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Sample records for quantitative ultrasound measurements

  1. Quantitative Ultrasound Measurements at the Heel

    DEFF Research Database (Denmark)

    Daugschies, M.; Brixen, K.; Hermann, P.

    2015-01-01

    Calcaneal quantitative ultrasound can be used to predict osteoporotic fracture risk, but its ability to monitor therapy is unclear possibly because of its limited precision. We developed a quantitative ultrasound device (foot ultrasound scanner) that measures the speed of sound at the heel...... with the foot ultrasound scanner reduced precision errors by half (p quantitative ultrasound measurements is feasible. (E-mail: m.daugschies@rad.uni-kiel.de) (C) 2015 World Federation for Ultrasound in Medicine & Biology....

  2. Quantitative Measurements using Ultrasound Vector Flow Imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2016-01-01

    Duplex Vector Flow Imaging (VFI) imaging is introduced as a replacement for spectral Doppler, as it automatically can yield fully quantitative flow estimates without angle correction. Continuous VFI data over 9 s for 10 pulse cycles were acquired by a 3 MHz convex probe connected to the SARUS......L/stroke (true: 1.15 mL/stroke, bias: 12.2%). Measurements down to 160 mm were obtained with a relative standard deviation and bias of less than 10% for the lateral component for stationary, parabolic flow. The method can, thus, find quantitative velocities, angles, and volume flows at sites currently...

  3. Ultrasound attenuation as a quantitative measure of fracture healing

    Science.gov (United States)

    Gheduzzi, Sabina; Humphrey, Victor F.; Dodd, Simon P.; Cunningham, James L.; Miles, Anthony W.

    2004-10-01

    The monitoring of fracture healing still relies upon the judgment of callus formation and on the manual assessment of the stiffness of the fracture. A diagnostic tool capable of quantitatively measuring healing progression of a fracture would allow the fine-tuning of the treatment regime. Ultrasound attenuation measurements were adopted as a possible method of assessing the healing process in human long bones. The method involves exciting ultrasonic waves at 200 kHz in the bone and measuring the reradiation along the bone and across the fracture zone. Seven cadaveric femora were tested in vitro in intact form and after creating a transverse fracture by sawing through the cortex. The effects of five different fracture types were investigated. A partial fracture, corresponding to a 50% cut through the cortex, a closed fracture, and fractures of widths varying between 1, 2, and 4 mm were investigated. The introduction of a fracture was found to produce a dramatic effect on the amplitude of the signal. Ultrasound attenuation was found to be sensitive to the presence of a fracture, even when the fracture was well reduced. It would therefore appear feasible to adopt attenuation across a fracture as a quantitative measurement of fracture healing.

  4. Ultrasound imaging for quantitative measurement of immersed plastic waste particles

    NARCIS (Netherlands)

    Sanaee, S.A.; Bakker, M.C.M.

    2012-01-01

    Ultrasound imaging techniques are proposed for measuring the shape and thickness of immersed waste particles (10-20 mm size) using a linear sensor array from a fixed position. For these purposes both the front and back surface of a particle needs to be reconstructed. Raw ultrasound pulse-echo and pl

  5. Quantitative measurement of ultrasound pressure field by optical phase contrast method and acoustic holography

    Science.gov (United States)

    Oyama, Seiji; Yasuda, Jun; Hanayama, Hiroki; Yoshizawa, Shin; Umemura, Shin-ichiro

    2016-07-01

    A fast and accurate measurement of an ultrasound field with various exposure sequences is necessary to ensure the efficacy and safety of various ultrasound applications in medicine. The most common method used to measure an ultrasound pressure field, that is, hydrophone scanning, requires a long scanning time and potentially disturbs the field. This may limit the efficiency of developing applications of ultrasound. In this study, an optical phase contrast method enabling fast and noninterfering measurements is proposed. In this method, the modulated phase of light caused by the focused ultrasound pressure field is measured. Then, a computed tomography (CT) algorithm used to quantitatively reconstruct a three-dimensional (3D) pressure field is applied. For a high-intensity focused ultrasound field, a new approach that combines the optical phase contrast method and acoustic holography was attempted. First, the optical measurement of focused ultrasound was rapidly performed over the field near a transducer. Second, the nonlinear propagation of the measured ultrasound was simulated. The result of the new approach agreed well with that of the measurement using a hydrophone and was improved from that of the phase contrast method alone with phase unwrapping.

  6. Quantitative muscle ultrasound measures rapid declines over time in children with SMA type 1.

    Science.gov (United States)

    Ng, Kay W; Connolly, Anne M; Zaidman, Craig M

    2015-11-15

    Muscles are small in spinal muscular atrophy (SMA). It is not known if muscle size changes over time in SMA type 1. We quantified changes over time in muscle size and echointensity during two repeated ultrasound examinations of unilateral proximal (biceps brachii/brachialis and quadriceps) and distal (anterior forearm flexors and tibialis anterior) muscles in three children with SMA type 1. We compared muscle thickness (MT) to body weight-dependent normal reference values. Children were 1, 6, and 11months old at baseline and had 2, 2 and 4 months between ultrasound examinations, respectively. At baseline, MT was normal for weight in all muscles except an atrophic quadriceps in the oldest child. MT decreased and echointensity increased (worsened) over time. At follow up, MT was below normal for weight in the quadriceps in all three children, in the biceps/brachioradialis in two, and in the anterior forearm in one. Tibialis anterior MT remained normal for weight in all three children. Muscle echointensity increased over time in all muscles and, on average, more than doubled in two children. In children with SMA type 1, muscle atrophies and becomes hyperechoic over time. Quantitative muscle ultrasound measures disease progression in SMA type 1 that warrants additional study in more children. Copyright © 2015. Published by Elsevier B.V.

  7. Estimation of multipath transmission parameters for quantitative ultrasound measurements of bone.

    Science.gov (United States)

    Dencks, Stefanie; Schmitz, Georg

    2013-09-01

    When applying quantitative ultrasound (QUS) measurements to bone for predicting osteoporotic fracture risk, the multipath transmission of sound waves frequently occurs. In the last 10 years, the interest in separating multipath QUS signals for their analysis awoke, and led to the introduction of several approaches. Here, we compare the performances of the two fastest algorithms proposed for QUS measurements of bone: the modified least-squares Prony method (MLSP), and the space alternating generalized expectation maximization algorithm (SAGE) applied in the frequency domain. In both approaches, the parameters of the transfer functions of the sound propagation paths are estimated. To provide an objective measure, we also analytically derive the Cramér-Rao lower bound of variances for any estimator and arbitrary transmit signals. In comparison with results of Monte Carlo simulations, this measure is used to evaluate both approaches regarding their accuracy and precision. Additionally, with simulations using typical QUS measurement settings, we illustrate the limitations of separating two superimposed waves for varying parameters with focus on their temporal separation. It is shown that for good SNRs around 100 dB, MLSP yields better results when two waves are very close. Additionally, the parameters of the smaller wave are more reliably estimated. If the SNR decreases, the parameter estimation with MLSP becomes biased and inefficient. Then, the robustness to noise of the SAGE clearly prevails. Because a clear influence of the interrelation between the wavelength of the ultrasound signals and their temporal separation is observable on the results, these findings can be transferred to QUS measurements at other sites. The choice of the suitable algorithm thus depends on the measurement conditions.

  8. Quantitative head ultrasound measurements to determine thresholds for preterm neonates requiring interventional therapies following intraventricular hemorrhage

    Science.gov (United States)

    Kishimoto, Jessica; Fenster, Aaron; Salehi, Fateme; Romano, Walter; Lee, David S. C.; de Ribaupierre, Sandrine

    2016-04-01

    Dilation of the cerebral ventricles is a common condition in preterm neonates with intraventricular hemorrhage (IVH). This post hemorrhagic ventricle dilation (PHVD) can lead to lifelong neurological impairment through ischemic injury due to increased intracranial pressure and without treatment, can lead to death. Clinically, 2D ultrasound (US) through the fontanelles ('soft spots') of the patients are serially acquired to monitor the progression of the ventricle dilation. These images are used to determine when interventional therapies such as needle aspiration of the built up cerebrospinal fluid (CSF) ('ventricle tap', VT) might be indicated for a patient; however, quantitative measurements of the growth of the ventricles are often not performed. There is no consensus on when a neonate with PHVD should have an intervention and often interventions are performed after the potential for brain damage is quite high. Previously we have developed and validated a 3D US system to monitor the progression of ventricle volumes (VV) in IVH patients. We will describe the potential utility of quantitative 2D and 3D US to monitor and manage PHVD in neonates. Specifically, we will look to determine image-based measurement thresholds for patients who will require VT in comparison to patients with PHVD who resolve without intervention. Additionally, since many patients who have an initial VT will require subsequent interventions, we look at the potential for US to determine which PHVD patients will require additional VT after the initial one has been performed.

  9. Registration-based segmentation of three-dimensional ultrasound images for quantitative measurement of fetal craniofacial structure.

    Science.gov (United States)

    Chen, Hsin-Chen; Tsai, Pei-Yin; Huang, Hsiao-Han; Shih, Hui-Hsuan; Wang, Yi-Ying; Chang, Chiung-Hsin; Sun, Yung-Nien

    2012-05-01

    Segmentation of a fetal head from three-dimensional (3-D) ultrasound images is a critical step in the quantitative measurement of fetal craniofacial structure. However, two main issues complicate segmentation, including fuzzy boundaries and large variations in pose and shape among different ultrasound images. In this article, we propose a new registration-based method for automatically segmenting the fetal head from 3-D ultrasound images. The proposed method first detects the eyes based on Gabor features to identify the pose of the fetus image. Then, a reference model, which is constructed from a fetal phantom and contains prior knowledge of head shape, is aligned to the image via feature-based registration. Finally, 3-D snake deformation is utilized to improve the boundary fitness between the model and image. Four clinically useful parameters including inter-orbital diameter (IOD), bilateral orbital diameter (BOD), occipital frontal diameter (OFD) and bilateral parietal diameter (BPD) are measured based on the results of the eye detection and head segmentation. Ultrasound volumes from 11 subjects were used for validation of the method accuracy. Experimental results showed that the proposed method was able to overcome the aforementioned difficulties and achieve good agreement between automatic and manual measurements.

  10. Quantitative ultrasound in cancer imaging.

    Science.gov (United States)

    Feleppa, Ernest J; Mamou, Jonathan; Porter, Christopher R; Machi, Junji

    2011-02-01

    Ultrasound is a relatively inexpensive, portable, and versatile imaging modality that has a broad range of clinical uses. It incorporates many imaging modes, such as conventional gray-scale "B-mode" imaging to display echo amplitude in a scanned plane; M-mode imaging to track motion at a given fixed location over time; duplex, color, and power Doppler imaging to display motion in a scanned plane; harmonic imaging to display nonlinear responses to incident ultrasound; elastographic imaging to display relative tissue stiffness; and contrast-agent imaging with simple contrast agents to display blood-filled spaces or with targeted agents to display specific agent-binding tissue types. These imaging modes have been well described in the scientific, engineering, and clinical literature. A less well-known ultrasonic imaging technology is based on quantitative ultrasound (QUS), which analyzes the distribution of power as a function of frequency in the original received echo signals from tissue and exploits the resulting spectral parameters to characterize and distinguish among tissues. This article discusses the attributes of QUS-based methods for imaging cancers and providing improved means of detecting and assessing tumors. The discussion will include applications to imaging primary prostate cancer and metastatic cancer in lymph nodes to illustrate the methods. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Epidemiological survey of the feasibility of broadband ultrasound attenuation measured using calcaneal quantitative ultrasound to predict the incidence of falls in the middle aged and elderly

    Science.gov (United States)

    Ou, Ling-Chun; Chang, Yin-Fan; Chang, Chin-Sung; Chiu, Ching-Ju; Chao, Ting-Hsing; Sun, Zih-Jie; Lin, Ruey-Mo; Wu, Chih-Hsing

    2017-01-01

    Objectives We investigated whether calcaneal quantitative ultrasound (QUS-C) is a feasible tool for predicting the incidence of falls. Design Prospective epidemiological cohort study. Setting Community-dwelling people sampled in central western Taiwan. Participants A cohort of community-dwelling people who were ≥40 years old (men: 524; women: 676) in 2009–2010. Follow-up questionnaires were completed by 186 men and 257 women in 2012. Methods Structured questionnaires and broadband ultrasound attenuation (BUA) data were obtained in 2009–2010 using QUS-C, and follow-up surveys were done in a telephone interview in 2012. Using a binary logistic regression model, the risk factors associated with a new fall during follow-up were analysed with all significant variables from the bivariate comparisons and theoretically important variables. Primary outcome measures The incidence of falls was determined when the first new fall occurred during the follow-up period. The mean follow-up time was 2.83 years. Results The total incidence of falls was 28.0 per 1000 person-years for the ≥40 year old group (all participants), 23.3 per 1000 person-years for the 40–70 year old group, and 45.6 per 1000 person-years for the ≥70 year old group. Using multiple logistic regression models, the independent factors were current smoking, living alone, psychiatric drug usage and lower BUA (OR 0.93; 95% CI 0.88 to 0.99, p<0.05) in the ≥70 year old group. Conclusions The incidence of falls was highest in the ≥70 year old group. Using QUS-C-derived BUA is feasible for predicting the incidence of falls in community-dwelling elderly people aged ≥70 years. PMID:28069623

  12. Urinary Mineral Concentrations in European Pre-Adolescent Children and Their Association with Calcaneal Bone Quantitative Ultrasound Measurements

    Directory of Open Access Journals (Sweden)

    Karen Van den Bussche

    2016-05-01

    Full Text Available This study investigates differences and associations between urinary mineral concentrations and calcaneal bone measures assessed by quantitative ultrasonography (QUS in 4322 children (3.1–11.9 years, 50.6% boys from seven European countries. Urinary mineral concentrations and calcaneal QUS parameters differed significantly across countries. Clustering revealed a lower stiffness index (SI in children with low and medium urinary mineral concentrations, and a higher SI in children with high urinary mineral concentrations. Urinary sodium (uNa was positively correlated with urinary calcium (uCa, and was positively associated with broadband ultrasound attenuation and SI after adjustment for age, sex and fat-free mass. Urinary potassium (uK was negatively correlated with uCa but positively associated with speed of sound after adjustment. No association was found between uCa and QUS parameters after adjustment, but when additionally adjusting for uNa, uCa was negatively associated with SI. Our findings suggest that urinary mineral concentrations are associated with calcaneal QUS parameters and may therefore implicate bone properties. These findings should be confirmed in longitudinal studies that include the food intake and repeated measurement of urinary mineral concentrations to better estimate usual intake and minimize bias.

  13. Urinary Mineral Concentrations in European Pre-Adolescent Children and Their Association with Calcaneal Bone Quantitative Ultrasound Measurements

    Science.gov (United States)

    Van den Bussche, Karen; Herrmann, Diana; De Henauw, Stefaan; Kourides, Yiannis A.; Lauria, Fabio; Marild, Staffan; Molnár, Dénes; Moreno, Luis A.; Veidebaum, Toomas; Ahrens, Wolfgang; Sioen, Isabelle

    2016-01-01

    This study investigates differences and associations between urinary mineral concentrations and calcaneal bone measures assessed by quantitative ultrasonography (QUS) in 4322 children (3.1–11.9 years, 50.6% boys) from seven European countries. Urinary mineral concentrations and calcaneal QUS parameters differed significantly across countries. Clustering revealed a lower stiffness index (SI) in children with low and medium urinary mineral concentrations, and a higher SI in children with high urinary mineral concentrations. Urinary sodium (uNa) was positively correlated with urinary calcium (uCa), and was positively associated with broadband ultrasound attenuation and SI after adjustment for age, sex and fat-free mass. Urinary potassium (uK) was negatively correlated with uCa but positively associated with speed of sound after adjustment. No association was found between uCa and QUS parameters after adjustment, but when additionally adjusting for uNa, uCa was negatively associated with SI. Our findings suggest that urinary mineral concentrations are associated with calcaneal QUS parameters and may therefore implicate bone properties. These findings should be confirmed in longitudinal studies that include the food intake and repeated measurement of urinary mineral concentrations to better estimate usual intake and minimize bias. PMID:27164120

  14. Imaging Performance of Quantitative Transmission Ultrasound

    Directory of Open Access Journals (Sweden)

    Mark W. Lenox

    2015-01-01

    Full Text Available Quantitative Transmission Ultrasound (QTUS is a tomographic transmission ultrasound modality that is capable of generating 3D speed-of-sound maps of objects in the field of view. It performs this measurement by propagating a plane wave through the medium from a transmitter on one side of a water tank to a high resolution receiver on the opposite side. This information is then used via inverse scattering to compute a speed map. In addition, the presence of reflection transducers allows the creation of a high resolution, spatially compounded reflection map that is natively coregistered to the speed map. A prototype QTUS system was evaluated for measurement and geometric accuracy as well as for the ability to correctly determine speed of sound.

  15. Multiparametric Quantitative Ultrasound Imaging in Assessment of Chronic Kidney Disease.

    Science.gov (United States)

    Gao, Jing; Perlman, Alan; Kalache, Safa; Berman, Nathaniel; Seshan, Surya; Salvatore, Steven; Smith, Lindsey; Wehrli, Natasha; Waldron, Levi; Kodali, Hanish; Chevalier, James

    2017-04-13

    To evaluate the value of multiparametric quantitative ultrasound imaging in assessing chronic kidney disease (CKD) using kidney biopsy pathologic findings as reference standards. We prospectively measured multiparametric quantitative ultrasound markers with grayscale, spectral Doppler, and acoustic radiation force impulse imaging in 25 patients with CKD before kidney biopsy and 10 healthy volunteers. Based on all pathologic (glomerulosclerosis, interstitial fibrosis/tubular atrophy, arteriosclerosis, and edema) scores, the patients with CKD were classified into mild (no grade 3 and quantitative ultrasound parameters included kidney length, cortical thickness, pixel intensity, parenchymal shear wave velocity, intrarenal artery peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index. We tested the difference in quantitative ultrasound parameters among mild CKD, moderate to severe CKD, and healthy controls using analysis of variance, analyzed correlations of quantitative ultrasound parameters with pathologic scores and the estimated glomerular filtration rate (GFR) using Pearson correlation coefficients, and examined the diagnostic performance of quantitative ultrasound parameters in determining moderate CKD and an estimated GFR of less than 60 mL/min/1.73 m(2) using receiver operating characteristic curve analysis. There were significant differences in cortical thickness, pixel intensity, PSV, and EDV among the 3 groups (all P quantitative ultrasound parameters, the top areas under the receiver operating characteristic curves for PSV and EDV were 0.88 and 0.97, respectively, for determining pathologic moderate to severe CKD, and 0.76 and 0.86 for estimated GFR of less than 60 mL/min/1.73 m(2) . Moderate to good correlations were found for PSV, EDV, and pixel intensity with pathologic scores and estimated GFR. The PSV, EDV, and pixel intensity are valuable in determining moderate to severe CKD. The value of shear wave velocity in

  16. Quantitative analysis with the optoacoustic/ultrasound system OPUS

    Science.gov (United States)

    Haisch, Christoph; Zell, Karin; Sperl, Jonathan; Vogel, Mika W.; Niessner, Reinhard

    2009-02-01

    The OPUS (Optoacoustic plus Ultrasound) system is a combination of a medical ultrasound scanner with a highrepetition rate, wavelength-tunable laser system and a suitable triggering interface to synchronize the laser and the ultrasound system. The pulsed laser generates an optoacoustic (OA), or photoacoustic (PA), signal which is detected by the ultrasound system. Alternatively, imaging in conventional ultrasound mode can be performed. Both imaging modes can be superimposed. The laser light is coupled into the tissue laterally, parallel to the ultrasound transducer, which does not require for any major modification to the transducer or the ultrasound beam forming. This was a basic requirement on the instrument, as the intention of the project was to establish the optoacoustic imaging modality as add-on to a conventional standard ultrasound instrument. We believe that this approach may foster the introduction of OA imaging as routine tool in medical diagnosis. Another key aspect of the project was to exploit the capabilities of OA imaging for quantitative analysis. The intention of the presented work is to summarize all steps necessary to extract the significant information from the PA raw data, which are required for the quantification of local absorber distributions. We show results of spatially resolved absorption measurements in scattering samples and a comparison of four different image reconstruction algorithms, regarding their influence on lateral resolution as well as on the signal to noise ratio for different sample depths and absorption values. The reconstruction algorithms are based on Fourier transformation, on a generalized 2D Hough transformation, on circular back-projection and the classical delay-and-sum approach which is implemented in most ultrasound scanners. Furthermore, we discuss the influence of a newly developed laser source, combining diode and flash lamp pumping. Compared to all-flash-lamp pumped systems it features a significantly higher

  17. Quantification of synovitis in Rheumatoid Arthritis: Do we really need quantitative measurement of contrast-enhanced ultrasound?

    Energy Technology Data Exchange (ETDEWEB)

    Platzgummer, Hannes; Schueller, Gerd [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Grisar, Johannes [Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Weber, Michael [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Schueller-Weidekamm, Claudia [Department of Diagnostic Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)], E-mail: claudia.schueller-weidekamm@meduniwien.ac.at

    2009-08-15

    Objective: The quantification of synovitis is of great significance for adequate therapy management and follow-up in patients with Rheumatoid Arthritis (RA). The purpose of this study was to validate a semi-quantitative Power Doppler (PD) scoring system by comparing the PD scores to the objective measurement of the synovial inflammation using dynamic contrast-enhanced Pulse-Inversion Harmonic Imaging (PIHI). Materials and methods: In 27 patients with RA, two radiologists performed semi-quantitative scoring of a PD examination, using a four-point scale from 0 to 3, in the metacarpophalangeal joints, proximal interphalangeal joints, and the wrists. The scores were compared to the area under the time-echo intensity curves obtained by contrast-enhanced PIHI examination. The interobserver agreement for PD scoring was evaluated using the Cohen's kappa test. Results: Preliminary results showed that the area under the curve of dynamic measurements of PIHI tended to correlate with PD scores. The interobserver agreement for PD scoring was good ({kappa} = 0.768). Discussion: Based on comparisons with dynamic contrast-enhanced PIHI, semi-quantitative PD scoring might meet the criteria for a reliable, reproducible, and practical scoring system. Although further studies that would include a larger study population are required, our preliminary results show that PIHI may not provide a real benefit for quantification of synovitis in day-to-day practice.

  18. Bone measurements of infants in the first 3 months of life by quantitative ultrasound: the influence of gestational age, season, and postnatal age

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Xiang-peng [Shanghai Second Medical University, Shanghai Institute for Pediatric Research, Shanghai Xinhua Hospital, Shanghai (China); Wuxi Hospital for Maternal and Children' s Health Care, Neonatal Intensive Care Unit, Wuxi (China); Zhang, Wei-li; He, Jiamin [Shanghai Second Medical University, Shanghai Institute for Pediatric Research, Shanghai Xinhua Hospital, Shanghai (China); Sun, Jian-hua; Huang, Ping [Shanghai Children' s Medical Center, Neonatal Intensive Care Unit, Shanghai (China)

    2005-09-01

    There are a few quantitative ultrasound (QUS) studies of bone status for Chinese children. To evaluate the clinical application and to investigate the bone status of neonates and young infants with QUS. An ultrasound bone sonometer was used to measure the bone speed of sound (SOS) of the tibia in 542 neonates within 3 months of birth. At birth, no significant difference of SOS was found between boys and girls, but there was a significant difference of SOS between premature infants and full-term infants. The SOS in neonates born during spring and summer was significantly lower than those born during autumn and winter. There were significant correlations between SOS and gestational age, and between bone SOS and birth weight in appropriate for gestational age (AGA) infants. Multiple regression analysis found that gestational age and infant birth season were two important factors influencing SOS. During the first 3 months, there was no significant difference in SOS between sexes. The SOS of infants showed an inverse correlation with postnatal age, and the decrease of bone SOS with age in premature infants was more marked than in full-term infants. QUS is suitable for evaluating bone status in infants with high precision. The study offers some basic data for neonates and young infants. (orig.)

  19. Assess the discrimination of Achilles InSight calcaneus quantitative ultrasound device for osteoporosis in Chinese women: Compared with dual energy X-ray absorptiometry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Jin Ningning, E-mail: ningning_jin@163.com [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China); Lin Shouqing, E-mail: Shouqing_Lin2003@yahoo.com.cn [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China); Zhang Ying, E-mail: steel_lee@sina.com.cn [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China); Chen Fengling, E-mail: bjzqk@126.com [Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100032 (China)

    2010-11-15

    Since the implementation of quantitative ultrasound (QUS) technology may become a part of future clinical decision making to identify osteoporosis and prevent fractures, this study was initiated to evaluate the correlations of QUS parameters and axial bone mineral density (BMD) using dual energy X-ray absorptiometry (DXA) and to assess the discrimination of QUS measurements for osteoporosis and osteopenia defined by WHO criteria. 106 native Chinese women (aged 50.2 {+-} 10.9 SD, 21-74 years) were involved. Each subject received both QUS measurements at left calcaneus with Achilles InSight and DXA measurements with DPX-L at lumbar spine (L{sub 2-4}), total hip and femoral neck. Achilles InSight provided the stiffness index (SI) which derived from Broadband Ultrasound Attenuation (BUA) and Speed of Sound (SOS), and the T-scores of SI were calculated. We found that the QUS parameter SI was statistically significant but medium correlated (r = 0.458-0.587) with DXA at the lumbar spine, total hip and femoral neck (P < 0.0001 for all correlations). With ROC analysis, the area under the ROC curve of diagnosis of osteoporosis and osteopenia were 0.933 and 0.796, respectively. To identify osteoporosis, when the T-score threshold of SI was defined as -1.4, the sensitivity was 100%, and the specificity was 73.7%. Our study confirmed that QUS measurements performed with Achilles InSight were capable to identify osteoporosis defined by axial BMD using DXA in Chinese women.

  20. Prediction of trabecular bone qualitative properties using scanning quantitative ultrasound

    Science.gov (United States)

    Qin, Yi-Xian; Lin, Wei; Mittra, Erik; Xia, Yi; Cheng, Jiqi; Judex, Stefan; Rubin, Clint; Müller, Ralph

    2012-01-01

    Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. While X-ray based imaging would not be practical in space, quantitative ultrasound may provide advantages to characterize bone density and strength through wave propagation in complex trabecular structure. This study used a scanning confocal acoustic diagnostic and navigation system (SCAN) to evaluate trabecular bone quality in 60 cubic trabecular samples harvested from adult sheep. Ultrasound image based SCAN measurements in structural and strength properties were validated by μCT and compressive mechanical testing. This result indicated a moderately strong negative correlations observed between broadband ultrasonic attenuation (BUA) and μCT-determined bone volume fraction (BV/TV, R2=0.53). Strong correlations were observed between ultrasound velocity (UV) and bone’s mechanical strength and structural parameters, i.e., bulk Young’s modulus (R2=0.67) and BV/TV (R2=0.85). The predictions for bone density and mechanical strength were significantly improved by using a linear combination of both BUA and UV, yielding R2=0.92 for BV/TV and R2=0.71 for bulk Young’s modulus. These results imply that quantitative ultrasound can characterize trabecular structural and mechanical properties through measurements of particular ultrasound parameters, and potentially provide an excellent estimation for bone’s structural integrity. PMID:23976803

  1. Prediction of trabecular bone qualitative properties using scanning quantitative ultrasound

    Science.gov (United States)

    Qin, Yi-Xian; Lin, Wei; Mittra, Erik; Xia, Yi; Cheng, Jiqi; Judex, Stefan; Rubin, Clint; Müller, Ralph

    2013-11-01

    Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. While X-ray based imaging would not be practical in space, quantitative ultrasound may provide advantages to characterize bone density and strength through wave propagation in complex trabecular structure. This study used a scanning confocal acoustic diagnostic and navigation system (SCAN) to evaluate trabecular bone quality in 60 cubic trabecular samples harvested from adult sheep. Ultrasound image based SCAN measurements in structural and strength properties were validated by μCT and compressive mechanical testing. This result indicated a moderately strong negative correlations observed between broadband ultrasonic attenuation (BUA) and μCT-determined bone volume fraction (BV/TV, R2=0.53). Strong correlations were observed between ultrasound velocity (UV) and bone's mechanical strength and structural parameters, i.e., bulk Young's modulus (R2=0.67) and BV/TV (R2=0.85). The predictions for bone density and mechanical strength were significantly improved by using a linear combination of both BUA and UV, yielding R2=0.92 for BV/TV and R2=0.71 for bulk Young's modulus. These results imply that quantitative ultrasound can characterize trabecular structural and mechanical properties through measurements of particular ultrasound parameters, and potentially provide an excellent estimation for bone's structural integrity.

