Standard Protocol Variables

Patient preparationMedication withholdingInstructions are given for withholding prokinetic agents (metoclopramide, domperidone, and erythromycin), opiates, anticholinergic/antispasmodic agents, atropine, nifedipine, progesterone, octreotide, theophylline, benzodiazepine, and phentolamine.
Withholding timeProtocol clearly states that all of the above medications should be withheld for 2 d.
Blood glucoseInstructions are given to test that serum glucose level is <200 mg/dL before the study.
Blood glucose recordingInstructions are given to record blood glucose level and include in final report.
MealConsensus mealMeal is properly prepared using 118 mL (4 oz) of liquid egg white, 120 mL of water, 2 slices of toast, 30 g of jam or jelly, and no other ingredients.
Nothing by mouthProtocol states that patient may not take anything by mouth for a minimum of 4 h.
Meal ingestion timeProtocol directs that the patient should eat the meal rapidly (in <10 min).
Partial mealProtocol requires documentation of vomiting or of ingestion of only a portion of the meal.
Radiopharmaceutical doseThe prescribed radiopharmaceutical is 99mTc-SC, and the dose is 18.5–37 MBq (0.5–1.0 mCi),
AcquisitionImage projectionsBoth anterior and posterior images are acquired.
Image frequencyImages are acquired immediately upon meal completion and hourly until 4 h.
ProcessingGeometric meanInstructions are given to calculate the geometric mean using anterior and posterior projections (geometric mean = √ (anterior counts × posterior counts).
Decay-correctedProtocol includes instructions for decay correction of counts in region of interest.
Percentage retentionFinal measurements are reported as percentage of gastric retention at each time point.