Scintigraphic evaluation of gastric emptying: are radiolabeled solids necessary?

Use of a high caloric liquid meal as an alternative to a solid meal for gastric emptying scintigraphy

BACKGROUND

Gastric emptying scintigraphy (GES) using a solid meal is often recommended for the evaluation of gastroparesis. However, some patients cannot tolerate the standardized egg-white sandwich (EWS) solid meal and an alternative meal is needed.

AIM

The aim of this study was to compare GES, regional gastric emptying, and gastric contractility using a liquid nutrient meal (LNM; Ensure Plus(®)) to those using EWS.

METHODS

Twenty healthy volunteers underwent GES using EWS and LNM on separate days. Gastric emptying was measured using scintigraphy and with a wireless motility capsule (WMC; SmartPill(®)).

RESULTS

The gastric emptying half-time with LNM was similar to that with EWS (1.41 ± 0.11 vs 1.52 ± 0.08 h; P = 0.28) and the two were significantly correlated (r = 0.53; P = 0.017). There were time-related differences in gastric emptying of the LNM compared to EWS: in the first hour, gastric retention of EWS was slightly greater than that of LNM, whereas at 3 and 4 h, gastric retention of EWS was slightly less than that of LNM. Regionally, the percentage retention of the meal in the proximal stomach was greater for EWS than for LNM at 0.5 h. WMC gastric emptying times and gastric contractility for the two meals were not significantly different.

CONCLUSIONS

Overall gastric emptying of the LNM was similar to that of the EWS meal. The LNM empties without a lag phase and takes slightly longer to empty from the distal stomach, likely due to its higher fat content. These differences are likely due to early accommodation with retention of solids in the proximal stomach and the need for trituration of solids. We conclude that this LNM can serve as an alternative to the conventional solid EWS for GES.

Gastric emptying of solids and liquids for evaluation for gastroparesis

BACKGROUND

Gastric emptying scintigraphy (GES) of solids is typically used to evaluate for gastroparesis.

AIMS

The purpose of this study was to determine the value of simultaneously measuring gastric emptying of liquids and solids for assessing patients for delayed gastric emptying.

METHODS

A total of 596 patients at our institution from September 2007 to January 2010 underwent GES with assessment of both solid and liquid gastric emptying. An EggBeaters® with jam sandwich meal radiolabeled with Tc-99 m was used for solid GES and water radiolabeled with In-111 for liquid GES.

RESULTS

Inclusion criteria (no medications affecting gastric motility in 48 h prior to test; no prior gastric surgery) was met by 449 patients. Liquid gastric emptying was significantly correlated to solid gastric emptying: 30 min (r=0.652, P<0.001), 60 min (r=0.624, P<0.001) and 120 min (r=0.766, P<0.001). Interestingly, 60 patients, of which 57 were nondiabetic, had normal solid GES but delayed liquid emptying and represented 26% of the 228 patients with normal solid GES. Gastric retention of solids was mildly correlated with nausea, vomiting, loss of appetite, early satiety and feeling excessively full after meals. Gastric emptying of liquids was associated with early satiety and loss of appetite.

CONCLUSIONS

Gastric emptying of liquids correlates well with gastric emptying of solids. When evaluating patients for gastroparesis, assessment of gastric emptying of liquids in addition to solids may help identify additional patients with delayed gastric emptying, particularly non-diabetic patients where 26% with normal solid emptying may have delayed emptying of liquids. Symptoms of gastroparesis, however, are primarily associated with delayed gastric emptying of solids.

Gastric emptying: a comparison of three methods

OBJECTIVE

A better understanding of the clinical relevance of delayed gastric emptying (e.g. in diabetes) requires a simple, easily accessible and inexpensive method for measuring it. Two "new" methods for measuring gastric emptying of liquids (the paracetamol absorption test and the 13C-acetate breath test) are compared with the gold standard (gastric emptying scintigraphy (GES)).

MATERIAL AND METHODS

The three techniques were used simultaneously in 10 healthy subjects. A gastric emptying time-retention curve was drawn for each technique and the results were compared at the 75%, 50% and 25% retention quartiles.

RESULTS

Agreement was found between the paracetamol absorption test and GES (p=0.95; Hotelling's T 2 test). Using the Wagner-Nelson one compartment correction produced a retention curve for the 13C-acetate breath test statistically significantly below GES (p<0.01).

CONCLUSION

In healthy subjects, the paracetamol absorption test produced results comparable to those of liquid GES, but not to the results of the 13C-acetate breath test.

Validation of the 13C-octanoic acid breath test for measurement of equine gastric emptying rate of solids using radioscintigraphy

REASONS FOR PERFORMING STUDY

Disordered gastric motility may be a significant factor in the pathogenesis of many equine conditions. Although tests for liquid phase emptying rate have been validated in the horse, there are no effective tests for solid phase emptying measurement that can be performed routinely in the field.

OBJECTIVES

The objective of this study was the assessment of a novel stable isotope technique, the 13C-octane acid breath test (13C-OABT), for the measurement of gastric emptying of solid ingesta, by direct comparison with the optimum method of gastric scintigraphy.

METHODS

To facilitate dual measurement of gastric emptying, a test meal was used containing baked egg yolk labelled with both 13C-octanoic acid and 99mtechnetium sulphur colloid. Simultaneous, serial lateral gastric scintigraphs and expiratory breath samples were obtained in 12 healthy horses after voluntary ingestion of the test meal. Analysis of breath 13CO2:12CO2 ratio was performed by continuous flow isotope ratio mass spectrometry. Power regression was used to determine the gastric emptying coefficient, the gastric half-emptying time (t 1/2) and duration of the lag phase (tlag).

