Image Analysis for Ultrasound Quality Assurance.
Authors: Aljahdali MH, Woodman A, Al-Jamea L, Albatati SM, Williams C Abstract The quality assurance (QA) of ultrasound transducers is often identified as an area requiring continuous development in terms of the tools available to users. Periodic evaluation of the transducers as part of the QA protocol is important, since the quality of the diagnostics. Some of the key criteria determining the process of developing a QA protocol include the complexity of setup, the time required, accuracy, and potential automation to achieve scale. For the current study, a total of eight different ultrasound machines (12 transducer...
Source: Ultrasonic Imaging - February 18, 2021 Category: Radiology Tags: Ultrason Imaging Source Type: research

Ultrasonic Imaging of High-contrasted Objects Based on Full-waveform Inversion: Limits under Fluid Modeling.
Authors: Espinosa L, Doveri E, Bernard S, Monteiller V, Guillermin R, Lasaygues P Abstract Quantitative ultrasound techniques have been previously used to evaluate biological hard tissues, characterized by a large acoustic impedance contrast. Here, we are interested in the imaging of experimental data from different test-targets with high acoustic impedance contrast, using the Full Waveform Inversion (FWI) method to solve the inverse problem. This method is based on high-resolution numerical modeling of the forward problem of interaction between waves and medium, considering the full time series. To reduce the comp...
Source: Ultrasonic Imaging - February 12, 2021 Category: Radiology Tags: Ultrason Imaging Source Type: research

Automatic Measurement of Pennation Angle from Ultrasound Images using Resnets.
In this study, an automatic pennation angle measuring approach based on deep learning is proposed. Firstly, the Local Radon Transform (LRT) is used to detect the superficial and deep aponeuroses on the ultrasound image. Secondly, a reference line are introduced between the deep and superficial aponeuroses to assist the detection of the orientation of muscle fibers. The Deep Residual Networks (Resnets) are used to judge the relative orientation of the reference line and muscle fibers. Then, reference line is revised until the line is parallel to the orientation of the muscle fibers. Finally, the pennation angle is obtained ...
Source: Ultrasonic Imaging - February 12, 2021 Category: Radiology Tags: Ultrason Imaging Source Type: research

Spatial-frequency Analysis of the Anatomical Differences in Hamstring Muscles.
Authors: Crawford SK, Lee KS, Bashford GR, Heiderscheit BC Abstract Spatial frequency analysis (SFA) is a quantitative ultrasound method that characterizes tissue organization. SFA has been used for research involving tendon injury, but may prove useful in similar research involving skeletal muscle. As a first step, we investigated if SFA could detect known architectural differences within hamstring muscles. Ultrasound B-mode images were collected bilaterally at locations corresponding to proximal, mid-belly, and distal thirds along the hamstrings from 10 healthy participants. Images were analyzed in the spatial fr...
Source: Ultrasonic Imaging - February 12, 2021 Category: Radiology Tags: Ultrason Imaging Source Type: research

Automatic Lumen Border Detection in IVUS Images Using Deep Learning Model and Handcrafted Features.
In this study, a fully automatic method based on deep learning model and handcrafted features is presented for the detection of the lumen borders in IVUS images. First, 193 handcrafted features are extracted from the IVUS images. Then hybrid feature vectors are constructed by combining handcrafted features with 64 high-level features extracted from U-Net. In order to obtain the feature subsets with larger contribution, we employ the extended binary cuckoo search for feature selection. Finally, the selected 36-dimensional hybrid feature subset is used to classify the test images using dictionary learning based on kernel spa...
Source: Ultrasonic Imaging - January 17, 2021 Category: Radiology Tags: Ultrason Imaging Source Type: research

