The Synthetic Aperture Real-time Ultrasound System (SARUS) for acquiring and processing synthetic aperture (SA) data research purposes is described. specifications design of the system are detailed, along with its performance SA, nonlinear, 3-D flow estimation imaging. SARUS acquires individual channel simultaneously up to 1024 transducer elements a couple heart beats, capable transmitting any kind excitation. 64 boards in house 16 transmit receive channels each, where sampled can be stored...

This paper presents a method for optimizing parameters affecting the image quality in plane wave imaging. More specifically, number of emissions and steering angles is optimized to attain best images with highest frame rate possible. The applied specific problem, where λ -pitch transducer compared /2-pitch transducer. Grating lobe artifacts transducers degrade contrast images, impact on studied. Field II simulations are made all combinations parameters, optimal setup selected based Pareto...

A 3-D super-resolution (SR) pipeline based on data from a row-column (RC) array is presented. The 3-MHz RC contains 62 rows and columns with half wavelength pitch. synthetic aperture (SA) pulse inversion sequence 32 positive negative row emissions used for acquiring volumetric using the SARUS research ultrasound scanner. Data received are beamformed GPU maximum volume rate of 156 Hz when repetition frequency 10 kHz. Simulated printed point flow microphantoms investigating approach....

Microbubble (MB) tracking plays an important role in ultrasound super-resolution imaging (SRI) by enabling velocity estimation and improving image quality. This work presents a new hierarchical Kalman (HK) tracker to achieve better performance at scenarios with high concentrations of MBs localization uncertainty. The method attempts follow different ranges using filters. An extended simulation framework for evaluating trackers is also presented used comparison the proposed HK...

Simulation and experimental results from 3-D vector flow estimations for a 62 + 2-D row-column (RC) array with integrated apodization are presented. A method implementing transverse oscillation (TO) velocity estimator on 3-MHz RC is developed validated. First, parametric simulation study conducted, where direction, ensemble length, number of pulse cycles, steering angles, transmit/receive apodization, TO profiles spacing varied, to find the optimal parameter configuration. The performance...

Current clinical ultrasound (US) systems are limited to show blood flow movement in either 1-D or 2-D. In this paper, a method for estimating 3-D vector velocities plane using the transverse oscillation method, 32×32 element matrix array, and experimental US scanner SARUS is presented. The aim of paper estimate precise rates peak derived from estimates. emission sequence provides estimates at up 1.145 frames/s plane, was used cross-sectional image plane. validated two phantom studies, where...

This study evaluates the volumetric imaging performance of two prototyped 62 + row-column-addressed (RCA) 2-D array transducer probes using three synthetic aperture (SAI) emission sequences and different beamformers. The are fabricated capacitive micromachined ultrasonic (CMUT) piezoelectric (PZT) technology. Both have integrated apodization to reduce ghost echoes designed with similar acoustical features, i.e., 3-MHz center frequency, λ /2 pitch, [Formula: see text] active footprint. Raw RF...

Delay-and-sum (DAS) beamforming is unable to identify individual scatterers when their density so high that point spread functions overlap. This paper proposes a convolutional neural network (CNN)-based method detect and localize high-density scatterers, some of which are closer than the resolution limit delay-andsum beamforming. A CNN was designed take radio frequency channel data return non-overlapping Gaussian confidence maps. The scatterer positions were estimated from maps by...

The 3-D transverse oscillation method is investigated by estimating velocities in an experimental flow-rig system. Measurements of the synthesized oscillating fields are presented as well. employs a 2-D transducer; decouples velocity estimation; and estimates axial, transverse, elevation components simultaneously. Data acquired using research ultrasound scanner. measurements conducted with steady flow sixteen different directions. For specific direction [α, ß] = [45, 15]°, mean estimated...

Several techniques can estimate the 2-D velocity vector in ultrasound. Directional beamforming (DB) estimates blood flow velocities with a higher precision and accuracy than transverse oscillation (TO), but at cost of high load when estimating angle. In this paper, it is proposed to use TO an initial angle, which then refined DB step. Velocity magnitude estimated along direction using cross correlation. It shown that suggested TO-DB method improve performance compared TO, load, 4.6 times...

This paper presents a novel approach for estimating 2-D flow angles using high-frame-rate ultrasound method. The angle estimator features high accuracy and low standard deviation (SD) over the full 360° range. method is validated on Field II simulations phantom measurements experimental scanner SARUS rig before being tested in vivo. An 8-MHz linear array transducer used with defocused beam emissions. In of spinning disk phantom, uniform behavior estimation observed median bias 1.01° SD 1.8°....