  2. Greater Calcium Intake is Associated with Better Bone Health Measured by Quantitative Ultrasound of the Phalanges in Pediatric Patients Treated with Anticonvulsant Drugs

    Directory of Open Access Journals (Sweden)

    Vicente Vera

    2015-12-01

    Full Text Available We aimed to investigate and compare the effects of chronic antiepileptic therapy on bone health in pediatric patients using quantitative ultrasound of the phalanges (QUS and controlling for potential confounding factors, particularly nutrient intake. The amplitude-dependent speed of sound (Ad-SoS was measured in 33 epileptic children and 32 healthy children aged 6.5 ± 3.1 and 6.3 ± 1.1 (mean ± SD years, respectively. There were no significant differences in the demographics such as age, weight and height between epileptic children and the control group children. None of the children in the epileptic or the treatment group were found to have a vitamin D deficiency. There were no significant differences in laboratory tests between groups. Lower QUS figures were found in the epileptic children (p = 0.001. After further adjustment for potential confounders such age, height, weight, calcium intake, vitamin D intake, physical activity and sex, the differences remained significant (p < 0.001. After further classification of the participants based on the tertile of calcium intake, no significant differences were found between patients and healthy controls in the greatest tertile of calcium intake (p = 0.217. We conclude that anticonvulsant therapy using valproate may lead to low bone mass in children and that an adequate intake of calcium might counteract such deleterious effects.

  3. Greater Calcium Intake is Associated with Better Bone Health Measured by Quantitative Ultrasound of the Phalanges in Pediatric Patients Treated with Anticonvulsant Drugs.

    Science.gov (United States)

    Vera, Vicente; Moran, Jose M; Barros, Patricia; Canal-Macias, Maria L; Guerrero-Bonmatty, Rafael; Costa-Fernandez, Carmen; Lavado-Garcia, Jesus M; Roncero-Martin, Raul; Pedrera-Zamorano, Juan D

    2015-12-01

    We aimed to investigate and compare the effects of chronic antiepileptic therapy on bone health in pediatric patients using quantitative ultrasound of the phalanges (QUS) and controlling for potential confounding factors, particularly nutrient intake. The amplitude-dependent speed of sound (Ad-SoS) was measured in 33 epileptic children and 32 healthy children aged 6.5 ± 3.1 and 6.3 ± 1.1 (mean ± SD) years, respectively. There were no significant differences in the demographics such as age, weight and height between epileptic children and the control group children. None of the children in the epileptic or the treatment group were found to have a vitamin D deficiency. There were no significant differences in laboratory tests between groups. Lower QUS figures were found in the epileptic children (p = 0.001). After further adjustment for potential confounders such age, height, weight, calcium intake, vitamin D intake, physical activity and sex, the differences remained significant (p anticonvulsant therapy using valproate may lead to low bone mass in children and that an adequate intake of calcium might counteract such deleterious effects.

  4. Quantitative ultrasound imaging detects degenerative changes in articular cartilage surface and subchondral bone

    Science.gov (United States)

    Saarakkala, Simo; Laasanen, Mikko S.; Jurvelin, Jukka S.; Töyräs, Juha

    2006-10-01

    Previous studies have suggested that quantitative ultrasound imaging could sensitively diagnose degeneration of the articular surface and changes in the subchondral bone during the development of osteoarthrosis (OA). We have recently introduced a new parameter, ultrasound roughness index (URI), for the quantification of cartilage surface roughness, and successfully tested it with normal and experimentally degraded articular surfaces. In this in vitro study, the applicability of URI was tested in bovine cartilage samples with spontaneously developed tissue degeneration. Simultaneously, we studied the sensitivity of quantitative ultrasound imaging to detect degenerative changes in the cartilage-bone interface. For reference, histological degenerative grade of the cartilage samples was determined. Mechanical reference measurements were also conducted. Cartilage surface roughness (URI) was significantly (p < 0.05) higher in histologically degenerated samples with inferior mechanical properties. Ultrasound reflection at the cartilage-bone interface was also significantly (p < 0.05) increased in degenerated samples. Furthermore, it was quantitatively confirmed that ultrasound attenuation in the overlying cartilage significantly affects the measured ultrasound reflection values from the cartilage-bone interface. To conclude, the combined ultrasound measurement of the cartilage surface roughness and ultrasound reflection at the cartilage-bone interface complement each other, and may together enable more sensitive and quantitative diagnosis of early OA or follow up after surgical cartilage repair.

  5. Quantitative ultrasound imaging detects degenerative changes in articular cartilage surface and subchondral bone

    Energy Technology Data Exchange (ETDEWEB)

    Saarakkala, Simo [Department of Nuclear Medicine, Etelae-Savo Hospital District, Mikkeli Central Hospital, Porrassalmenkatu 35-37, 50100 Mikkeli (Finland); Laasanen, Mikko S [Information Technology R and D Unit, Engineering Kuopio, Savonia Polytechnic, POB 1188, FIN-70211 Kuopio (Finland); Jurvelin, Jukka S [Department of Physics, University of Kuopio, POB 1627, FIN-70211 Kuopio (Finland); Toeyraes, Juha [Department of Clinical Neurophysiology, Kuopio University Hospital and University of Kuopio, POB 1777, FIN-70211 Kuopio (Finland)

    2006-10-21

    Previous studies have suggested that quantitative ultrasound imaging could sensitively diagnose degeneration of the articular surface and changes in the subchondral bone during the development of osteoarthrosis (OA). We have recently introduced a new parameter, ultrasound roughness index (URI), for the quantification of cartilage surface roughness, and successfully tested it with normal and experimentally degraded articular surfaces. In this in vitro study, the applicability of URI was tested in bovine cartilage samples with spontaneously developed tissue degeneration. Simultaneously, we studied the sensitivity of quantitative ultrasound imaging to detect degenerative changes in the cartilage-bone interface. For reference, histological degenerative grade of the cartilage samples was determined. Mechanical reference measurements were also conducted. Cartilage surface roughness (URI) was significantly (p < 0.05) higher in histologically degenerated samples with inferior mechanical properties. Ultrasound reflection at the cartilage-bone interface was also significantly (p < 0.05) increased in degenerated samples. Furthermore, it was quantitatively confirmed that ultrasound attenuation in the overlying cartilage significantly affects the measured ultrasound reflection values from the cartilage-bone interface. To conclude, the combined ultrasound measurement of the cartilage surface roughness and ultrasound reflection at the cartilage-bone interface complement each other, and may together enable more sensitive and quantitative diagnosis of early OA or follow up after surgical cartilage repair.

  6. Quantitative ultrasound of denervated hand muscles.

    Science.gov (United States)

    Simon, Neil G; Ralph, Jeffrey W; Lomen-Hoerth, Catherine; Poncelet, Ann N; Vucic, Steve; Kiernan, Matthew C; Kliot, Michel

    2015-08-01

    Presentations to the neuromuscular clinic commonly involve hand muscle denervation, but few studies have evaluated hand muscle ultrasound. Ultrasound studies of abductor pollicis brevis, first dorsal interosseous, and abductor digit minimi were prospectively performed in a cohort of 34 patients (77 muscles) with electromyography (EMG)-confirmed denervation, compared with 58 healthy control subjects. In control subjects, muscle thickness was highly reproducible [intraclass correlation coefficient (ICC) = 0.88-0.98], and echogenicity was moderately reproducible (ICC = 0.542-0.686). Age, gender, and body mass index influenced muscle thickness and echogenicity. Ultrasound changes in denervated muscles correlated with the severity of EMG abnormalities. A z-score cutoff of 0 identified denervated muscles with a sensitivity of 100% and 89% for echogenicity and muscle thickness, respectively. Hand muscle ultrasound provides a noninvasive method to quantify muscle denervation and may be useful as a screening tool before EMG studies. © 2014 Wiley Periodicals, Inc.

  7. Gradient-Based Quantitative Image Reconstruction in Ultrasound-Modulated Optical Tomography: First Harmonic Measurement Type in a Linearised Diffusion Formulation.

    Science.gov (United States)

    Powell, Samuel; Arridge, Simon R; Leung, Terence S

    2016-02-01

    Ultrasound-modulated optical tomography is an emerging biomedical imaging modality which uses the spatially localised acoustically-driven modulation of coherent light as a probe of the structure and optical properties of biological tissues. In this work we begin by providing an overview of forward modelling methods, before deriving a linearised diffusion-style model which calculates the first-harmonic modulated flux measured on the boundary of a given domain. We derive and examine the correlation measurement density functions of the model which describe the sensitivity of the modality to perturbations in the optical parameters of interest. Finally, we employ said functions in the development of an adjoint-assisted gradient based image reconstruction method, which ameliorates the computational burden and memory requirements of a traditional Newton-based optimisation approach. We validate our work by performing reconstructions of optical absorption and scattering in two- and three-dimensions using simulated measurements with 1% proportional Gaussian noise, and demonstrate the successful recovery of the parameters to within ±5% of their true values when the resolution of the ultrasound raster probing the domain is sufficient to delineate perturbing inclusions.

  8. Gradient-based quantitative reconstruction of optical absorption and scattering coefficients in ultrasound-modulated optical tomography: first harmonic measurement type

    CERN Document Server

    Powell, Samuel; Leung, Terence S

    2014-01-01

    Ultrasound-modulated optical tomography is an emerging biomedical imaging modality which uses the spatially localised acoustically-driven modulation of coherent light as a probe of the structure and optical properties of biological tissues. In this work we pose the inverse problem of simultaneously recovering the optical absorption and scattering coefficients in a given domain from measurement of the power-spectral density of the optical field modulated to the acoustic frequency. As part of this exposition we provide an overview of forward modelling techniques, and derive an efficient linearised diffusion-style model. To ameliorate the computational burden and memory requirements of a traditional Newton-based optimisation approach, we develop an adjoint-assisted gradient based method. We validate our reconstruction in two- and three-dimensions using simulated measurements with 1% proportional Gaussian noise, and demonstrate the successful recovery of the parameters to within +/-5% of their true values when th...

  9. Characterization and differentiation of three solid tumors using quantitative ultrasound

    Science.gov (United States)

    Oelze, Michael L.; O'Brien, William D.; Zachary, James F.

    2004-05-01

    Three kinds of solid tumors were acquired and scanned in vivo ultrasonically. The first tumor series (fibroadenoma) was acquired from tumors that had spontaneously developed in rats. The second tumor series was acquired by culturing a carcinoma cell line (4T1-MMT) in culture media and injecting the cells into Balb/c mice. The third tumor was acquired by transplanting a soft-tissue sarcoma cell line (EHS) into C57BL mice. The tumors were allowed to grow to 1 cm in size and then scanned ultrasonically. The scatterer properties of average scatterer diameter and acoustic concentration were estimated using a Gaussian form factor from the backscattered ultrasound measured from the tumors. Parametric images of the tumors were constructed utilizing estimated scatterer properties for regions of interest inside the tumors. The parametric images showed distinct differences between the various tumor types. Quantitatively, the tumors could be distinguished through feature analysis plots of average scatterer size versus acoustic concentration. Comparison with photomicrographs of the tumors showed structures similar in size to the ultrasound estimates. [Work supported by NIH Grant F32 CA96419 to MLO and by the University of Illinois Research Board.

  10. Quantitative ultrasound tissue characterization in shoulder and thigh muscles – a new approach

    DEFF Research Database (Denmark)

    Nielsen, P.K.; Jensen, B.R.; Darvann, Tron Andre

    2006-01-01

    Background: The echogenicity patterns of ultrasound scans contain information of tissue composition in muscles. The aim was: ( 1) to develop a quantitative ultrasound image analysis to characterize tissue composition in terms of intensity and structure of the ultrasound images, and ( 2) to use...... the method for characterization of ultrasound images of the supraspinatus muscle, and the vastus lateralis muscle. Methods: Computerized texture analyses employing first-order and higher-order grey-scale statistics were developed to objectively characterize ultrasound images of m. supraspinatus and m. vastus...... lateralis from 9 healthy participants. Results: The mean grey-scale intensity was higher in the vastus lateralis muscle ( p muscle ( average value of middle measuring site 51.4 compared to 35.0). Furthermore, the number of spatially connected and homogeneous regions ( blobs...

  11. A Temporal View of Soft Tissue Quantitative Ultrasound

    Science.gov (United States)

    O'Brien, William D.

    The objective of soft tissue quantitative ultrasound (QUS) is to improve diagnostic ultrasound imaging capabilities via quantitative outcomes. Over the past three or so decades, there have been an increasing number of QUS successes. A temporal view moves us back in history almost six decades when techniques and theoretical developments were in their earliest stages that impacted modern QUS successes. The earliest theoretical developments and techniques some six decades ago can be attributed to Lev Chernov, Philip Morse, Herman Feshbach, Uno Ingard, John Wild and Jack Reid. Later, Floyd Dunn developed important views as to how connective tissue affected the interaction between ultrasound and soft tissue. Then, as the theory of wave propagation in soft tissues with random inhomogeneities was extended and applied by Fred Lizzi, Jim Zagzebski and Mike Insana (and their colleagues), contemporary QUS successes started to emerge.

  12. Relation between qualitative and quantitative 3-dimensional ultrasound and ki-67 expression in breast cancer.

    Science.gov (United States)

    Wang, Xiao-Yan; Zhang, Bing; He, Yan; Ning, Bing; Nong, Mei-Fen; Wei, Hai-Ming; Huang, Xiang-Hong

    2015-01-01

    To investigate the relation between quantitative blood flow parameters on 3-dimensional (3D) color histogram, 3D ultrasound characteristics and Ki-67 expression in breast cancer. Three-dimensional ultrasound characteristics and histological classifications of 76 breast tumors in 75 confirmed cases were analyzed. Relations of tumor volume (V), vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) on 3D color histogram to Ki-67 expression were studied by statistical methods. VI and VFI measurements of tumors in positive Ki-67 expression group were obviously increased compared with the negative expression group (P0.05). Cases showing positive expression of Ki-67 were more likely to have lymph node metastases (P0.05). Qualitative and quantitative 3D ultrasound characteristics correlated with positive expression of Ki-67 in breast cancer. Quantitative analysis with 3D color histogram more accurately evaluates blood supply of breast tumors, providing references for predicting biological behaviors and prognosis of breast cancer.

  13. Quantitative ultrasound characterization of tumor cell death: ultrasound-stimulated microbubbles for radiation enhancement.

    Directory of Open Access Journals (Sweden)

    Hyunjung Christina Kim

    Full Text Available The aim of this study was to assess the efficacy of quantitative ultrasound imaging in characterizing cancer cell death caused by enhanced radiation treatments. This investigation focused on developing this ultrasound modality as an imaging-based non-invasive method that can be used to monitor therapeutic ultrasound and radiation effects. High-frequency (25 MHz ultrasound was used to image tumor responses caused by ultrasound-stimulated microbubbles in combination with radiation. Human prostate xenografts grown in severe combined immunodeficiency (SCID mice were treated using 8, 80, or 1000 µL/kg of microbubbles stimulated with ultrasound at 250, 570, or 750 kPa, and exposed to 0, 2, or 8 Gy of radiation. Tumors were imaged prior to treatment and 24 hours after treatment. Spectral analysis of images acquired from treated tumors revealed overall increases in ultrasound backscatter intensity and the spectral intercept parameter. The increase in backscatter intensity compared to the control ranged from 1.9±1.6 dB for the clinical imaging dose of microbubbles (8 µL/kg, 250 kPa, 2 Gy to 7.0±4.1 dB for the most extreme treatment condition (1000 µL/kg, 750 kPa, 8 Gy. In parallel, in situ end-labelling (ISEL staining, ceramide, and cyclophilin A staining demonstrated increases in cell death due to DNA fragmentation, ceramide-mediated apoptosis, and release of cyclophilin A as a result of cell membrane permeabilization, respectively. Quantitative ultrasound results indicated changes that paralleled increases in cell death observed from histology analyses supporting its use for non-invasive monitoring of cancer treatment outcomes.

  14. Quantitative ultrasound for the monitoring of novel microbubble and ultrasound radiosensitization.

    Science.gov (United States)

    Lee, Justin; Karshafian, Raffi; Papanicolau, Naum; Giles, Anoja; Kolios, Michael C; Czarnota, Gregory J

    2012-07-01

    There is a need for cancer imaging to provide "real-time" information about the metabolic and cellular responses of tumours. Quantitative ultrasound techniques have recently been demonstrated to be a potential method of assessing tumour response at the cellular level. Anti-cancer treatments administered to xenograft-bearing mice consisted of radiotherapy and a novel antivascular therapy utilizing encapsulated microbubble agents in the presence of ultrasound. Radiation dose and microbubble concentrations were varied and the treatment modalities were given in combination to assess the possible enhancement of tumour cell death. Quantitative methods were used to non-invasively assess responses. Results demonstrated statistically significant changes in backscatter parameters (midband fit, spectral intercept) in tumours treated with high doses of radiotherapy or a high concentration of microbubbles. Combined treatments demonstrated further increases in ultrasound parameters. Histopathologic assessment was used and tumour cell death was found to correlate with increases in ultrasound parameters. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  15. Spinal curvature measurement by tracked ultrasound snapshots.

    Science.gov (United States)

    Ungi, Tamas; King, Franklin; Kempston, Michael; Keri, Zsuzsanna; Lasso, Andras; Mousavi, Parvin; Rudan, John; Borschneck, Daniel P; Fichtinger, Gabor

    2014-02-01

    Monitoring spinal curvature in adolescent kyphoscoliosis requires regular radiographic examinations; however, the applied ionizing radiation increases the risk of cancer. Ultrasound imaging is favored over radiography because it does not emit ionizing radiation. Therefore, we tested an ultrasound system for spinal curvature measurement, with the help of spatial tracking of the ultrasound transducer. Tracked ultrasound was used to localize vertebral transverse processes as landmarks along the spine to measure curvature angles. The method was tested in two scoliotic spine models by localizing the same landmarks using both ultrasound and radiographic imaging and comparing the angles obtained. A close correlation was found between tracked ultrasound and radiographic curvature measurements. Differences between results of the two methods were 1.27 ± 0.84° (average ± SD) in an adult model and 0.96 ± 0.87° in a pediatric model. Our results suggest that tracked ultrasound may become a more tolerable and more accessible alternative to radiographic spine monitoring in adolescent kyphoscoliosis.

  16. Measurement of tissue viscoelasticity with ultrasound

    Science.gov (United States)

    Greenleaf, J. F.; Alizad, A.

    2017-02-01

    Tissue properties such as elasticity and viscosity have been shown to be related to such tissue conditions as contraction, edema, fibrosis, and fat content among others. Magnetic Resonance Elastography has shown outstanding ability to measure the elasticity and in some cases the viscosity of tissues, especially in the liver, providing the ability to stage fibrotic liver disease similarly to biopsy. We discuss ultrasound methods of measuring elasticity and viscosity in tissues. Many of these methods are becoming widely available in the extant ultrasound machines distributed throughout the world. Some of the methods to be discussed are in the developmental stage. The advantages of the ultrasound methods are that the imaging instruments are widely available and that many of the viscoelastic measurements can be made during a short addition to the normal ultrasound examination time. In addition, the measurements can be made by ultrasound repetitively and quickly allowing evaluation of dynamic physiologic function in circumstances such as muscle contraction or artery relaxation. Measurement of viscoelastic tissue mechanical properties will become a consistent part of clinical ultrasound examinations in our opinion.

  17. Ultrasound introscopic image quantitative characteristics for medical diagnosis

    Science.gov (United States)

    Novoselets, Mikhail K.; Sarkisov, Sergey S.; Gridko, Alexander N.; Tcheban, Anatoliy K.

    1993-09-01

    The results on computer aided extraction of quantitative characteristics (QC) of ultrasound introscopic images for medical diagnosis are presented. Thyroid gland (TG) images of Chernobil Accident sufferers are considered. It is shown that TG diseases can be associated with some values of selected QCs of random echo distribution in the image. The possibility of these QCs usage for TG diseases recognition in accordance with calculated values is analyzed. The role of speckle noise elimination in the solution of the problem on TG diagnosis is considered too.

  18. Breast tumour visualization using 3D quantitative ultrasound methods

    Science.gov (United States)

    Gangeh, Mehrdad J.; Raheem, Abdul; Tadayyon, Hadi; Liu, Simon; Hadizad, Farnoosh; Czarnota, Gregory J.

    2016-04-01

    Breast cancer is one of the most common cancer types accounting for 29% of all cancer cases. Early detection and treatment has a crucial impact on improving the survival of affected patients. Ultrasound (US) is non-ionizing, portable, inexpensive, and real-time imaging modality for screening and quantifying breast cancer. Due to these attractive attributes, the last decade has witnessed many studies on using quantitative ultrasound (QUS) methods in tissue characterization. However, these studies have mainly been limited to 2-D QUS methods using hand-held US (HHUS) scanners. With the availability of automated breast ultrasound (ABUS) technology, this study is the first to develop 3-D QUS methods for the ABUS visualization of breast tumours. Using an ABUS system, unlike the manual 2-D HHUS device, the whole patient's breast was scanned in an automated manner. The acquired frames were subsequently examined and a region of interest (ROI) was selected in each frame where tumour was identified. Standard 2-D QUS methods were used to compute spectral and backscatter coefficient (BSC) parametric maps on the selected ROIs. Next, the computed 2-D parameters were mapped to a Cartesian 3-D space, interpolated, and rendered to provide a transparent color-coded visualization of the entire breast tumour. Such 3-D visualization can potentially be used for further analysis of the breast tumours in terms of their size and extension. Moreover, the 3-D volumetric scans can be used for tissue characterization and the categorization of breast tumours as benign or malignant by quantifying the computed parametric maps over the whole tumour volume.

  19. Objective breast tissue image classification using Quantitative Transmission ultrasound tomography

    Science.gov (United States)

    Malik, Bilal; Klock, John; Wiskin, James; Lenox, Mark

    2016-12-01

    Quantitative Transmission Ultrasound (QT) is a powerful and emerging imaging paradigm which has the potential to perform true three-dimensional image reconstruction of biological tissue. Breast imaging is an important application of QT and allows non-invasive, non-ionizing imaging of whole breasts in vivo. Here, we report the first demonstration of breast tissue image classification in QT imaging. We systematically assess the ability of the QT images’ features to differentiate between normal breast tissue types. The three QT features were used in Support Vector Machines (SVM) classifiers, and classification of breast tissue as either skin, fat, glands, ducts or connective tissue was demonstrated with an overall accuracy of greater than 90%. Finally, the classifier was validated on whole breast image volumes to provide a color-coded breast tissue volume. This study serves as a first step towards a computer-aided detection/diagnosis platform for QT.

  20. Quantitative ultrasound and photoacoustic imaging for the assessment of vascular parameters

    CERN Document Server

    Meiburger, Kristen M

    2017-01-01

    This book describes the development of quantitative techniques for ultrasound and photoacoustic imaging in the assessment of architectural and vascular parameters. It presents morphological vascular research based on the development of quantitative imaging techniques for the use of clinical B-mode ultrasound images, and preclinical architectural vascular investigations on quantitative imaging techniques for ultrasounds and photoacoustics. The book is divided into two main parts, the first of which focuses on the development and validation of quantitative techniques for the assessment of vascular morphological parameters that can be extracted from B-mode ultrasound longitudinal images of the common carotid artery. In turn, the second part highlights quantitative imaging techniques for assessing the architectural parameters of vasculature that can be extracted from 3D volumes, using both contrast-enhanced ultrasound (CEUS) imaging and photoacoustic imaging without the addition of any contrast agent. Sharing and...

  1. Changes in quantitative ultrasound in preterm and term infants during the first year of life

    Energy Technology Data Exchange (ETDEWEB)

    Tansug, Nermin, E-mail: ntansug@hotmail.com [Celal Bayar University, Faculty of Medicine, Department of Pediatrics, 45020 Manisa (Turkey); Yildirim, Sule Aslan, E-mail: sulesln@yahoo.com [Celal Bayar University, Faculty of Medicine, Department of Pediatrics, 45020 Manisa (Turkey); Canda, Ebru, E-mail: ebruerbass@hotmail.com [Celal Bayar University, Faculty of Medicine, Department of Pediatrics, 45020 Manisa (Turkey); Ozalp, Deniz, E-mail: bluexxdeniz@hotmail.com [Celal Bayar University, Faculty of Medicine, Department of Pediatrics, 45020 Manisa (Turkey); Yilmaz, Ozge, E-mail: oyilmaz_76@hotmail.com [Celal Bayar University, Faculty of Medicine, Department of Pediatrics, 45020 Manisa (Turkey); Taneli, Fatma, E-mail: fatma.taneli@bayar.edu.tr [Celal Bayar University, Faculty of Medicine, Department of Biochemistry, 45020 Manisa (Turkey); Ersoy, Betuel, E-mail: betul_e@hotmail.com [Celal Bayar University, Faculty of Medicine, Department of Pediatrics, 45020 Manisa (Turkey)

    2011-09-15

    Since most of in utero bone mass accretion occurs during the third trimester and postnatal need for bone nutrients is increased, preterm infants have an increased risk of low bone mass. Early identification of the risk is of crucial importance. Quantitative ultrasound, which is a relatively inexpensive, portable, noninvasive, and radiation-free method, gives information about bone density, cortical thickness, elasticity and microarchitecture. The aim of this study was to obtain quantitative ultrasound measurements of tibial speed of sound of preterm and term infants and to assess clinical factors associated with these measurements during the first year of life. Seventy-eight preterm and 48 term infants were enrolled in this study. Measurements were made on the 10th day of life in both groups, and were repeated on the 2nd, 6th and 12th months for preterm infants and on the12th month for the term infants. Speed of sound on preterm infants was significantly decreased on the 2nd month but significantly increased on the 12th month (P = 0.00). Comparing speed of sound of term and preterm infants, 10th day measurements were significantly different (P = 0.00), but there was not any significant difference between the 12th month values (P = 0.26). There was not any relation between biochemical parameters and speed of sound. The technique has potential clinical value for assessment of bone status. Further studies with long term follow up are needed to evaluate the value of quantitative ultrasound with other bone markers to predict the risk of fracture.

  2. Quantitative ultrasound at the hand phalanges in patients with bisphosphonate-related osteonecrosis of the jaws

    Directory of Open Access Journals (Sweden)

    Ana Carolina Fragoso MOTTA

    2015-01-01

    Full Text Available Patients with bisphosphonate-related osteonecrosis of the jaws (BRONJ who received intravenous or oral bisphosphonates (BP were selected for determination of their bone microarchitecture as a risk predictor of BRONJ development. The diagnosis of BRONJ was made based on clinical and radiographic findings. The control group consisted of healthy patients. All patients underwent quantitative and qualitative ultrasound measurements of bone at the hand phalanges carried out using the DBM Sonic BP. Ultrasound bone profile index (UBPI, amplitude-dependent speed of sound (AD-SoS, bone biophysics profile (BBP, and bone transmission time (BTT were measured. The BRONJ group consisted of 17 patients (62 ± 4.24; range: 45-82; 10 (58.8% were male and seven (41.1% were female, of whom 11 (64.7% suffered from multiple myeloma, three (17.6% from osteoporosis, one (5.8% from prostate cancer, one (5.8% from kidney cancer, and one (5.8% from leukemia. Fourteen (82.3% of them received intravenous BP whereas three (17.6% received oral BP. Nine (9/17; 52.9% patients developed bone exposure: two in the maxilla and seven in the mandible. Regarding quantitative parameters, Ad-SoS was low in the BRONJ group, but not significant. The UBPI score was significantly reduced in BRONJ patients with exposed bone when compared to controls (0.47 ± 0.12 vs. 0.70 ± 0.15; p = 0.004. The present study demonstrated that quantitative ultrasound was able to show bone microarchitecture alterations in BRONJ patients, and suggests that these analyses may be an important tool for early detection of bone degeneration associated with BRONJ.