Automated Pleural Line Detection Based on Radon Transform Using Ultrasound.
In this study, we developed a computer-aided technique for automated pleural line detection using ultrasound. The method first utilized the Radon transform to detect line objects in the ultrasound images. The relation of the body mass index and chest wall thickness was then applied to estimate the range of the pleural thickness, based on which the pleural line was detected together with the consideration of the ultrasonic properties of the pleural line. The proposed method was validated by testing 83 ultrasound data sets collected from 21 pneumothorax patients. The pleural lines were successfully identified in 76 data sets...
Source: Ultrasonic Imaging - December 30, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Computation of Photoacoustic Absorber Size from Deconvolved Photoacoustic Signal Using Estimated System Impulse Response.
Authors: Rathi N, Sinha S, Chinni B, Dogra V, Rao N Abstract Photoacoustic signal recorded by photoacoustic imaging system can be modeled as convolution of initial photoacoustic response by the photoacoustic absorber with the system impulse response. Our goal was to compute the size of photoacoustic absorber using the initial photoacoustic response, deconvolved from the recorded photoacoustic data. For deconvolution, we proposed to use the impulse response of the photoacoustic system, estimated using discrete wavelet transform based homomorphic filtering. The proposed method was implemented on experimentally acquir...
Source: Ultrasonic Imaging - December 30, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Nipple Localization in Automated Whole Breast Ultrasound Coronal Scans Using Ensemble Learning.
Authors: Raj ANJ, Nersisson R, Mahesh VGV, Zhuang Z Abstract Nipple is a vital landmark in the breast lesion diagnosis. Although there are advanced computer-aided detection (CADe) systems for nipple detection in breast mediolateral oblique (MLO) views of mammogram images, few academic works address the coronal views of breast ultrasound (BUS) images. This paper addresses a novel CADe system to locate the Nipple Shadow Area (NSA) in ultrasound images. Here the Hu Moments and Gray-level Co-occurrence Matrix (GLCM) were calculated through an iterative sliding window for the extraction of shape and texture features. Th...
Source: Ultrasonic Imaging - December 30, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

A Low-complexity Minimum-variance Beamformer Based on Orthogonal Decomposition of the Compounded Subspace.
In this study, we propose a novel MV beamformer based on orthogonal decomposition of the compounded subspace (CS) of the covariance matrix in synthetic aperture (SA) imaging, which aims to reduce the dimensions of the covariance matrix and therefore reduce the computational complexity. Multiwave spatial smoothing is applied to the echo signals for the accurate estimation of the covariance matrix, and adaptive weight vectors are calculated from the low-dimensional subspace of the original covariance matrix. We conducted simulation, experimental and in vivo studies to verify the performance of the proposed method. The result...
Source: Ultrasonic Imaging - December 30, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

