On the dual contrast enhancement mechanism in frequency-selective inversion-recovery magnetic resonance angiography (IRON-MRA).
The susceptibility of blood changes after administration of a paramagnetic contrast agent that shortens T(1). Concomitantly, the resonance frequency of the blood vessels shifts in a geometry-dependent way. This frequency change may be exploited for incremental contrast generation by applying a frequency-selective saturation prepulse prior to the imaging sequence. The dual origin of vascular enhancement depending first on off-resonance and second on T(1) lowering was investigated in vitro, together with the geometry dependence of the signal at 3T. First results obtained in an in vivo rabbit model are presented.
Vonken
Evert-jan
EJ
Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. evertjan@isi.uu.nl
Korosoglou
Grigorios
G
Yu
Jing
J
Schär
Michael
M
Weissleder
Ralph
R
Stuber
Matthias
M
D000465:Algorithms; D001011:Aorta / Q000033:anatomy & histology*; D003287:Contrast Media; D005290:Ferric Compounds; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D053758:Nanoparticles
D003287:Contrast Media; D005290:Ferric Compounds; C000499:ferric oxide