  3. Quantitative ultrasound imaging for monitoring in situ high-intensity focused ultrasound exposure.

    Science.gov (United States)

    Ghoshal, Goutam; Kemmerer, Jeremy P; Karunakaran, Chandra; Abuhabsah, Rami; Miller, Rita J; Sarwate, Sandhya; Oelze, Michael L

    2014-10-01

    Quantitative ultrasound (QUS) imaging is hypothesized to map temperature elevations induced in tissue with high spatial and temporal resolution. To test this hypothesis, QUS techniques were examined to monitor high-intensity focused ultrasound (HIFU) exposure of tissue. In situ experiments were conducted on mammary adenocarcinoma tumors grown in rats and lesions were formed using a HIFU system. A thermocouple was inserted into the tumor to provide estimates of temperature at one location. Backscattered time-domain waveforms from the tissue during exposure were recorded using a clinical ultrasonic imaging system. Backscatter coefficients were estimated using a reference phantom technique. Two parameters were estimated from the backscatter coefficient (effective scatterer diameter (ESD) and effective acoustic concentration (EAC). The changes in the average parameters in the regions corresponding to the HIFU focus over time were correlated to the temperature readings from the thermocouple. The changes in the EAC parameter were consistently correlated to temperature during both heating and cooling of the tumors. The changes in the ESD did not have a consistent trend with temperature. The mean ESD and EAC before exposure were 120 ± 16 μm and 32 ± 3 dB/cm3, respectively, and changed to 144 ± 9 μm and 51 ± 7 dB/cm3, respectively, just before the last HIFU pulse was delivered to the tissue. After the tissue cooled down to 37 °C, the mean ESD and EAC were 126 ± 8 μm and 35 ± 4 dB/cm3, respectively. Peak temperature in the range of 50-60 °C was recorded by a thermocouple placed just behind the tumor. These results suggest that QUS techniques have the potential to be used for non-invasive monitoring of HIFU exposure.

  4. Normative data for multisite quantitative ultrasound: the Canadian Multicenter Osteoporosis Study.

    Science.gov (United States)

    Olszynski, Wojciech P; Brown, Jacques P; Adachi, Jonathan D; Hanley, David A; Ioannidis, George; Davison, K Shawn

    2014-01-01

    Multisite quantitative ultrasound (mQUS) machines are attractive tools for assessing fragility fracture risk as they are often portable, comparatively inexpensive, require little training for their use, and emit no ionizing radiation. The primary objective of this investigation was to generate an mQUS normative database of speed of sound (SOS, in m/s) measures from a large sample of randomly selected community-based individuals. mQUS (BeamMed Omnisense MultiSite Quantitative Ultrasound 7000 S) measurements were obtained and assessed at the distal radius, tibia, and phalanx. All analyses were made separately for men and women and for each anatomical site. Scatterplots (SOS vs age) identified 30-39 yr of age as periods of both maximal SOS and of relative stability for all 3 sites over the age span investigated (30-96 yr of age; 2948 women and 1176 men) and, thus, was used as the "reference" population. For cross-sectional comparison of trends over aging, a number of age groupings were created: 30-39, 40-49, 50-59, 60-69, 70-79, and 80+ yr. In general, there were decreases in SOS over increasing age groupings. The normative data generated can be used to compare a given patient's mQUS measurement with reference to a young, healthy population, assigning them a gender-appropriate T-score. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  5. Quantitative ultrasound molecular imaging by modeling the binding kinetics of targeted contrast agent.

    Science.gov (United States)

    Turco, Simona; Tardy, Isabelle; Frinking, Peter; Wijkstra, Hessel; Mischi, Massimo

    2017-03-21

    Ultrasound molecular imaging (USMI) is an emerging technique to monitor diseases at the molecular level by the use of novel targeted ultrasound contrast agents (tUCA). These consist of microbubbles functionalized with targeting ligands with high-affinity for molecular markers of specific disease processes, such as cancer-related angiogenesis. Among the molecular markers of angiogenesis, the vascular endothelial growth factor receptor 2 (VEGFR2) is recognized to play a major role. In response, the clinical-grade tUCA BR55 was recently developed, consisting of VEGFR2-targeting microbubbles which can flow through the entire circulation and accumulate where VEGFR2 is over-expressed, thus causing selective enhancement in areas of active angiogenesis. Discrimination between bound and free microbubbles is crucial to assess cancer angiogenesis. Currently, this is done non-quantitatively by looking at the late enhancement, about 10 min after injection, or by calculation of the differential targeted enhancement, requiring the application of a high-pressure ultrasound (US) burst to destroy all the microbubbles in the acoustic field and isolate the signal coming only from bound microbubbles. In this work, we propose a novel method based on mathematical modeling of the binding kinetics during the tUCA first pass, thus reducing the acquisition time and with no need for a destructive US burst. Fitting time-intensity curves measured with USMI by the proposed model enables the assessment of cancer angiogenesis at both the vascular and molecular levels. This is achieved by estimation of quantitative parameters related to the microvascular architecture and microbubble binding. The proposed method was tested in 11 prostate-tumor bearing rats by performing USMI after injection of BR55, and showed good agreement with current USMI methods. The novel information provided by the proposed method, possibly combined with the current non-quantitative methods, may bring deeper insight into

  6. Quantitative ultrasound molecular imaging by modeling the binding kinetics of targeted contrast agent

    Science.gov (United States)

    Turco, Simona; Tardy, Isabelle; Frinking, Peter; Wijkstra, Hessel; Mischi, Massimo

    2017-03-01

    Ultrasound molecular imaging (USMI) is an emerging technique to monitor diseases at the molecular level by the use of novel targeted ultrasound contrast agents (tUCA). These consist of microbubbles functionalized with targeting ligands with high-affinity for molecular markers of specific disease processes, such as cancer-related angiogenesis. Among the molecular markers of angiogenesis, the vascular endothelial growth factor receptor 2 (VEGFR2) is recognized to play a major role. In response, the clinical-grade tUCA BR55 was recently developed, consisting of VEGFR2-targeting microbubbles which can flow through the entire circulation and accumulate where VEGFR2 is over-expressed, thus causing selective enhancement in areas of active angiogenesis. Discrimination between bound and free microbubbles is crucial to assess cancer angiogenesis. Currently, this is done non-quantitatively by looking at the late enhancement, about 10 min after injection, or by calculation of the differential targeted enhancement, requiring the application of a high-pressure ultrasound (US) burst to destroy all the microbubbles in the acoustic field and isolate the signal coming only from bound microbubbles. In this work, we propose a novel method based on mathematical modeling of the binding kinetics during the tUCA first pass, thus reducing the acquisition time and with no need for a destructive US burst. Fitting time-intensity curves measured with USMI by the proposed model enables the assessment of cancer angiogenesis at both the vascular and molecular levels. This is achieved by estimation of quantitative parameters related to the microvascular architecture and microbubble binding. The proposed method was tested in 11 prostate-tumor bearing rats by performing USMI after injection of BR55, and showed good agreement with current USMI methods. The novel information provided by the proposed method, possibly combined with the current non-quantitative methods, may bring deeper insight into

  7. Study on the use of quantitative ultrasound evaluation of diabetic neuropathy in the rat sciatic nerve.

    Science.gov (United States)

    Huang, Yunxia; Hu, Bing; Zhu, Jiaan

    2016-12-01

    Ultrasound is an effective tool for peripheral disease with direct imaging of morphological and echogenic changes, but it has limitations when applied to evaluation of diabetic peripheral neuropathy. The aim of this study was to assess the role of ultrasound to quantitatively evaluate diabetic peripheral neuropathy in rat sciatic nerve. In our experiments, ultrasound imaging and electrophysiological examination testing of sciatic nerves were monitored in diabetic and control rats at the period of 1st and 4th month of hyperglycemia. Cross sectional area, intraneural echo intensity, inner diameter, motor nerve conduction velocity, and histological changes were measured and compared between diabetic and control groups. Intraneural hyperechoic were observed in the diabetic rats, and the echo intensity of the sciatic nerve was increased in diabetic rats rather than control lean rats at 4th month of hyperglycemia (p diabetic peripheral neuropathy. We conclude that the echo intensity is potentially useful in detecting diabetic peripheral neuropathy, which can pave the way for more accurate and efficient diagnosis in clinical study.

  8. Quantitative evaluation of hidden defects in cast iron components using ultrasound activated lock-in vibrothermography.

    Science.gov (United States)

    Montanini, R; Freni, F; Rossi, G L

    2012-09-01

    This paper reports one of the first experimental results on the application of ultrasound activated lock-in vibrothermography for quantitative assessment of buried flaws in complex cast parts. The use of amplitude modulated ultrasonic heat generation allowed selective response of defective areas within the part, as the defect itself is turned into a local thermal wave emitter. Quantitative evaluation of hidden damages was accomplished by estimating independently both the area and the depth extension of the buried flaws, while x-ray 3D computed tomography was used as reference for sizing accuracy assessment. To retrieve flaw's area, a simple yet effective histogram-based phase image segmentation algorithm with automatic pixels classification has been developed. A clear correlation was found between the thermal (phase) signature measured by the infrared camera on the target surface and the actual mean cross-section area of the flaw. Due to the very fast cycle time (casting components.

  9. Quantitative ultrasound bone measurements of different gestational age premature infants at birth in Guangzhou zone%广州地区不同胎龄早产儿出生时骨定量超声值测定

    Institute of Scientific and Technical Information of China (English)

    瞿柳红; 李思涛; 庄桂英; 徐庆活; 杨文欢; 肖昕

    2013-01-01

    目的 测定广州地区不同胎龄早产儿出生时的骨定量超声值,并与高加索白人种早产儿比较,了解广州地区早产儿骨骼发育的状况,评价定量超声技术的实用性.方法 采用以色列Sunlight公司生产的Omnisense定量超声仪,对2010年6月至2012年6月在广州市花都区妇幼保健院出生的不同胎龄的早产儿进行左侧胫骨声波速度(SOS)测量,并与高加索白人种进行比较.结果 广州地区出生的1039例不同胎龄早产儿根据胎龄分为A、B、C、D组(≤30周、30+1 ~32周、32+1~34周和34+1~ 36+6周4组).4组早产儿出生时所测得的SOS值分别为(2892.05±139.17) m/s、(2936.84±137.87) m/s、(2966.65±116.60) m/s和(2988.63±120.74) m/s,SOS值随胎龄增加而增加,差别有统计学意义(F=15.758,P=0.000),但各组中男女童之间SOS值无明显差异(F =2.665,P =0.103).广州地区不同胎龄的早产儿出生时SOS值的差距(定义为Z值)与高加索白人种比较差异无统计学意义(P=0.117),男女比较差异亦无统计学意义(F=3.494,P=0.062).结论 早产儿SOS值随早产儿成熟度增加而升高;广州地区的不同胎龄早产儿出生时骨强度与高加索白人种无明显差距;骨定量超声技术可用于临床评价早产儿骨发育情况.%Objective To measure the values of quantitative ultrasound(QUS) of different gestational age preterm infants at birth in Guangzhou area,and compare them with the values of Caucasian preterm infants in order to get insight into the bone development status of preterm infants in Guangzhou area and to evaluate the practicability of QUS.Methods The Omnisense quantitative ultrasound produced by Israel Sunlight company was used to measure the bone speed of sound(SOS) of left tibia of preterm infants born between Jun.2010 and Jun.2012 in Maternity and Children Health Hospital of Huadu District in Guangzhou,and the values of SOS of Caucasian preterm infants was compared.Results There were totally

  10. Quantitative measures for redox signaling.

    Science.gov (United States)

    Pillay, Ché S; Eagling, Beatrice D; Driscoll, Scott R E; Rohwer, Johann M

    2016-07-01

    Redox signaling is now recognized as an important regulatory mechanism for a number of cellular processes including the antioxidant response, phosphokinase signal transduction and redox metabolism. While there has been considerable progress in identifying the cellular machinery involved in redox signaling, quantitative measures of redox signals have been lacking, limiting efforts aimed at understanding and comparing redox signaling under normoxic and pathogenic conditions. Here we have outlined some of the accepted principles for redox signaling, including the description of hydrogen peroxide as a signaling molecule and the role of kinetics in conferring specificity to these signaling events. Based on these principles, we then develop a working definition for redox signaling and review a number of quantitative methods that have been employed to describe signaling in other systems. Using computational modeling and published data, we show how time- and concentration- dependent analyses, in particular, could be used to quantitatively describe redox signaling and therefore provide important insights into the functional organization of redox networks. Finally, we consider some of the key challenges with implementing these methods. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Comparison of sound speed measurements on two different ultrasound tomography devices

    OpenAIRE

    Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Sherman, Mark; Gierach, Gretchen; Malyarenko, Antonina

    2014-01-01

    Ultrasound tomography (UST) employs sound waves to produce three-dimensional images of breast tissue and precisely measures the sound speed of breast tissue composition. High breast density is a strong breast cancer risk factor and sound speed is directly proportional to breast density. UST provides a quantitative measure of breast density based on three-dimensional imaging without compression, thereby overcoming the shortcomings of many other imaging modalities. The quantitative nature of th...

  12. Awareness of osteoporosis and its relationship with calcaneus quantitative ultrasound in a large Chinese community population

    Directory of Open Access Journals (Sweden)

    Xu J

    2013-06-01

    Full Text Available Jingjing Xu,1,* Min Sun,1,* Zhixiao Wang,1,* Qi Fu,1 Mengdei Cao,1 Zhenxin Zhu,1 Chuchen Meng,1 Yan Yan,1 Jia Mao,1 Hua Tao,1 Xiaoping Huang,1 Zheng Lin,2 Tao Yang,1 Wei He1 1Department of Endocrinology, 2Department of Nursing, The First Affiliated Hospital of Nanjing Medical University, Nanjing, People's Republic of China *These authors contributed equally to this work Background: The People’s Republic of China has the largest population affected by osteoporosis in the world. However, no population-based survey of osteoporosis awareness in People’s Republic of China has been reported. This study investigated the level of basic awareness of osteoporosis in a large community in People’s Republic of China. The relationship between level of awareness and quantitative ultrasound (US measurements at the calcaneus was also assessed. Methods: A questionnaire was completed by 9983 men and women aged 40 years or older in Nanjing, People’s Republic of China, between June and December 2011. During this time, the study participants underwent quantitative US measurement. Data from 9049 of the subjects were included in the final analysis. Results: The proportion of subjects who were aware of osteoporosis was very low. Only 30.7% had heard of osteoporosis, and only 18.5% had heard of osteoporotic fracture. In total, 52.9% of the subjects drank milk, 16.0% took calcium, 7.1% took vitamin D, and 47.2% were performing regular physical activity. Logistic regression showed that more highly educated older women had significantly better awareness of osteoporosis (P < 0.05. Subjects with a history of a previous osteoporotic fracture also had better awareness (P < 0.05 than subjects without such a history, except for those who drank milk. Similar to previous reports, female sex, old age, a low education level, and a personal history of osteoporotic fracture were significantly associated with a low quantitative US measurement (P < 0.001. Further, drinking milk

  13. Low-frequency quantitative ultrasound imaging of cell death in vivo.

    Science.gov (United States)

    Sadeghi-Naini, Ali; Papanicolau, Naum; Falou, Omar; Tadayyon, Hadi; Lee, Justin; Zubovits, Judit; Sadeghian, Alireza; Karshafian, Raffi; Al-Mahrouki, Azza; Giles, Anoja; Kolios, Michael C; Czarnota, Gregory J

    2013-08-01

    Currently, no clinical imaging modality is used routinely to assess tumor response to cancer therapies within hours to days of the delivery of treatment. Here, the authors demonstrate the efficacy of ultrasound at a clinically relevant frequency to quantitatively detect changes in tumors in response to cancer therapies using preclinical mouse models. Conventional low-frequency and corresponding high-frequency ultrasound (ranging from 4 to 28 MHz) were used along with quantitative spectroscopic and signal envelope statistical analyses on data obtained from xenograft tumors treated with chemotherapy, x-ray radiation, as well as a novel vascular targeting microbubble therapy. Ultrasound-based spectroscopic biomarkers indicated significant changes in cell-death associated parameters in responsive tumors. Specifically changes in the midband fit, spectral slope, and 0-MHz intercept biomarkers were investigated for different types of treatment and demonstrated cell-death related changes. The midband fit and 0-MHz intercept biomarker derived from low-frequency data demonstrated increases ranging approximately from 0 to 6 dBr and 0 to 8 dBr, respectively, depending on treatments administrated. These data paralleled results observed for high-frequency ultrasound data. Statistical analysis of ultrasound signal envelope was performed as an alternative method to obtain histogram-based biomarkers and provided confirmatory results. Histological analysis of tumor specimens indicated up to 61% cell death present in the tumors depending on treatments administered, consistent with quantitative ultrasound findings indicating cell death. Ultrasound-based spectroscopic biomarkers demonstrated a good correlation with histological morphological findings indicative of cell death (r2=0.71, 0.82; p<0.001). In summary, the results provide preclinical evidence, for the first time, that quantitative ultrasound used at a clinically relevant frequency, in addition to high-frequency ultrasound

  14. Low-frequency quantitative ultrasound imaging of cell death in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi-Naini, Ali; Falou, Omar; Czarnota, Gregory J. [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Papanicolau, Naum; Tadayyon, Hadi [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Lee, Justin [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Zubovits, Judit [Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Sadeghian, Alireza [Department of Computer Science, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Karshafian, Raffi [Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Al-Mahrouki, Azza; Giles, Anoja [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Kolios, Michael C. [Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5, Canada and Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)

    2013-08-15

    Purpose: Currently, no clinical imaging modality is used routinely to assess tumor response to cancer therapies within hours to days of the delivery of treatment. Here, the authors demonstrate the efficacy of ultrasound at a clinically relevant frequency to quantitatively detect changes in tumors in response to cancer therapies using preclinical mouse models.Methods: Conventional low-frequency and corresponding high-frequency ultrasound (ranging from 4 to 28 MHz) were used along with quantitative spectroscopic and signal envelope statistical analyses on data obtained from xenograft tumors treated with chemotherapy, x-ray radiation, as well as a novel vascular targeting microbubble therapy.Results: Ultrasound-based spectroscopic biomarkers indicated significant changes in cell-death associated parameters in responsive tumors. Specifically changes in the midband fit, spectral slope, and 0-MHz intercept biomarkers were investigated for different types of treatment and demonstrated cell-death related changes. The midband fit and 0-MHz intercept biomarker derived from low-frequency data demonstrated increases ranging approximately from 0 to 6 dBr and 0 to 8 dBr, respectively, depending on treatments administrated. These data paralleled results observed for high-frequency ultrasound data. Statistical analysis of ultrasound signal envelope was performed as an alternative method to obtain histogram-based biomarkers and provided confirmatory results. Histological analysis of tumor specimens indicated up to 61% cell death present in the tumors depending on treatments administered, consistent with quantitative ultrasound findings indicating cell death. Ultrasound-based spectroscopic biomarkers demonstrated a good correlation with histological morphological findings indicative of cell death (r{sup 2}= 0.71, 0.82; p < 0.001).Conclusions: In summary, the results provide preclinical evidence, for the first time, that quantitative ultrasound used at a clinically relevant frequency

  15. Measurement of a PAGAT gel dosimeter by ultrasound computed tomography

    Science.gov (United States)

    Khoei, S.; Trapp, J. V.; Langton, C. M.

    2013-06-01

    In this work we used a 3D quantitative CT ultrasound imaging system to characterise polymer gel dosimeters. The system comprised of two identical 5 MHz 128 element phased-array ultrasound transducers co-axially aligned and submerged in water as a coupling agent. Rotational and translational movement of the gel dosimeter sample between the transducers were performed using a robotic arm. Ultrasound signals were generated and received using an Olympus Omniscan unit. Dose sensitivity of attenuation and time of flight ultrasonic parameters were assessed using this system.

  16. Quantitative assessment of tumor angiogenesis using real-time motion-compensated contrast-enhanced ultrasound imaging

    Science.gov (United States)

    Pysz, Marybeth A.; Guracar, Ismayil; Foygel, Kira; Tian, Lu; Willmann, Jürgen K.

    2015-01-01

    Purpose To develop and test a real-time motion compensation algorithm for contrast-enhanced ultrasound imaging of tumor angiogenesis on a clinical ultrasound system. Materials and methods The Administrative Institutional Panel on Laboratory Animal Care approved all experiments. A new motion correction algorithm measuring the sum of absolute differences in pixel displacements within a designated tracking box was implemented in a clinical ultrasound machine. In vivo angiogenesis measurements (expressed as percent contrast area) with and without motion compensated maximum intensity persistence (MIP) ultrasound imaging were analyzed in human colon cancer xenografts (n = 64) in mice. Differences in MIP ultrasound imaging signal with and without motion compensation were compared and correlated with displacements in x- and y-directions. The algorithm was tested in an additional twelve colon cancer xenograft-bearing mice with (n = 6) and without (n = 6) anti-vascular therapy (ASA-404). In vivo MIP percent contrast area measurements were quantitatively correlated with ex vivo microvessel density (MVD) analysis. Results MIP percent contrast area was significantly different (P < 0.001) with and without motion compensation. Differences in percent contrast area correlated significantly (P < 0.001) with x- and y-displacements. MIP percent contrast area measurements were more reproducible with motion compensation (ICC = 0.69) than without (ICC = 0.51) on two consecutive ultrasound scans. Following anti-vascular therapy, motion-compensated MIP percent contrast area significantly (P = 0.03) decreased by 39.4 ± 14.6 % compared to non-treated mice and correlated well with ex vivo MVD analysis (Rho = 0.70; P = 0.05). Conclusion Real-time motion-compensated MIP ultrasound imaging allows reliable and accurate quantification and monitoring of angiogenesis in tumors exposed to breathing-induced motion artifacts. PMID:22535383

  17. Ultrasound image velocimetry for rheological measurements

    Science.gov (United States)

    Gurung, A.; Haverkort, J. W.; Drost, S.; Norder, B.; Westerweel, J.; Poelma, C.

    2016-09-01

    Ultrasound image velocimetry (UIV) allows for the non-intrusive measurement of a wide range of flows without the need for optical transparency. In this study, we used UIV to measure the local velocity field of a model drilling fluid that exhibits yield stress flow behavior. The radial velocity profile was used to determine the yield stress and the Herschel-Bulkley model flow index n and the consistency index k. Reference data were obtained using the conventional offline Couette rheometry. A comparison showed reasonable agreement between the two methods. The discrepancy in model parameters could be attributed to inherent differences between the methods, which cannot be captured by the three-parameter model used. Overall, with a whole flow field measurement technique such as UIV, we were able to quantify the complex rheology of a model drilling fluid. These preliminary results show that UIV can be used as a non-intrusive diagnostic for in situ, real-time measurement of complex opaque flow rheology.

  18. In vitro atherosclerotic plaque and calcium quantitation by intravascular ultrasound and electron-beam computed tomography.

    Science.gov (United States)

    Gutfinger, D E; Leung, C Y; Hiro, T; Maheswaran, B; Nakamura, S; Detrano, R; Kang, X; Tang, W; Tobis, J M

    1996-05-01

    The purpose of this investigation was to compare the accuracy of intravascular ultrasound (IVUS) and electron-beam computed tomography (EBCT) in quantitating human atherosclerotic plaque and calcium. In experiment 1, 12 human atherosclerotic arterial segments were obtained at autopsy and imaged by using IVUS and EBCT. The plaque from each arterial segment was dissected and a volume measurement of the dissected plaque was obtained by water displacement. The plaque from each arterial segment was ashed at 700 degrees F, and the weight of the remaining ashes was used as an estimate of the calcium mass. In experiment II, 11 calcified arterial segments were obtained at autopsy and imaged by using IVUS at one site along the artery. A corresponding histologic cross section stained with Masson's trichrome was prepared. In experiment I, the mean plaque volume measured by water displacement was 165.3 +/- 118.4 microliters. The mean plaque volume calculated by IVUS was 166.1 +/- 114.4 microliters and correlated closely with that by water displacement (r = 0.98, p volume by IVUS was 18.6 +/- 11.2 microliters and correlated linearly with the calcium mass by ashing (r = 0.87, p volume as well as the cross-sectional area and volume of intralesional calcium, especially if the calcium is localized at the base of the plaque. IVUS underestimates the amount of calcium present because of signal drop-off when the calcium is too thick for the ultrasound to completely penetrate. In comparison, EBCT accurately quantitates calcium mass regardless of the intralesional calcium morphologic characteristics; however, EBCT does not accurately quantitate plaque volume and will miss noncalcified atherosclerotic lesions.

  19. Quantitative measurements of inventory control.

    Science.gov (United States)

    Noel, M W

    1984-11-01

    The use of quantitative measurements for improving inventory management efficiency in hospital pharmacy is reviewed. Proper management of the pharmacy inventory affects the financial operation of the entire hospital. Problems associated with maintaining inadequate or excessive inventory investment are discussed, and the use of inventory valuation and turnover rate for assessing inventory control efficiency is described. Frequency of order placement has an important effect on inventory turnover, carrying costs, and ordering costs. Use of the ABC system of inventory classification for identifying products constituting the majority of inventory dollar investment is outlined, and the economic order value concept is explained. With increasing regulations aimed at controlling hospital costs, pharmacy managers must seek every possible means to improve efficiency. Reducing the amount of money obligated to inventory can substantially improve the financial position of the hospital without requiring a reduction in personnel or quality of service.

  20. Ultrasound imaging for quantitative evaluation of magnetic density separation

    NARCIS (Netherlands)

    Sanaee, S.A.

    2013-01-01

    This thesis is dedicated to an investigation of the potential and technological possibilities of an inline ultrasound system as a quality control system for wet recycling of solid waste. The main targeted recycling technology is magnetic density separation (MDS), a novel technique that was

  1. Ultrasound imaging for quantitative evaluation of magnetic density separation

    NARCIS (Netherlands)

    Sanaee, S.A.

    2013-01-01

    This thesis is dedicated to an investigation of the potential and technological possibilities of an inline ultrasound system as a quality control system for wet recycling of solid waste. The main targeted recycling technology is magnetic density separation (MDS), a novel technique that was investiga

  2. Ultrasound field measurement using a binary lens

    CERN Document Server

    Clement, Gregory T; Kamakura, Tomoo

    2014-01-01

    Field characterization methods using a scattering target in the absence of a point-like receiver have been well described in which scattering is recorded by a relatively large receiver located outside the field of measurement. Unfortunately, such methods are prone to artifacts due to averaging across the receiver surface. To avoid this problem while simultaneously increasing the gain of a received signal, the present study introduces a binary plate lens designed to focus spherically-spreading waves onto a planar region having a nearly-uniform phase proportional to that of the target location. The lens is similar to a zone plate, but modified to produce a bi-convex-like behavior, such that it focuses both planar and spherically spreading waves. A measurement device suitable for characterizing narrowband ultrasound signals in air is designed around this lens by coupling it to a target and planar receiver. A prototype device is constructed and used to characterize the field of a highly-focused 400 kHz air transd...

  3. Ultrasound biomicroscopy measurement of skin thickness change induced by cosmetic treatment with ultrasound stimulation.