An Ultrasound Image Enhancement Method Using Neutrosophic Similarity Score.
Authors: Bharti P, Mittal D Abstract Ultrasound images, having low contrast and noise, adversely impact in the detection of abnormalities. In view of this, an enhancement method is proposed in this work to reduce noise and improve contrast of ultrasound images. The proposed method is based on scaling with neutrosophic similarity score (NSS), where an image is represented in the neutrosophic domain through three membership subsets T, I, and F denoting the degree of truth, indeterminacy, and falseness, respectively. The NSS measures the belonging degree of pixel to the texture using multi-criteria that is based on in...
Source: Ultrasonic Imaging - October 8, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Application of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Different Molecular Subtypes of Breast Cancer.
Authors: Liang X, Li Z, Zhang L, Wang D, Tian J Abstract To explore the value of contrast-enhanced ultrasound (CEUS) in the differential diagnosis of molecular subtypes of breast cancer. Sixty-two cases of breast cancer were divided into luminal epithelium A or B subtype (luminal A/B), Her-2 over-expression subtype and triple negative subtype (TN). CEUS and routine ultrasonography were performed for all patients before surgery. (1) The luminal epithelium subtype contrast enhancement pattern was more likely to present with radial edge (76.92%, p
Source: Ultrasonic Imaging - October 8, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Fully Automatic Measurement of Intima-Media Thickness in Ultrasound Images of the Common Carotid Artery Based on Improved Otsu's Method and Adaptive Wind Driven Optimization.
Authors: Wang K, Pu Y, Zhang Y, Wang P Abstract The intima media thickness (IMT) of the common carotid artery (CCA) can be used to predict the risk of atherosclerosis. Many image segmentation techniques have been used for IMT measurement. However, severe noise in the ultrasound image can lead to erroneous segmentation results. To improve the robustness to noise, a fully automatic method, based on an improved Otsu's method and an adaptive wind-driven optimization technique, is proposed for estimating the IMT (denoted as "improved Otsu-AWDO"). First, an advanced despeckling filter, i.e., " Nagare's fil...
Source: Ultrasonic Imaging - September 21, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Deep Learning for Carotid Plaque Segmentation using a Dilated U-Net Architecture.
We report on 101 severely stenotic carotid plaque patients. A standard U-Net is compared with a dilated U-Net architecture in which the dilated convolution layers were used in the bottleneck. Both a fully automatic and a semi-automatic approach with a bounding box was implemented. The performance degradation in plaque segmentation due to errors in the bounding box is quantified. We found that the bounding box significantly improved the performance of the networks with U-Net Dice coefficients of 0.48 for automatic and 0.83 for semi-automatic segmentation of plaque. Similar results were also obtained for the dilated U-Net wi...
Source: Ultrasonic Imaging - September 6, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Skeletal Muscle Fatigue State Evaluation with Ultrasound Image Entropy.
In this study, we evaluated changes in the ultrasound image entropy (USIE) during the fatigue process. Twelve volunteers performed static sustained contractions of biceps brachii at four different intensities (20%, 30%, 40%, and 50% of maximal voluntary contraction torque). The ultrasound images and surface electromyography (sEMG) signals were acquired during exercise to fatigue. We found that (1) the root-mean-square of the sEMG signal increased, the USIE decreased significantly with time during the sustained contractions; (2) the maximum endurance time (MET) and the decline percentage of USIE were significantly different (p
Source: Ultrasonic Imaging - August 30, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Artificial Intelligence Medical Ultrasound Equipment: Application of Breast Lesions Detection.
Authors: Zhang X, Lin X, Zhang Z, Dong L, Sun X, Sun D, Yuan K Abstract Breast cancer ranks first among cancers affecting women's health. Our work aims to realize the intelligence of the medical ultrasound equipment with limited computational capability, which is used for the assistant detection of breast lesions. We embed the high-computational deep learning algorithm into the medical ultrasound equipment with limited computational capability by two techniques: (1) lightweight neural network: considering the limited computational capability of ultrasound equipment, a lightweight neural network is designed, which g...
Source: Ultrasonic Imaging - June 19, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Classification of breast masses on ultrasound shear wave elastography using convolutional neural networks.
Authors: Fujioka T, Katsuta L, Kubota K, Mori M, Kikuchi Y, Kato A, Oda G, Nakagawa T, Kitazume Y, Tateishi U Abstract We aimed to use deep learning with convolutional neural networks (CNNs) to discriminate images of benign and malignant breast masses on ultrasound shear wave elastography (SWE). We retrospectively gathered 158 images of benign masses and 146 images of malignant masses as training data for SWE. A deep learning model was constructed using several CNN architectures (Xception, InceptionV3, InceptionResNetV2, DenseNet121, DenseNet169, and NASNetMobile) with 50, 100, and 200 epochs. We analyzed SWE image...
Source: Ultrasonic Imaging - June 7, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Burr, Lomax, Pareto, and Logistic Distributions from Ultrasound Speckle.
Authors: Parker KJ, Poul SS Abstract After 100 years of theoretical treatment of speckle patterns from coherent illumination, there remain some open questions about the nature of ultrasound speckle from soft vascularized tissues. A recent hypothesis is that the fractal branching vasculature is responsible for the dominant echo pattern from organs such as the liver. In that case, an analysis of cylindrical scattering structures arranged across a power law distribution of sizes is warranted. Using a simple model of echo strength and basic transformation rules from probability, we derive the first order statist...
Source: Ultrasonic Imaging - June 4, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Toward Quantitative and Operator-independent Quasi-static Ultrasound Elastography: An Ex Vivo Feasibility Study.
Authors: Selladurai S, Verma A, Thittai AK Abstract It is known that the elasticity of liver reduces progressively in the case of diffuse liver disease. Currently, the diagnosis of diffuse liver disease requires a biopsy, which is an invasive procedure. In this paper, we evaluate and report a noninvasive method that can be used to quantify liver stiffness using quasi-static ultrasound elastography approach. Quasi-static elastography is popular in clinical applications where the qualitative assessment of relative tissue stiffness is enough, whereas its potential is relatively underutilized in liver imaging due to la...
Source: Ultrasonic Imaging - May 28, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

