title: Low-Cost 3-D Flow Estimation of Blood With Clutter.
abstract: Volumetric flow rate estimation is an important ultrasound medical imaging modality that is used for diagnosing cardiovascular diseases. Flow rates are obtained by integrating velocity estimates over a cross-sectional plane. Speckle tracking is a promising approach that overcomes the angle dependency of traditional Doppler methods, but suffers from poor lateral resolution. Recent work improves lateral velocity estimation accuracy by reconstructing a synthetic lateral phase (SLP) signal. However, the estimation accuracy of such approaches is compromised by the presence of clutter. Eigen-based clutter filtering has been shown to be effective in removing the clutter signal; but it is computationally expensive, precluding its use at high volume rates. In this paper, we propose low-complexity schemes for both velocity estimation and clutter filtering. We use a two-tiered motion estimation scheme to combine the low complexity sum-of-absolute-difference and SLP methods to achieve subpixel lateral accuracy. We reduce the complexity of eigen-based clutter filtering by processing in subgroups and replacing singular value decomposition with less compute-intensive power iteration and subspace iteration methods. Finally, to improve flow rate estimation accuracy, we use kernel power weighting when integrating the velocity estimates. We evaluate our method for fast- and slow-moving clutter for beam-to-flow angles of 90° and 60° using Field II simulations, demonstrating high estimation accuracy across scenarios. For instance, for a beam-to-flow angle of 90° and fast-moving clutter, our estimation method provides a bias of -8.8% and standard deviation of 3.1% relative to the actual flow rate.
authors.forename: Siyuan
authors.initials: S
authors.lastname: Wei
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Richard
authors.initials: R
authors.lastname: Sampson
authors.forename: Oliver D
authors.initials: OD
authors.lastname: Kripfgans
authors.forename: J Brian
authors.initials: JB
authors.lastname: Fowlkes
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Wenisch
authors.forename: Chaitali
authors.initials: C
authors.lastname: Chakrabarti
mesh_terms: D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D019047:Phantoms, Imaging; D014463:Ultrasonography / Q000379:methods*