Haruo Isoda MD, PhD, Abstract Co-Author: Stockholder, Flowtech Research, Inc

Kazushige Ichikawa, Abstract Co-Author: Nothing to Disclose

Atsushi Fukuyama, Abstract Co-Author: Nothing to Disclose

Yoshiaki Komori, Abstract Co-Author: Nothing to Disclose

Yasuo Takehara MD, Presenter: Research Grant, Hitachi, Ltd

Takashi Kosugi, Abstract Co-Author: President, R'Tech Co, Ltd

Yuki Onishi, Abstract Co-Author: Nothing to Disclose

Shinji Naganawa MD, Abstract Co-Author: Nothing to Disclose

Cerebral arterial hemodynamics is thought to play an important role in aneurysmal initiation, growth and rupture. MR fluid dynamics (MRFD) using 3D cine phase-contrast MR imaging (3D cine PC MRI) would be a promising technique for assessment of hemodynamics. The purpose of our study was to validate the accuracy of hemodynamics and wall shear stress (WSS) obtained from MRFD using two phantoms.

We ran blood-mimicking fluid through a 3 mm-diameter straight tube with a steady flow measuring about 2.50 ml/sec and performed 3D cine PC MRI using 3T MR system. We performed MRFD by Flova software and compared analyzed time averaged volume flow rates (VFRs) with values measured with a digital Coriolis flowmeter and also compared WSS with theoretical values. We also performed MRFD for a left internal carotid artery-posterior communicating artery aneurysm (IC-PC An) model with blood mimicking fluid for three different steady VFRs in an internal carotid artery (ICA) set at 7.59 ml/sec, 4.63 ml/sec and 2.84 ml/sec. We compared analyzed time averaged VFRs in ICA，anterior cerebral artery (ACA) and middle cerebral artery (MCA) with values measured with the flowmeters. We also compared our software-calculated velocity components and WSS with values obtained from computational fluid dynamics (CFD) and calculated correlation coefficients. We also compare MRFD and CFD streamlines.

In the straight tube phantom, relative errors of time averaged VFR and WSS were 4 % and 6 %, respectively. In the cerebral artery phantom, relative errors of time averaged VFRs in ICA，ACA and MCA were 10 %～30 %. Correlation coefficients of velocity components in ICA were 0.60～0.94 and those of WSS in ICA were 0.68～0.72. Correlation coefficients of velocity components in IC-PC An were 0.58～0.94, and that of its WSS was 0.34～0.63. Distribution of WSS and streamlines in MRFD and CFD were similar.

Accuracy of time averaged VFR obtained from MRFD was relatively good in this phantom study. Although accuracy of WSS obtained from MRFD was poor in IC-PC An in the model, it was good in a straight tube phantom and ICA. WSS and streamlines patterns obtained in MRFD were similar in CFD.

(dealing with MRFD using 3D cine PC MRI) "Although WSS might not be accurate; VFR, distribution of WSS and streamlines were relatively good in MRFD in cerebral arteries."

Isoda, H, Ichikawa, K, Fukuyama, A, Komori, Y, Takehara, Y, Kosugi, T, Onishi, Y, Naganawa, S, Investigation of Accuracy of Hemodynamics and Wall Shear Stress for Intracranial Arteries Obtained from MR Fluid Dynamics (MRFD) using 3D Cine Phase-contrast MR Imaging.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14008892.html