    Science.gov (United States)

    Mak, Tak-Man; Huang, Yan-Ping; Wang, Li-Ke; Zheng, Yong-Ping

    2014-07-01

    Moisturizing creams and lotions are commonly used in daily life for beauty and treatment of different skin conditions such as dryness and wrinkling, and ultrasound stimulation has been used to enhance the delivery of ingredients into skin. However, there is a lack of convenient methods to study the effect of ultrasound stimulation on lotion absorption by skin in vivo. Ultrasound biomicroscopy was adopted as a viable tool in this study to investigate the effectiveness of ultrasound stimulation on the enhancement of lotion delivery into skin. The forearm skin of 10 male and 10 female young subjects was tested at three different sites, including two lotion treatment sites with (Ultrasound Equipment - UE ON) and without (UE OFF) ultrasound stimulation and a control site without any lotion treatment. 1 MHz ultrasound with a duty cycle of 1.7%, a spatial peak temporal peak pressure of 195 kPa and an average power of 0.43 W was used for the stimulation. The skin thickness before, immediately after (0 min), and 15 and 30 min after the treatment was measured by an ultrasound biomicroscopic system (55 MHz). It was found that the skin thickness significantly increased immediately after the lotion treatment for both UE ON (from 1.379 ± 0.187 mm to 1.466 ± 0.182 mm, pultrasound stimulation was more effective for the female subjects than the male subjects (7.6 ± 2.3% vs. 5.4 ± 2.0% immediately after treatment, p=0.017). In conclusion, this study demonstrated that ultrasound biomicroscopy was a feasible method for studying the effectiveness of lotion treatment in vivo, and ultrasound stimulation was effective to enhance the rate of lotion absorption into skin.

  4. Ultrasound specific similarity measures for three-dimensional mosaicing

    Science.gov (United States)

    Wachinger, Christian; Navab, Nassir

    2008-03-01

    The introduction of 2D array ultrasound transducers enables the instantaneous acquisition of ultrasound volumes in the clinical practice. The next step coming along is the combination of several scans to create compounded volumes that provide an extended field-of-view, so called mosaics. The correct alignment of multiple images, which is a complex task, forms the basis of mosaicing. Especially the simultaneous intensity-based registration has many properties making it a good choice for ultrasound mosaicing in comparison to the pairwise one. Fundamental for each registration approach is a suitable similarity measure. So far, only standard measures like SSD, NNC, CR, and MI were used for mosaicing, which implicitly assume an additive Gaussian distributed noise. For ultrasound images, which are degraded by speckle patterns, alternative noise models based on multiplicative Rayleigh distributed noise were proposed in the field of motion estimation. Setting these models into the maximum likelihood estimation framework, which enables the mathematical modeling of the registration process, led us to ultrasound specific bivariate similarity measures. Subsequently, we used an extension of the maximum likelihood estimation framework, which we developed in a previous work, to also derive multivariate measures. They allow us to perform ultrasound specific simultaneous registration for mosaicing. These measures have a higher potential than afore mentioned standard measures since they are specifically designed to cope with problems arising from the inherent contamination of ultrasound images by speckle patterns. The results of the experiments that we conducted on a typical mosaicing scenario with only partly overlapping images confirm this assumption.

  5. Submental ultrasound measurement of dynamic tongue base thickness in patients with obstructive sleep apnea.

    Science.gov (United States)

    Chen, Jeng-Wen; Chang, Chun-Hsiang; Wang, Shou-Jen; Chang, Yen-Teh; Huang, Chih-Chung

    2014-11-01

    Dynamic tongue base thickness (TBT) may be an important anatomic factor in airway narrowing in patients with obstructive sleep apnea (OSA). The development of an accurate clinical assessment of the retroglossal airway in patients with OSA is still evolving. Submental ultrasound was used to investigate the association between measurements of TBT in response to negative airway pressure and the existence of OSA. Twenty OSA patients and 20 control participants underwent ultrasound measurement of TBT on eupneic breathing and with the Mueller maneuver, as well as clinical and polysomnographic assessments. Logistic regression analyses indicated that after adjustment for confounding factors, independent predictors of OSA included TBT in response to negative airway pressure, as measured by submental ultrasound with the Mueller maneuver (odds ratio: 2.11, 95% confidence interval: 1.15-3.87, p measurement of TBT during the Mueller maneuver provides a quantitative assessment of the retroglossal airway in OSA patients with minimal invasiveness and easy accessibility.

  6. Quantitative Ultrasound Spectroscopic Imaging for Characterization of Disease Extent in Prostate Cancer Patients1

    Science.gov (United States)

    Sadeghi-Naini, Ali; Sofroni, Ervis; Papanicolau, Naum; Falou, Omar; Sugar, Linda; Morton, Gerard; Yaffe, Martin J.; Nam, Robert; Sadeghian, Alireza; Kolios, Michael C.; Chung, Hans T.; Czarnota, Gregory J.

    2015-01-01

    Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~ 5 MHz) ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r2 value of 0.71 (P < .0001). The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r2 = 0.764, P < .05), implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation. PMID:25749174

  7. Quantitative Ultrasound Spectroscopic Imaging for Characterization of Disease Extent in Prostate Cancer Patients

    Directory of Open Access Journals (Sweden)

    Ali Sadeghi-Naini

    2015-02-01

    Full Text Available Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~5 MHz ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r2 value of 0.71 (P < .0001. The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r2 = 0.764, P < .05, implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation.

  8. Quantitative ultrasound spectroscopic imaging for characterization of disease extent in prostate cancer patients.

    Science.gov (United States)

    Sadeghi-Naini, Ali; Sofroni, Ervis; Papanicolau, Naum; Falou, Omar; Sugar, Linda; Morton, Gerard; Yaffe, Martin J; Nam, Robert; Sadeghian, Alireza; Kolios, Michael C; Chung, Hans T; Czarnota, Gregory J

    2015-02-01

    Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~5MHz) ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r(2) value of 0.71 (P<.0001). The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r(2)=0.764, P<.05), implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation. Copyright © 2014 Neoplasia Press, Inc. Published by

  9. Quantitative ultrasound method for assessing stress-strain properties and the cross-sectional area of Achilles tendon

    Science.gov (United States)

    Du, Yi-Chun; Chen, Yung-Fu; Li, Chien-Ming; Lin, Chia-Hung; Yang, Chia-En; Wu, Jian-Xing; Chen, Tainsong

    2013-12-01

    The Achilles tendon is one of the most commonly observed tendons injured with a variety of causes, such as trauma, overuse and degeneration, in the human body. Rupture and tendinosis are relatively common for this strong tendon. Stress-strain properties and shape change are important biomechanical properties of the tendon to assess surgical repair or healing progress. Currently, there are rather limited non-invasive methods available for precisely quantifying the in vivo biomechanical properties of the tendons. The aim of this study was to apply quantitative ultrasound (QUS) methods, including ultrasonic attenuation and speed of sound (SOS), to investigate porcine tendons in different stress-strain conditions. In order to find a reliable method to evaluate the change of tendon shape, ultrasound measurement was also utilized for measuring tendon thickness and compared with the change in tendon cross-sectional area under different stress. A total of 15 porcine tendons of hind trotters were examined. The test results show that the attenuation and broadband ultrasound attenuation decreased and the SOS increased by a smaller magnitude as the uniaxial loading of the stress-strain upon tendons increased. Furthermore, the tendon thickness measured with the ultrasound method was significantly correlated with tendon cross-sectional area (Pearson coefficient = 0.86). These results also indicate that attenuation of QUS and ultrasonic thickness measurement are reliable and potential parameters for assessing biomechanical properties of tendons. Further investigations are needed to warrant the application of the proposed method in a clinical setting.

  10. Relation of Reproductive Factors and Heel Quantitative Ultrasound Parameters in Normal Women of Tehran

    Directory of Open Access Journals (Sweden)

    B Larijani

    2004-03-01

    Full Text Available Quantitative Ultrasound (QUS is a noninvasive, inexpensive and portable method for bone densitometry. It may measure some other parameters in addition to BMD, like elasticity and micro architecture. This study designed to determine the relation between reproductive factors and calcaneus QUS parameters in normal women of Tehran. BMD of heel in 151 normal women, 20-72Y/O (participator of Iranian Multi center Osteoporosis Study was assessed using Achilles+ (GE, Lunar Corporation, USA. After assessment of normal values, Stiffness Index percentiles acquired. With consideration of correlation between variables, multiple regression analysis was used. Mean±SD values of Speed of Sound (SOS, Broad Band Ultrasound Attenuation (BUA and Stiffness Index (SI, was 36/751527/25, 121/4215/1, 94/4617/92, respectively. Parameters decreased with age (P<0/01. Years of menopause significantly related with QUS parameters and age of menopause significant related with SOS and SI. Results show effectiveness of some reproductive factors on QUS parameters.

  11. Quantitative ultrasound evaluation of tumor cell death response in locally advanced breast cancer patients receiving chemotherapy.

    Science.gov (United States)

    Sadeghi-Naini, Ali; Papanicolau, Naum; Falou, Omar; Zubovits, Judit; Dent, Rebecca; Verma, Sunil; Trudeau, Maureen; Boileau, Jean Francois; Spayne, Jacqueline; Iradji, Sara; Sofroni, Ervis; Lee, Justin; Lemon-Wong, Sharon; Yaffe, Martin; Kolios, Michael C; Czarnota, Gregory J

    2013-04-15

    Quantitative ultrasound techniques have been recently shown to be capable of detecting cell death through studies conducted on in vitro and in vivo models. This study investigates for the first time the potential of early detection of tumor cell death in response to clinical cancer therapy administration in patients using quantitative ultrasound spectroscopic methods. Patients (n = 24) with locally advanced breast cancer received neoadjuvant chemotherapy treatments. Ultrasound data were collected before treatment onset and at 4 times during treatment (weeks 1, 4, and 8, and preoperatively). Quantitative ultrasound parameters were evaluated for clinically responsive and nonresponding patients. Results indicated that quantitative ultrasound parameters showed significant changes for patients who responded to treatment, and no similar alteration was observed in treatment-refractory patients. Such differences between clinically and pathologically determined responding and nonresponding patients were statistically significant (P < 0.05) after 4 weeks of chemotherapy. Responding patients showed changes in parameters related to cell death with, on average, an increase in mid-band fit and 0-MHz intercept of 9.1 ± 1.2 dBr and 8.9 ± 1.9 dBr, respectively, whereas spectral slope was invariant. Linear discriminant analysis revealed a sensitivity of 100% and a specificity of 83.3% for distinguishing nonresponding patients by the fourth week into a course of chemotherapy lasting several months. This study reports for the first time that quantitative ultrasound spectroscopic methods can be applied clinically to evaluate cancer treatment responses noninvasively. The results form a basis for monitoring chemotherapy effects and facilitating the personalization of cancer treatment.

  12. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    Science.gov (United States)

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  13. Mechanical impedance measurement and damage detection using noncontact laser ultrasound.

    Science.gov (United States)

    Lee, Hyeonseok; Lim, Hyeong Uk; Hong, Jung-Wuk; Sohn, Hoon

    2014-06-01

    This Letter proposes a mechanical impedance (MI) measurement technique using noncontact laser ultrasound. The ultrasound is generated by shooting a pulse laser beam onto a target structure, and its response is measured using a laser vibrometer. Once ultrasound propagation converges to structural vibration, MI is formed over the entire structure. Because noncontact lasers are utilized, this technique is applicable in harsh environments, free of electromagnetic interference, and able to perform wide-range scanning. The formation of MI and its feasibility for damage detection are verified through thermo-mechanical finite element analysis and lab-scale experiments.

  14. Correlation between Parameters of Calcaneal Quantitative Ultrasound and Hip Structural Analysis in Osteoporotic Fracture Patients.

    Directory of Open Access Journals (Sweden)

    Licheng Zhang

    Full Text Available Calcaneal quantitative ultrasound (QUS, which is used in the evaluation of osteoporosis, is believed to be intimately associated with the characteristics of the proximal femur. However, the specific associations of calcaneal QUS with characteristics of the hip sub-regions remain unclear.A cross-sectional assessment of 53 osteoporotic patients was performed for the skeletal status of the heel and hip.We prospectively enrolled 53 female osteoporotic patients with femoral fractures. Calcaneal QUS, dual energy X-ray absorptiometry (DXA, and hip structural analysis (HSA were performed for each patient. Femoral heads were obtained during the surgery, and principal compressive trabeculae (PCT were extracted by a three-dimensional printing technique-assisted method. Pearson's correlation between QUS measurement with DXA, HSA-derived parameters and Young's modulus were calculated in order to evaluate the specific association of QUS with the parameters for the hip sub-regions, including the femoral neck, trochanteric and Ward's areas, and the femoral shaft, respectively.Significant correlations were found between estimated BMD (Est.BMD and BMD of different sub-regions of proximal femur. However, the correlation coefficient of trochanteric area (r = 0.356, p = 0.009 was higher than that of the neck area (r = 0.297, p = 0.031 and total proximal femur (r = 0.291, p = 0.034. Furthermore, the quantitative ultrasound index (QUI was significantly correlated with the HSA-derived parameters of the trochanteric area (r value: 0.315-0.356, all p<0.05 as well as with the Young's modulus of PCT from the femoral head (r = 0.589, p<0.001.The calcaneal bone had an intimate association with the trochanteric cancellous bone. To a certain extent, the parameters of the calcaneal QUS can reflect the characteristics of the trochanteric area of the proximal hip, although not specifically reflective of those of the femoral neck or shaft.

  15. Higher body mass, older age and higher monounsaturated fatty acids intake reflect better quantitative ultrasound parameters in Inuit preschoolers

    Directory of Open Access Journals (Sweden)

    Jessy El Hayek

    2012-07-01

    Full Text Available Objectives. Investigate the effects of selected factors associated with quantitative ultrasound parameters among Inuit preschoolers living in Arctic communities (56° 32′–72° 40′N. Materials and methods. Children were selected randomly in summer and early fall (n=296. Dietary intake was assessed through the administration of a 24-h dietary recall (24-h recall and a food frequency questionnaire (FFQ. Anthropometry was measured using standardized procedures. Plasma 25-hydroxy vitamin D (25(OHD and parathyroid hormone (PTH were measured using a chemiluminescent assay (Liaison, Diasorin. Quantitative ultrasound parameters were measured using Sahara Sonometer, (Hologic Inc.. Results. Children divided by speed of sound (SoS and broadband ultrasound attenuation (BUA quartiles were not different for age (years, sex (M/F, calcium (mg/d and vitamin D intake (µg/d and plasma 25(OHD concentration (nmol/L. However, children in the highest BUA and SoS quartile had higher body mass index (BMI compared to those in quartile 1. Using multivariate linear regression, higher BMI, older age and monounsaturated fatty acids (MUFA intake were predictors of BUA while only BMI was a predictor of SoS. Conclusions. Further investigation assessing intakes of traditional foods (TF and nutrients affecting bone parameters along with assessment of vitamin D status of Inuit children across seasons is required.

  16. Higher body mass, older age and higher monounsaturated fatty acids intake reflect better quantitative ultrasound parameters in Inuit preschoolers

    Science.gov (United States)

    Hayek, Jessy El; Egeland, Grace; Weiler, Hope

    2012-01-01

    Objectives Investigate the effects of selected factors associated with quantitative ultrasound parameters among Inuit preschoolers living in Arctic communities (56° 32′–72° 40′N). Materials and methods Children were selected randomly in summer and early fall (n=296). Dietary intake was assessed through the administration of a 24-h dietary recall (24-h recall) and a food frequency questionnaire (FFQ). Anthropometry was measured using standardized procedures. Plasma 25-hydroxy vitamin D (25(OH)D) and parathyroid hormone (PTH) were measured using a chemiluminescent assay (Liaison, Diasorin). Quantitative ultrasound parameters were measured using Sahara Sonometer, (Hologic Inc.). Results Children divided by speed of sound (SoS) and broadband ultrasound attenuation (BUA) quartiles were not different for age (years), sex (M/F), calcium (mg/d) and vitamin D intake (µg/d) and plasma 25(OH)D concentration (nmol/L). However, children in the highest BUA and SoS quartile had higher body mass index (BMI) compared to those in quartile 1. Using multivariate linear regression, higher BMI, older age and monounsaturated fatty acids (MUFA) intake were predictors of BUA while only BMI was a predictor of SoS. Conclusions Further investigation assessing intakes of traditional foods (TF) and nutrients affecting bone parameters along with assessment of vitamin D status of Inuit children across seasons is required. PMID:22789515

  17. Learning evaluation of ultrasound image segmentation using combined measures

    Science.gov (United States)

    Fang, Mengjie; Luo, Yongkang; Ding, Mingyue

    2016-03-01

    Objective evaluation of medical image segmentation is one of the important steps for proving its validity and clinical applicability. Although there are many researches presenting segmentation methods on medical image, while with few studying the evaluation methods on their results, this paper presents a learning evaluation method with combined measures to make it as close as possible to the clinicians' judgment. This evaluation method is more quantitative and precise for the clinical diagnose. In our experiment, the same data sets include 120 segmentation results of lumen-intima boundary (LIB) and media-adventitia boundary (MAB) of carotid ultrasound images respectively. And the 15 measures of goodness method and discrepancy method are used to evaluate the different segmentation results alone. Furthermore, the experimental results showed that compared with the discrepancy method, the accuracy with the measures of goodness method is poor. Then, by combining with the measures of two methods, the average accuracy and the area under the receiver operating characteristic (ROC) curve of 2 segmentation groups are higher than 93% and 0.9 respectively. And the results of MAB are better than LIB, which proved that this novel method can effectively evaluate the segmentation results. Moreover, it lays the foundation for the non-supervised segmentation evaluation system.

  18. Two-dimensional ultrasound measurement of thyroid gland volume: a new equation with higher correlation with 3-D ultrasound measurement.

    Science.gov (United States)

    Ying, Michael; Yung, Dennis M C; Ho, Karen K L

    2008-01-01

    This study aimed to develop a new two-dimensional (2-D) ultrasound thyroid volume estimation equation using three-dimensional (3-D) ultrasound as the standard of reference, and to compare the thyroid volume estimation accuracy of the new equation with three previously reported equations. 2-D and 3-D ultrasound examinations of the thyroid gland were performed in 150 subjects with normal serum thyrotropin (TSH, thyroid-stimulating hormone) and free thyroxine (fT4) levels (63 men and 87 women, age range: 17 to 71 y). In each subject, the volume of both thyroid lobes was measured by 3-D ultrasound. On 2-D ultrasound, the craniocaudal (CC), lateromedial (LM) and anteroposterior (AP) dimensions of the thyroid lobes were measured. The equation was derived by correlating the volume of the thyroid lobes measured with 3-D ultrasound and the product of the three dimensions measured with 2-D ultrasound using linear regression analysis, in 75 subjects without thyroid nodule. The accuracy of thyroid volume estimation of the new equation and the three previously reported equations was evaluated and compared in another 75 subjects (without thyroid nodule, n = 30; with thyroid nodule, n = 45). It is suggested that volume of thyroid lobe may be estimated as: volume of thyroid lobe = 0.38.(CC.LM.AP) + 1.76. Result showed that the new equation (16.9% to 36.1%) had a significantly smaller thyroid volume estimation error than the previously reported equations (20.8% to 54.9%) (p thyroid volume estimation error when thyroid glands with nodules were examined (p thyroid volume equation, 2-D ultrasound can be a useful alternative in thyroid volume measurement when 3-D ultrasound is not available.

  19. Quantitative Diagnostic Method for Biceps Long Head Tendinitis by Using Ultrasound

    OpenAIRE

    Shih-Wei Huang; Wei-Te Wang

    2013-01-01

    Objective. To investigate the feasibility of grayscale quantitative diagnostic method for biceps tendinitis and determine the cut-off points of a quantitative biceps ultrasound (US) method to diagnose biceps tendinitis. Design. Prospective cross-sectional case controlled study. Setting. Outpatient rehabilitation service. Methods. A total of 336 shoulder pain patients with suspected biceps tendinitis were recruited in this prospective observational study. The grayscale pixel data of the range ...

  20. Quantitative muscle ultrasound and muscle force in healthy children: A 4-year follow-up study

    NARCIS (Netherlands)

    Jacobs, J.; Jansen, M; Janssen, H.; Raijmann, W.; Alfen, N. van; Pillen, S.

    2013-01-01

    INTRODUCTION: No longitudinal data on the normal development of muscle thickness (MT), quantitative muscle ultrasound echo intensity (EI), and muscle force (MF) in healthy children are yet available. METHODS: Reference values of MT, EI, and MF of 4 muscles from infancy to age 16 years were establish

  1. Quantitative ultrasound of the tongue and submental muscles in children and young adults

    NARCIS (Netherlands)

    I. de Groot; Bert de Swart; N. van Alfen; L. van den Engel-Hoek; S. Pillen

    2012-01-01

    The purpose of this study was to assess the feasibility of quantitative muscle ultrasound (QMUS) to visualize oral muscles and to establish normative data for muscle thickness and echo intensity of submental and tongue muscles in healthy children and young adults. The data were compared with those

  2. Quantitative ultrasound of the tongue and submental muscles in children and young adults.

    NARCIS (Netherlands)

    Engel-Hoek, L. van den; Alfen, N. van; Swart, B.J.M. de; Groot, I.J.M. de; Pillen, S.

    2012-01-01

    INTRODUCTION: The purpose of this study was to assess the feasibility of quantitative muscle ultrasound (QMUS) to visualize oral muscles and to establish normative data for muscle thickness and echo intensity of submental and tongue muscles in healthy children and young adults. The data were

  3. Quantitative ultrasound technique at the phalanges in discriminating between uremic and osteoporotic patients

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmi, G. [Department of Radiology, Scientific Institute Hospital ' Casa Sollievo della Sofferenza' , Viale Cappuccini 1, 71013 San Giovanni Rotondo (Italy)]. E-mail: guglielmi_g@hotmail.com; De Terlizzi, F. [IGEA srl, Carpi (Italy); Aucella, F. [Division of Nephrology, Scientific Institute Hospital ' Casa Sollievo della Sofferenza' , San Giovanni Rotondo (Italy); Scillitani, A. [Division of Endocrinology, Scientific Institute Hospital ' Casa Sollievo della Sofferenza' , San Giovanni Rotondo (Italy)

    2006-10-15

    This study was conducted to test the ability of quantitative ultrasound technique (QUS) at the phalanges to discriminate between uremic and osteoporotic patients. Three groups of subjects (38 dialytic women, 16 osteoporotic women with vertebral fractures, 19 non-dialytic and non-fractured women) were recruited at the Department of Radiology at 'Casa Sollievo della Sofferenza' Hospital, San Giovanni Rotondo, Italy. The groups were matched for age and body mass index (BMI). On all subjects the following measurements were performed: spinal BMD by QCT and by DXA, Femoral BMD by DXA, phalangeal QUS. For QUS measurements, the DBM Sonic (IGEA, Carpi, Italy) was applied to the metaphysis of the proximal phalanges of the last four fingers of the hand. Osteoporotic women with vertebral fractures showed significantly lower values of spinal BMD by QCT and DXA and Ward's Triangle BMD with respect to hemodialytic patients (p < 0.005). All QUS values, except for BTT and SoS, showed lower values in osteoporotic women with respect to hemodialytic patients (p < 0.05). Control group showed higher values of AD-SoS, BTT and SoS than hemodialytic patients (p < 0.005) while the two groups did not differ for BMD values measured with both QCT and DXA. UBPI and FWA data showed a similar behaviour to DXA and QCT results, whereas BTT and SoS showed a completely different behaviour. AD-SoS was the only parameter that could effectively discriminate among the three groups (ANOVA, p < 0.0001). We conclude that phalangeal QUS can discriminate between hemodialysed patients and controls with similar bone mineral density, and can also discriminate between hemodialysed and osteoporotic subjects with vertebral fractures. Different characteristics of ultrasound signal can be ascribed to each bone tissue condition, enabling a clear differentiation of bone tissue changes occurring in menopause, osteoporosis and renal osteodystrophy.

  4. Quantitative evaluation of acute renal failure in rabbits with contrast-enhanced ultrasound

    Institute of Scientific and Technical Information of China (English)

    DONG Yi; WANG Wen-ping; CAO Jia-ying; FAN Pei-li; LIN Xi-yuan

    2012-01-01

    Background Assessment of perfusion in the early period of acute renal failure (ARF) is important,and can not be made by conventional ultrasound.The aim of this study was to prospectively test in a rabbit ARF model whether real-time contrast-enhanced ultrasound (CEUS) can quantitatively evaluate the hemodynamic changes of renal cortex in the early period.Methods The model of ARF was induced in 30 healthy New Zealand white rabbits (2.5-3.0 kg),by intramuscular injection of 50% glycerin solution (12 ml/kg).CEUS were performed on right kidneys before,6 and 24 hours after glycerin injection.CEUS quantitative indexes were measured in renal cortex using QLAB software.Comparisons between different stages were performed using paired t test.The sensitivity of CEUS in diagnosing ARF was compared with blood serum urea nitrogen (BUN),serum creatinine (SCr) level and color Doppler flow imaging (CDFI).Results Among quantitative indexes,time to peak (TTP) and area under curve (AUC) increased significantly from (5.86±2.57) seconds and (124.4±46.7) dB.s before glycerin injection to (7.66±2.05) seconds and (288.1±64.9) dB.s 6 hours after injection (P <0.05).Slope rate of ascending curve (A) and descending curve (α) decreased slightly from (3.00±1.22) dB/s and (0.19±0.15) 1/s to (2.80±1.45) dB.s and (0.09±0.02) 1/s (P <0.05).Twenty-four hours later,only AUC increased significantly from (124.4±46.7) dB.s to (466.2±52.2) dB.s (P<0.05).Conclusion Quantitative indexes of CEUS might be useful in predicting the hemodynamic changes of renal cortex in the early six hours of ARF model.

  5. Ultrasound

    Science.gov (United States)

    Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and ... liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound ...

  6. Force-controlled ultrasound to measure passive mechanical properties of muscle in Duchenne muscular dystrophy.

    Science.gov (United States)

    Pigula, Anne J; Wu, Jim S; Gilbertson, Matthew W; Darras, Basil T; Rutkove, Seward B; Anthony, Brian W

    2016-08-01

    The purpose of this study is to assess differences in skeletal muscle compressibility between patients with Duchenne muscular dystrophy (DMD) and normal subjects. The transverse passive mechanical properties of muscle, particularly those related to stiffness and elasticity, can be measured using force-controlled ultrasound. We acquired ultrasound videos of muscle compression under known pressures in the biceps and quadriceps in 23 boys with DMD and 20 age-matched healthy controls. We calculated the bulk linear spring constant, nonlinear stress-strain response, and average Young's modulus for each. Young's modulus was found to be significantly higher in the DMD population in both the biceps (normal: 33 ± 6 kPa, DMD: 45 ± 14, p Muscle compressibility measured by force-controlled ultrasound is an objective and robust technique to quantitatively monitor the effects of DMD and distinguish from normal subjects.

  7. Quantitative ultrasound imaging of therapy response in bladder cancer in vivo.

    Science.gov (United States)

    Tran, William T; Sannachi, Lakshmanan; Papanicolau, Naum; Tadayyon, Hadi; Al Mahrouki, Azza; El Kaffas, Ahmed; Gorjizadeh, Alborz; Lee, Justin; Czarnota, Gregory J

    2016-01-01

    Quantitative ultrasound (QUS) was investigated to monitor bladder cancer treatment response in vivo and to evaluate tumor cell death from combined treatments using ultrasound-stimulated microbubbles and radiation therapy. Tumor-bearing mice (n=45), with bladder cancer xenografts (HT- 1376) were exposed to 9 treatment conditions consisting of variable concentrations of ultrasound-stimulated Definity microbubbles [nil, low (1%), high (3%)], combined with single fractionated doses of radiation (0 Gy, 2 Gy, 8 Gy). High frequency (25 MHz) ultrasound was used to collect the raw radiofrequency (RF) data of the backscatter signal from tumors prior to, and 24 hours after treatment in order to obtain QUS parameters. The calculated QUS spectral parameters included the mid-band fit (MBF), and 0-MHz intercept (SI) using a linear regression analysis of the normalized power spectrum. There were maximal increases in QUS parameters following treatments with high concentration microbubbles combined with 8 Gy radiation: (ΔMBF = +6.41 ± 1.40 (±SD) dBr and SI= + 7.01 ± 1.20 (±SD) dBr. Histological data revealed increased cell death, and a reduction in nuclear size with treatments, which was mirrored by changes in quantitative ultrasound parameters. QUS demonstrated markers to detect treatment effects in bladder tumors in vivo.