On the Effects of Constitutive Properties and Roughness of a Hard Inclusion in Soft Tissue on B-mode Images.
Authors: Karve PM, Duddu R, Tierney J, Dei K, Hsi R, Byram B Abstract We perform finite element modeling of pulse-echo ultrasound of a hard inclusion in a soft tissue to gain a better understanding of B-mode image brightness characteristics. We simulate a pressure wave emitted by an ultrasound transducer through the inclusion-tissue medium by prescribing suitable boundary conditions, and collect the scattered wave response to simulate the behavior of the transducer array used for pulse-echo ultrasound. We form B-mode images from simulated channel data using standard delay and sum beamforming. We establish the accur...
Source: Ultrasonic Imaging - May 5, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Automated Ultrasound Measurement of the Inferior Vena Cava: An Animal Study.
In this study, we developed a cross-correlation (CC)-based method for automated IVC movement tracking and measurement, which requires minimal manual input and avoids manual selection of reference markers. Based on the CC method, two approaches, named direct and relative approaches, were used to calculate the maximum, minimum, and variation of the IVC diameter, and compared with the manual measurement. Fifty-four ultrasound cine-loops collected from nine pigs were tested. The results reveal that both the proposed approaches were well agreed with the manual measurement. The errors of the direct approach were less than 9%, wh...
Source: Ultrasonic Imaging - April 4, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Machine Learning Diagnostic Modeling for Classifying Fibromyalgia Using B-mode Ultrasound Images.
Authors: Behr M, Saiel S, Evans V, Kumbhare D Abstract Fibromyalgia (FM) diagnosis remains a challenge for clinicians due to a lack of objective diagnostic tools. One proposed solution is the use of quantitative ultrasound (US) techniques, such as image texture analysis, which has demonstrated discriminatory capabilities with other chronic pain conditions. From this, we propose the use of image texture variables to construct and compare two machine learning models (support vector machine [SVM] and logistic regression) for differentiating between the trapezius muscle in healthy and FM patients. US videos of the righ...
Source: Ultrasonic Imaging - March 18, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Temporal Super-resolution of Ultrasound Imaging Using Matrix Completion.
Authors: Hosseinpour M, Behnam H, Shojaeifard M Abstract The temporal super-resolution of the dynamic ultrasound imaging, a means to observe rapid heart movements, is considered an important subject in medical diagnosis of cardiac conditions. Here, a new technique based on the acquisition scheme using the matrix completion (MC) theory is offered for the temporal super-resolution of the two-dimensional (2D) and three-dimensional (3D) ultrasound imaging. MC mentions the problem of completing a low-rank matrix when only a subset of its elements can be observed. Here, the lower scan lines are acquired. Whereby, the pro...
Source: Ultrasonic Imaging - March 6, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Ultrasound Backscatter Envelope Statistics Parametric Imaging for Liver Fibrosis Characterization: A Review.
We presented the theoretical background and algorithms for liver fibrosis assessment by ultrasound backscatter envelope statistics parametric imaging. Then, the specific applications of ultrasound backscatter envelope statistics parametric imaging techniques to liver fibrosis evaluation were reviewed and analyzed. Finally, the pros and cons of each technique were discussed, and the future development was suggested. PMID: 32100633 [PubMed - as supplied by publisher] (Source: Ultrasonic Imaging)
Source: Ultrasonic Imaging - February 28, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Neural Network-based Motion Tracking for Breast Ultrasound Strain Elastography: An Initial Assessment of Performance and Feasibility.
In this study, we investigate the feasibility of using three published convolution neural network (CNN) models built for optical flow (hereafter referred to as CNN-based tracking) by the computer vision community for breast ultrasound strain elastography. Elastographic datasets produced by finite element and ultrasound simulations were used to retrain three published CNN models: FlowNet-CSS, PWC-Net, and LiteFlowNet. After retraining, the three improved CNN models were evaluated using computer-simulated and tissue-mimicking phantoms, and in vivo breast ultrasound data. CNN-based tracking results were compared with two publ...
Source: Ultrasonic Imaging - February 1, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Adaptive Ultrasound Tissue Harmonic Imaging Based on an Improved Ensemble Empirical Mode Decomposition Algorithm.
In conclusion, the S_CEEMDAN method provides improved harmonic images owing to its good adaptivity and lower motion artifacts, and is thus a potential alternative to the current methods for ultrasonic harmonic imaging. PMID: 31994455 [PubMed - as supplied by publisher] (Source: Ultrasonic Imaging)
Source: Ultrasonic Imaging - January 31, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Toward Noninvasive Mapping of Diffuse Scattering in the Presence of Motion.
Authors: Lindsey BD, Collins GC Abstract Ultrasonic coda wave analysis techniques localize defects in fields such as seismography and nondestructive testing. In medical ultrasound, these techniques might provide novel mapping of tissue properties in diseases characterized by local fibrosis. In this work, we present an approach for localizing variation in scattering properties in the diffuse regime with an array transducer in medical ultrasound. This approach estimates coda wave decorrelation as the array is displaced by 0.5 mm, allowing data acquisition at two slightly different spatial locations. An inverse proble...
Source: Ultrasonic Imaging - January 16, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

