Accurate quantification of steady and pulsatile flow with segmented k-space magnetic resonance velocimetry

Abstract.

Conventional non-segmented magnetic resonance phase velocity mapping (MRPVM) is an accurate but relatively slow velocimetric technique. Therefore, the aim of this study was to evaluate the accuracy of the much faster segmented k-space MRPVM in quantifying flow. The axial velocity was measured in four straight tubes (inner diameter: 5.6–26.2 mm), using a segmented MRPVM sequence with seven lines of k-space per segment. The flow rate and flow volume were accurately quantified (errors<5%) under steady (r ²=0.99) and pulsatile flow (r ²=0.98), respectively. The measured velocity profiles and flow rates from the segmented sequence agreed with those from the non-segmented (p>0.05). Changing the slice thickness or the field of view did not affect the accuracy of the measurements. The results of this study suggest that fast, segmented MRPVM can be used for accurate flow quantification.