Independent validation of four-dimensional flow MR velocities and vortex ring volume using particle imaging velocimetry and planar laser-Induced fluorescence.
OBJECTIVE
This study aimed to: (i) present and characterize a phantom setup for validation of four-dimensional (4D) flow using particle imaging velocimetry (PIV) and planar laser-induced fluorescence (PLIF); (ii) validate 4D flow velocity measurements using PIV; and (iii) validate 4D flow vortex ring volume (VV) using PLIF.


METHODS
A pulsatile pump and a tank with a 25-mm nozzle were constructed. PIV measurements (1.5 × 1.5 mm pixels, temporal resolution 10 ms) were obtained on two occasions. The 4D flow (3 × 3 × 3 mm voxels, temporal resolution 50 ms) was acquired using SENSE = 2. VV was quantified using PLIF and 4D flow.


RESULTS
PIV showed excellent day-to-day stability (R(2) = 0.99, bias -0.04 ± 0.72 cm/s). The 4D flow mean velocities agreed well with PIV (R(2) = 0.95, bias 0.16 ± 2.65 cm/s). Peak velocities in 4D flow were underestimated by 7-18% compared with PIV (y = 0.79x + 2.7, R(2) = 0.96, -12 ± 5%). VV showed excellent agreement between PLIF and 4D flow (R(2) = 0.99, 2.4 ± 1.5 mL).


CONCLUSIONS
This study shows: (i) The proposed phantom enables reliable validation of 4D flow. (ii) 4D flow velocities show good agreement with PIV, but peak velocities were underestimated due to low spatial and temporal resolution. (iii) Vortex ring volume (VV) can be quantified using 4D flow.
Department of Clinical Physiology, Lund University Hospital, Lund, Lund University, Lund, Sweden.|Department of Numerical Analysis, Centre for Mathematical Sciences, Lund University, Lund, Sweden.
Johannes
http://orcid.org/0000-0002-3365-7282
J
Töger
Department of Clinical Physiology, Lund University Hospital, Lund, Lund University, Lund, Sweden.|Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
Sebastian
S
Bidhult
Department of Energy Sciences, Faculty of Engineering, Lund University, Lund, Sweden.
Johan
J
Revstedt
Department of Clinical Physiology, Lund University Hospital, Lund, Lund University, Lund, Sweden.
Marcus
M
Carlsson
Department of Clinical Physiology, Lund University Hospital, Lund, Lund University, Lund, Sweden.
Håkan
H
Arheden
Department of Clinical Physiology, Lund University Hospital, Lund, Lund University, Lund, Sweden.|Department of Numerical Analysis, Centre for Mathematical Sciences, Lund University, Lund, Sweden.|Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
Einar
E
Heiberg
D001783:Blood Flow Velocity / Q000502:physiology*; D004867:Equipment Design; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012212:Rheology / Q000379:methods*
4D flow; CMR; blood flow; particle imaging velocimetry; validation; vortex ring formation