geometric Modellingmentioning

confidence: 99%

Biomechanical functional and sensory modelling of the gastrointestinal tract

Liao

Lelic

Gao

et al. 2008

Phil. Trans. R. Soc. A.

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The aim of this review is to describe the biomechanical, functional and sensory modelling work that can be used to integrate the physiological, anatomical and medical knowledge of the gastrointestinal (GI ) system. The computational modelling in the GI tract was designed, implemented and evaluated using a series of information and communication technologies-based tools. These tools modelled the morphometry, biomechanics, functions and sensory aspects of the human GI tract. The research presented in this review is based on the virtual physiological human concept that pursues a holistic approach to representation of the human body. Such computational modelling combines imaging data, GI physiology, the gut-brain axis, geometrical and biomechanical reconstruction, and computer graphics for mechanical, electronic and pain analysis. The developed modelling will aid research and ensure that medical professionals benefit through the provision of relevant and precise information about a patient's condition. It will also improve the accuracy and efficiency of the medical procedures that could result in reduced cost for diagnosis and treatment.

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Analysis of surface geometry of the human stomach using real‐time 3‐D ultrasonography in vivo

Cited by 61 publications

References 18 publications

Comparative effects of oral and intraduodenal glucose on blood pressure, heart rate, and splanchnic blood flow in healthy older subjects

Comparative effects of oral and intraduodenal glucose on blood pressure, heart rate, and splanchnic blood flow in healthy older subjects

Methods for measurement of gastric motility

Biomechanical functional and sensory modelling of the gastrointestinal tract

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