E2055. Outside Looking In: The Role of Outpatient versus Inpatient Gastric Emptying Studies
  1. Jennifer Wu; Westchester Medical
  2. Michael Frohlinger; New York Medical College
  3. Edison Tsui; New York Medical College
  4. Perry Gerard; New York Medical College
Normal gastrointestinal motility requires a complex series of events and coordination. Gastroparesis occurs when this process is dysfunctional in the absence of mechanical obstruction, and is becoming increasingly more common. Uncontrolled gastroparesis may have significant impacts on quality of life, and many of these patients present for evaluation in the acute setting. The diagnosis is often made clinically, but is often confirmed with gastric motility studies. As a consequence, gastric emptying studies are frequently being requested during the hospitalization. Previous studies have suggested that there is a higher incidence of abnormal findings when these are performed in the inpatient setting; which may be contributed by various confounding factors that limit a radiologist’s interpretation. These limitations should be taken into account, and the optimal timing for when to evaluate patients with suspected gastroparesis has not yet been defined.

Educational Goals / Teaching Points
We present a series of cases both illustrating and comparing the various findings in patients that underwent a gastric emptying study in the inpatient or outpatient setting, and review key imaging characteristics.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The gastric study technique we use at our institution includes 1.0 mCi of Tc-99 sulfur-colloid cooked into egg whites and made into a sandwich with jelly. We then obtain imaging hourly for 4 hours in anterior and posterior positions after ingestion.

Abnormal findings on gastric emptying studies are much more common in hospitalized patients, and this is consistent with observations from other studies. The increased number of false-positive as well as the severity may be influenced by multiple confounding factors in hospitalized patients including medications, immobility, acute infections, and neurologic disease. Gastric emptying studies performed in the inpatient setting have limitations, and this should be taken into account to determine the optimal timing for performing this study as well as its clinical interpretation.