Regularized Capon Beamformer Using ℓ1-Norm Applied to Photoacoustic Imaging

Delay-and-Sum (DAS), as a non-adaptive beamforming method, is one of the most common algorithms used in Photoacoustic imaging due to its simple implementation. The results obtained from this algorithm suffer from low resolution and high sidelobes. The adaptive Minimum variance (MV) method improves the image quality compared to DAS in terms of...

Frequency Domain Two-Stage Beamforming for Phased Array Imaging Using the Fast Hankel Transform

The huge amount of data that needs to be transferred between probe and imaging system becomes a major issue when the data transfer capacity is limited, e.g. in handheld systems, wireless probes and miniaturized probes. The amount of data can be significantly reduced by using two-stage beamforming. The first stage consists of a fixed focus...

High Frequency Functional Ultrasound in Mice

Functional ultrasound (fUS) is a relatively new imaging modality to study the brain with a high spatiotemporal resolution and a wide field-of-view. In fUS detailed images of cerebral blood flow and volume are used to derive functional information, as changes in local flow and/or volume may reflect neuronal activation through neurovascular...

Efficient and Flexible Spatiotemporal Clutter Filtering of High Frame Rate Images Using Subspace Tracking

Current methods to measure blood flow using ultrafast Doppler imaging often make use of a Singular Value Decomposition (SVD). The SVD has been shown to be an effective way to remove clutter signals associated with slow moving tissue. Conventionally, the SVD is calculated from an ensemble of frames, after which the first dominant eigenvectors...