  8. Ultrasound as an Outcome Measure in Gout. A Validation Process by the OMERACT Ultrasound Working Group

    DEFF Research Database (Denmark)

    Terslev, Lene; Gutierrez, Marwin; Schmidt, Wolfgang A

    2015-01-01

    OBJECTIVE: To summarize the work performed by the Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Working Group on the validation of US as a potential outcome measure in gout. METHODS: Based on the lack of definitions, highlighted in a recent literature review on US as an outcome tool...

  9. Quantitative Ultrasound at the Hand Phalanges in Adolescent Girls is Related to Their Overall Physical Fitness.

    Science.gov (United States)

    Bolanowski, Marek; Pluskiewicz, Wojciech; Syrycka, Joanna; Chwałczyńska, Agnieszka

    2016-01-01

    Growing of the skeleton, depends on genetic, health, nutritional and environmental influences. The aim of the study was to assess the ultrasound properties of bone measured at hand phalanges in adolescent girls regarding the influence of pubertal status and level of physical fitness. The study group was 56 adolescent girls aged 12-14 yrs, the controls were 86 girls matched for age, recruited from 1256 subjects undergoing bone measurement for screening purposes. The skeletal status (amplitude-dependent speed of sound - Ad-SoS) was assessed by quantitative ultrasound (QUS) at proximal phalanges using DBM Sonic 1200. Physical fitness was assessed by the Zuchora index and pubertal development by the Tanner scale. The adolescent girls from our study group had greater body weight, height, BMI and Ad-SoS values than the controls. Overall physical fitness was highest in girls with the lowest BMI and lowest in girls with the highest BMI values. The highest results of the Ad-SoS were reported in girls presenting highest level of physical fitness. They were statistically significantly higher than in girls with a minimal level of physical fitness. There was a statistically significant correlation between the overall physical fitness score and Ad-SoS results. No correlations between Ad-SoS and the Tanner scale, particular the elements of physical fitness (speed, jumping ability, flexibility, shoulder muscular strength, abdominal muscle strength) and BMI were shown. The bone properties assessed by QUS at the hand phalanges in adolescent girls aged 12-14 years depend on their overall physical fitness. Pubertal development, body size and particular elements of physical fitness, especially shoulder muscular strength, have limited influence.

  10. Clinical workflow for spinal curvature measurement with portable ultrasound

    Science.gov (United States)

    Tabanfar, Reza; Yan, Christina; Kempston, Michael; Borschneck, Daniel; Ungi, Tamas; Fichtinger, Gabor

    2016-03-01

    PURPOSE: Spinal curvature monitoring is essential in making treatment decisions in scoliosis. Monitoring entails radiographic examinations, however repeated ionizing radiation exposure has been shown to increase cancer risk. Ultrasound does not emit ionizing radiation and is safer for spinal curvature monitoring. We investigated a clinical sonography protocol and challenges associated with position-tracked ultrasound in spinal curvature measurement in scoliosis. METHODS: Transverse processes were landmarked along each vertebra using tracked ultrasound snapshots. The transverse process angle was used to determine the orientation of each vertebra. We tested our methodology on five patients in a local pediatric scoliosis clinic, comparing ultrasound to radiographic curvature measurements. RESULTS: Despite strong correlation between radiographic and ultrasound curvature angles in phantom studies, we encountered new challenges in the clinical setting. Our main challenge was differentiating transverse processes from ribs and other structures during landmarking. We observed up to 13° angle variability for a single vertebra and a 9.85° +/- 10.81° difference between ultrasound and radiographic Cobb angles for thoracic curvatures. Additionally, we were unable to visualize anatomical landmarks in the lumbar region where soft tissue depth was 25-35mm. In volunteers with large Cobb angles (greater than 40° thoracic and 60° lumbar), we observed spinal protrusions resulting in incomplete probe-skin contact and partial ultrasound images not suitable for landmarking. CONCLUSION: Spinal curvature measurement using tracked ultrasound is viable on phantom spine models. In the clinic, new challenges were encountered which must be resolved before a universal sonography protocol can be developed.

  11. Evaluation of the Relationship Between Quantitative Ultrasound Parameters and Pain and Demographic Features in Pre and Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    Erdal Yücel

    2015-12-01

    Full Text Available Osteoporosis is a systemic metabolic disease which is characterized by low bone mass and microarchitectural damage of bone tissue resulting in increased bone fragility. History, physical examination, laboratory investigations and different imaging technics are used in diagnosis of osteoporosis. Quantitative ultrasound (QUS is an alternative method for diagnosis of osteoporosis and evaluation of fracture risk. In this study we aimed to evaluate the association between quantitative ultrasound values and pain and demographic features in pre- and postmenopausal women. One hundred voluntary women aged over 40 years who were admitted to hospital in one day were included. Eight of these were excluded for different reasons. Demographic features and pain parameters were inquired. Quantitative ultrasound evaluation was performed with Hologic Sahara Clinical Bone Sonometer equipment. Speed of sound (SOS and broadband ultrasound attenuation (BUA values and stiffness parameters were used for evaluation. Twenty four (26.1% of the objects were premenopausal and 68 (73.9% were postmenopausal. 24 (100% of premenopausal objects and 57 (% 83.8 of postmenopausal objects had pain (p=0.061. In evaluation with QUS, mean BUA values were 67.9 ± 13.5 in premenopausal and 60.0 ± 15.8 in postmenopausal women (p=0.026. Mean stiffness values were found 91.2 ± 13.6 in premenopausal and 80.1 ± 17.6 in postmenopausal women (p=0.013. In all of the subjects, QUS parameters were found negatively corraleted with age, while no relationship was found with occupation, education level, body mass index (BMI and pain. Consequently, we found negative correlation between age and QUS parameters, but for other demographic features there was no correlation. This study will be more sensitive and specific if performed on more patients and supported by other measurement methods.

  12. Comparison of Simulated and Measured Non-linear Ultrasound Fields

    DEFF Research Database (Denmark)

    Du, Yigang; Jensen, Henrik; Jensen, Jørgen Arendt

    2011-01-01

    In this paper results from a non-linear AS (angular spectrum) based ultrasound simulation program are compared to water-tank measurements. A circular concave transducer with a diameter of 1 inch (25.4 mm) is used as the emitting source. The measured pulses are rst compared with the linear...... simulation program Field II, which will be used to generate the source for the AS simulation. The generated non-linear ultrasound eld is measured by a hydrophone in the focal plane. The second harmonic component from the measurement is compared with the AS simulation, which is used to calculate both...

  13. Quantitative roughness measurements with iTIRM

    NARCIS (Netherlands)

    Bijl, R.J.M. van der; Fähnle, O.W.; Brug, H. van; Braat, J.J.M.

    2000-01-01

    A new method, iTIRM, is used for quantitative surface roughness measurements of ground and polished surfaces and it is shown to be a useful tool for measuring total surface quality instead of individual roughness parameters.

  14. Quantitative ultrasound texture analysis for clinical decision making support

    Science.gov (United States)

    Wu, Jie Ying; Beland, Michael; Konrad, Joseph; Tuomi, Adam; Glidden, David; Grand, David; Merck, Derek

    2015-03-01

    We propose a general ultrasound (US) texture-analysis and machine-learning framework for detecting the presence of disease that is suitable for clinical application across clinicians, disease types, devices, and operators. Its stages are image selection, image filtering, ROI selection, feature parameterization, and classification. Each stage is modular and can be replaced with alternate methods. Thus, this framework is adaptable to a wide range of tasks. Our two preliminary clinical targets are hepatic steatosis and adenomyosis diagnosis. For steatosis, we collected US images from 288 patients and their pathology-determined values of steatosis (%) from biopsies. Two radiologists independently reviewed all images and identified the region of interest (ROI) most representative of the hepatic echotexture for each patient. To parameterize the images into comparable quantities, we filter the US images at multiple scales for various texture responses. For each response, we collect a histogram of pixel features within the ROI, and parameterize it as a Gaussian function using its mean, standard deviation, kurtosis, and skew to create a 36-feature vector. Our algorithm uses a support vector machine (SVM) for classification. Using a threshold of 10%, we achieved 72.81% overall accuracy, 76.18% sensitivity, and 65.96% specificity in identifying steatosis with leave-ten-out cross-validation (p<0.0001). Extending this framework to adenomyosis, we identified 38 patients with MR-confirmed findings of adenomyosis and previous US studies and 50 controls. A single rater picked the best US-image and ROI for each case. Using the same processing pipeline, we obtained 76.14% accuracy, 86.00% sensitivity, and 63.16% specificity with leave-one-out cross-validation (p<0.0001).

  15. Noninvasive measurement of local thermal diffusivity using backscattered ultrasound and focused ultrasound heating.

    Science.gov (United States)

    Anand, Ajay; Kaczkowski, Peter J

    2008-09-01

    Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create a brief local temperature rise of no more than 10 degrees C. Beamformed radio-frequency (RF) data are collected during heating and cooling using a clinical ultrasound scanner. Measurements of the time-varying "acoustic strain", that is, spatiotemporal variations in the RF echo shifts induced by the temperature related sound speed changes, are related to a solution of the heat transfer equation to estimate the thermal diffusivity in the heated zone. Numerical simulations and experiments performed in vitro in tissue mimicking phantoms and excised turkey breast muscle tissue demonstrate agreement between the ultrasound derived thermal diffusivity estimates and independent estimates made by a traditional hot-wire technique. The new noninvasive ultrasonic method has potential applications in thermal therapy planning and monitoring, physiological monitoring and as a means of noninvasive tissue characterization.

  16. Damage Detection in Concrete Using Diffuse Ultrasound Measurements

    Science.gov (United States)

    Deroo, Frederik; Jacobs, Laurence J.; Kim, Jin-Yeon; Qu, Jianmin; Sabra, Karim

    2010-02-01

    Heterogeneities in concrete caused by the random distribution of aggregate in the cement-paste matrix lead to strong scattering of ultrasonic waves at wavelengths on the order of the aggregate. Use of these high frequencies is necessary to detect damage at an early stage, something that is not possible with conventional ultrasonic methods. The ultrasound energy density in that regime can be described by the diffusion equation. The objective of this research is to develop a quantitative understanding of the effects of additional scattering sources, such as small cracks in the cement-paste matrix, on the parameters of the diffusion equation; these parameters are the diffusion and the dissipation coefficients. Applying diffusion theory, the diffusivity and dissipation coefficients are experimentally determined as functions of frequency using ultrasonic waves. The cuboid shaped samples employed are made of a Portland cement-paste matrix and regular aggregate, such as gravel and sand. The results provide a basic understanding of repeatability and consistency of diffusion measurements, with an emphasis on the nondestructive evaluation of concrete.

  17. Quantitative Assessment of First Annular Pulley and Adjacent Tissues Using High-Frequency Ultrasound

    Science.gov (United States)

    Lin, Yi-Hsun; Yang, Tai-Hua; Wang, Shyh-Hau; Su, Fong-Chin

    2017-01-01

    Due to a lack of appropriate image resolution, most ultrasound scanners are unable to sensitively discern the pulley tissues. To extensively investigate the properties of the A1 pulley system and the surrounding tissues for assessing trigger finger, a 30 MHz ultrasound system was implemented to perform in vitro experiments using the hypodermis, A1 pulley, and superficial digital flexor tendon (SDFT) dissected from cadavers. Ultrasound signals were acquired from both the transverse and sagittal planes of each tissue sample. The quantitative ultrasonic parameters, including sound speed, attenuation coefficient, integrated backscatter (IB) and Nakagami parameter (m), were subsequently estimated to characterize the tissue properties. The results demonstrated that the acquired ultrasound images have high resolution and are able to sufficiently differentiate the variations of tissue textures. Moreover, the attenuation slope of the hypodermis is larger than those of the A1 pulley and SDFT. The IB of A1 pulley is about the same as that of the hypodermis, and is very different from SDFT. The m parameter of the A1 pulley is also very different from those of hypodermis and SDFT. This study demonstrated that high-frequency ultrasound images in conjunction with ultrasonic parameters are capable of characterizing the A1 pulley system and surrounding tissues. PMID:28067854

  18. A comparison of portable ultrasound and fully-equipped clinical ultrasound unit in the thyroid size measurement of the Indo-Pacific bottlenose dolphin.

    Directory of Open Access Journals (Sweden)

    Brian C W Kot

    Full Text Available Measurement of thyroid size and volume is a useful clinical parameter in both human and veterinary medicine, particularly for diagnosing thyroid diseases and guiding corrective therapy. Procuring a fully-equipped clinical ultrasound unit (FCUS may be difficult in most veterinary settings. The present study evaluated the inter-equipment variability in dolphin thyroid ultrasound measurements between a portable ultrasound unit (PUS and a FCUS; for both units, repeatability was also assessed. Thyroid ultrasound examinations were performed on 15 apparently healthy bottlenose dolphins with both PUS and FCUS under identical scanning conditions. There was a high level of agreement between the two ultrasound units in dolphin thyroid measurements (ICC = 0.859-0.976. A high intra-operator repeatability in thyroid measurements was found (PUS: ICC = 0.854-0.984, FCUS: ICC = 0.709-0.954. As a conclusion, no substantial inter-equipment variability was found between PUS and FCUS in dolphin thyroid size measurements under identical scanning conditions, supporting further application of PUS for quantitative analyses of dolphin thyroid gland in both research and clinical practices at aquarium settings.

  19. A comparison of portable ultrasound and fully-equipped clinical ultrasound unit in the thyroid size measurement of the Indo-Pacific bottlenose dolphin.

    Science.gov (United States)

    Kot, Brian C W; Ying, Michael T C; Brook, Fiona M

    2012-01-01

    Measurement of thyroid size and volume is a useful clinical parameter in both human and veterinary medicine, particularly for diagnosing thyroid diseases and guiding corrective therapy. Procuring a fully-equipped clinical ultrasound unit (FCUS) may be difficult in most veterinary settings. The present study evaluated the inter-equipment variability in dolphin thyroid ultrasound measurements between a portable ultrasound unit (PUS) and a FCUS; for both units, repeatability was also assessed. Thyroid ultrasound examinations were performed on 15 apparently healthy bottlenose dolphins with both PUS and FCUS under identical scanning conditions. There was a high level of agreement between the two ultrasound units in dolphin thyroid measurements (ICC = 0.859-0.976). A high intra-operator repeatability in thyroid measurements was found (PUS: ICC = 0.854-0.984, FCUS: ICC = 0.709-0.954). As a conclusion, no substantial inter-equipment variability was found between PUS and FCUS in dolphin thyroid size measurements under identical scanning conditions, supporting further application of PUS for quantitative analyses of dolphin thyroid gland in both research and clinical practices at aquarium settings.

  20. Qualitative and quantitative ultrasound assessment of gastric content

    Directory of Open Access Journals (Sweden)

    Flora Margarida Barra Bisinotto

    Full Text Available Summary Objective: Pulmonary aspiration of the gastric contents is one of the most feared complications in anesthesia. Its prevention depends on preoperative fasting as well as identification of risky patients. A reliable diagnostic tool to assess gastric volume is currently lacking. The aim of this study performed on volunteers was to evaluate the feasibility of ultrasonography to identify qualitative and quantitative gastric content. Method: A standardized gastric scanning protocol was applied on 67 healthy volunteers to assess the gastric antrum in four different situations: fasting, after ingesting clear fluid, milk and a solid meal. A qualitative and quantitative assessment of the gastric content in the antrum was performed by a blinded sonographer. The antrum was considered either as empty, or containing clear or thick fluid, or solids. Total gastric volume was predicted based on a cross-sectional area of the antrum. A p-value less than 0.05 was considered statistically significant. Results: For each type of gastric content, the sonographic characteristics of the antrum and its content were described and illustrated. Sonographic qualitative assessment allowed to distinguish between an empty stomach and one with different kinds of meal. The predicted gastric volume was significantly larger after the consumption of any food source compared to fasting. Conclusion: Bedside sonography can determine the nature of gastric content. It is also possible to estimate the difference between an empty gastric antrum and one that has some food in it. Such information may be useful to estimate the risk of aspiration, particularly in situations when prandial status is unknown or uncertain.

  1. Development and Measurement of Preschoolers' Quantitative Knowledge

    Science.gov (United States)

    Geary, David C.

    2015-01-01

    The collection of studies in this special issue make an important contribution to our understanding and measurement of the core cognitive and noncognitive factors that influence children's emerging quantitative competencies. The studies also illustrate how the field has matured, from a time when the quantitative competencies of infants and young…

  2. Response monitoring using quantitative ultrasound methods and supervised dictionary learning in locally advanced breast cancer

    Science.gov (United States)

    Gangeh, Mehrdad J.; Fung, Brandon; Tadayyon, Hadi; Tran, William T.; Czarnota, Gregory J.

    2016-03-01

    A non-invasive computer-aided-theragnosis (CAT) system was developed for the early assessment of responses to neoadjuvant chemotherapy in patients with locally advanced breast cancer. The CAT system was based on quantitative ultrasound spectroscopy methods comprising several modules including feature extraction, a metric to measure the dissimilarity between "pre-" and "mid-treatment" scans, and a supervised learning algorithm for the classification of patients to responders/non-responders. One major requirement for the successful design of a high-performance CAT system is to accurately measure the changes in parametric maps before treatment onset and during the course of treatment. To this end, a unified framework based on Hilbert-Schmidt independence criterion (HSIC) was used for the design of feature extraction from parametric maps and the dissimilarity measure between the "pre-" and "mid-treatment" scans. For the feature extraction, HSIC was used to design a supervised dictionary learning (SDL) method by maximizing the dependency between the scans taken from "pre-" and "mid-treatment" with "dummy labels" given to the scans. For the dissimilarity measure, an HSIC-based metric was employed to effectively measure the changes in parametric maps as an indication of treatment effectiveness. The HSIC-based feature extraction and dissimilarity measure used a kernel function to nonlinearly transform input vectors into a higher dimensional feature space and computed the population means in the new space, where enhanced group separability was ideally obtained. The results of the classification using the developed CAT system indicated an improvement of performance compared to a CAT system with basic features using histogram of intensity.

  3. Noninvasive Quantitative Imaging of Collagen Microstructure in Three-Dimensional Hydrogels Using High-Frequency Ultrasound

    OpenAIRE

    Mercado, Karla P.; Helguera, María; Hocking, Denise C.; Dalecki, Diane

    2015-01-01

    Collagen I is widely used as a natural component of biomaterials for both tissue engineering and regenerative medicine applications. The physical and biological properties of fibrillar collagens are strongly tied to variations in collagen fiber microstructure. The goal of this study was to develop the use of high-frequency quantitative ultrasound to assess collagen microstructure within three-dimensional (3D) hydrogels noninvasively and nondestructively. The integrated backscatter coefficient...

  4. The effect of age, weight, and lifestyle factors on calcaneal quantitative ultrasound: the ESOPO study.

    Science.gov (United States)

    Adami, Silvano; Giannini, Sandro; Giorgino, Ruben; Isaia, GianCarlo; Maggi, Stefania; Sinigaglia, Luigi; Filipponi, Paolo; Crepaldi, Gaetano; Di Munno, Ombretta

    2003-05-01

    Quantitative ultrasound (QUS) techniques have been shown to be as good as bone mineral density (BMD) assessed by dual-energy X-ray absorptiometry (DXA), in predicting fracture risk: QUS technique could increase substantially the accessibility to a reliable bone osteoporosis risk evaluation, but little is know regarding the relationship of QUS to risk factors that have been found to predict DXA-BMD values and this is even more true in men. We studied 6,811 postmenopausal women 40 to 80 years of age and 4,981 men 60-80 years of age representative of the general population of all regions of Italy. All participants were questioned on lifestyle habits and on their medical history. After a physical examination "bone stiffness" (called here for simplicity, stiffness), which is derived from the values of broadband ultrasound attenuation (BUA) and speed of sounds (SoS) was measured by a heel QUS device (Achilles apparatus, Lunar, Madison, USA). The most common recognized determinants of bone mass (either categorical or continuous variables) were modeled with stiffness by multiple regression analysis or ANOVA. Stiffness was strongly related to age and weight. After adjusting for these variables, the women who had taken hormone replacement therapy for more than a year had significantly higher stiffness values. The difference versus nonusers remained significant for up to 20 years-since-menopause (YSM). This effect was so strong that for further analysis these women were excluded. By multivariate analysis, stiffness was then found to be significantly related to recalled body weight at 25 years of age, actual and past cigarettes smoked per day, and dairy calcium intake. Stiffness was also associated with a number of categorial factors adjusted for age, weight, and YSM: prior ovariectomy, history of more than 2 months confined to bed, outdoor physical activity, smoking, chronic use of any drug, and past corticosteroid use. All these categorial and continuous variables predicted

  5. Categorizing extent of tumor cell death response to cancer therapy using quantitative ultrasound spectroscopy and maximum mean discrepancy.

    Science.gov (United States)

    Gangeh, Mehrdad J; Sadeghi-Naini, Ali; Diu, Michael; Tadayyon, Hadi; Kamel, Mohamed S; Czarnota, Gregory J

    2014-06-01

    Quantitative ultrasound (QUS) spectroscopic techniques in conjunction with maximum mean discrepancy (MMD) have been proposed to detect, and to classify noninvasively the levels of cell death in response to cancer therapy administration in tumor models. Evaluation of xenograft tumor responses to cancer treatments were carried out using conventional-frequency ultrasound at different times after chemotherapy exposure. Ultrasound data were analyzed using spectroscopic techniques and multi-parametric QUS spectral maps were generated. MMD was applied as a distance criterion, measuring alterations in each tumor in response to chemotherapy, and the extent of cell death was classified into less/more than 20% and 40% categories. Statistically significant differences were observed between "pre-" and "post-treatment" groups at different times after chemotherapy exposure, suggesting a high capability of proposed framework for detecting tumor response noninvasively. Promising results were also obtained for categorizing the extent of cell death response in each tumor using the proposed framework, with gold standard histological quantification of cell death as ground truth. The best classification results were obtained using MMD when applied on histograms of QUS parametric maps. In this case, classification accuracies of 84.7% and 88.2% were achieved for categorizing extent of tumor cell death into less/more than 20% and 40%, respectively.

  6. The influence of cortical end-plate on broadband ultrasound attenuation measurements at the human calcaneus using scanning confocal ultrasound

    Science.gov (United States)

    Xia, Yi; Lin, Wei; Qin, Yi-Xian

    2005-09-01

    Quantitative ultrasound (QUS) assessment, including broadband ultrasound attenuation (BUA), is an efficient technique for assessing bone quality in various statuses, e.g., osteoporosis. While assessing trabecular bone loss is essential to bone quality, the existence of cortical bone can substantially reduce the accuracy of BUA measurement. In this study, we developed an approach to quantify the influence of the cortical end-plate in the QUS on 18 cadaver calcanei using both analytical and experimental analyses. A simplified cortical-trabecular-cortical sandwich model has been developed for simulation of wave propagations. Results show that the cortical end-plate has a significant effect on BUA (yielding 8.5+/-3.6 dB/MHz in cortical bone alone), approximately 15% of the BUA value over the whole bone BUA measurement (54.1+/-20.1 dB/MHz). The phenomenon has been predicted by the developed analytical model with a high correlation (r2=0.63,pdiagnosis of bone diseases.

  7. Locally adaptive Nakagami-based ultrasound similarity measures.

    Science.gov (United States)

    Wachinger, Christian; Klein, Tassilo; Navab, Nassir

    2012-04-01

    The derivation of statistically optimal similarity measures for intensity-based registration is possible by modeling the underlying image noise distribution. The parameters of these distributions are, however, commonly set heuristically across all images. In this article, we show that the estimation of the parameters on the present images largely improves the registration, which is a consequence of the more accurate characterization of the image noise. More precisely, instead of having constant parameters over the entire image domain, we estimate them on patches, leading to a local adaptation of the similarity measure. While this basic idea of creating locally adaptive metrics is interesting for various fields of application, we present the derivation for ultrasound imaging. The domain of ultrasound is particularly appealing for this approach, due to the inherent contamination with speckle noise. Furthermore, there exist detailed analyses of suitable noise distributions in the literature. We present experiments for applying a bivariate Nakagami distribution that facilitates modeling of several scattering scenarios prominent in medical ultrasound. Depending on the number of scatterers per resolution cell and the presence of coherent structures, different Nakagami parameters are required to obtain a valid approximation of the intensity statistics and to account for distributional locality. Our registration results on radio-frequency ultrasound data confirm the theoretical necessity for a spatial adaptation of similarity metrics.

  8. Epidemiological survey of quantitative ultrasound in risk assessment of falls in middle-aged and elderly people.

    Directory of Open Access Journals (Sweden)

    Ling-Chun Ou

    Full Text Available The risk assessment of falls is important, but still unsatisfactory and time-consuming. Our objective was to assess quantitative ultrasound (QUS in the risk assessment of falls. Our study was designed as epidemiological cross-sectional study occurring from March 2009 to February 2010 by community survey at a medical center. The participants were collected from systemic sample of 1,200 community-dwelling people (Male/Female = 524/676 40 years old and over in Yunlin County, Mid-Taiwan. Structural questionnaires including socioeconomic status, living status, smoking and drinking habits, exercise and medical history were completed. Quantitative ultrasound (QUS at the non-dominant distal radial area (QUS-R and the left calcaneal area (QUS-C were measured. The overall prevalence of falls was 19.8%. In men, the independently associated factors for falls were age (OR: 1.04; 95%CI: 1.01~1.06, fracture history (OR: 1.89; 95%CI: 1.12~3.19, osteoarthritis history (OR: 3.66; 95%CI: 1.15~11.64 and speed of sound (OR: 0.99; 95%CI: 0.99~1.00; p<0.05 by QUS-R. In women, the independently associated factors for falls were current drinking (OR: 3.54; 95%CI: 1.35∼9.31 and broadband ultrasound attenuation (OR: 0.98; 95%CI: 0.97~0.99; p<0.01 by QUS-C. The cutoffs at -2.5< T-score<-1 derived using QUS-R (OR: 2.85; 95%CI: 1.64~4.96; p<0.01 in men or T-score ≦-2.5 derived using QUS-C (OR: 2.72; 95%CI: 1.42~5.21; p<0.01 in women showed an independent association with falls. The lowest T-score derived using either QUS-R or QUS-C was also revealed as an independent factor for falls in both men (OR: 2.13; 95%CI: 1.03~4.43; p<0.05 and women (OR: 2.36; 95%CI: 1.13~4.91; p<0.05.Quantitative ultrasounds, measured either at the radial or calcaneal area, are convenient tools by which to assess the risk of falls in middle-aged and elderly people.

  9. Quantitative ultrasound for the detection and management of osteoporosis Ultrasonido cuantitativo para la detección y manejo de osteoporosis

    OpenAIRE

    Didier Hans; Marc-Antoine Krieg

    2009-01-01

    Quantitative ultrasound (QUS) appears to be developing into an acceptable, low-cost and readily-accessible alternative to dual X-ray absorptiometry (DXA) measurements of bone mineral density (BMD) in the detection and management of osteoporosis. Perhaps the major difficulty with their widespread use is that many different QUS devices exist that differ substantially from each other, in terms of the parameters they measure and the strength of empirical evidence supporting their use. But another...

  10. A priori Prediction of Neoadjuvant Chemotherapy Response and Survival in Breast Cancer Patients using Quantitative Ultrasound

    Science.gov (United States)

    Tadayyon, Hadi; Sannachi, Lakshmanan; Gangeh, Mehrdad J.; Kim, Christina; Ghandi, Sonal; Trudeau, Maureen; Pritchard, Kathleen; Tran, William T.; Slodkowska, Elzbieta; Sadeghi-Naini, Ali; Czarnota, Gregory J.

    2017-04-01

    Quantitative ultrasound (QUS) can probe tissue structure and analyze tumour characteristics. Using a 6-MHz ultrasound system, radiofrequency data were acquired from 56 locally advanced breast cancer patients prior to their neoadjuvant chemotherapy (NAC) and QUS texture features were computed from regions of interest in tumour cores and their margins as potential predictive and prognostic indicators. Breast tumour molecular features were also collected and used for analysis. A multiparametric QUS model was constructed, which demonstrated a response prediction accuracy of 88% and ability to predict patient 5-year survival rates (p = 0.01). QUS features demonstrated superior performance in comparison to molecular markers and the combination of QUS and molecular markers did not improve response prediction. This study demonstrates, for the first time, that non-invasive QUS features in the core and margin of breast tumours can indicate breast cancer response to neoadjuvant chemotherapy (NAC) and predict five-year recurrence-free survival.

  11. Color doppler ultrasound and quantitative histologic study of angiogenesis in ovarian tumors.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate whether there is any correlation between minimum resistance index (RImin) and mierovessel density (MVD) in ovarian tumors. Methods: The intratumor artery RImin of 61 patients with ovarian tumor was measured by color doppler ultra-sound (CDU) preoperatively. MVD i-

  12. Validation of ultrasound as a noninvasive tool to measure subcutaneous fat depth in leatherback sea turtles (Dermochelys coriacea)

    Science.gov (United States)

    Harris, Heather S.; Benson, Scott R.; James, Michael C.; Martin, Kelly J.; Stacy, Brian A.; Daoust, Pierre-Yves; Rist, Paul M.; Work, Thierry M.; Balazs, George H.; Seminoff, Jeffrey A.

    2016-01-01

    Leatherback turtles (Dermochelys coriacea) undergo substantial cyclical changes in body condition between foraging and nesting. Ultrasonography has been used to measure subcutaneous fat as an indicator of body condition in many species but has not been applied in sea turtles. To validate this technique in leatherback turtles, ultrasound images were obtained from 36 live-captured and dead-stranded immature and adult turtles from foraging and nesting areas in the Pacific and Atlantic oceans. Ultrasound measurements were compared with direct measurements from surgical biopsy or necropsy. Tissue architecture was confirmed histologically in a subset of turtles. The dorsal shoulder region provided the best site for differentiation of tissues. Maximum fat depth values with the front flipper in a neutral (45–90°) position demonstrated good correlation with direct measurements. Ultrasound-derived fat measurements may be used in the future for quantitative assessment of body condition as an index of health in this critically endangered species.

  13. VALIDATION OF ULTRASOUND AS A NONINVASIVE TOOL TO MEASURE SUBCUTANEOUS FAT DEPTH IN LEATHERBACK SEA TURTLES (DERMOCHELYS CORIACEA).

    Science.gov (United States)

    Harris, Heather S; Benson, Scott R; James, Michael C; Martin, Kelly J; Stacy, Brian A; Daoust, Pierre-Yves; Rist, Paul M; Work, Thierry M; Balazs, George H; Seminoff, Jeffrey A

    2016-03-01

    Leatherback turtles (Dermochelys coriacea) undergo substantial cyclical changes in body condition between foraging and nesting. Ultrasonography has been used to measure subcutaneous fat as an indicator of body condition in many species but has not been applied in sea turtles. To validate this technique in leatherback turtles, ultrasound images were obtained from 36 live-captured and dead-stranded immature and adult turtles from foraging and nesting areas in the Pacific and Atlantic oceans. Ultrasound measurements were compared with direct measurements from surgical biopsy or necropsy. Tissue architecture was confirmed histologically in a subset of turtles. The dorsal shoulder region provided the best site for differentiation of tissues. Maximum fat depth values with the front flipper in a neutral (45-90°) position demonstrated good correlation with direct measurements. Ultrasound-derived fat measurements may be used in the future for quantitative assessment of body condition as an index of health in this critically endangered species.

  14. Electric Field Quantitative Measurement System and Method

    Science.gov (United States)

    Generazio, Edward R. (Inventor)

    2016-01-01

    A method and system are provided for making a quantitative measurement of an electric field. A plurality of antennas separated from one another by known distances are arrayed in a region that extends in at least one dimension. A voltage difference between at least one selected pair of antennas is measured. Each voltage difference is divided by the known distance associated with the selected pair of antennas corresponding thereto to generate a resulting quantity. The plurality of resulting quantities defined over the region quantitatively describe an electric field therein.

  15. The influence of dairy consumption and physical activity on ultrasound bone measurements in Flemish children.

    Science.gov (United States)

    De Smet, Stephanie; Michels, Nathalie; Polfliet, Carolien; D'Haese, Sara; Roggen, Inge; De Henauw, Stefaan; Sioen, Isabelle

    2015-03-01

    The study's aim was to analyse whether children's bone status, assessed by calcaneal ultrasound measurements, is influenced by dairy consumption and objectively measured physical activity (PA). Moreover, the interaction between dairy consumption and PA on bone mass was studied. Participants of this cross-sectional study were 306 Flemish children (6-12 years). Body composition was measured with air displacement plethysmography (BodPod), dairy consumption with a Food Frequency Questionnaire, PA with an accelerometer (only in 234 of the 306 children) and bone mass with quantitative ultrasound, quantifying speed of sound (SOS), broadband ultrasound attenuation (BUA) and Stiffness Index (SI). Regression analyses were used to study the associations between dairy consumption, PA, SOS, BUA and SI. Total dairy consumption and non-cheese dairy consumption were positively associated with SOS and SI, but no significant association could be demonstrated with BUA. In contrast, milk consumption, disregarding other dairy products, had no significant effect on calcaneal bone measurements. PA [vigorous PA, moderate to vigorous physical activity (MVPA) and counts per minute] was positively associated and sedentary time was negatively associated with BUA and SI, but no significant influence on SOS could be detected. Dairy consumption and PA (sedentary time and MVPA) did not show any interaction influencing bone measurements. In conclusion, even at young age, PA and dairy consumption positively influence bone mass. Promoting PA and dairy consumption in young children may, therefore, maximize peak bone mass, an important protective factor against osteoporosis later in life.

  16. Ultrasound settings significantly alter arterial lumen and wall thickness measurements

    Directory of Open Access Journals (Sweden)

    Green Daniel J

    2008-01-01

    Full Text Available Abstract Background Flow-mediated dilation (FMD and carotid intima-medial thickness (CIMT, measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR and gain set at five decibel (dB increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p Conclusion DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects.

  17. Using Ultrasound to Measure Mud Rheological Properties

    Science.gov (United States)

    Maa, P. Y. P. Y.; Kwon, J. I.; Park, K. S.

    2015-12-01

    In order to predict the dynamic responses of newly consolidated cohesive sediment beds, a better understanding of the material rheological properties (bulk density, ρ, kinematic viscosity, ν, and shear modulus, G, assuming mud is a simple Voigt viscoelastic model) of these sediment beds is needed. An acoustic approach that uses a commercially available 250 kHz shear wave transducer and tone-burst waves has been developed to measure those properties. This approach uses a 86.3 mm long delay-line (DL) to separate the generated pressure and shear waves, and measures the reflected shear waves as well as the reflected pressure waves caused at the interface between the delay line and the mud to interpret these properties. By using materials (i.e., air, water, olive oil, and honey) with available rheological properties to establish a calibration relationship between the information carried by the measured reflected waves and those given material properties, the mud properties as well as thνe change of these properties during consolidation can be interpreted. Using jelly pudding as a check, a value of G ≈ 12310 N/m2 and ν ≈ 5 x 10-5 m2/s were estimated. For the consolidating kaolinite bed (with zero salinity and initial suspended sediment concentration about 420 g/cm3), the measurements show that the shear modulus developed after about 40 hours and approached a value on the order of 15000 N/m2 after about 100 hours. The initial kinematic viscosity was about 5 x 10-4 m2/s, and it decreased slowly with time and approached a low plateau between 10-6 and 10-7 m2/s after 300 hours. The measured bulk density showed a small increasing rate during the entire consolidation period, except at a short period between 80 and 90 hours after consolidation. Results from this study suggest a promising approach for developing an in-situ instrument to measure mud properties, as well as many other materials in other industries.

  18. Ultrasound Tomography in Circular Measurement Configuration using Nonlinear Reconstruction Method

    Directory of Open Access Journals (Sweden)

    Tran Quang-Huy

    2015-12-01

    Full Text Available Ultrasound tomography offers the potential for detecting of very small tumors whose sizes are smaller than the wavelength of the incident pressure wave without ionizing radiation. Based on inverse scattering technique, this imaging modality uses some material properties such as sound contrast and attenuation in order to detect small objects. One of the most commonly used methods in ultrasound tomography is the Distorted Born Iterative Method (DBIM. The compressed sensing technique was applied in the DBIM as a promising approach for the image reconstruction quality improvement. Nevertheless, the random measurement configuration of transducers in this method is very difficult to set up in practice. Therefore, in this paper, we take advantages of simpler sparse uniform measurement configuration set-up of transducers and high-quality image reconstruction of 1 non-linear regularization in sparse scattering domain. The simulation results demonstrate the high performance of the proposed approach in terms of tremendously reduced total runtime and normalized error.

  19. On Measuring Quantitative Interpretations of Reasonable Doubt

    Science.gov (United States)

    Dhami, Mandeep K.

    2008-01-01

    Beyond reasonable doubt represents a probability value that acts as the criterion for conviction in criminal trials. I introduce the membership function (MF) method as a new tool for measuring quantitative interpretations of reasonable doubt. Experiment 1 demonstrated that three different methods (i.e., direct rating, decision theory based, and…

  20. Methods for blood flow measurements using ultrasound contrast agents

    Science.gov (United States)

    Fowlkes, J. Brian

    2003-10-01

    Blood flow measurements using ultrasound contrast agents are being investigated for myocardial perfusion and more recently in other organ systems. The methods are based largely on the relative increase in echogenicity due to the concentration of bubbles present in the ultrasound beam. In the simplest form, regional differences in blood volume can be inferred but the possibility exists to extract perfusion from the transit of contrast agent through tissue. Perfusion measurements rely on determining the flux of blood through a tissue volume and as such require knowledge of the fractional blood volume (FBV), i.e., ml blood/g tissue and the rate of exchange, commonly measured as the mean transit time (MTT). This presentation will discuss methods of determining each of these values and their combination to estimate tissue perfusion. Underlying principles of indicator-dilution theory will be provided in the context of ultrasound contrast agents. Current methods for determining MTT will include imaging of the intravenous bolus, in-plane contrast disruption with interval and real-time contrast recovery imaging, and control of contrast agent flow using arterial disruption (contrast interruption). The advantages and limitations of the methods will be examined along with current applications. [Work supported in part by NIH.

  1. Blood flow measurements during hemodialysis vascular access interventions - Catheter-based thermodilution or Doppler ultrasound?

    DEFF Research Database (Denmark)

    Heerwagen, Søren T; Hansen, Marc A; Schroeder, Torben V

    2012-01-01

    Purpose: To test the clinical performance of catheter-based thermodilution and Doppler ultrasound of the feeding brachial artery for blood flow measurements during hemodialysis vascular access interventions.Methods: Thirty patients with arteriovenous fistulas who underwent 46 interventions had...... access blood flow measured before and after every procedure. Two methods, catheter-based thermodilution and Doppler ultrasound, were compared to the reference method of ultrasound dilution. Catheter-based thermodilution and Doppler ultrasound were performed during the endovascular procedures while flow...

  2. Ultrasound measurements of the masseter muscle as predictors of cephalometric indices in orthodontics: a pilot study.

    Science.gov (United States)

    Naser-Ud-Din, S; Sampson, W J; Dreyer, C W; Thoirs, K

    2010-09-01

    This study investigated the potential of ultrasound measurements of the masseter muscle to accurately predict indices normally derived from cephalograms. Masseter muscle measurements on 11 adults (22 to 30 y) were made using lateral cephalometrics and extended field-of-view ultrasound. The ultrasound technique was validated in a simulation pilot study using 12 dry skulls and raw chicken breasts. Twenty cephalometric variables were analyzed against four ultrasound measurements of the masseter muscle. Highly significant correlations (r = 0.81-0.85, p = 0.001-0.002) between ultrasound measurements of the masseter muscle and cephalometric measurements representing the length of the superficial masseter muscle, the length and shape of the mandible and vertical facial proportions were demonstrated. Predictive equations from regression analyses were constructed to deduce ramus length and shape from the ultrasound measurements. The results provide pilot data suggesting that ultrasound is a potential clinical tool for sequential evaluation of masseter muscle length in orthodontics and facial muscle growth studies.

  3. Ultrasound

    Science.gov (United States)

    ... Saunders; 2014:chap 66. Cosgrove DO, Eckersley RJ, Harvey CJ, Lim A. Ultrasound. In: Adam A, Dixon AK, Gillard ... Northside Radiology Associates, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  4. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, E F; Strandberg, C; Bendtsen, F

    1999-01-01

    BACKGROUND: Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler with that of tran......BACKGROUND: Endoscopic ultrasound (EUS) is a new technique that makes it possible to measure portal venous flow when transabdominal ultrasound fails. As the technique has not been evaluated previously, we compared simultaneous measurements of portal venous flow using EUS Doppler...... with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated. METHODS: Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA...... echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug...

  5. Quantitative Cerebral Blood Flow Measurements Using MRI

    OpenAIRE

    Muir, Eric R; Watts, Lora Talley; Tiwari, Yash Vardhan; Bresnen, Andrew; Timothy Q Duong

    2014-01-01

    Magnetic resonance imaging utilized as a quantitative and noninvasive method to image cerebral blood flow. The two most common techniques used to detect cerebral blood flow are dynamic susceptibility contrast (DSC) perfusion MRI and arterial spin labeling perfusion MRI. Herein we describe the use of these two techniques to measure cerebral blood flow in rodents, including methods, analysis, and important considerations when utilizing these techniques.

  6. Preterm neonatal lateral ventricle volume from three-dimensional ultrasound is not strongly correlated to two-dimensional ultrasound measurements.

    Science.gov (United States)

    Kishimoto, Jessica; de Ribaupierre, Sandrine; Salehi, Fateme; Romano, Walter; Lee, David S C; Fenster, Aaron

    2016-10-01

    The aim of this study is to compare longitudinal two-dimensional (2-D) and three-dimensional (3-D) ultrasound (US) estimates of ventricle size in preterm neonates with posthemorrhagic ventricular dilatation (PHVD) using quantitative measurements of the lateral ventricles. Cranial 2-D US and 3-D US images were acquired from neonatal patients with diagnosed PHVD within 10 min of each other one to two times per week and analyzed offline. Ventricle index, anterior horn width, third ventricle width, and thalamo-occipital distance were measured on the 2-D images and ventricle volume (VV) was measured from 3-D US images. Changes in the measurements between successive image sets were also recorded. No strong correlations were found between VV and 2-D US measurements ([Formula: see text] between 0.69 and 0.36). Additionally, weak correlations were found between changes in 2-D US measurements and 3-D US VV ([Formula: see text] between 0.13 and 0.02). A trend was found between increasing 2-D US measurements and 3-D US-based VV, but this was not the case when comparing changes between 3-D US VV and 2-D US measurements. If 3-D US-based VV provides a more accurate estimate of ventricle size than 2-D US measurements, moderate-weak correlations with 3-D US suggest that monitoring preterm patients with PHVD using 2-D US measurements alone might not accurately represent whether the ventricles are progressively dilating. A volumetric measure (3-D US or MRI) could be used instead to more accurately represent changes.

  7. Quantitative tomographic measurements of opaque multiphase flows

    Energy Technology Data Exchange (ETDEWEB)

    GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN; O' HERN,TIMOTHY J.; CECCIO,STEVEN L.

    2000-03-01

    An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDT and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.

  8. Validation of a novel ultrasound measurement of achilles tendon length

    DEFF Research Database (Denmark)

    Barfod, Kristoffer Weisskirchner; Riecke, Anja Falk; Boesen, Anders

    2014-01-01

    PURPOSE: A clinically applicable and accurate method for measuring Achilles tendon length is needed to investigate the influence of elongation of the Achilles tendon after acute rupture. The purpose of this study was to develop and validate an ultrasonographic (US) length measurement...... of the Achilles tendon-aponeurosis complex. METHODS: Both legs of 19 non-injured subjects were examined by magnetic resonance imaging (MRI) and US. The length from calcaneus to the medial head of m. Gastrocnemius was measured by three independent US examiners. Repeated US measurements were performed and compared...... to be further assessed in the setting of acute Achilles tendon rupture. CLINICAL RELEVANCE: This new ultrasound measurement might allow for length measurement of ruptured Achilles tendons in the acute and chronic state after rupture. LEVEL OF EVIDENCE: II....

  9. EX VIVO STUDY OF QUANTITATIVE ULTRASOUND PARAMETERS IN FATTY RABBIT LIVERS

    Science.gov (United States)

    Ghoshal, Goutam; Lavarello, Roberto J.; Kemmerer, Jeremy P.; Miller, Rita J.; Oelze, Michael L.

    2012-01-01

    Nonalcoholic fatty liver disease (NAFLD) affects more than 30% of Americans, and with increasing problems of obesity in the United States, NAFLD is poised to become an even more serious medical concern. At present, accurate classification of steatosis (fatty liver) represents a significant challenge. In this study, the use of high-frequency (8 to 25 MHz) quantitative ultrasound (QUS) imaging to quantify fatty liver was explored. QUS is an imaging technique that can be used to quantify properties of tissue giving rise to scattered ultrasound. The changes in the ultrasound properties of livers in rabbits undergoing atherogenic diets of varying durations were investigated using QUS. Rabbits were placed on a special fatty diet for 0, 3, or 6 weeks. The fattiness of the livers was quantified by estimating the total lipid content of the livers. Ultrasonic properties, such as speed of sound, attenuation, and backscatter coefficients, were estimated in ex vivo rabbit liver samples from animals that had been on the diet for varying periods. Two QUS parameters were estimated based on the backscatter coefficient: effective scatterer diameter (ESD) and effective acoustic concentration (EAC), using a spherical Gaussian scattering model. Two parameters were estimated based on the backscattered envelope statistics (the k parameter and the μ parameter) according to the homodyned K distribution. The speed of sound decreased from 1574 to 1565 m/s and the attenuation coefficient increased from 0.71 to 1.27 dB/cm/MHz, respectively, with increasing fat content in the liver. The ESD decreased from 31 to 17 μm and the EAC increased from 38 to 63 dB/cm3 with increasing fat content in the liver. A significant increase in the μ parameter from 0.18 to 0.93 scatterers/mm3 was observed with increasing fat content in the liver samples. The results of this study indicate that QUS parameters are sensitive to fat content in the liver. PMID:23062376

  10. Concentration measurement of yeast suspensions using high frequency ultrasound backscattering.

    Science.gov (United States)

    Elvira, Luis; Vera, Pedro; Cañadas, Francisco Jesús; Shukla, Shiva Kant; Montero, Francisco

    2016-01-01

    This work proposes the use of an ultrasound based technique to measure the concentration of yeasts in liquid suspension. This measurement was achieved by the detection and quantification of ultrasonic echoes backscattered by the cells. More specifically, the technique was applied to the detection and quantification of Saccharomyces cerevisiae. A theoretical approach was proposed to get the average density and sound speed of the yeasts, which were found to be 1116 kg/m(3) and 1679 m/s, respectively. These parameters were needed to model the waves backscattered by each single cell. A pulse-echo arrangement working around 50 MHz, being able to detect echoes from single yeasts was used to characterize experimentally yeast solutions from 10(2) to 10(7)cells/ml. The Non-negative Matrix Factorization denoising technique was applied for data analysis. This technique required a previous learning of the spectral patterns of the echoes reflected from yeasts in solution and the base noise from the liquid medium. Comparison between pulse correlation (without denoising) and theoretical and experimental pattern learning was made to select the best signal processing. A linear relation between ultrasound output and concentration was obtained with correlation coefficient R(2)=0.996 for the experimental learning. Concentrations from 10(4) to 10(7)cells/ml were detected above the base noise. These results show the viability of using the ultrasound backscattering technique to detect yeasts and measure their concentration in liquid cultures, improving the sensitivity obtained using spectrophotometric methods by one order of magnitude.

  11. Quantitative ultrasound facilitates the exploration of morphological association of the long head biceps tendon with supraspinatus tendon full thickness tear.

    Directory of Open Access Journals (Sweden)

    Ke-Vin Chang

    Full Text Available Pathology of the long head biceps tendon (LHBT is associated with rotator cuff tears but whether the LHBT texture changes following supraspinatus tendon full thickness tear (SSFT can be detected at the extra-articular segment remains unknown. This cross-sectional study aimed to explore the morphological differences of the LHBT in shoulders with and without deficient rotator cuffs by using quantitative ultrasound.We selected 145 cases with SSFT and 145 age-and- gender-matched controls. The width, thickness, flattening ratio, cross-sectional area, and echogenicity ratio of the LHBT were measured and a general linear model was used to clarify the relationship between rotator cuff pathology and LHBT morphology. The receiver operating characteristic curves of each parameter were constructed for SSFT discrimination and the maximal Youden indexes were used to define the best cut-off points.We found increased thickness and cross-sectional area but decreased flattening ratio in shoulders with SSFT, and no between-group differences in the width and echogenicity ratio. The LHBT appearance was modified by biceps peritendinous effusion and medial subluxation, but not by the size of SSFT. The flattening ratio was the best discriminator for SSFT with an area under curve of 0.81 (95% confidence interval, 0.76-0.86. The cut-off values to differentiate between the non-tear and tear groups were 2.00 mm of the thickness, 1.73 of the flattening ratio and 10.53 mm(2 of the cross-sectional area.Quantitative ultrasound facilitated the detection of the LHBT morphological changes following SSFT and demonstrated its potential utility in discriminating rotator cuff deficiency.

  12. Evaluation of breast lesions by contrast enhanced ultrasound: qualitative and quantitative analysis.

    Science.gov (United States)

    Wan, Caifeng; Du, Jing; Fang, Hua; Li, Fenghua; Wang, Lin

    2012-04-01

    To evaluate and compare the diagnostic performance of qualitative, quantitative and combined analysis for characterization of breast lesions in contrast enhanced ultrasound (CEUS), with histological results used as the reference standard. Ninety-one patients with 91 breast lesions BI-RADS 3-5 at US or mammography underwent CEUS. All lesions underwent qualitative and quantitative enhancement evaluation. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of different analytical method for discrimination between benign and malignant breast lesions. Histopathologic analysis of the 91 lesions revealed 44 benign and 47 malignant. For qualitative analysis, benign and malignant lesions differ significantly in enhancement patterns (pquantitative analysis, malignant lesions showed significantly higher (p=0.031) and faster enhancement (p=0.025) than benign ones, and its time to peak was significantly shorter (p=0.002). The areas under the ROC curve for qualitative, quantitative and combined analysis were 0.910 (A(z1)), 0.768 (A(z2)) and 0.926(A(z3)) respectively. The values of A(z1) and A(z3) were significantly higher than that for A(z2) (p=0.024 and p=0.008, respectively). But there was no significant difference between the values of A(z1) and A(z3) (p=0.625). The diagnostic performance of qualitative and combined analysis was significantly higher than that for quantitative analysis. Although quantitative analysis has the potential to differentiate benign from malignant lesions, it has not yet improved the final diagnostic accuracy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Quantitative Ultrasound Assessment of Myofascial Pain Syndrome Affecting the Trapezius: A Reliability Study.

    Science.gov (United States)

    Kumbhare, Dinesh; Shaw, Saurabh; Grosman-Rimon, Liza; Noseworthy, Michael D

    2017-07-03

    Myofascial pain syndrome is one of the most common causes of chronic pain and is highlighted by the presence of myofascial trigger points. The current practice of diagnosing myofascial pain syndrome among clinicians involves manual detection of myofascial trigger points, which can be inconsistent. However, the detection process can be strengthened with the assistance of ultrasound (US). Therefore, this study aimed to characterize the upper trapezius by using quantitative techniques in healthy asymptomatic individuals with neck pain. Study participants were recruited on the basis of the inclusion and exclusion criteria established, and US images of the trapezius, along the axial and longitudinal orientations, were obtained. Each set was obtained by 2 investigators: experienced and inexperienced personnel. Fifteen participants were recruited. The mean gray scale US echo intensity distribution obtained was 41.9. A paired t test of the global mean echo intensity value obtained for each image from the US operators did not show any significant difference (P = .77). A t test was performed, comparing the echo intensity of the group of patients with neck pain and healthy control participants, and the difference was found to be significant (P = .052). The median blob area was 2.71. The quartile range for the blob area was 1.72 for the 25th percentile to 4.90 for the 75th percentile. This study demonstrated that quantitative analysis of the echo intensity of US images can provide important information. However, further research is necessary to explore the relationships among sex, age, blob area, count, body mass index, regional anatomy, and extent of training or exercise of the particular muscle. © 2017 by the American Institute of Ultrasound in Medicine.

  14. Towards quantitative measures in applied ontology

    CERN Document Server

    Hoehndorf, Robert; Gkoutos, Georgios V

    2012-01-01

    Applied ontology is a relatively new field which aims to apply theories and methods from diverse disciplines such as philosophy, cognitive science, linguistics and formal logics to perform or improve domain-specific tasks. To support the development of effective research methodologies for applied ontology, we critically discuss the question how its research results should be evaluated. We propose that results in applied ontology must be evaluated within their domain of application, based on some ontology-based task within the domain, and discuss quantitative measures which would facilitate the objective evaluation and comparison of research results in applied ontology.

  15. Equipment, measurement and dose—a survey for therapeutic ultrasound

    OpenAIRE

    2016-01-01

    Background Dosimetry for Ultrasound Therapy (DUTy) is a large international project which addresses the development of a metrological infrastructure for the determination of ultrasound exposure and dose to tissue. Methods In order to seek the views of the wider therapy ultrasound community and to review dose and in situ exposure quantities that have been suggested or used previously, a web-based questionnaire containing a range of questions covering the type of ultrasound equipment that is us...

  16. Assessment of performance measures and learning curves for use of a virtual-reality ultrasound simulator in transvaginal ultrasound examination

    DEFF Research Database (Denmark)

    Madsen, M E; Konge, L; Nørgaard, L N

    2014-01-01

    OBJECTIVE: To assess the validity and reliability of performance measures, develop credible performance standards and explore learning curves for a virtual-reality simulator designed for transvaginal gynecological ultrasound examination. METHODS: A group of 16 ultrasound novices, along with a group......-6), corresponding to an average of 219 min (range, 150-251 min) of training. The test/retest reliability was high, with an intraclass correlation coefficient of 0.93. CONCLUSIONS: Competence in the performance of gynecological ultrasound examination can be assessed in a valid and reliable way using virtual-reality...... of 12 obstetrics/gynecology (Ob/Gyn) consultants, were included in this experimental study. The first two performances of the two groups on seven selected modules on a high-fidelity ultrasound simulator were used to identify valid and reliable metrics. Performance standards were determined and novices...

  17. NONINVASIVE MEASUREMENT OF LOCAL THERMAL DIFFUSIVITY USING BACKSCATTERED ULTRASOUND AND FOCUSED ULTRASOUND HEATING

    OpenAIRE

    2008-01-01

    Previously, noninvasive methods of estimating local tissue thermal and acoustic properties using backscattered ultrasound have been proposed in the literature. In this article, a noninvasive method of estimating local thermal diffusivity in situ during focused ultrasound heating using beamformed acoustic backscatter data and applying novel signal processing techniques is developed. A high intensity focused ultrasound (HIFU) transducer operating at subablative intensities is employed to create...

  18. Intravascular ultrasound radiofrequency analysis after optimal coronary stenting with initial quantitative coronary angiography guidance: An ATHEROREMO sub-study

    NARCIS (Netherlands)

    G. Sarno (Giovanna); S.A. Garg (Scot); J. Gomez-Lara (Josep); H.M. Garcia-Garcia (Hector); J.M.R. Ligthart (Jürgen); N. Bruining (Nico); Y. Onuma (Yoshinobu); K. Witberg (Karen); R.J.M. van Geuns (Robert Jan); S.P.M. de Boer (Sanneke); J.J. Wykrzykowska (Joanna); C.J. Schultz (Carl); H.J. Duckers (Henricus); E.S. Regar (Eveline); P.P.T. de Jaegere (Peter); P.J. de Feyter (Pim); G.A. van Es (Gerrit Anne); H. Boersma (Eric); W.J. van der Giessen (Wim); P.W.J.C. Serruys (Patrick)

    2011-01-01

    textabstractAims: To investigate whether the use of intravascular ultrasound virtual histology (IVUS-VH) leads to any improvements in stent deployment, when performed in patients considered to have had an optimal percutaneous coronary intervention (PCI) by quantitative coronary angiography (QCA). Me

  19. Agreement between anatomic and ultrasound measurements of femoral trochlear depth

    DEFF Research Database (Denmark)

    Miles, James Edward; Westrup, Ulrik; Eriksen, Thomas

    over the five regions examined. Measurement reliability for the ultrasonographic examinations was markedly less that for the skyline views (repeatability coefficient of 0.5mm vs 0.25mm), but still adequate for clinical use. A likely reason is the relative amount of detail recorded in the respective...... and ultrasonographic measurements of trochlear depth using the red fox hind limb as a canine surrogate, dividing the trochlea into five regions from the origin of the caudal cruciate ligament to the proximal aspect of the trochlea. We found reasonable agreement between anatomic and ultrasonographic measurements...... as assessed by Bland-Altman difference charting and limits of agreement (approximately ±0.7mm). Differences may be accounted for by ultrasound probe positioning errors, which should be taken into consideration during clinical investigations. Skyline views were difficult to standardise to a distinct position...

  20. Quantitative ultrasound of the hand phalanges in a cohort of monozygotic twins: influence of genetic and environmental factors

    Energy Technology Data Exchange (ETDEWEB)

    Guglielmi, G. [Scientific Institute Hospital, Department of Radiology, San Giovanni Rotondo (Italy); Terlizzi, F. de [IGEA Biophysics Lab, Carpi (Italy); Torrente, I.; Mingarelli, R. [Mendel Institute, Rome (Italy); Dallapiccola, B. [Scientific Institute Hospital, Department of Radiology, San Giovanni Rotondo (Italy); Mendel Institute, Rome (Italy)

    2005-11-01

    Our objective was to evaluate the similarities and differences in bone mass and structure between pairs of monozygotic twins as measured by means of the quantitative ultrasound (QUS) technique. A cohort of monozygotic twins was measured by QUS of the hand phalanges using the DBM sonic bone profiler (IGEA, Carpi, Italy). The parameters studied were amplitude-dependent speed of sound (AD-SoS), ultrasound bone profile index (UBPI), signal dynamics (SDy) and bone transmission time (BTT). Linear correlation coefficients, multivariate linear analysis and the ANOVA test were used to assess intrapair associations between variables and to determine which factors influence the intrapair differences in QUS variables. One hundred and six pairs of monozygotic twins were enrolled in the study, 68 females and 38 males in the age range 5 to 71 years. Significant intrapair correlations were obtained in the whole population and separately for males and females, regarding height (r =0.98-0.99, p <0.0001), weight (r =0.95-0.96, p <0.0001), AD-SoS (r =0.90-0.92, p <0.0001), BTT (r =0.94-0.95, p <0.0001) and other QUS parameters (r >0.74, p <0.0001). Multivariate analysis revealed that intrapair differences between AD-SoS, SDy, UBPI and BTT are significantly influenced by age in the whole population and in the female population. Furthermore, the ANOVA test showed, for the female group, a significant increase in the intrapair differences in SDy and UBPI above 40 years. A relative contribution of genetic factors to skeletal status could be observed by phalangeal QUS measurement in monozygotic twins. A significant increase in the intrapair difference in QUS parameters with increasing age and onset of menopause also suggests the importance of environmental factors in the female twin population. (orig.)

  1. Quantitative diagnostic method for biceps long head tendinitis by using ultrasound.

    Science.gov (United States)

    Huang, Shih-Wei; Wang, Wei-Te

    2013-01-01

    To investigate the feasibility of grayscale quantitative diagnostic method for biceps tendinitis and determine the cut-off points of a quantitative biceps ultrasound (US) method to diagnose biceps tendinitis. Design. Prospective cross-sectional case controlled study. Outpatient rehabilitation service. A total of 336 shoulder pain patients with suspected biceps tendinitis were recruited in this prospective observational study. The grayscale pixel data of the range of interest (ROI) were obtained for both the transverse and longitudinal views of the biceps US. A total of 136 patients were classified with biceps tendinitis, and 200 patients were classified as not having biceps tendinitis based on the diagnostic criteria. Based on the Youden index, the cut-off points were determined as 26.85 for the transverse view and 21.25 for the longitudinal view of the standard deviation (StdDev) of the ROI values, respectively. When the ROI evaluation of the US surpassed the cut-off point, the sensitivity was 68% and the specificity was 90% in the StdDev of the transverse view, and the sensitivity was 81% and the specificity was 73% in the StdDev of the longitudinal view to diagnose biceps tendinitis. For equivocal cases or inexperienced sonographers, our study provides a more objective method for diagnosing biceps tendinitis in shoulder pain patients.

  2. Quantitative assessment of wound healing using high-frequency ultrasound image analysis.

    Science.gov (United States)

    Mohafez, H; Ahmad, S A; Hadizadeh, M; Moghimi, S; Roohi, S A; Marhaban, M H; Saripan, M I; Rampal, S

    2017-05-29

    We aimed to develop a method for quantitative assessment of wound healing in ulcerated diabetic feet. High-frequency ultrasound (HFU) images of 30 wounds were acquired in a controlled environment on post-debridement days 7, 14, 21, and 28. Meaningful features portraying changes in structure and intensity of echoes during healing were extracted from the images, their relevance and discriminatory power being verified by analysis of variance. Relative analysis of tissue healing was conducted by developing a features-based healing function, optimised using the pattern-search method. Its performance was investigated through leave-one-out cross-validation technique and reconfirmed using principal component analysis. The constructed healing function could depict tissue changes during healing with 87.8% accuracy. The first principal component derived from the extracted features demonstrated similar pattern to the constructed healing function, accounting for 86.3% of the data variance. The developed wound analysis technique could be a viable tool in quantitative assessment of diabetic foot ulcers during healing. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Bone status in rheumatoid arthritis assessed at peripheral sites by three different quantitative ultrasound devices

    DEFF Research Database (Denmark)

    Madsen, O R; Suetta, C; Egsmose, C

    2004-01-01

    sites in 27 women with RA (mean disease duration 15 years) and in 36 healthy women matched for age, height and weight. Speed of sound (SOS, m/s), broadband ultrasound attenuation (BUA, dB/MHz) and stiffness of the calcaneus were assessed by a Lunar Achilles device. Amplitude-dependent SOS (Ad-SOS, m....../s) of the second to fifth phalanx was measured by a DBM Sonic 1200, and SOS of the distal forearm and third phalanx was measured by a Omnisense multisite scanner. Bone mass (g/cm2 or g) of the hip, spine, distal forearm and total body was measured by dual-energy X-ray absorptiometry. QUS values were significantly...

  4. Prediction of neonatal respiratory morbidity by quantitative ultrasound lung texture analysis: a multicenter study.

    Science.gov (United States)

    Palacio, Montse; Bonet-Carne, Elisenda; Cobo, Teresa; Perez-Moreno, Alvaro; Sabrià, Joan; Richter, Jute; Kacerovsky, Marian; Jacobsson, Bo; García-Posada, Raúl A; Bugatto, Fernando; Santisteve, Ramon; Vives, Àngels; Parra-Cordero, Mauro; Hernandez-Andrade, Edgar; Bartha, José Luis; Carretero-Lucena, Pilar; Tan, Kai Lit; Cruz-Martínez, Rogelio; Burke, Minke; Vavilala, Suseela; Iruretagoyena, Igor; Delgado, Juan Luis; Schenone, Mauro; Vilanova, Josep; Botet, Francesc; Yeo, George S H; Hyett, Jon; Deprest, Jan; Romero, Roberto; Gratacos, Eduard

    2017-08-01

    Prediction of neonatal respiratory morbidity may be useful to plan delivery in complicated pregnancies. The limited predictive performance of the current diagnostic tests together with the risks of an invasive procedure restricts the use of fetal lung maturity assessment. The objective of the study was to evaluate the performance of quantitative ultrasound texture analysis of the fetal lung (quantusFLM) to predict neonatal respiratory morbidity in preterm and early-term (Digital Imaging and Communication in Medicine format, and analyzed with quantusFLM. Physicians were blinded to the analysis. At delivery, perinatal outcomes and the occurrence of neonatal respiratory morbidity, defined as either respiratory distress syndrome or transient tachypnea of the newborn, were registered. The performance of the ultrasound texture analysis test to predict neonatal respiratory morbidity was evaluated. A total of 883 images were collected, but 17.3% were discarded because of poor image quality or exclusion criteria, leaving 730 observations for the final analysis. The prevalence of neonatal respiratory morbidity was 13.8% (101 of 730). The quantusFLM predicted neonatal respiratory morbidity with a sensitivity, specificity, positive and negative predictive values of 74.3% (75 of 101), 88.6% (557 of 629), 51.0% (75 of 147), and 95.5% (557 of 583), respectively. Accuracy was 86.5% (632 of 730) and positive and negative likelihood ratios were 6.5 and 0.3, respectively. The quantusFLM predicted neonatal respiratory morbidity with an accuracy similar to that previously reported for other tests with the advantage of being a noninvasive technique. Copyright © 2017. Published by Elsevier Inc.

  5. Assessment of tumor response to radiation and vascular targeting therapy in mice using quantitative ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    El Kaffas, Ahmed; Sadeghi-Naini, Ali; Falou, Omar; Tran, William Tyler; Czarnota, Gregory J., E-mail: gregory.czarnota@sunnybrook.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Imaging Research and Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Departments of Medical Biophysics and Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5G 1L7 (Canada); Zhou, Stephanie; Fernandes, Jason; Giles, Anoja [Imaging Research and Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Hashim, Amr [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Imaging Research and Physical Sciences, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada)

    2015-08-15

    Purpose: It is now recognized that the tumor vasculature is in part responsible for regulating tumor responses to radiation therapy. However, the extent to which radiation-based vascular damage contributes to tumor cell death remains unknown. In this work, quantitative ultrasound spectroscopy (QUS) methods were used to investigate the acute responses of tumors to radiation-based vascular treatments. Methods: Tumor xenografts (MDA-MB-231) were treated with single radiation doses of 2 or 8 Gy alone, or in combination with pharmacological agents that modulate vascular radiosensitivity. The midband fit, the slope, and the 0-MHz intercept QUS parameters were obtained from a linear-regression fit to the averaged power spectrum of frequency-dependent ultrasound backscatter and were used to quantify acute tumor responses following treatment administration. Power spectrums were extracted from raw volumetric radio-frequency ultrasound data obtained before and 24 h following treatment administration. These parameters have previously been correlated to tumor cell death. Staining using in situ end labeling, carbonic anhydrase 9 and cluster of differentiation 31 of tumor sections were used to assess cell death, oxygenation, and vasculature distributions, respectively. Results: Results indicate a significant midband fit QUS parameter increases of 3.2 ± 0.3 dBr and 5.4 ± 0.5 dBr for tumors treated with 2 and 8 Gy radiation combined with the antiangiogenic agent Sunitinib, respectively. In contrast, tumors treated with radiation alone demonstrated a significant midband fit increase of 4.4 ± 0.3 dBr at 8 Gy only. Preadministration of basic fibroblast growth factor, an endothelial radioprotector, acted to minimize tumor response following single large doses of radiation. Immunohistochemical analysis was in general agreement with QUS findings; an R{sup 2} of 0.9 was observed when quantified cell death was correlated with changes in midband fit. Conclusions: Results from QUS

  6. Comparison of sound speed measurements on two different ultrasound tomography devices

    Science.gov (United States)

    Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Sherman, Mark; Gierach, Gretchen; Malyarenko, Antonina

    2014-03-01

    Ultrasound tomography (UST) employs sound waves to produce three-dimensional images of breast tissue and precisely measures the attenuation of sound speed secondary to breast tissue composition. High breast density is a strong breast cancer risk factor and sound speed is directly proportional to breast density. UST provides a quantitative measure of breast density based on three-dimensional imaging without compression, thereby overcoming the shortcomings of many other imaging modalities. The quantitative nature of the UST breast density measures are tied to an external standard, so sound speed measurement in breast tissue should be independent of specific hardware. The work presented here compares breast sound speed measurement obtained with two different UST devices. The Computerized Ultrasound Risk Evaluation (CURE) system located at the Karmanos Cancer Institute in Detroit, Michigan was recently replaced with the SoftVue ultrasound tomographic device. Ongoing clinical trials have used images generated from both sets of hardware, so maintaining consistency in sound speed measurements is important. During an overlap period when both systems were in the same exam room, a total of 12 patients had one or both of their breasts imaged on both systems on the same day. There were 22 sound speed scans analyzed from each system and the average breast sound speeds were compared. Images were either reconstructed using saved raw data (for both CURE and SoftVue) or were created during the image acquisition (saved in DICOM format for SoftVue scans only). The sound speed measurements from each system were strongly and positively correlated with each other. The average difference in sound speed between the two sets of data was on the order of 1-2 m/s and this result was not statistically significant. The only sets of images that showed a statistical difference were the DICOM images created during the SoftVue scan compared to the SoftVue images reconstructed from the raw data

  7. Bone QUS measurement performed under loading condition, a more accuracy ultrasound method for osteoporosis diagnosis.

    Science.gov (United States)

    Liu, Chengrui; Niu, Haijun; Fan, Yubo; Li, Deyu

    2012-10-01

    Osteoporosis is a worldwide health problem with enormous social and economic impact. Quantitative ultrasound (QUS) method provides comprehensive information on bone mass, microstructure and mechanical properties of the bone. And the cheap, safe and portable ultrasound equipment is more suitable for public health monitoring. QUS measurement was normally performed on bone specimens without mechanical loading. But human bones are subjected to loading during routine daily activities, and physical loading leads to the changes of bone microstructure and mechanical properties. We hypothesized that bone QUS parameters measured under loading condition differ from those measured without loading because the microstructure of bone was changed when loading subjected to bone. Furthermore, when loading was subjected on bone, the loading-lead microstructure change of osteoporosis bone may larger than that of health bone. By considering the high relationship between bone microstructure and QUS parameters, the QUS parameters of osteoporosis bone may changed larger than that of health bone. So osteoporosis may be detected more effectively by the combination of QUS method and mechanical loading.

  8. Ultrasound measurements of intraabdominal fat estimate the metabolic syndrome better than do measurements of waist circumference

    NARCIS (Netherlands)

    Stolk, RP; Meijer, Rudy; Mali, WPTM; Grobbee, DE; van der Graaf, Y

    2003-01-01

    Background: We recently developed an ultrasound technique to estimate intraabdominal fat (IAF). This method is more accurate than measurement of waist and hip circumferences and is simpler and less expensive than computed tomography or magnetic resonance imaging. Objective: We compared the associati

  9. Performance of phalangeal quantitative ultrasound parameters in the evaluation of reduced bone mineral density assessed by DX in patients with 21 hydroxylase deficiency.

    Science.gov (United States)

    Gonçalves, Ezequiel M; Sewaybricker, Leticia E; Baptista, Fatima; Silva, Analiza M; Carvalho, Wellington R G; Santos, Allan O; de Mello, Maricilda P; Lemos-Marini, Sofia H V; Guerra, Gil

    2014-07-01

    The purpose of this study was to verify the performance of quantitative ultrasound (QUS) parameters of proximal phalanges in the evaluation of reduced bone mineral density (BMD) in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21 OHD). Seventy patients with 21 OHD (41 females and 29 males), aged between 6-27 y were assessed. The QUS measurements, amplitude-dependent speed of sound (AD-SoS), bone transmission time (BTT), and ultrasound bone profile index (UBPI) were obtained using the BMD Sonic device (IGEA, Carpi, Italy) on the last four proximal phalanges in the non-dominant hand. BMD was determined by dual energy X-ray (DXA) across the total body and lumbar spine (LS). Total body and LS BMD were positively correlated to UBPI, BTT and AD-SoS (correlation coefficients ranged from 0.59-0.72, p bone mass in patients with 21 OHD.

  10. Quantitative parameter character of choroidal melanoma in contrast-enhanced ultrasound

    Institute of Scientific and Technical Information of China (English)

    YANG Wen-li; WEI Wen-bin; LI Dong-jun

    2012-01-01

    Background Choroidal melanoma is the most common intraocular malignant tumor in adults.It threatens not only the visual function but also the patient's life.Therefore,it is important to find a non-traumatic,quantitative and repetitive diagnostic method.This study investigated the value of quantitative analysis of contrast-enhanced ultrasound (CEUS) in the diagnosis of choroidal melanoma.Methods CEUS were performed in 51 cases of choroidal melanoma,which were diagnosed either pathologically or clinically and in 14 cases of choroidal hemangioma.The characteristics of the time-intensity curve of the contrast agent were analyzed.For the quantitative analysis,the following parameters of the contrast agent in the lesion were included:rising time (RT),time to peak (TTP),maximum intensity (MI) and the mean transit time (MTT).Results Choroidal melanoma had the following characteristics on CEUS:Choroidal lesions were completely filled with contrast agent.The typical filling pattern was centripetal,with the peripheral of the choroidal lesion filled with the contrast agent first and then the center of the lesion.In some cases,areas with contrast agent filling defect were obseved in the lesions.The contrast agent filled the lesion slower than the normal eye and orbital tissue but faded faster in the lesion.Quantitative analysis showed that in choroidal melanoma,MI of contrast agent (191.31%±146.90%) was significantly more than that of the normal tissue (100.00%±0.00%) (P <0.05) and MTT ((63.56±26.04) seconds) was significanly less than that of the normal tissue ((149.87±182.68)seconds) (P <0.05).TTP (22.80±9.85) was less than that of the normal tissue ((29.57±24.76) seconds) and RT ((18.52±7.09) seconds) was less than that of the normal tissue ((26.45±21.83) seconds).Both the differences of TTP and RT were not statistically significant though.Logistic regression showed that to predict choroidal melanoma and choroidal hemangioma with MI and MTT

  11. Non-Invasive Measurement of Pulsatile Intracranial Pressures Using Ultrasound

    Science.gov (United States)

    Ueno, Toshiaki; Ballard, Richard E.; Shuer, Lawrence M.; Cantrell, John H.; Cantrell, John H.; Hargens, Alan R.

    1997-01-01

    Early detection of elevated intracranial pressure (ICP) will aid clinical decision-making for head trauma, brain tumor and other cerebrovascular diseases. Conventional methods, however, require surgical procedures which take time and are accompanied by increased risk of infection. Accordingly we have developed and refined a new ultrasound device to measure skull movements which are known to occur in conjunction with altered ICP. The principle of this device is based upon pulse phase locked loop (PPLL), which enables us to detect changes in distance on the order of microns between an ultrasound transducer on one side of the skull and the opposite inner surface of the cranium. The present study was designed to verify this measurement technique in cadavera. Transcranial distance was increased in steps of 10 mmHg from zero to 50 mmHg by saline infusion into the lateral ventricle of two cadavera. In separate experiments, pulsations of ICP with the amplitudes of zero to 2 mmHg were generated by rhythmic injections of saline using a syringe. When the ICP was stepwise increased from zero to 50 mmHg, transcranial distance increased in proportion with the ICP increase (y=12 x - 76, r=0.938), where y is changes in transcranial distance in microns and x is ICP in mmHg. In the data recorded while ICP pulsations were generated, fast Fourier transform analysis demonstrated that cranial pulsations were clearly associated with ICP pulsations. The results indicate that changes in transcranial distance is linearly correlated with those in ICP, and also that the PPLL device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. By analyzing the magnitude of cranial pulsations, we may be able to estimate the pressure-volume index in the cranium. As a result, estimates of intracranial compliance may be possible by using the PPLL device. Further studies are necessary in normal subjects and patients.

  12. Non-Invasive Measurement of Pulsatile Intracranial Pressures Using Ultrasound

    Science.gov (United States)

    Ueno, Toshiaki; Ballard, Richard E.; Shuer, Lawrence M.; Cantrell, John H.; Cantrell, John H.; Hargens, Alan R.

    1997-01-01

    Early detection of elevated intracranial pressure (ICP) will aid clinical decision-making for head trauma, brain tumor and other cerebrovascular diseases. Conventional methods, however, require surgical procedures which take time and are accompanied by increased risk of infection. Accordingly we have developed and refined a new ultrasound device to measure skull movements which are known to occur in conjunction with altered ICP. The principle of this device is based upon pulse phase locked loop (PPLL), which enables us to detect changes in distance on the order of microns between an ultrasound transducer on one side of the skull and the opposite inner surface of the cranium. The present study was designed to verify this measurement technique in cadavera. Transcranial distance was increased in steps of 10 mmHg from zero to 50 mmHg by saline infusion into the lateral ventricle of two cadavera. In separate experiments, pulsations of ICP with the amplitudes of zero to 2 mmHg were generated by rhythmic injections of saline using a syringe. When the ICP was stepwise increased from zero to 50 mmHg, transcranial distance increased in proportion with the ICP increase (y=12 x - 76, r=0.938), where y is changes in transcranial distance in microns and x is ICP in mmHg. In the data recorded while ICP pulsations were generated, fast Fourier transform analysis demonstrated that cranial pulsations were clearly associated with ICP pulsations. The results indicate that changes in transcranial distance is linearly correlated with those in ICP, and also that the PPLL device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. By analyzing the magnitude of cranial pulsations, we may be able to estimate the pressure-volume index in the cranium. As a result, estimates of intracranial compliance may be possible by using the PPLL device. Further studies are necessary in normal subjects and patients.

  13. Automatic Ultrasound Scanning

    DEFF Research Database (Denmark)

    Moshavegh, Ramin

    Medical ultrasound has been a widely used imaging modality in healthcare platforms for examination, diagnostic purposes, and for real-time guidance during surgery. However, despite the recent advances, medical ultrasound remains the most operator-dependent imaging modality, as it heavily relies...... on the user adjustments on the scanner interface to optimize the scan settings. This explains the huge interest in the subject of this PhD project entitled “AUTOMATIC ULTRASOUND SCANNING”. The key goals of the project have been to develop automated techniques to minimize the unnecessary settings...... on the scanners, and to improve the computer-aided diagnosis (CAD) in ultrasound by introducing new quantitative measures. Thus, four major issues concerning automation of the medical ultrasound are addressed in this PhD project. They touch upon gain adjustments in ultrasound, automatic synthetic aperture image...

  14. Time-resolved quantitative multiphase interferometric imaging of a highly focused ultrasound pulse

    CERN Document Server

    Souris, Fabien; Jacquier, Philippe; Dupont-Roc, Jacques; Arvengas, Arnaud; Caupin, Frédéric; 10.1364/AO.49.006127

    2010-01-01

    Interferometric imaging is a well established method to image phase objects by mixing the image wavefront with a reference one on a CCD camera. It has also been applied to fast transient phenomena, mostly through the analysis of single interferograms. It is shown that for repetitive phenomena multiphase acquisition brings significant advantages. A 1 MHz focused sound field emitted by a hemispherical piezotransducer in water is imaged as an example. Quantitative image analysis provides high resolution sound field profiles. Pressure at focus determined by this method agrees with measurements from a fiber-optic probe hydrophone. This confirms that multiphase interferometric imaging can indeed provide quantitative measurements.

  15. Quantitative Measurement of Oxygen in Microgravity Combustion

    Science.gov (United States)

    Silver, Joel A.

    1997-01-01

    A low-gravity environment, in space or in ground-based facilities such as drop towers, provides a unique setting for studying combustion mechanisms. Understanding the physical phenomena controlling the ignition and spread of flames in microgravity has importance for space safety as well as for better characterization of dynamical and chemical combustion processes which are normally masked by buoyancy and other gravity-related effects. Due to restrictions associated with performing measurements in reduced gravity, diagnostic methods which have been applied to microgravity combustion studies have generally been limited to capture of flame emissions on film or video, laser Schlieren imaging and (intrusive) temperature measurements using thermocouples. Given the development of detailed theoretical models, more sophisticated diagnostic methods are needed to provide the kind of quantitative data necessary to characterize the properties of microgravity combustion processes as well as provide accurate feedback to improve the predictive capabilities of the models. When the demands of space flight are considered, the need for improved diagnostic systems which are rugged, compact, reliable, and operate at low power becomes apparent. The objective of this research is twofold. First, we want to develop a better understanding of the relative roles of diffusion and reaction of oxygen in microgravity combustion. As the primary oxidizer species, oxygen plays a major role in controlling the observed properties of flames, including flame front speed (in solid or liquid flames), extinguishment characteristics, flame size and flame temperature. The second objective is to develop better diagnostics based on diode laser absorption which can be of real value in both microgravity combustion research and as a sensor on-board Spacelab as either an air quality monitor or as part of a fire detection system. In our prior microgravity work, an eight line-of-sight fiber optic system measured

  16. Femoral anteversion measured by ultrasound and CT: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Aamodt, A. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Terjesen, T. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Eine, J. [Dept. of Orthopaedic Surgery, Trondheim Univ. Hospital (Norway); Kvistad, K.A. [Dept. of Radiology, Trondheim Univ. Hospital (Norway)

    1995-02-01

    Both computed tomography (CT) and ultrasonography have been used successfully to estimate the femoral anteversion (AV) angle. In this study, AV angles in 20 human adult femurs were determined by ultrasonography and CT and the measurements compared. On CT the real AV angle was measured as the angle between the head-neck centreline and the posterior condylar plane. In addition, the angle between the anterior head-trochanter (HT) tangent and the posterior condylar plane was determined. The latter angle was also measured by ultrasonography using the tilted transducer technique. The mean interobserver variation in the ultrasound measurements was 1.9 . We found ultrasonography to correlate very well with CT, both when comparing with the HT angle (r=0.95) and with the AV angle (r=0.93). The HT angle was on average 4 greater than the AV angle. In this study the accuracy of ultrasonography was {+-}5 and the method is recommended for screening in patients with rotational disorders of the femur. (orig.)

  17. Quantitative measurement of resist outgassing during exposure

    Science.gov (United States)

    Maxim, Nicolae; Houle, Frances A.; Huijbregtse, Jeroen; Deline, Vaughn R.; Truong, Hoa; van Schaik, Willem

    2009-03-01

    Determination of both the identity and quantity of species desorbing from photoresists during exposure at any wavelength - 248nm, 193nm and EUV - has proved to be very challenging, adding considerable uncertainty to the evaluation of risks posed by specific photoresists to exposure tool optics. Measurements using a variety of techniques for gas detection and solid film analysis have been reported but analytical results have not in general been easy to compare or even in apparent agreement, in part due to difficulties in establishing absolute calibrations. In this work we describe two measurement methods that can be used for any exposure wavelength, and show that they provide self-consistent quantitative outgassing data for 2 all-organic and 2 Si-containing 193 nm resists. The first method, based upon gas collection, uses two primary chromatographic techniques. Organic products containing C, S and Si are determined by collection of vapors emitted during exposure in a cold trap and analysis by Gas Chromatography-Flame Ionization Detector-Pulsed Flame Photometric Detector-Mass Spectrometry (GC-FID-PFPD-MS). Inorganic products such as SO2 are identified by adsorbent bed with analysis by Gas Particle-Ion Chromatography (GP-IC). The calibration procedure used provides reasonable accuracy without exhaustive effort. The second method analyzes the elemental concentrations in resist films before and after exposure by secondary ion mass spectrometry technique (SIMS), which requires only knowledge of the resist compositions to be quantitative. The extent of outgassing of C and S determined by the two methods is in good agreement for all 4 resists, especially when taking their fundamentally different characters into account. Overall, the gas collection techniques yielded systematically lower outgassing numbers than did SIMS, and the origins of the spread in values, which likely bracket the true values, as well as detection limits will be discussed. The data for Si were found to

  18. Comparative study of contrast-enhanced ultrasound qualitative and quantitative analysis for identifying benign and malignant breast tumor lumps.

