Read by QxMD icon Read

Ultrasonic Imaging

Yuqi Wang, Haidy G Nasief, Sarah Kohn, Andy Milkowski, Tom Clary, Stephen Barnes, Paul E Barbone, Timothy J Hall
Ultrasound elasticity imaging has demonstrated utility in breast imaging, but it is typically performed with handheld transducers and two-dimensional imaging. Two-dimensional (2D) elastography images tissue stiffness of only a plane and hence suffers from errors due to out-of-plane motion, whereas three-dimensional (3D) data acquisition and motion tracking can be used to track out-of-plane motion that is lost in 2D elastography systems. A commercially available automated breast volume scanning system that acquires 3D ultrasound data with precisely controlled elevational movement of the 1D array ultrasound transducer was employed in this study...
June 1, 2017: Ultrasonic Imaging
Jacinto Javier Martínez-Payá, José Ríos-Díaz, María Elena Del Baño-Aledo, Jose Ignacio Tembl-Ferrairó, Juan Francisco Vazquez-Costa, Francesc Medina-Mirapeix
The purpose of this study was to analyze differences in gray-level co-occurrence matrix (GLCM) parameters, as assessed by muscle ultrasound (MUS), between amyotrophic lateral sclerosis (ALS) patients and healthy controls, and to compare the diagnostic accuracy of these GLCM parameters with first-order MUS parameters (echointensity [EI], echovariation [EV], and muscle thickness [MTh]) in different muscle groups. Twenty-six patients with ALS and 26 healthy subjects underwent bilateral and transverse ultrasound of the biceps/brachialis, forearm flexor, quadriceps femoris, and tibialis anterior muscle groups...
May 1, 2017: Ultrasonic Imaging
Yoshiki Nagatani, Séraphin Guipieri, Vu-Hieu Nguyen, Christine Chappard, Didier Geiger, Salah Naili, Guillaume Haїat
Degenerative discopathy is a common pathology that may require spine surgery. A metallic cylindrical pin is inserted into the vertebral body to maintain soft tissues and may be used as a reflector of ultrasonic wave to estimate bone density. The first aim of this paper is to validate a three-dimensional (3-D) model to simulate the ultrasonic propagation in a trabecular bone sample in which a metallic pin has been inserted. We also aim at determining the effect of changes of bone volume fraction (BV/TV) and of positioning errors on the quantitative ultrasound (QUS) parameters in this specific configuration...
May 1, 2017: Ultrasonic Imaging
Niraj Nirmal Pandey, Gaurav Shanker Pradhan, Alpana Manchanda, Anju Garg
The objective of this study was to evaluate the role of ultrasound elastography using acoustic radiation force impulse (ARFI) quantification in characterizing and differentiating malignant versus benign thyroid nodules. A total of 40 thyroid nodules were evaluated with conventional sonography and ultrasound elastography using ARFI quantification. The final diagnosis was obtained from histologic findings. A total of 14 malignant and 26 benign nodules were diagnosed on the basis of histologic examination. Majority of the malignant thyroid nodules demonstrated presence of intranodular vascular flow, hypoechoic echotexture, absent halo, irregular margins and microcalcifications...
May 1, 2017: Ultrasonic Imaging
Xinhua Guo, Song Sun, Xiantao Yu, Pan Wang, Kentaro Nakamura
Extraction and display of frequency information in three-dimensional (3D) acoustic data are important steps to analyze object characteristics, because the characteristics, such as profiles, sizes, surface structures, and material properties, may show frequency dependence. In this study, frequency representation (FR) based on phase information in multispectral acoustic imaging (MSAI) is proposed to overcome the limit of intensity or amplitude information in image display. Experiments are performed on 3D acoustic data collected from a rigid surface engraved with five different letters...
May 1, 2017: Ultrasonic Imaging
Zeyu Chen, Limei Zheng, Wenwu Cao, Xiaoyang Chen, Ruimin Chen, Runze Li, Kirk Shung, Qifa Zhou
Lead-free (Na,K)(Nb,Ta)O3 (KNNT) piezoelectric single crystal has been successfully grown using the top-seeded solution growth technique. The electromechanical coupling factors are very high ( k33 = 0.827, kt = 0.646), and the dielectric loss tangent is as low as 0.004. Acoustic impedance was calculated to be 26.5 MRayl. From the single crystal, a single element transducer was fabricated. The transducer achieved a 57.6% -6 dB bandwidth and 32.3 µm axial resolution at the center frequency of 45.4 MHz, which can identify the cornea of porcine eyeball with high resolution...
