title: Superparamagnetic iron oxide-enhanced magnetic resonance imaging of the liver in beagle dogs.
abstract: The role of superparamagnetic iron oxide as a tissue-specific contrast medium has been established in humans, especially for hepatic imaging. Superparamagnetic iron oxide particles exhibit a tissue-specific biodistribution to the reticuloendothelial system, where they predominantly shorten transverse T2 relaxation time. Most hepatic tumors lack Kupffer cells; therefore, the T2 of tumors remains virtually unchanged after administration of superparamagnetic iron oxide. The resulting loss of signal intensity from the liver, with unchanged tumor signal intensity, increases lesion-to-liver contrast. In this study, MR images were acquired with fast gradient echo recalled at steady state (FGRE) in five Beagle dogs before and after injection of superparamagnetic iron oxide. The effect of superparamagnetic iron oxide on signal intensity of the liver with time was assessed. A signal intensity decrease of 65.7+/-10.0% was detected at 20 minutes, and it continued to decrease until the last time point of MR scanning (200 minutes). The liver intensity of all dogs dropped to half its value after 20 minutes. The effect of motion was minimized by breath holding. Superparamagnetic iron oxide did not have any adverse effects on the dogs.
authors.affiliation: Department of Laboratory Animal Medicine, Medical Research Center, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dongwoo
authors.initials: D
authors.lastname: Chang
authors.forename: Bongkyeong
authors.initials: B
authors.lastname: Kim
authors.forename: Youngmin
authors.initials: Y
authors.lastname: Yun
authors.forename: Yongmin
authors.initials: Y
authors.lastname: Hur
authors.forename: Youngwon
authors.initials: Y
authors.lastname: Lee
authors.forename: Mincheol
authors.initials: M
authors.lastname: Choi
authors.forename: Junghee
authors.initials: J
authors.lastname: Yoon
authors.forename: Jekyung
authors.initials: J
authors.lastname: Seong
mesh_terms: D000818:Animals; D004285:Dogs; D005290:Ferric Compounds / Q000493:pharmacokinetics*; D007089:Image Enhancement; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide