The Reproducibility of Tc-Pertechnetate Single Photon Emission Computed Tomography (SPECT) for Measurement of Gastric Accommodation in Healthy Humans: Evaluation of the Test Results Performed at the Same Time and Different Time of the Day

Acute Effects of Red Chili, a Natural Capsaicin Receptor Agonist, on Gastric Accommodation and Upper Gastrointestinal Symptoms in Healthy Volunteers and Gastroesophageal Reflux Disease Patients

The effects of chili on gastric accommodation (GA) in gastroesophageal reflux disease (GERD) patients have not been explored. Methods: In total, 15 healthy volunteers (HV) and 15 pH-positive non-erosive GERD (NERD) patients underwent single-photon emission computed tomography after ingesting 2 g of chili or placebo in capsules in a randomized double-blind crossover fashion with a one-week washout period. GA was the maximal postprandial gastric volume (GV) after 250 mL of Ensure^® minus the fasting GV. Upper gastrointestinal symptoms were evaluated by using a visual analog scale. Results: NERD patients but not HV had significantly greater GA after chili compared to a placebo (451 ± 89 vs. 375 ± 81 mL, p < 0.05). After chili, the postprandial GVs at 10, 20, and 30 min in NERD patients were significantly greater than HV (10 min, 600 ± 73 vs. 526 ± 70 mL; 20 min, 576 ± 81 vs. 492 ± 78 mL; 30 min, 532 ± 81 vs. 466 ± 86 mL, all p < 0.05). In NERD, chili was associated with significantly less satiety, more severe abdominal burning (p < 0.05), and a trend of more severe heartburn (p = 0.06) compared to the placebo. In HV, postprandial symptoms after chili and placebo ingestion were similar (p > 0.05). Conclusions: Chili enhanced GA in NERD patients but not in HV. This suggests that the modulation of GA in NERD is abnormal and likely involves transient receptor potential vanilloid 1 (TRPV1) sensitive pathways.

Enhancing Scintigraphy for Evaluation of Gastric, Small Bowel, and Colonic Motility

This article reviews the latest enhancements in standards and technology for performing gastric emptying and associated small bowel and colon transit scintigraphic studies. It discusses how developments in appropriate use criteria, American Medical Association Current Procedural Terminology coding, and advanced commercial software permit clinicians to obtain more comprehensive physiologic studies of gastric, small bowel, and colon gastrointestinal motility disorders. It shows how gastrointestinal scintigraphy has expanded to permit assessments of global and regional (fundic and antral) gastric motility and how it permits a single study (whole-gut transit scintigraphy), including measurement of solid and liquid gastric emptying and small bowel and colon transit.

Towards a Fuller Assessment of Gastric Motility in Patients With Upper GI Dyspepsia: Time to Accommodate!

There is increasing recognition of the importance of assessing patients with unexplained upper gastrointestinal symptoms for impaired gastric accommodation. New therapeutic approaches to treat impaired accommodation are being developed. This increasing interest in diagnosing and treating impaired gastric accommodation emphasizes the need to have a clinically available method to measure the gastric accommodation response. In this editorial, gastric accommodation is discussed along with the currently available methods for its assessment. We summarize our thoughts on what are the next steps needed to make a readily accessible method for assessing gastric accommodation more widely available.

Assessment of Gastric Accommodation in Patients with Functional Dyspepsia by 99mTc-Pertechtenate Single Photon Emission Computed Tomography Imaging: Practical but not Widely Accepted

Objective:

Impaired gastric accommodation is one of the main symptoms in patients with functional dyspepsia. The aim of the present study was to assess gastric accommodation in patients with functional dyspepsia using single photon emission computed tomography (SPECT) imaging.

Methods:

Twenty-four patients with functional dyspepsia and 50 healthy volunteers as control group were enrolled in this study. All participants were given 5 mCi 99mTc-pertechtenate intravenously, served with a low fat meal, and underwent SPECT scanning 20 minutes after the meal.

Results:

Based on the scintigraphic data, gastric volumes were found to be significantly increased after food ingestion in both patient and control groups. We also found that while there was no significant difference between patient and control groups in terms of fasting gastric volumes, postprandial gastric volume was significantly lower in patients as compared to healthy individuals (p<0.05).

Conclusion:

Measuring gastric volume by using SPECT can be a valuable method in the detection of functional dyspepsia and in differentiation of this entity from other organic disorders.

Progress in measurements of proximal gastric accommodation in patients with functional dyspepsia

Since gastric accommodation is an important parameter for investigating the pathophysiology of functional dyspepsia, the measurement of gastric accommodation has aroused widespread interests. Gastric barostat remains the gold standard, but it needs intubation and is invasive. In recent years, emerging modalities including single photon emission computed tomography (SPECT), three-dimensional ultrasound and magnetic resonance imaging have been developed to measure gastric volumes accurately and non-invasively; however, these technologies are sophisticated and expensive, which limits their clinical application. The satiety drinking test is simple and non-invasive and is often used in clinical and research studies, but the differences in the types of meals and the drinking speed among different studies often cause differences in the evaluation of gastric accommodation. The aim of this review is to summarize the advantages and disadvantages of various measurements of gastric accommodation.

Simplifying the measurement of gastric accommodation using SPECT

BACKGROUND

Non-invasive single photon emission computed tomography (SPECT) has been validated as a test for postprandial gastric volume accommodation, with volumes measured twice over 30 min and averaged. The purpose of this study is to simplify the SPECT measurement of gastric accommodation.

METHODS

The primary aim of this study was to compare two postprandial gastric volume measurements with data collected retrospectively from 443 patients and healthy volunteers who had undergone SPECT in the last decade. The differences in the two gastric volumes were compared in the entire group and each subgroup, and the correlation between the two measurements and their differences across a wide range of gastric volumes were plotted.

KEY RESULTS

There was a median difference of <2% (P = 0.041) between postprandial scan 1 (757 mL) and scan 2 (743 mL), with significant correlation (rs  = 0.859, P < 0.01) and excellent agreement (SD 60 mL) between the two scans across the entire range of observed postprandial gastric volumes.

CONCLUSIONS & INFERENCES

A single postprandial scan can detect gastric accommodation with the same accuracy as averaging two postprandial scans. These data support simplifying SPECT measurement of postprandial gastric volume with a scan in the first 15 min after a meal.

Measurement of gastric accommodation: a reappraisal of conventional and emerging modalities

Impaired gastric accommodation is an important cause of functional dyspepsia. Currently available tests that evaluate gastric accommodation provide relevant physiological information, but they pose technical difficulties and their clinical impact remains controversial. Gastric barostat remains the gold standard, but it is an invasive procedure. In recent years, emerging modalities including single photon emission computed tomography (SPECT), three-dimensional ultrasound and magnetic resonance imaging have been developed to measure gastric volumes and hold promise as alternative methods of assessing gastric accommodation non-invasively. Studies are underway to validate these techniques with recent data proving the performance characteristics of SPECT. The non-invasive nutrient drink test measures satiety scores as a surrogate marker of gastric accommodation and remains controversial. More recently, intragastric monitoring has been proposed as yet another non-invasive modality to assess gastric accommodation. Each of these different modalities brings its associated advantages and disadvantages, as is discussed in this review. Ongoing studies to validate these new techniques are in progress and are likely to lead to further progress in neurogastroenterology.