April 1, 2017: Ultrasonic Imaging
Yuling Chen, Yang Lou, Jesse Yen
During conventional ultrasound imaging, the need for multiple transmissions for one image and the time of flight for a desired imaging depth limit the frame rate of the system. Using a single plane wave pulse during each transmission followed by parallel receive processing allows for high frame rate imaging. However, image quality is degraded because of the lack of transmit focusing. Beamforming by spatial matched filtering (SMF) is a promising method which focuses ultrasonic energy using spatial filters constructed from the transmit-receive impulse response of the system...
July 2017: Ultrasonic Imaging
Tiexiang Wen, Ling Li, Qingsong Zhu, Wenjian Qin, Jia Gu, Feng Yang, Yaoqin Xie
Volume reconstruction method plays an important role in improving reconstructed volumetric image quality for freehand three-dimensional (3D) ultrasound imaging. By utilizing the capability of programmable graphics processing unit (GPU), we can achieve a real-time incremental volume reconstruction at a speed of 25-50 frames per second (fps). After incremental reconstruction and visualization, hole-filling is performed on GPU to fill remaining empty voxels. However, traditional pixel nearest neighbor-based hole-filling fails to reconstruct volume with high image quality...
July 2017: Ultrasonic Imaging
Kayvan Samimi, Tomy Varghese
Ultrasonic attenuation is one of the primary parameters of interest in Quantitative Ultrasound (QUS). Non-invasive monitoring of tissue attenuation can provide valuable diagnostic and prognostic information to the physician. The Reference Phantom Method (RPM) was introduced as a way of mitigating some of the system-related effects and biases to facilitate clinical QUS applications. In this paper, under the assumption of diffuse scattering, a probabilistic model of the backscattered signal spectrum is used to derive a theoretical lower bound on the estimation variance of the attenuation coefficient using the Spectral-Difference RPM...
May 2017: Ultrasonic Imaging
Lokesh B, Bhaskara Rao Chintada, Arun Kumar Thittai
It is well-documented in literature that benign breast lesions, such as fibroadenomas, are loosely bonded to their surrounding tissue and tend to slip under a small quasi-static compression, whereas malignant lesions being firmly bonded to their surrounding tissue do not slip. Recent developments in quasi-static ultrasound elastography have shown that an image of the axial-shear strain distribution can provide information about the bonding condition at the lesion-surrounding tissue boundary. Further studies analyzing the axial-shear strain elastograms revealed that nonzero axial-shear strain values appear inside the lesion, referred to as fill-in, only when a lesion is loosely bonded and asymmetrically oriented to the axis of compression...
May 2017: Ultrasonic Imaging
Naoki Sunaguchi, Yoshiki Yamakoshi, Takahito Nakajima
This study investigates shear wave phase map reconstruction using a limited number of color flow images (CFIs) acquired with a color Doppler ultrasound imaging instrument. We propose an efficient reconstruction method to considerably reduce the number of CFIs required for reconstruction and compare this method with Fourier analysis-based color Doppler shear wave imaging. The proposed method uses a two-step phase reconstruction process, including an initial phase map derived from four CFIs using an advanced iterative algorithm of optical interferometry...
May 2017: Ultrasonic Imaging
Guo-Chung Dong, Li-Chen Chiu, Chien-Kun Ting, Jia-Ruei Hsu, Chih-Chung Huang, Yin Chang, Gin-Shin Chen
Ultrasound guidance for epidural block has improved clinical blind-trial problems but the design of present ultrasonic probes poses operating difficulty of ultrasound-guided catheterization, increasing the failure rate. The purpose of this study was to develop a novel ultrasonic probe to avoid needle contact with vertebral bone during epidural catheterization. The probe has a central circular passage for needle insertion. Two focused annular transducers are deployed around the passage for on-axis guidance. A 17-gauge insulated Tuohy needle containing the self-developed fiber-optic-modified stylet was inserted into the back of the anesthetized pig, in the lumbar region under the guidance of our ultrasonic probe...
March 1, 2017: Ultrasonic Imaging
Sandeep K Kasoji, Emily H Chang, Lee B Mullin, Wui K Chong, W Kimryn Rathmell, Paul A Dayton
Malignant renal cell carcinoma (RCC) is a diverse set of diseases, which are independently difficult to characterize using conventional MRI and CT protocols due to low temporal resolution to study perfusion characteristics. Because different disease subtypes have different prognoses and involve varying treatment regimens, the ability to determine RCC subtype non-invasively is a clinical need. Contrast-enhanced ultrasound (CEUS) has been assessed as a tool to characterize kidney lesions based on qualitative and quantitative assessment of perfusion patterns, and we hypothesize that this technique might help differentiate disease subtypes...