Constructing a double-curved row-column-addressed (RCA) 2-D array or applying diverging lens over the flat RCA can extend imaging field-of-view (FOV) to curvilinear volume without increasing aperture size, which is necessary for applications, such as abdominal and cardiac imaging. Extended FOV low channel count of arrays make 3-D possible with equipment in price range conventional This paper proposes delay-and-sum beamformation scheme specific validates its focusing ability based on...

Two delay-and-sum beamformers for 3-D synthetic aperture imaging with row-column addressed arrays are presented. Both software implementations graphics processing unit (GPU) execution dynamic apodizations and third-order polynomial subsample interpolation. The first beamformer was written in the MATLAB programming language second C/C++ compute unified device architecture (CUDA) extensions by NVIDIA. Performance measured as volume rate sample throughput on three different GPUs: a 1050 Ti,...

Super resolution (SR) imaging is currently conducted using fragile ultrasound contrast agents. This precludes the full acoustic pressure range, and distribution of bubbles has to be sparse for them isolated SR imaging. Images have acquired over minutes accumulate enough positions visualizing vasculature. A new method SUper Resolution Erythrocytes (SURE) as targets introduced, which makes it possible maximize emitted good signal-to-noise ratios. The abundant number erythrocyte make...

This work presents a beamforming procedure that significantly reduces the number of operations when performing volumetric synthetic aperture imaging with row-column addressed arrays (RCAs). The proposed beamformer uses image values along elevation direction low-resolution volume (LRV) are approximately constant. It is thus hypothesized entire LRV could be reconstructed from single 2-D cross section LRV. presented method contains two stages. first stage beamforms, for each emission, using...

Tensor velocity imaging (TVI) performance with a row-column probe was assessed for constant flow in straight vessel phantom and pulsatile carotid artery phantom. TVI, i.e., estimating the 3-D vector as function of time spatial position, performed using transverse oscillation cross-correlation estimator, acquired Vermon 128+128 array connected to Verasonics 256 research scanner. The emission sequence used 16 emissions per image, TVI volume rate 234 Hz obtained pulse repetition frequency...

The SARUS scanner (Synthetic Aperture Real-time Ultrasound System) for research purposes is described. It can acquire individual channel data multi-element transducers a couple of heart beats, and capable transmitting any kind excitation. houses generous flexible processing resources that be reprogrammed tailored to many kinds algorithms. 64 boards in the system house 16 transmit receive channels each, where stored 2 GB RAM processed using four Virtex 4FX100 one FX60 FPGAs. VHDL code perform...

A method for rapid measurement of intensities (Ispta), mechanical index (MI), and probe surface temperature any ultrasound scanning sequence is presented. It uses the scanner's sampling capability to give an accurate whole imaging all emissions yield true distributions. The several orders magnitude faster than approaches using oscilloscope, it also facilitates validating emitted pressure field emission software. has been implemented experimental synthetic aperture real-time system (SARUS)...

This article presents a reconfigurable network-on-chip architecture called ReNoC, which is intended for use in general-purpose multiprocessor system-on-chip platforms, and enables application-specific logical NoC topologies to be configured, thus providing both efficiency flexibility. The three novel algorithms that synthesize an topology, map it onto the physical ReNoC architecture, create deadlock-free, routing algorithms. We apply our mixture of real synthetic applications target...

A 3 MHz, λ/2-pitch 62+62 channel row-column addressed 2-D CMUT array designed to be mounted in a probe handle and connected commercial BK Medical scanner for real-time volumetric imaging is presented. It wire-bonded on flexible PCB, which two rigid PCBs with pre-amplifiers driving the cable scanner. The are encapsulated 3-D printed handle, grounded shielding layer silicone coating applied front-side of physical electrical isolation. assembled together 192-channel coaxial that connects it...

In this work, the accuracy of row-column tensor velocity imaging (TVI), i.e., 3-D vector flow (VFI) in space over time, is quantified on a complex, clinically relevant flow. The quantification achieved by transferring simulated using computational fluid dynamics (CFD) to Field II simulation environment, and allows for direct comparison between actual estimated velocities. carotid bifurcation simulations were performed with peak inlet 80 cm/s, nonrigid vessel walls, cycle duration 1.2 s. was...