title: Gd-DOTA as a gastrointestinal contrast agent for gastric emptying measurements with MRI.
abstract: Current MR meal markers may interfere with gastric motility and secretion restricting the use of MRI in the measurement of gastric physiology. We therefore evaluated Gd-DOTA as a liquid phase marker, in vitro by determining dissociation, and adherence to the solids, and in vivo by simultaneous MRI (0.35 T scanner, multiple T1-weighted sections of the upper abdomen) and double indicator (perfusion marker PEG 4000, meal marker 99mTc-DTPA) measurements of emptying and secretion, following ingestion of 500 ml 10% glucose. In vitro Gd-DOTA was stable at a pH > 2 with < 2% dissociation at 24 h during incubation with HCl. Dissociation during incubation with HCl was linearly dependent on H+ concentration (0.77 < pH < 2.02). Less Gd-DOTA was absorbed onto the solid phase than 99mTc-DTPA (25% cf 36%). In vivo Gd-DOTA marked gastric contents provided strong positive contrast. Similar emptying curves were observed with both MRI and double-indicator techniques (r = 0.987, P < 0.001). Gd-DOTA has the potential to be a useful liquid phase contrast agent in MR studies on gastric function.
authors.affiliation: Division of Gastroenterology PMU/CHUV, Lausanne, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Schwizer
authors.forename: R
authors.initials: R
authors.lastname: Fraser
authors.forename: H
authors.initials: H
authors.lastname: Maecke
authors.forename: K
authors.initials: K
authors.lastname: Siebold
authors.forename: R
authors.initials: R
authors.lastname: Funck
authors.forename: M
authors.initials: M
authors.lastname: Fried
mesh_terms: D000328:Adult; D003287:Contrast Media; D004064:Digestive System / Q000033:anatomy & histology; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D006571:Heterocyclic Compounds; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009942:Organometallic Compounds; D012016:Reference Values
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate