title: Negative gastrointestinal contrast enhancement and image distortion induced by superparamagnetic particles at 0.02 Tesla.
abstract: Gastrointestinal contrast enhancement and image distortion induced by superparamagnetic particles were evaluated in vitro and in rabbits at 0.02 Tesla. Test tubes containing 0.01-1.0 mg particles/ml were imaged in an oil or water bath in order to demonstrate the concentration-dependent signal void and image distortion in vitro at several pulse sequences. The lowest concentration of particles tested clearly decreased the signal intensity. Image distortion was observed when the concentration exceeded 0.07 mg/ml and was more pronounced on the T2-weighted images. The in vitro T2 relaxation time decreased from 122 ms to 56 ms with an increase in the particle concentration from 0.01 to 0.06 mg/ml. A loss of the GI-tract signal was observed in rabbits after the administration of 1 mg particles/kg, given as a 0.03 mg/ml suspension. At a dose of 20 mg/kg (0.6 mg/ml suspension) significant image distortion was observed.
authors.affiliation: Department of Diagnostic Radiology, University of Turku, Finland.
authors.forename: P
authors.initials: P
authors.lastname: Niemi
authors.forename: H
authors.initials: H
authors.lastname: Paajanen
authors.forename: P A
authors.initials: PA
authors.lastname: Hals
authors.forename: M
authors.initials: M
authors.lastname: Tertti
authors.forename: M
authors.initials: M
authors.lastname: Komu
authors.forename: M
authors.initials: M
authors.lastname: Kormano
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage / Q000592:standards*; D004064:Digestive System / Q000033:anatomy & histology*; D005290:Ferric Compounds / Q000008:administration & dosage / Q000592:standards*; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D013997:Time Factors
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds