The Quantification of Cerebral Blood Flow by Phase Contrast MRA: Basics and Applications.

Phase-contrast magnetic resonance (PCMRA) flow quantification can determine vascular velocities and volumetric flow rate (VFR) non-invasively for in vitro and in vivo studies. Recently, the increasing power of MR imaging units and the reduced time for data acquisition and post-processing have led to an increasing number of investigations on the use of phase-contrast flow measurements as an additional source of quantitative functional information in MR imaging. In addition, PCMRA can be added to morphologic MRI sequences, offering the option to correlate flow to morphology based on data generated during one examination. This review discusses the basics of phase-contrast imaging, describing the errors and avoiding methods associated with PCMRA, providing guidelines for flow measurement and data analysis, and presenting the current clinical cerebral applications.