Efficient method for volumetric assessment of peak blood flow velocity using 4D flow MRI

• Published in: Journal of magnetic resonance imaging Vol. 44; no. 6; pp. 1673 - 1682
• Main Authors: Rose, Michael J., Jarvis, Kelly, Chowdhary, Varun, Barker, Alex J., Allen, Bradley D., Robinson, Joshua D., Markl, Michael, Rigsby, Cynthia K., Schnell, Susanne
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.12.2016; Wiley Subscription Services, Inc
• Subjects: 4D flow; Adolescent; Algorithms; Aortic Valve - abnormalities; Aortic Valve - physiopathology; bicuspid aortic valve; Bicuspid Aortic Valve Disease; Blood Flow Velocity - physiology; Blood Volume - physiology; Blood Volume Determination - methods; Child; Child, Preschool; Feasibility Studies; Female; Heart Valve Diseases - diagnosis; Heart Valve Diseases - physiopathology; Humans; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Imaging, Three-Dimensional - methods; Magnetic Resonance Angiography - methods; Magnetic resonance imaging; Male; MRI; pediatric; phase contrast; Reproducibility of Results; Sensitivity and Specificity; Young Adult; phase contrast; MRI; bicuspid aortic valve; 4D flow; pediatric
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.25305

Purpose To test the feasibility and effectiveness of using maximum intensity plots (MIPs) based on 4D flow magnetic resonance imaging (MRI) velocity data to assess systolic peak velocities in a cohort of bicuspid aortic valve (BAV) patients. Materials and Methods 4D flow MRI at 1.5T was performed on 51 BAV patients. MIPs were generated from the 4D flow MRI velocity data and used by two users to determine peak velocities in three regions of interest (ROIs): ascending aorta (AAo), aortic arch, and descending aorta. 4D flow MRI peak velocities in the AAo were compared to peak velocities recorded by 2D phase contrast MRI (2D PCMRI) in a subcohort of 36 patients and by Doppler echocardiography in a subcohort of 34 patients. 4D flow MRI peak velocities recorded by each observer were compared for all ROIs to test for interobserver variability. Results 4D flow MRI recorded significantly higher velocities compared to 2D PCMRI (2.04 ± 0.71 m/s vs. 1.69 ± 0.79 m/s, 17.2% difference, P < 0.001) and similar velocities compared to Doppler echocardiography. There was excellent agreement between the observers, with a mean difference of 0.005 m/s and an intraclass correlation coefficient of 0.98. Conclusion 4D flow MRI velocity MIPs allow for efficient measurement of peak velocities in BAV patients with higher accuracy than 2D PCMRI and similar accuracy to Doppler echocardiography. J. Magn. Reson. Imaging 2016;44:1673–1682.