LOCALIZED REAL-TIME VELOCITY SPECTRA DETERMINATION

The accurate measurement of flow velocity has long been a subject of N MR research. In the field of medical imaging, a variety of techniques primarily based on the principle of Fourier encoding have been describ ed. Due to time constraints, necessary trade-offs exist between spatia l versus velocity spectral resolution. In general, either the average velocity of individual pixels is displayed or velocity spectral determ inations are made at the cost of spatial localization. The recent deve lopment of multidimensional excitation pulses makes spatial localizati on possible during the excitation phase of the pulse sequences. This a pproach, coupled with time varying gradient readout, can be used to ob tain single-shot localized velocity spectra. Using these concepts, we have obtained in vivo real-time measurements of localized velocity spe ctra on our clinical imager.