A VALIDATION OF A FLOW QUANTIFICATION BY MR PHASE MAPPING SOFTWARE

Aim: We evaluated a Siemens software of flow quantification (FQ) by MR phase mapping, in the framework of a common practical use. Methods: E xperiments with a laminar flow phantom and in vivo pulsatile flow were performed. In particular, FQ in ascending aorta was investigated in h ealthy volunteers. Results and conclusion: Flow phantom experiments re veal that the FQ slightly underestimates (8% on the average) actual ve locities (mean velocities over a vessel area), and also that velocity uncertainties are related to the encoding velocity value, whatever the measured velocity. Furthermore, using well characterized working crit eria, we found low intraobserver variability and negligible interobser ver variability in ascending aorta FQs. The role played by the choice of reference area in FQ accuracy is emphasized. When recording several cardiac cycles during the same acquisition, it is shown that the FQ s oftware may provide erroneous results. Several comments for FQ softwar e use in the ascending aorta are added. (C) 1998 Elsevier Science Irel and Ltd. All rights reserved.