title: Estimation of turbulent kinetic energy using 4D phase-contrast MRI: Effect of scan parameters and target vessel size.
abstract: Quantifying turbulence velocity fluctuation is important because it indicates the fluid energy dissipation of the blood flow, which is closely related to the pressure drop along the blood vessel. This study aims to evaluate the effects of scan parameters and the target vessel size of 4D phase-contrast (PC)-MRI on quantification of turbulent kinetic energy (TKE). Comprehensive 4D PC-MRI measurements with various velocity-encoding (VENC), echo time (TE), and voxel size values were carried out to estimate TKE distribution in stenotic flow. The total TKE (TKEsum), maximum TKE (TKEmax), and background noise level (TKEnoise) were compared for each scan parameter. The feasibility of TKE estimation in small vessels was also investigated. Results show that the optimum VENC for stenotic flow with a peak velocity of 125cm/s was 70cm/s. Higher VENC values overestimated the TKEsum by up to six-fold due to increased TKEnoise, whereas lower VENC values (30cm/s) underestimated it by 57.1%. TE and voxel size did not significantly influence the TKEsum and TKEnoise, although the TKEmax significantly increased as the voxel size increased. TKE quantification in small-sized vessels (3-5-mm diameter) was feasible unless high-velocity turbulence caused severe phase dispersion in the reference image.
authors.affiliation: POSTECH Biotech Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, South Korea.
authors.forename: Hojin
authors.initials: H
authors.lastname: Ha
authors.affiliation: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784, South Korea.
authors.forename: Dongha
authors.initials: D
authors.lastname: Hwang
authors.affiliation: Asan Institute of Life Science, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea.
authors.forename: Guk Bae
authors.initials: GB
authors.lastname: Kim
authors.affiliation: Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea.
authors.forename: Jihoon
authors.initials: J
authors.lastname: Kweon
authors.affiliation: POSTECH Biotech Center, Pohang University of Science and Technology, San 31, Hyoja-dong, Pohang 790-784, South Korea; Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784, South Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784, South Korea.
authors.forename: Jehyun
authors.initials: J
authors.lastname: Baek
authors.affiliation: Department of Cardiology, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea.
authors.forename: Young-Hak
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Convergence Medicine, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea; Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea.
authors.forename: Namkug
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap-dong, Songpa-gu, Seoul 138-736, South Korea. Electronic address: donghyun.yang@gmail.com.
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Yang
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000503:physiopathology; D005240:Feasibility Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008954:Models, Biological; D019047:Phantoms, Imaging
keywords: 4D phase-contrast magnetic resonance imaging; Intravoxel standard deviation; Stenotic flow; Turbulent kinetic energy