title: Rapid spectroscopic velocity quantification using periodically oscillating gradients.
abstract: In this work two spectroscopic methods are described which allow rapid flow velocity quantification in the presence of a parabolic velocity distribution. This method requires only a single excitation and is based on flow encoding by periodically oscillating gradients. In the shown spin echo variant additional refocusing pulses correct for field inhomogeneities. A theoretical model is introduced, which describes the course of the derived spectra even in high flow region, where a significant part of the encoded spins leaves the sensitive area of the coil during data acquisition (outflow-effect). It was demonstrated that both methods can quantify flow velocities within the velocity range of 1mm/s up to 36 cm/s in the presence of a parabolic flow velocity distribution. The maximum velocity of the parabolic distribution is indicated in this method by a peak in the acquired spectrum from which the velocity could be quantified. Flow velocity quantification by periodically oscillating gradients seems a reasonable and fast alternative to established imaging techniques.
authors.affiliation: Research Center Magnetic-Resonance-Bavaria, Am Hubland, D-97074 Würzburg, Germany.
authors.forename: Constanze
authors.initials: C
authors.lastname: Schelhorn
authors.forename: Peter Michael
authors.initials: PM
authors.lastname: Jakob
authors.forename: Florian
authors.initials: F
authors.lastname: Fidler
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D009991:Oscillometry / Q000379:methods*