A Spline Interpolation-based Data Reconstruction Technique for Estimation of Strain Time Constant in Ultrasound Poroelastography.
Authors: Islam MT, Righetti R Abstract Ultrasound poroelastography is a cost-effective and noninvasive imaging technique, which can be used to reconstruct mechanical parameters of tissues such as Young's modulus, Poisson's ratio, interstitial permeability, and vascular permeability. To estimate interstitial permeability and vascular permeability using poroelastography, accurate estimation of the strain time constant (TC) is required. This can be a challenging task due to the nonlinearity of the exponential strain curve and noise affecting the experimental data. Due to motion artifacts caused by the sonographer, ani...
Source: Ultrasonic Imaging - January 16, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Actuator-assisted Subpitch Translation-capable Transducer for Elastography: Preliminary Performance Assessment.
Authors: Selladurai S, Thittai AK Abstract In conventional linear array (CLA)-based elastography tissue compression in one direction (e.g., axial) leads to an expansion in all other directions (lateral, elevation). Therefore, the estimation of the lateral displacements and strains may provide additional information on the tissue mechanical properties. However, these are not exploited fully due to the inherent limitation in lateral sampling. Recently, a method named actuator-assisted beam translation (ABT) was demonstrated to address this issue, wherein the focused beam was translated at subpitch locations using an ...
Source: Ultrasonic Imaging - January 16, 2020 Category: Radiology Tags: Ultrason Imaging Source Type: research

Converting Coherence to Signal-to-noise Ratio for Enhancement of Adaptive Ultrasound Imaging.
In this study, a new method based on the signal-to-noise ratio (SNR) among the element echo signals was developed for enhancement of the effect of the coherence factor (CF), which was previously developed for improvement in spatial resolution and contrast. In the proposed method, a new factor, namely, SNR factor, was introduced, and the relationship between the previously developed CF and SNR factor was discussed. The proposed method was implemented in plane wave imaging, and the performance was evaluated by simulated and phantom experiments. In simulation, the lateral spatial resolution and contrast obtained with the conv...
Source: Ultrasonic Imaging - December 6, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Ultrasonic Diagnosis of Breast Nodules Using Modified Faster R-CNN.
The objective of this study is to (a) propose a diagnostic method based on Breast Imaging Reporting and Data System (BI-RADS) and (b) increase its detectability of small lesions. We modified the framework of Faster R-CNN (Faster Region-based Convolutional Neural Network) by introducing multi-scale feature extraction and multi-resolution candidate bound extraction into the network. Then, it was trained using 852 images of BI-RADS C2, 739 images of C3, and 1662 images of malignancy (BI-RADS 4a/4b/4c/5/6). We compared our model with unmodified Faster R-CNN and YOLO v3 (You Only Look Once v3). The mean average precision (mAP) ...
Source: Ultrasonic Imaging - October 17, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Validation of Echodynamography in Comparison with Particle-image Velocimetry.
In conclusion, the EDG method has potentially greater clinical acceptance as a tool assessment of LV during the cardiac cycle. PMID: 31615353 [PubMed - in process] (Source: Ultrasonic Imaging)
Source: Ultrasonic Imaging - October 17, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Performance Characteristics of Photoacoustic Imaging Probes with Varying Frequencies and Light Delivery Schemes.
Authors: Rich LJ, Chamberlain SR, Falcone DR, Bruce R, Heinmiller A, Xia J, Seshadri M Abstract Photoacoustic imaging (PAI) is an emerging biomedical imaging technique that utilizes a combination of light and ultrasound to detect photoabsorbers embedded within tissues. While the clinical utility of PAI has been widely explored for several applications, limitations in light penetration and detector sensitivity have restricted these studies to mostly superficial sites. Given the importance of PA signal generation and detection on light delivery and ultrasound detector frequency, there is an ongoing effort to optimize...
Source: Ultrasonic Imaging - October 3, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Single-image Bayesian Restoration and Multi-image Super-resolution Restoration for B-mode Ultrasound Using an Accurate System Model Involving Correlated Nature of the Speckle Noise.
In this study, new single-image Bayesian restoration (BR) and multi-image super-resolution restoration (BSRR) methods are proposed for in-plane B-mode ultrasound images. The spatially correlated nature of the speckle was modeled, allowing for examination of two different models for BR and BSRR for uncorrelated Gaussian (BR-UG, BSRR-UG) and correlated Gaussian (BR-CG, BSRR-CG). The performances of these models were compared with common image restoration methods (Wiener filter, bilateral filtering, and anisotropic diffusion). Well-recognized metrics (peak signal-to-noise ratio, contrast-to-noise ratio, and normalized informa...
Source: Ultrasonic Imaging - August 3, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Assessment of Age-related Oxygenation Changes in Calf Skeletal Muscle by Photoacoustic Imaging: A Potential Tool for Peripheral Arterial Disease.
This study is designed to demonstrate the ability of photoacoustic imaging to noninvasively determine changes in tissue oxygenation that occur in mice's hind limb skeletal muscle as they age. Mice from two age cohorts were scanned bilaterally with a pulsed laser. The photoacoustic signal was unmixed to generate a parametric map of estimated oxygen saturation and then overlaid on grayscale ultrasound images. Tissue oxygenation measured in young and old mice was compared. Photoacoustic imaging visually and quantitatively showed the decrease in skeletal muscle oxygenation that occurs with age. Percent tissue oxygenation decre...
Source: Ultrasonic Imaging - July 21, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

