Gastric emptying scintigraphy: is four hours necessary?

Area of Science:

• Gastroenterology
• Nuclear Medicine
• Medical Imaging

Background:

• Current recommendations for gastric emptying scintigraphy (GES) suggest imaging up to 4 hours for accurate gastroparesis diagnosis.
• The clinical utility of assessing gastric emptying at earlier time points remains under investigation.

Purpose of the Study:

• To evaluate the diagnostic value of earlier time points in GES for detecting delayed gastric emptying.
• To determine if earlier imaging can reliably identify gastroparesis.

Main Methods:

• Gastric emptying scintigraphy (GES) was performed using a liquid egg white meal.
• Imaging was conducted at multiple time points: 0, 0.5, 1, 2, 3, and 4 hours post-ingestion.
• Patients completed a gastrointestinal symptom questionnaire prior to the scan.

Main Results:

• A significant proportion of patients showed delayed gastric emptying at 1 hour (10.7%), 2 hours (27%), 3 hours (38.4%), and 4 hours (42%).
• Gastric retention at 4 hours showed strong correlations with retention at 3 hours (r=0.890) and 2 hours (r=0.738), but only a fair correlation with 1 hour (r=0.510).
• Patient symptoms, including early satiety and vomiting, correlated better with gastric retention at later time points (e.g., 4 hours).

Conclusions:

• Gastric retention at 4 hours is a reliable indicator of gastroparesis, correlating well with 3-hour and 2-hour retention.
• Assessing gastric emptying at 1 hour may lead to underdiagnosis, potentially missing up to 36% of patients with delayed emptying at 4 hours.
• Symptom correlation with delayed gastric emptying is stronger at later imaging time points.