RESULTS

Significant correlations (P < 0.001) were found between the 2 techniques for measurement of both t 1/2 and tlag. In addition, scintigraphic left t 1/2 was correlated significantly to breath test gastric emptying coefficient (P < 0.001).

CONCLUSIONS

It was concluded that the 13C-octanoic acid breath test is a reliable diagnostic procedure to measure gastric emptying rate of solids in the horse.

POTENTIAL RELEVANCE

Being safe, noninvasive and easy to perform, this test has potential value as both sensitive diagnostic modality and humane research tool for motility studies.

Scintigraphic evaluation of esophageal transit and gastric emptying in familial dysautonomia

Gastroesophageal dysfunction is a major cause of morbidity and mortality in patients with familial dysautonomia (FD). Most studies evaluating esophageal and gastric function in FD patients are either insensitive or invasive. Thus we have used a "milk" scan to quantitate abnormalities in esophageal transit and gastric emptying, while searching for gastroesophageal reflux and aspiration in these patients. The quantitative scintigraphic evaluation was performed in 35 patients with FD, 10 of whom were studied after fundoplication, pyloroplasty and gastrostomy. A prolonged esophageal transit time, ranging from 8 s to more than 60 s duration, was demonstrated in 11 patients. Gastroesophageal reflux was detected in 26 patients. In 16 patients delayed gastric emptying ranging from 63-94% was detected at 30 min, and in 13 patients delayed emptying ranging from 37-86% was observed at 120 min. Pulmonary aspiration was detected in 8 non-operated patients, four of whom had abnormal gastric emptying. The scintigraphic analysis of both esophageal transit and gastric emptying in familial dysautonomia is presented, and its role in evaluation and management of these patients discussed.

Gastric emptying of solids and liquids in obesity

The purpose of this study was to determine whether obese patients have different rates of solid and liquid gastric emptying compared to healthy controls. Twenty-four obese patients (7 males, 17 females) were investigated prior to dietary restriction. The patients had a weight excess above ideal weight ranging from 25% to 216% (mean weight 118.1 +/- 6.5 kg). The control group consisted of 8 healthy subjects (4 males, 4 females), within 10% of the ideal weight. The solid phase of the test meal consisted of 40 g bread, 30 g ham, 10 g margarine, and two scrambled eggs labeled with 99mTc. For the liquid phase, 200 ml orange juice was labeled with 201Tl. Three-minute counts of both tracers were taken for 106 min using a large field-of-view gamma camera. In obese patients, a significantly shortened lag phase for the emptying of solids was observed (27.0 +/- 3.3 versus 38.4 +/- 4.1 min; P < 0.05). Half-emptying time (105.9 +/- 6.7 versus 100.7 +/- 5.7 min), emptying rate (0.60 +/- 0.04 versus 0.71 +/- 0.07%/min), and total emptying of solids (49.4 +/- 3.6 versus 50.5 +/- 5.0%) were not different from controls. Obese subjects had a trend to slowed liquid emptying (half-time 82.7 +/- 4.8 versus 69.9 +/- 6.9 min; emptying rate 0.59 +/- 0.03 versus 0.65 +/- 0.03%/min; total emptying 59.8 +/- 2.9 versus 66.0 +/- 3.3%), but this was not statistically significant. There was no correlation between weight or body surface area and rate of solid or liquid gastric emptying.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of verapamil on human intestinal transit

Although constipation is a well-known side effect of calcium channel blockers such as verapamil, this side effect has not been evaluated in a quantitative manner. In a double-blind, randomized, crossover trial, the effect of verapamil (240 mg/day) was compared to placebo in 15 normal male volunteers. Subjects recorded their bowel movements and any side effects. Scintigraphy was used to quantitate gastric emptying, small intestinal transit, and colonic transit. In the study period of four days, verapamil did not change the frequency, consistency, or passage of bowel movements. A significantly increased number of side effects was noted during verapamil treatment--notably abdominal pain and dry mouth. The slope of gastric emptying was not significantly different for verapamil (0.012 +/- 0.02) than for placebo (0.013 +/- 0.001). Distal ileum filling was also not different for verapamil (0.41 +/- 0.13%/min) than placebo (0.33 +/- 0.05%/min). Progression of the colonic geometric center was significantly delayed at 48 hr by verapamil (5.2 +/- 0.4 vs 6.2 +/- 0.23; P less than 0.01). This study suggests that the constipating effect of verapamil is due to a delay of colonic transit and not due to an effect on upper gastrointestinal transit.

Biphasic solid and liquid gastric emptying in normal controls and diabetics using continuous acquisition in LAO view

The purpose of this study was to investigate the various phases of gastric emptying using a dual-isotope liquid-solid meal ([99mTc]SC egg sandwich and [111In]DPTA in water) and continuous acquisition in the left anterior oblique view. The study groups consisted of 10 normal controls and 20 diabetics with symptoms suggestive of diabetic gastroparesis. Solid-phase emptying in both groups almost always had a lag phase followed by linear emptying. Liquid-phase emptying was biexponential in 4/10 normals and 12/20 diabetics, with a short early rapid emptying rate (mean T1/2 = 48 min in normals and 79 min in diabetics). Solid emptying was delayed in 10, normal in eight, and rapid in two diabetics. Liquid emptying was delayed in 9/10 diabetics who had delayed solid emptying. Diabetics as a group had a significantly delayed solid lag phase (P less than 0.025), rate of emptying (P less than 0.05) and percent emptying at 90 min (P less than 0.025) compared to normal controls. Diabetic liquid emptying was also significantly delayed (P less than 0.025). The second component of liquid emptying strongly correlated with the solid rate of emptying (r = 0.826 in normals and 0.855 in diabetics). Continuous acquisition of gastric emptying studies in the LAO view has allowed us to better define the various phases of solid and liquid gastric emptying.