GPU-accelerated Double-Stage Delay-Multiply-and-Sum Algorithm for Fast Photoacoustic Tomography Using LED Excitation and Linear Arrays.
Authors: Miri Rostami SR, Mozaffarzadeh M, Ghaffari-Miab M, Hariri A, Jokerst J Abstract Double-stage delay-multiply-and-sum (DS-DMAS) is an algorithm proposed for photoacoustic image reconstruction. The DS-DMAS algorithm offers a higher contrast than conventional delay-and-sum and delay-multiply and-sum but at the expense of higher computational complexity. Here, we utilized a compute unified device architecture (CUDA) graphics processing unit (GPU) parallel computation approach to address the high complexity of the DS-DMAS for photoacoustic image reconstruction generated from a commercial light-emitting diode (LE...
Source: Ultrasonic Imaging - July 21, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

The Ability of Ultrasonic Backscatter Parametric Imaging to Characterize Bovine Trabecular Bone.
Authors: Li Y, Li B, Li Y, Liu C, Xu F, Zhang R, Ta D, Wang W Abstract The ultrasonic backscatter technique holds the promise of characterizing bone density and microstructure. This paper conducts ultrasonic backscatter parametric imaging based on measurements of apparent integrated backscatter (AIB), spectral centroid shift (SCS), frequency slope of apparent backscatter (FSAB), and frequency intercept of apparent backscatter (FIAB) for representing trabecular bone mass and microstructure. We scanned 33 bovine trabecular bone samples using a 7.5 MHz focused transducer in a 20 mm × 20 mm region of interest (RO...
Source: Ultrasonic Imaging - July 18, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Intraocular Pressure-Dependent Corneal Elasticity Measurement Using High-Frequency Ultrasound.
This study demonstrates the potential of high-frequency ultrasound elastography in the characterization of spatially resolved corneal biomechanical properties. PMID: 31271117 [PubMed - as supplied by publisher] (Source: Ultrasonic Imaging)
Source: Ultrasonic Imaging - July 5, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Deconvolution in Intravascular Ultrasound to Improve Lateral Resolution.
Authors: Li M, Shao W, Jiang X, Feng Z Abstract Intravascular ultrasound (IVUS) is an important diagnostic method for coronary disease. The lateral and axial resolutions of IVUS systems under study are typically ~120 and ~30 µm, respectively. The lateral resolution has a lower quality than the axial one and is restricted by the aperture size of transducers. In addition, this resolution is difficult to further improve physically. However, IVUS is inherently suitable for lateral deconvolution because of its circular imaging area. In this paper, magnitude-based deconvolution was demonstrated to be feasible in IV...
Source: Ultrasonic Imaging - April 18, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Automatic ROI Placement in the Upper Trapezius Muscle in B-mode Ultrasound Images.
Authors: Behr M, McNabb E, Noseworthy M, Sidkar S, Kumbhare D Abstract Research involving B-mode ultrasound imaging often requires user defined regions of interest (ROIs) for analysis, traditionally drawn/selected by a trained operator. This manual process is incredibly time consuming and subjective. Here, we propose a fast and simple method of detecting the average location of aponeurosis layers in ultrasound images of the upper trapezius to place a rectangular ROI for quantitative image analysis. A total of 56 B-mode ultrasound images were analyzed, where rectangular ROIs were manually placed in the skeletal musc...
Source: Ultrasonic Imaging - April 18, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