March 2017: Ultrasonic Imaging
David Rosen, Yu Wang, Jingfeng Jiang
Viscoelasticity Imaging (VEI) has been proposed to measure relaxation time constants for characterization of in vivo breast lesions. In this technique, an external compression force on the tissue being imaged is maintained for a fixed period of time to induce strain creep. A sequence of ultrasound echo signals is then utilized to generate time-resolved strain measurements. Relaxation time constants can be obtained by fitting local time-resolved strain measurements to a viscoelastic tissue model (e.g., a modified Kevin-Voigt model)...
March 2017: Ultrasonic Imaging
Jinxin Zhao, Yuanyuan Wang, Jinhua Yu, Wei Guo, Shun Zhang, Saeid Aliabadi
The short-lag spatial coherence (SLSC) imaging has been demonstrated to be advantageous over the traditional B-mode ultrasound imaging. With focused scanning beams, the SLSC imaging has an excellent performance in clutter reduction and lesion detection, especially in the low signal-to-noise ratio (SNR) scenarios. The synthetic aperture (SA) imaging is an appropriate mode for the SLSC imaging as the dynamic transmit focusing could keep a good focusing quality at any depth. However, the SLSC image may still suffer a bad resolution performance when a low lag value is used in the coherence summation to ensure the contrast enhancement...
January 1, 2017: Ultrasonic Imaging
K M Prabusankarlal, P Thirumoorthy, R Manavalan
Earliest detection and diagnosis of breast cancer reduces mortality rate of patients by increasing the treatment options. A novel method for the segmentation of breast ultrasound images is proposed in this work. The proposed method utilizes undecimated discrete wavelet transform to perform multiresolution analysis of the input ultrasound image. As the resolution level increases, although the effect of noise reduces, the details of the image also dilute. The appropriate resolution level, which contains essential details of the tumor, is automatically selected through mean structural similarity...
November 2016: Ultrasonic Imaging
Chi Ma, Xiao Wang, Tomy Varghese
Accurate description of myocardial deformation in the left ventricle is a three-dimensional problem, requiring three normal strain components along its natural axis, that is, longitudinal, radial, and circumferential strains. Although longitudinal strains are best estimated from long-axis views, radial and circumferential strains are best depicted in short-axis views. An algorithm that utilizes a polar grid for short-axis views previously developed in our laboratory for a Lagrangian description of tissue deformation is utilized for radial and circumferential displacement and strain estimation...
November 2016: Ultrasonic Imaging
Anuj Chaudhry, Namhee Kim, Ginu Unnikrishnan, Sanjay Nair, J N Reddy, Raffaella Righetti
Ultrasound elastography is an imaging modality that has been used to diagnose tumors of the breast, thyroid, and prostate. Both axial strain elastography and axial shear strain elastography (ASSE) have shown significant potentials to differentiate between benign and malignant tumors. Elevated interstitial fluid pressure (IFP) is a characteristic of many malignant tumors and a major barrier in targeted drug delivery therapies. This parameter, however, has not received significant attention in ultrasound elastography and, in general, in most diagnostic imaging modalities yet...
September 29, 2016: Ultrasonic Imaging
Rebecca E Geist, Chase H DuBois, Timothy C Nichols, Melissa C Caughey, Elizabeth P Merricks, Robin Raymer, Caterina M Gallippi
Acoustic radiation force impulse (ARFI) Surveillance of Subcutaneous Hemorrhage (ASSH) has been previously demonstrated to differentiate bleeding phenotype and responses to therapy in dogs and humans, but to date, the method has lacked experimental validation. This work explores experimental validation of ASSH in a poroelastic tissue-mimic and in vivo in dogs. The experimental design exploits calibrated flow rates and infusion durations of evaporated milk in tofu or heparinized autologous blood in dogs. The validation approach enables controlled comparisons of ASSH-derived bleeding rate (BR) and time to hemostasis (TTH) metrics...
September 2016: Ultrasonic Imaging
Teng Ma, Bill Zhou, Tzung K Hsiai, K Kirk Shung
Catheter-based intravascular imaging modalities are being developed to visualize pathologies in coronary arteries, such as high-risk vulnerable atherosclerotic plaques known as thin-cap fibroatheroma, to guide therapeutic strategy at preventing heart attacks. Mounting evidences have shown three distinctive histopathological features-the presence of a thin fibrous cap, a lipid-rich necrotic core, and numerous infiltrating macrophages-are key markers of increased vulnerability in atherosclerotic plaques. To visualize these changes, the majority of catheter-based imaging modalities used intravascular ultrasound (IVUS) as the technical foundation and integrated emerging intravascular imaging techniques to enhance the characterization of vulnerable plaques...
September 2016: Ultrasonic Imaging
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"