Sparse Ultrasound Imaging via Manifold Low-Rank Approximation and Non-Convex Greedy Pursuit.
Thiago Alberto Rigo PassarinMarcelo Victor Wüst ZibettiDaniel Rodrigues PipaPublished in: Sensors (Basel, Switzerland) (2018)
Model-based image reconstruction has improved contrast and spatial resolution in imaging applications such as magnetic resonance imaging and emission computed tomography. However, these methods have not succeeded in pulse-echo applications like ultrasound imaging due to the typical assumption of a finite grid of possible scatterer locations in a medium⁻an assumption that does not reflect the continuous nature of real world objects and creates a problem known as off-grid deviation. To cope with this problem, we present a method of dictionary expansion and constrained reconstruction that approximates the continuous manifold of all possible scatterer locations within a region of interest. The expanded dictionary is created using a highly coherent sampling of the region of interest, followed by a rank reduction procedure. We develop a greedy algorithm, based on the Orthogonal Matching Pursuit, that uses a correlation-based non-convex constraint set that allows for the division of the region of interest into cells of any size. To evaluate the performance of the method, we present results of two-dimensional ultrasound imaging with simulated data in a nondestructive testing application. Our method succeeds in the reconstructions of sparse images from noisy measurements, providing higher accuracy than previous approaches based on regular discrete models.
Keyphrases
- magnetic resonance imaging
- computed tomography
- deep learning
- contrast enhanced
- magnetic resonance
- induced apoptosis
- high resolution
- blood pressure
- machine learning
- diffusion weighted
- cell cycle arrest
- convolutional neural network
- minimally invasive
- single molecule
- image quality
- electronic health record
- artificial intelligence
- optical coherence tomography
- big data
- cell proliferation
- endoplasmic reticulum stress
- fluorescence imaging