A Variance-Reduction Approach to Detection of Thyroid Nodule Boundary on Ultrasound Images.
In conclusion, our proposed method is reliable and effective in detecting thyroid nodule boundary on ultrasound images. PMID: 30990130 [PubMed - as supplied by publisher] (Source: Ultrasonic Imaging)
Source: Ultrasonic Imaging - April 18, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

An Optimum Imaging Scheme for IVUS Arrays: Eccentric Cylinder Wave Compounding.
Authors: Li M, Feng Z Abstract With the development of integrated circuit (IC) technologies, complex transmitting and receiving circuits can be integrated into miniature intravascular ultrasound (IVUS) catheters, making it possible to adopt better synthesizing schemes for better imaging. Eccentric cylinder wave compounding should be an optimum synthesizing scheme for the small size cylinder shaped catheter. Eccentric cylinder waves centered at different points are emitted, signals are collected after each emission, and images can be synthesized with easy post processing. Detailed analyses about resolution and grati...
Source: Ultrasonic Imaging - March 23, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Predictive Value of Contrast-enhanced Ultrasound for Early Recurrence of Single Lesion Hepatocellular Carcinoma After Curative Resection.
Authors: Xiachuan Q, Xiang Z, Xuebing L, Yan L Abstract This retrospective study aimed to use preoperative and contrast-enhanced ultrasound (CEUS) factors to assess and reveal risk factors of early recurrence (ER) in patients with hepatocellular carcinoma (HCC). We enrolled 141 patients with primary HCC who had undergone surgical resection. The assessment of the CEUS scan includes (a) the maximum diameter of the lesion, (b) the tumor echogenicity of gray-scale ultrasound (US), (c) the morphology of the tumor, (d) the margin of the tumor, (e) the peripheral hypoechoic halo, (f) tumor necrosis, (g) nutritional arteri...
Source: Ultrasonic Imaging - February 27, 2019 Category: Radiology Tags: Ultrason Imaging Source Type: research

Detecting the Media-adventitia Border in Intravascular Ultrasound Images through a Classification-based Approach.
Authors: Wang YY, Qiu CH, Jiang J, Xia SR Abstract The detection of the media-adventitia (MA) border in intravascular ultrasound (IVUS) images is essential for vessel assessment and disease diagnosis. However, it remains a challenging task, considering the existence of plaque, calcification, and various artifacts. In this article, an effective method based on classification is proposed to extract the MA border in IVUS images. First, a novel morphologic feature describing the relative position of each structure relative to the MA border, called RPES for short, is proposed. Then, the RPES feature and other features a...
Source: Ultrasonic Imaging - December 19, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research

Ultrasonographic Multimodality Diagnostic Model of Thyroid Nodules.
Authors: Zhao RN, Zhang B, Jiang YX, Yang X, Lai XJ, Zhu SL, Zhang XY Abstract The aim of this study was to identify independent risk factors for thyroid cancer, establish an ultrasonographic multimodality diagnostic model for thyroid nodules, and explore the diagnostic value of the model. From November 2011 to February 2015, 307 patients with a total of 367 thyroid nodules underwent conventional ultrasound, contrast-enhanced ultrasound (CEUS), and ultrasound elastography examinations before surgery. A binary logistic regression analysis was performed to identify independent risk factors for thyroid cancer and to e...
Source: Ultrasonic Imaging - November 29, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research

