Beyond the Standard Meal: An Observational Analysis of Meals Used in Nuclear Medicine Gastric Emptying Studies

Rationale Standardized guidelines for meals used in adult gastric emptying studies (GES) have been available since 2009; however, there is still great variability in the diets that are clinically used in these studies. The purpose of this retrospective study is to perform an observational analysis of GES meals that are used within a national radiology practice to assess for compliance. It is hypothesized that despite having well-validated standardized meal protocols, there remains great variability in its use and interpretation. Methods This retrospective observational analysis included 11,458 GESs and their associated reports. GES meals were divided into 5 categories including solid, liquid, dual liquid and solid, alternative meals, and other. Further analysis was performed on the solid and liquid meal GESs. The total amount of studies performed with each meal was collected as well as the percentages of the results of each study categorized as normal, delayed, rapid, and limited. Results A total of 10,602 studies were included in the analysis, which included 9974 solid meals and 628 liquid meals. Of the solid meal type, the standard recommended meal was used most often followed by the protein variant meal. The oatmeal protocol had the least number of delayed results; however, there was otherwise a similar distribution of results for the remaining solid meal variants. The most common liquid meal utilized the nutritional drink or protein shake, and compared with the solid meal types, there were less rapid or limited results. Conclusions Variability remains in clinical practice regarding the type of meal that is used in GESs as well as in the interpretation of the study. Continued reinforcement of the standardized solid meal diet and validated cutoff values for interpretation remains crucial until there is increased validation and standardization of other diets.