title: Use of Technegas as a radiopharmaceutical for the measurement of gastric emptying.
abstract: Many radiopharmaceuticals and test meals that are used to measure gastric emptying are less than optimal. A vegetable-based solid meal, such as rice, labelled with a radiopharmaceutical that also has the capacity to measure gastric emptying of liquids, is likely to be ideal. The role of Technegas as a radioisotopic marker to measure gastric emptying of rice and liquids was evaluated. Technegas-labelled rice was incubated in 0.9% saline, 1 M HCl and simulated gastric fluid (3.2 g/l pepsinogen, pH 2-3) to assess stability of the label. In eight healthy volunteers gastric emptying of two meals - 200 g rice (370 kcal) and 75 g dextrose dissolved in 300 ml water (300 kcal), both labelled with 20 MBq of Technegas - was measured scintigraphically. Over 4 h, the average label stability was 93.7%+/-0.5% in 0.9% saline, 91.0%+/-0.4% in 1 M HCl and 93.6%+/-0.7% in simulated gastric juice. The lag phase was longer for rice than dextrose (25+/-7 min vs 4+/-2 min; P<0.05), but there was no difference in the post-lag emptying rate (2.1+/-0.3 kcal/min vs 1.7+/-0.2 kcal/min; P=0.2) between the two meals. We conclude that Technegas is a suitable radiopharmaceutical for measurement of gastric emptying of rice and nutrient-containing liquids.
authors.affiliation: School of Medical Radiation, University of South Australia, Adelaide, Australia.
authors.forename: M A
authors.initials: MA
authors.lastname: Kwiatek
authors.forename: K L
authors.initials: KL
authors.lastname: Jones
authors.forename: W M
authors.initials: WM
authors.lastname: Burch
authors.forename: M
authors.initials: M
authors.lastname: Horowitz
authors.forename: F D
authors.initials: FD
authors.lastname: Bartholomeusz
mesh_terms: D000328:Adult; D005260:Female; D005502:Food; D005746:Gastric Emptying; D006108:Graphite; D006801:Humans; D008297:Male; D012275:Oryza; D019275:Radiopharmaceuticals; D013670:Sodium Pertechnetate Tc 99m
chemical_list: D019275:Radiopharmaceuticals; C056708:Technegas; D006108:Graphite; D013670:Sodium Pertechnetate Tc 99m