On Factors Affecting Subharmonic-aided Pressure Estimation (SHAPE).
Authors: Gupta I, Eisenbrey JR, Machado P, Stanczak M, Wallace K, Forsberg F Abstract Subharmonic-aided pressure estimation (SHAPE) estimates hydrostatic pressure using the inverse relationship with subharmonic amplitude variations of ultrasound contrast agents (UCAs). We studied the impact of varying incident acoustic outputs (IAO), UCA concentration, and hematocrit on SHAPE. A Logiq 9 scanner with a 4C curvilinear probe (GE, Milwaukee, Wisconsin) was used with Sonazoid (GE Healthcare, Oslo, Norway) transmitting at 2.5 MHz and receiving at 1.25 MHz. An improved IAO selection algorithm provided improved correlation...
Source: Ultrasonic Imaging - November 14, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research

On the Feasibility of Ultrasound Imaging Enrichment by Medium-Temperature Changes.
We describe the concept of a new imaging modality based on the tracking and dynamic modeling of local intensity changes (ICs) observed in conventional ultrasound images collected during a medium-temperature change. We computed the pixel-by-pixel IC from averaged B-mode images that exhibited different behaviors with varying temperature resulting from changes in the speed of sound, which consequently induce changes in the backscattered energy. Moreover, for each pixel, a first-order polynomial model was adjusted to the different temperature-dependent ICs. The representation of the polynomial angular parameter in 2D pixel spa...
Source: Ultrasonic Imaging - September 23, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research

A Locally Adaptive Phase Aberration Correction (LAPAC) Method for Synthetic Aperture Sequences.
Authors: Chau G, Jakovljevic M, Lavarello R, Dahl J Abstract Phase aberration is a phenomenon caused by heterogeneity of the speed of sound in tissue, in which the actual speed of sound of the tissue is different than the assumed speed of sound used for beamforming. It reduces the quality and resolution of ultrasonic images and impairs clinical diagnostic capabilities. Although phase aberration correction (PAC) methods can reduce these detrimental effects, most practical implementations of PAC methods are based on the near field phase screen model, which have limited ability to represent the true aberration induced...
Source: Ultrasonic Imaging - September 19, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research

Robust Waveform Design of Ultrasound Arrays for Medical Imaging.
Authors: Gholampour A, Sakhaei SM, Andargoli SMH Abstract Sound speed is an effective parameter in designing an optimal beamformer. In conventional ultrasound imaging systems, the beamformer is designed assuming a fixed value of speed, whereas the speed in a tissue is not known precisely and also may fluctuate by a great value. The errors in estimating sound speed may lead to a severe degradation in the reconstructed image, as mainlobe width and sidelobe level of the beampattern are sensitive to the speed variations. In this paper, we consider the design of a transmit beamformer, which is robust to the speed variat...
Source: Ultrasonic Imaging - September 13, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research

Group versus Phase Velocity of Shear Waves in Soft Tissues.
Authors: Parker KJ, Ormachea J, Hah Z Abstract Across the varieties of waves that have been studied in physics, it is well established that group velocities can be significantly greater than or less than phase velocities measured within comparable frequency bands, depending on the particular mechanisms involved. The distinction between group and phase velocities is important in elastography, because diagnoses are made based on shear wave speed estimations from a variety of techniques. We review the general definitions of group and phase velocity and examine their specific relations within an important general class...
Source: Ultrasonic Imaging - September 6, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research

Evaluation of the Effect of Tissue Compression on the Results of Shear Wave Elastography Measurements.
Authors: Vachutka J, Sedlackova Z, Furst T, Herman M, Herman J, Salzman R, Dolezal L Abstract Shear wave imaging is considered to be more precise and less operator dependent when compared with strain imaging. It enables quantitative and reproducible data (Young's modulus of the imaged tissue). However, results of shear wave imaging can be affected by a variety of different factors. The aim of this study is to evaluate the effect of the pressure applied by the ultrasound probe during examination on the measured values of Young's modulus. The effect of the tissue compression on the results of the real-time shear wave...
Source: Ultrasonic Imaging - August 14, 2018 Category: Radiology Tags: Ultrason Imaging Source Type: research