Normal Gastric Emptying Scintigraphy Values for Limited Meal Ingestion

Area of Science:

• Gastroenterology
• Nuclear Medicine
• Diagnostic Imaging

Background:

• Gastric emptying scintigraphy (GES) is standard for gastroparesis diagnosis.
• Patients may not complete the full meal due to symptoms, affecting test accuracy.
• This study investigates the impact of ingested meal size on GES results in normal subjects.

Purpose of the Study:

• To quantify the effect of different ingested meal sizes on gastric emptying in healthy individuals.
• To determine how variations in meal size affect the interpretation of gastric emptying scintigraphy (GES).
• To provide reference values for delayed gastric emptying based on reduced meal intake.

Main Methods:

• 24 healthy subjects underwent three GES tests using a Tc-99m radiolabeled egg white sandwich.
• Subjects ingested full (100%), half (50%), or quarter (25%) of the standard meal.
• Gastric retention and half-emptying time (T1/2) were calculated at various time points.

Main Results:

• Significantly lower gastric retention at 0.5, 1, 2, and 3 hours for 50% and 25% meals compared to the full meal.
• Mean + 2SD gastric retention at 2 hours was 41.6% for 50% meal and 59.5% for 25% meal.
• Half-emptying time (T1/2) was significantly shorter for half (67 min) and quarter (69 min) meals compared to the full meal (94 min).

Conclusions:

• Ingested meal amount significantly affects gastric emptying measurements.
• Reduced meal sizes result in shorter T1/2 and lower postprandial retention.
• For patients ingesting 50% of the standard meal, >41.6% retention at 2 hours or T1/2 >105.2 minutes suggests delayed gastric emptying.