title: A gluten-free vegan meal for gastric emptying scintigraphy: establishment of reference values and its utilization in the evaluation of diabetic gastroparesis.
abstract: OBJECTIVE
  The aim of this study was to describe the preparation of radiolabeled idli (savory cake) meal for use as an alternate to the egg white sandwich (EWS) meal in gastric emptying scintigraphy (GES). Furthermore, the aim of this study was to establish normal emptying rates for this meal and present our experience in using it in the evaluation of diabetic gastroparesis.
  
  
  METHODS
  The meal was prepared using a universally available packaged mix labeled with 1 mCi 99mTc sulfur colloid, and the stability of labeling was tested up to 4 hours in simulated gastric fluid. One hundred thirteen healthy volunteers (aged 20-78 years; 54 women, 59 men) underwent GES study using the idli meal. Gastric retention at one-half, 1, 2, and 4 hours after ingestion of the meal was estimated, and the normal limits were set using the fifth and 95th percentile values at each period. Having established its normal emptying rates, the idli meal was further used to evaluate 70 patients suspected with diabetic gastroparesis.
  
  
  RESULTS
  The idli meal, with a calorific value ≈282 kcal, has a relatively higher fat content (8% of total mass) than EWS. More than 96% of 99mTc sulfur colloid remained bound to the meal after 4 hours suspension in simulated gastric fluid. Gastric retention greater than 30% and greater than 6% at 2 hours and 4 hours, respectively, indicated delayed gastric emptying, whereas retention less than 30% at 1 hour suggested rapid emptying. Among patients suspected with diabetic gastroparesis, delayed gastric emptying was identified in 76%, and rapid emptying was seen in 4.2%.
  
  
  CONCLUSIONS
  Radiolabeled idli meal is a good alternative to EWS meal for routine GES, especially among patients with specific dietary restrictions.
authors.affiliation: From the Department of Nuclear Medicine and PET-CT, Amrita School of Medicine, Amrita Institute of Medical Sciences and Research Center, Kochi, Kerala, India.
authors.forename: Vijay Harish
authors.initials: VH
authors.lastname: Somasundaram
authors.forename: Padma
authors.initials: P
authors.lastname: Subramanyam
authors.forename: Shanmuga Sundaram
authors.initials: SS
authors.lastname: Palaniswamy
mesh_terms: D000328:Adult; D000368:Aged; D048909:Diabetes Complications / Q000000981:diagnostic imaging*; D055050:Diet, Gluten-Free; D014676:Diet, Vegetarian; D005260:Female; D018589:Gastroparesis / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D062407:Meals; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000493:pharmacokinetics; D012016:Reference Values; D013671:Technetium Tc 99m Sulfur Colloid / Q000008:administration & dosage / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed / Q000592:standards*
chemical_list: D019275:Radiopharmaceuticals; D013671:Technetium Tc 99m Sulfur Colloid