Abstract
3045
Purpose: According to the Guideline for Adult Solid-Meal Gastric-Emptying Study 3.0, the SNMMI recommends that imaging be performed immediately and at one hour intervals up to 4 hours post-meal ingestion. However, arranging a 4-hour study can be problematic for some patients due to the greater distance they must travel to get to our facility. The purpose of this study is to determine if the 4-hour image is necessary for predicting normal or abnormal gastric emptying results.
Methods: Fifteen volunteers with normal gastrointestinal health, based on a physician approved questionnaire, underwent a gastric emptying procedure consisting of two scrambled eggs, two slices of bread, 300 mL of water, 3 pats of butter, and salt and pepper for taste. For each meal, 2 beaten eggs were mixed with 1 mCi of 99mTc-sulfur colloid and cooked in a skillet with 1 pat of melted butter. The remaining pats of butter were each spread on one slice of bread and served as part of the meal. The volunteer was asked to consume the meal within 10 minutes followed by images of the digestive tract at 0, 30, 60, 90, 120, 180, and 240 minutes. Regions of interest (ROI) were drawn around the stomach on each anterior image and the geometric mean values were used to determine the emptying rates for each study. The 120, 180, and 240 minute rates were compared to the SNMMI normal limits to determine if significant differences exist.
Results: The average meal emptying rates were 20%, 38%, 59%, 74%, 94%, 98% for 30, 60, 90, 120, 180, 240 minutes, respectively. After converting the SNMMI gastric retention values to gastric emptying values, the emptying rates of the meal at each time point fell within the established SNMMI gastric emptying normal limits. A t-test demonstrated significant correlation (p = 0.211) with the SNMMI upper limits, however there was a significant difference (p = 0.012) when compared to the lower limits. Conclusion: Since our values fell within the SNMMI gastric emptying normal limits and the data correlated well with the upper limits, shortening the study time frame from 4-hours to 2-hours is possible. This study demonstrated no difference in clinical results when imaging beyond 2-hours among our volunteers with normal gastrointestinal health. However, the significant difference between our results and the SNMMI lower limits may indicate the need to extend imaging to three or four hours post-meal ingestion for patients with gastroparesis. Further investigation of this research is warranted due to the small study population.
