  Purpose: To develop and validate an acquisition and processing technique that
enables fully self-gated 4D flow imaging with whole-heart coverage in a fixed
five-minute scan.
  Theory and Methods: The data are acquired continuously using Cartesian
sampling and sorted into respiratory and cardiac bins using the self-gating
signal. The reconstruction is performed using a recently proposed Bayesian
method called ReVEAL4D. ReVEAL4D is validated using data from eight healthy
volunteers and two patients and compared with a compressed sensing technique,
L1-SENSE.
  Results: Healthy subjects -- Compared to 2D phase-contrast MRI (2D-PC), flow
quantification from ReVEAL4D shows no significant bias. In contrast, the peak
velocity and peak flow rate for L1-SENSE are significantly underestimated.
Compared to traditional parallel MRI-based 4D flow imaging, ReVEAL4D
demonstrates small but significant biases in net flow and peak flow rate, with
no significant bias in peak velocity. All three indices are significantly and
more markedly underestimated by L1-SENSE. Patients -- Flow quantification from
ReVEAL4D agrees well with the 2D-PC reference. In contrast, L1-SENSE markedly
underestimated peak velocity.
  Conclusions: The combination of highly accelerated five-minute Cartesian
acquisition, self-gating, and ReVEAL4D enables whole-heart 4D flow imaging with
accurate flow quantification.