    Science.gov (United States)

    Liu, Jian; Gao, Yun-Hua; Li, Ding-Dong; Gao, Yan-Chun; Hou, Ling-Mi; Xie, Ting

    2014-01-01

    To compare the value of contrast-enhanced ultrasound (CEUS) qualitative and quantitative analysis in the identification of breast tumor lumps. Qualitative and quantitative indicators of CEUS for 73 cases of breast tumor lumps were retrospectively analyzed by univariate and multivariate approaches. Logistic regression was applied and ROC curves were drawn for evaluation and comparison. The CEUS qualitative indicator-generated regression equation contained three indicators, namely enhanced homogeneity, diameter line expansion and peak intensity grading, which demonstrated prediction accuracy for benign and malignant breast tumor lumps of 91.8%; the quantitative indicator-generated regression equation only contained one indicator, namely the relative peak intensity, and its prediction accuracy was 61.5%. The corresponding areas under the ROC curve for qualitative and quantitative analyses were 91.3% and 75.7%, respectively, which exhibited a statistically significant difference by the Z test (Pqualitative analysis to identify breast tumor lumps is better than with quantitative analysis.

  19. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, E F; Strandberg, C; Bendtsen, F;

    1999-01-01

    with that of transit time ultrasound (TTU) in healthy pigs. The ability of EUS to detect changes in the portal venous flow after pharmacologic intervention was also investigated. METHODS: Six anaesthetized pigs were studied. Portal venous flow was measured simultaneously by EUS duplex scanning, using a Pentax FG-32UA...

  20. Endoscopic ultrasound duplex scanning for measurement of portal venous flow. Validation against transit time ultrasound flowmetry in pigs

    DEFF Research Database (Denmark)

    Hansen, Erik Feldager; Strandberg, C; Bendtsen, F;

    1999-01-01

    echoendoscope connected to a Hitachi EUB 515-A ultrasound scanner, and by TTU with a Cardiomed CM 4000 flowmeter probe placed on the portal vein. Terlipressin, 1 mg, and placebo were administered in a blind, randomized, crossover design. Measurements were taken at base line and 30 min after each drug...

  1. Validation of Doppler ultrasound and magnetic resonance imaging velocity measurements by means of a test object

    NARCIS (Netherlands)

    Oostayen, J.A. van; Bezemer, R.A.; Wasser, M.N.J.M.; Teirlinck, C.J.P.M.

    1996-01-01

    Objective: To validate Doppler ultrasound and MRI mean velocity measurements in a test object in which mean velocities are known and can be chosen within a range of 10-100 cm/s in tubes of 4 and 8 mm. This validation was carried out to check the performance of a duplex Doppler ultrasound system that

  2. Correlation between self-reported gestational age and ultrasound measurements

    DEFF Research Database (Denmark)

    Olesen, Annette Wind; Westergaard, Jes Grabow; Thomsen, Sten Grove;

    2004-01-01

    Hospital Discharge Register. METHODS: The ultrasound-estimated gestational length was based on the size of the biparietal diameter. The ultrasound-estimated gestational length was related to corrected and uncorrected last menstrual period estimates in the Danish National Cohort Study......, and to the gestational length recorded in the Danish National Discharge Register. Non-parametric statistics were used in the analysis. RESULTS: The gestational ages estimated by ultrasound were 2-3 days shorter than gestational ages estimated by the other methods. The gestational ages recorded by the Discharge Register...

  3. Radial Quantitative Ultrasound and Dual Energy X-Ray Absorptiometry: Intermethod Agreement for Bone Status Assessment in Children

    Directory of Open Access Journals (Sweden)

    Kar Hau Chong

    2015-01-01

    Full Text Available Aim. To validate a radial quantitative ultrasound (QUS system with dual energy X-ray absorptiometry (DXA, a criterion technique in bone status assessment among children. Methods. Bone health was evaluated using a radial QUS system (Sunlight Omnisense 8000P to measure the speed of sound (SOS at one-third distal radius of the nondominant hand and DXA (Hologic QDR was used to assess whole body bone mineral density (BMD. Results. Some 29.9% of the children were grossly misclassified according to quartiles of BMD and radial SOS. Poor agreement was observed between Z-scores of radial SOS and whole-body BMD (mean difference = 0.6 ± 0.9; 95% limits of agreement = −1.4 to 2.6. With a cut-off value of −1.0, radial SOS yielded satisfactory sensitivity (80% and specificity (93% for the detection of children with low BMD. Conclusion. The observed poor agreement in the present study suggests that radial QUS and DXA are not comparable and hence are not interchangeable in evaluating bone status of the children.

  4. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network.

    Science.gov (United States)

    Xing, Jida; Chen, Jie

    2015-06-23

    In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared to our previous

  5. Comparison of portable and conventional ultrasound imaging in spinal curvature measurement

    Science.gov (United States)

    Yan, Christina; Tabanfar, Reza; Kempston, Michael; Borschneck, Daniel; Ungi, Tamas; Fichtinger, Gabor

    2016-03-01

    PURPOSE: In scoliosis monitoring, tracked ultrasound has been explored as a safer imaging alternative to traditional radiography. The use of ultrasound in spinal curvature measurement requires identification of vertebral landmarks, but bones have reduced visibility in ultrasound imaging and high quality ultrasound machines are often expensive and not portable. In this work, we investigate the image quality and measurement accuracy of a low cost and portable ultrasound machine in comparison to a standard ultrasound machine in scoliosis monitoring. METHODS: Two different kinds of ultrasound machines were tested on three human subjects, using the same position tracker and software. Spinal curves were measured in the same reference coordinate system using both ultrasound machines. Lines were defined by connecting two symmetric landmarks identified on the left and right transverse process of the same vertebrae, and spinal curvature was defined as the transverse process angle between two such lines, projected on the coronal plane. RESULTS: Three healthy volunteers were scanned by both ultrasound configurations. Three experienced observers localized transverse processes as skeletal landmarks and obtained transverse process angles in images obtained from both ultrasounds. The mean difference per transverse process angle measured was 3.00 +/-2.1°. 94% of transverse processes visualized in the Sonix Touch were also visible in the Telemed. Inter-observer error in the Telemed was 4.5° and 4.3° in the Sonix Touch. CONCLUSION: Price, convenience and accessibility suggest the Telemed to be a viable alternative in scoliosis monitoring, however further improvements in measurement protocol and image noise reduction must be completed before implementing the Telemed in the clinical setting.

  6. Measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography.

    Science.gov (United States)

    Chino, Kentaro; Akagi, Ryota; Dohi, Michiko; Takahashi, Hideyuki

    2014-09-01

    The B-mode ultrasound image that can measure muscle architecture is displayed side by side with the ultrasound strain elastogram that can assess muscle hardness. Consequently, muscle architecture can be measured concurrently with muscle hardness using ultrasound strain elastography. To demonstrate the measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography. Concurrent measurements of muscle architectural parameters (muscle thickness, pennation angle, and fascicle length) and muscle hardness of the medial gastrocnemius were performed with ultrasound strain elastography. Separate measurements of the muscle architectural parameters were also performed for use as reference values for the concurrent measurements. Both types of measurements were performed twice at 20° dorsiflexion, neutral position, and 30° plantar flexion. Coefficients of variance of the muscle architectural parameters obtained from the concurrent measurements (≤7.6%) were significantly higher than those obtained from the separate measurements (≤2.4%) (all P muscle architectural parameters between the concurrent and separate measurements (all P > 0.05). The use of ultrasound strain elastography for the concurrent measurement of muscle architecture and muscle hardness is feasible. © The Foundation Acta Radiologica 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  7. Reliability of period of gestation determined by ultrasound scan measurements

    Directory of Open Access Journals (Sweden)

    Chrishantha Abeysena

    2011-05-01

    Full Text Available Methods: One hundred and eighty pregnant women were divided into three equal groups. Each group was assigned a rater to perform ultrasound scan to measure bi-parietal diameter, femur length, abdominal circumference and head circumference and to compute the respective periods of gestation using these four measurements. Reliability between periods of gestation derived by each rater from above four measurements were analysed using repeated measure ANOVA. Results were expressed as intra-class correlation coefficients (ICCs and coefficients of variation (CsOV.Results: For Raters I (F= 6.47; p=0.001 and II, (F= 4.80; p= 0.003, computations using abdominal circumferences resulted in the lowest mean periods of gestation (PsOG. For Rater III, computations using both femur length and abdominal circumference resulted in the lowest mean periods of gestation (F= 7.5; p=0.001. ICCs were 0.73 (95%CI 0.64–0.81 for Rater I, 0.78 (95% CI 0.70–0.85 for Rater II and 0.87 (95% CI 0.81– 0.91 for Rater IIIWhen comparing CsOV, the highest variation for Raters I and III was observed for femur length. For Rater II it was bi-parietal diameter. The lowest variation for Rater I was observed for head circumference and for Raters II and III for abdominal circumference. The highest CsOV of all the PsOG were demonstrated by Rater III.When comparing the differences between the highest and the lowest values for each period of gestation determined, the difference was more than two weeks for 38% (n=23, 24% (n=14 and 22% (n=13 of observations made by Raters I, II and III respectively. Conclusions: Reliability of period of gestation depends on the type of measurement taken, method of assessment and the rater who performs the measurements. Our findings are not conclusive enough to recommend any PsOG based on specific measurement more reliable than others. In-service training of the obstetricians is likely to improve the reliability of PsOG determined using ultra sound scan

  8. Head-to-head comparison of quantitative and semi-quantitative ultrasound scoring systems for rheumatoid arthritis

    DEFF Research Database (Denmark)

    Terslev, Lene; Ellegaard, Karen; Christensen, Robin;

    2012-01-01

    To evaluate the reliability and agreement of semi-quantitative scoring (SQS) and quantitative scoring (QS) systems. To compare the two types of scoring system and investigate the construct validity for both scoring systems.......To evaluate the reliability and agreement of semi-quantitative scoring (SQS) and quantitative scoring (QS) systems. To compare the two types of scoring system and investigate the construct validity for both scoring systems....

  9. The correlation of contrast-enhanced ultrasound and MRI perfusion quantitative analysis in rabbit VX2 liver cancer.

    Science.gov (United States)

    Xiang, Zhiming; Liang, Qianwen; Liang, Changhong; Zhong, Guimian

    2014-12-01

    Our objective is to explore the value of liver cancer contrast-enhanced ultrasound (CEUS) and MRI perfusion quantitative analysis in liver cancer and the correlation between these two analysis methods. Rabbit VX2 liver cancer model was established in this study. CEUS was applied. Sono Vue was applied in rabbits by ear vein to dynamically observe and record the blood perfusion and changes in the process of VX2 liver cancer and surrounding tissue. MRI perfusion quantitative analysis was used to analyze the mean enhancement time and change law of maximal slope increasing, which were further compared with the pathological examination results. Quantitative indicators of liver cancer CEUS and MRI perfusion quantitative analysis were compared, and the correlation between them was analyzed by correlation analysis. Rabbit VX2 liver cancer model was successfully established. CEUS showed that time-intensity curve of rabbit VX2 liver cancer showed "fast in, fast out" model while MRI perfusion quantitative analysis showed that quantitative parameter MTE of tumor tissue increased and MSI decreased: the difference was statistically significant (P 0.05). However, the quantitative parameter of them were significantly positively correlated (P liver cancer lesion and surrounding liver parenchyma, and the quantitative parameters of them are correlated. The combined application of both is of importance in early diagnosis of liver cancer.

  10. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    Directory of Open Access Journals (Sweden)

    Jorge J

    2013-02-01

    Full Text Available J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry, School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT and anterior chamber depth (ACD with that of CCT measurements obtained by ultrasound pachymetry and ACD measurements obtained by ultrasound biometry, respectively.Methods: CCT and ACD was measured in 50 right eyes from 50 healthy subjects using a Sirius Scheimpflug camera, SP100 ultrasound pachymetry, and US800 ultrasound biometry.Results: CCT measured with the Sirius was 546 ± 39 µm and 541 ± 35 µm with SP100 ultrasound pachymetry (P = 0.003. The difference was statistically significant (mean difference 4.68 ± 10.5 µm; limits of agreement −15.8 to 25.20 µm. ACD measured with the Sirius was 2.96 ± 0.3 mm compared with 3.36 ± 0.29 mm using US800 ultrasound biometry (P < 0.001. The difference was statistically significant (mean difference −0.40 ± 0.16 mm; limits of agreement −0.72 to 0.07 mm. When the ACD values obtained using ultrasound biometry were corrected according to the values for CCT measured by ultrasound, the agreement increased significantly between both technologies for ACD measurements (mean difference 0.15 ± 0.16 mm; limits of agreement −0.16 to 0.45 mm.Conclusion: CCT and ACD measured by Sirius and ultrasound methods showing good agreement between repeated measurements obtained in the same subjects (repeatability with either instrument. However, CCT and ACD values, even after correcting ultrasound ACD by subtracting the CCT value obtained with either technology should not be used interchangeably.Keywords: Scheimpflug corneal tomography, ultrasound biometry, ultrasound pachymetry, limits of agreement

  11. Measuring Femoral Torsion In Vivo Using Freehand 3-D Ultrasound Imaging.

    Science.gov (United States)

    Passmore, Elyse; Pandy, Marcus G; Graham, H Kerr; Sangeux, Morgan

    2016-02-01

    Despite variation in bone geometry, muscle and joint function is often investigated using generic musculoskeletal models. Patient-specific bone geometry can be obtained from computerised tomography, which involves ionising radiation, or magnetic resonance imaging (MRI), which is costly and time consuming. Freehand 3-D ultrasound provides an alternative to obtain bony geometry. The purpose of this study was to determine the accuracy and repeatability of 3-D ultrasound in measuring femoral torsion. Measurements of femoral torsion were performed on 10 healthy adults using MRI and 3-D ultrasound. Measurements of femoral torsion from 3-D ultrasound were, on average, smaller than those from MRI (mean difference = 1.8°; 95% confidence interval: -3.9°, 7.5°). MRI and 3-D ultrasound had Bland and Altman repeatability coefficients of 3.1° and 3.7°, respectively. Accurate measurements of femoral torsion were obtained with 3-D ultrasound offering the potential to acquire patient-specific bone geometry for musculoskeletal modelling. Three-dimensional ultrasound is non-invasive and relatively inexpensive and can be integrated into gait analysis.

  12. Quantitative Method of Measuring Metastatic Activity

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    1999-01-01

    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated uroldnase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  13. Coumarin fluorometry to quantitatively detectable OH radicals in ultrasound aqueous medium.

    Science.gov (United States)

    Hirano, Kohsuke; Kobayashi, Takaomi

    2016-05-01

    When ultrasound (US) was exposed to aqueous coumarin solution in air atmosphere, the UV-visible and fluorescence spectra of the probe were measured at different US exposure times. The US exposure was carried out at 43 kHz and 500 kHz with different out-put power. It was found that the 500 kHz US produced umbelliferone fluorescence, while the 43 kHz US had no fluorescence. In addition, the coumarin absorbance at 270 nm maximum was decreased with in cases of the US exposure time. In contrary, the fluorescent intensity of umbelliferone at 460 nm increased with increasing of US exposure time. This exhibited that the coumarin probe was converted to umbelliferone by the US exposure, when the 500 kHz US was operated. This was facted that the coumarin framework was caused with addition of OH groups which was generated by the 500 kHz US. Therefore, the umbelliferone fluorescent became a probe to estimate OH radical in US medium. Furthermore, the chemo-fluorometry showed that the emission maximum of the formed umbelliferone could probe the bulk pHs in the US aqueous medium.

  14. An automated in vitro model for the evaluation of ultrasound modalities measuring myocardial deformation

    Directory of Open Access Journals (Sweden)

    Stigö Albin

    2010-09-01

    Full Text Available Abstract Background Echocardiography is the method of choice when one wishes to examine myocardial function. Qualitative assessment of the 2D grey scale images obtained is subjective, and objective methods are required. Speckle Tracking Ultrasound is an emerging technology, offering an objective mean of quantifying left ventricular wall motion. However, before a new ultrasound technology can be adopted in the clinic, accuracy and reproducibility needs to be investigated. Aim It was hypothesized that the collection of ultrasound sample data from an in vitro model could be automated. The aim was to optimize an in vitro model to allow for efficient collection of sample data. Material & Methods A tissue-mimicking phantom was made from water, gelatin powder, psyllium fibers and a preservative. Sonomicrometry crystals were molded into the phantom. The solid phantom was mounted in a stable stand and cyclically compressed. Peak strain was then measured by Speckle Tracking Ultrasound and sonomicrometry. Results We succeeded in automating the acquisition and analysis of sample data. Sample data was collected at a rate of 200 measurement pairs in 30 minutes. We found good agreement between Speckle Tracking Ultrasound and sonomicrometry in the in vitro model. Best agreement was 0.83 ± 0.70%. Worst agreement was -1.13 ± 6.46%. Conclusions It has been shown possible to automate a model that can be used for evaluating the in vitro accuracy and precision of ultrasound modalities measuring deformation. Sonomicrometry and Speckle Tracking Ultrasound had acceptable agreement.

  15. Cardiac In-vivo Measurements Using Synthetic Transmit Aperture Ultrasound

    DEFF Research Database (Denmark)

    Andresen, Henrik; Nikolov, Svetoslav; Hassager, Christian

    2006-01-01

    This paper investigates the feasibility of acquiring cardiac images using synthetic transmit aperture (STA) ultrasound. Focusing in STA is done by beamforming all points in the image for every emission, creating a low-resolution image. The low-resolution images for each emission are summed......, together with the RASMUS experimental ultrasound scanner. Both transducers have a pitch of half a wavelength. To ensure an adequate signal-to-noise ratio, a 20 mus non-linear frequency modulated chirp and a 7-element de-focused virtual source were used for transmission. The number of virtual sources used...

  16. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... kidneys. There are three types of Doppler ultrasound: Color Doppler uses a computer to convert Doppler measurements ...

  17. Indium adhesion provides quantitative measure of surface cleanliness

    Science.gov (United States)

    Krieger, G. L.; Wilson, G. J.

    1968-01-01

    Indium tipped probe measures hydrophobic and hydrophilic contaminants on rough and smooth surfaces. The force needed to pull the indium tip, which adheres to a clean surface, away from the surface provides a quantitative measure of cleanliness.

  18. Estimation of femoral bone density from trabecular direct wave and cortical guided wave ultrasound velocities measured at the proximal femur in vivo

    DEFF Research Database (Denmark)

    Barkmann, Reinhard; Dencks, Stefanie; Bremer, Alexander

    2008-01-01

    Bone mineral density (BMD) of the proximal femur is a predictor of hip fracture risk. We developed a Quantitative Ultrasound (QUS) scanner for measurements at this site with similar performance (FemUS). In this study we tested if ultrasound velocities of direct waves through trabecular bone...... echoes reflected from the skin of the leg to yield speed-of-sound (SOS) of different wave components. Data were cross-calibrated and pooled (62 women). Bivariate correlations and a multivariate model were calculated for the estimation of femur BMD. BMD correlated both with trabecular and cortical SOS...

  19. Factors Affecting Estimated Fetal Weight Measured by Ultrasound

    Directory of Open Access Journals (Sweden)

    Hasan Energin

    2016-06-01

    Full Text Available Objective: In this study, we aimed to evaluate the fac­tors that affect the accuracy of estimated fetal weight in ultrasound. Methods: This study was conducted in 3rd degree hospi­tal antenatal outpatient clinic and perinatology inpatient clinic between June 2011 and January 2012. The data were obtained from 165 pregnant women. Inclusion cri­teria were; no additional diseases, giving birth within 48 hours after ultrasound. The same physician executed all ultrasound process. Age, height, weight, obstetric history and obstetric follow –up findings were recorded. Results: Fetal gender, fetal presentation, presence of meconium in amniotic fluid, maternal parity, did not sig­nificantly affect the accuracy of fetal weight estimation by ultrasound. The mean difference between estimated fetal weight and birth weight was 104.48±84 gr in nullipars and 94.2±81 gr in multipars (p=0.44; mean difference was 98.22±79 gr in male babies and 98.15±86 gr in female babies (p=0.99. Mean difference between estimated fetal weight and birth weight was 96.92±81 gr in babies with cephalic presentation and 110.9±90 gr in babies with breech presentation (p=0.53; this difference was 95.36±79 gr in babies with amniotic fluid with meconium and 98.82± 83 gr in babies with amniotic fluid without me­conium (p=0.83. Conclusion: Fetal weight is estimation is one of key points in the obstetrician’s intrapartum managament. And it is important to make fetal weight estimation accurately. In our study, consistent with literature, we observed that fetal gender; meconium presence in amniotic fluid, fetal presentation, maternal parity does not significantly effect the accuracy of fetal weight estimation by ultrasound.

  20. Measurement of Thermal Effects of Doppler Ultrasound: An In Vitro Study.

    Directory of Open Access Journals (Sweden)

    Samir Helmy

    Full Text Available Ultrasound is considered a safe imaging modality and is routinely applied during early pregnancy. However, reservations are expressed concerning the application of Doppler ultrasound in early pregnancy due to energy emission of the ultrasound probe and its conversion to heat. The objective of this study was to evaluate the thermal effects of emitted Doppler ultrasound of different ultrasound machines and probes by means of temperature increase of in-vitro test-media.We investigated the energy-output of 5 vaginal and abdominal probes of 3 ultrasound machines (GE Healthcare, Siemens, Aloka. Two in-vitro test objects were developed at the Center for Medical Physics and Biomedical Engineering, Medical University Vienna (water bath and hydrogel bath. Temperature increase during Doppler ultrasound emission was measured via thermal sensors, which were placed inside the test objects or on the probes' surface. Each probe was emitting for 5 minutes into the absorbing test object with 3 different TI/MI settings in Spectral Doppler mode.During water bath test, temperature increase varied between 0.1 and 1.0°C, depending on probe, setting and focus, and was found highest for spectral Doppler mode alone. Maximum temperature increase was found during the surface heating test, where values up to 2.4°C could be measured within 5 minutes of emission.Activation of Doppler ultrasound in the waterbath model causes a significant increase of temperature within one minute. Thermally induced effects on the embryo cannot be excluded when using Doppler ultrasound in early pregnancy.

  1. Measurement of neonatal heart rate using handheld Doppler ultrasound.

    Science.gov (United States)

    Dyson, Amanda; Jeffrey, Michele; Kluckow, Martin

    2017-03-01

    This pilot study aimed to determine whether handheld Doppler ultrasound is feasible and reliable for measuring neonatal heart rate (HR) when compared with ECG. Stable newborns were recruited from the neonatal intensive care unit and postnatal ward between July 2014 and January 2015 at Royal North Shore Hospital, Sydney, Australia. Each newborn had their HR recorded every 15 s over 145 s using four different modalities: ECG, counted audible Doppler (AD) over 10 s, pulse oximetry (PO) and the Doppler display (DD). The correlation and variation between each modality and ECG. 51 newborns with a median gestational age of 38 weeks (27-41) and a mean weight of 2.78 kg (0.82 to 4.76) with a median postnatal age of 3 days (0-87) were studied. There was a mean difference of 0.69 bpm (95% CI -2.9 to +1.5) between AD-HR and ECG-HR with good correlation between modalities (r=0.94, p<0.01). The median time to achieve AD-HR was 3 s (1-45). The mean difference between DD-HR and ECG-HR was 5.37 bpm (95% CI -12.8 to +2.1) with moderate correlation (r=0.37, p=0.04). The mean difference between PO-HR and ECG-HR was 0.49 bpm (95% CI -1.5 to +0.51) with good correlation (r=0.99, p<0.01). The variability between AD-HR and ECG-HR decreased with decreasing weight. AD-HR correlates well with ECG-HR. Further research in the delivery room is recommended before using AD-HR in this area. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Diagnostics for conformity of paired quantitative measurements.

    Science.gov (United States)

    Hawkins, Douglas M

    2002-07-15

    Matched pairs data arise in many contexts - in case-control clinical trials, for example, and from cross-over designs. They also arise in experiments to verify the equivalence of quantitative assays. This latter use (which is the main focus of this paper) raises difficulties not always seen in other matched pairs applications. Since the designs deliberately vary the analyte levels over a wide range, issues of variance dependent on mean, calibrations of differing slopes, and curvature all need to be added to the usual model assumptions such as normality. Violations in any of these assumptions invalidate the conventional matched pairs analysis. A graphical method, due to Bland and Altman, of looking at the relationship between the average and the difference of the members of the pairs is shown to correspond to a formal testable regression model. Using standard regression diagnostics, one may detect and diagnose departures from the model assumptions and remedy them - for example using variable transformations. Examples of different common scenarios and possible approaches to handling them are shown.

  3. Non-invasive measurement of pressure gradients using ultrasound

    DEFF Research Database (Denmark)

    Olesen, Jacob Bjerring; Traberg, Marie Sand; Pihl, Michael Johannes

    2013-01-01

    A non-invasive method for estimating 2-D pressure gradients from ultrasound vector velocity data is presented. The method relies on in-plane vector velocity fields acquired using the Transverse Oscillation method. The pressure gradients are estimated by applying the Navier-Stokes equations...... Medical 2202 UltraView Pro Focus scanner. The results are validated through finite element simulations of the carotid flow model where the geometry is determined from MR images. This proof of concept study was conducted at nine ultrasound frames per second. Estimated pressure gradients along...... the longitudinal direction of the constriction varied from 0 kPa/m to 10 kPa/m with a normalized bias of -9.1% for the axial component and -7.9% for the lateral component. The relative standard deviation of the estimator, given in reference to the peak gradient, was 28.4% in the axial direction and 64...

  4. Quantitative ultrasound of the calcaneus with parametric imaging: correlation with bone mineral density at different sites and with anthropometric data in menopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Louis, O.; Kaufman, L.; Osteaux, M

    2000-07-01

    Objective: To prospectively study the relationship of quantitative ultrasound of the calcaneus with anthromopometric variables and with bone mineral density (BMD) assessed at the level of the calcaneus as well as at other sites. Method: Osteosonography of the non-dominant calcaneus was performed in 135 menopausal women, using a DTU-one device with parametric imaging. Broadband ultrasound attenuation (BUA) and speed of sound (SOS) were assessed. BMD of the calcaneus (BMDcal) was measured using dual energy X-ray absorptiometry (DXA), in a subregion matched with the region of interest for osteosonography. BMD of the lumbar trabecular bone was measured using quantitative computed tomography (BMD QCT) while the non-dominant hip was studied using DXA, which provided the total bone mineral density (BMDhip) and that of the Ward triangle (BMDWard). Results: The Pearson correlation coefficients between BUA, SOS and the various measurements of BMD ranged from 0.305 (SOS versus BMDhip) to 0.717 (BUA versus BMDcal). BMD QCT and BMDWard were found to depend on age, but not on weight or height, while BUA, SOS, BMDcal, BMDhip were unrelated to age, but correlated with weight (SOS, BMDhip) or with weight and height (BUA, BMDcal). In a multiple stepwise regression analysis, age was a significant predictor for BMD QCT, BMD hip and BMDWard; BMD QCT, BMDWard and BMDhip admitted BUA as sole predictor, while BMDcal was significantly related to both BUA and SOS. Conclusion: BUA and SOS of the calcaneus, assessed in 135 menopausal women using a parametric imaging device, reflected BMDcal, measured with DXA at a matched region of interest, and did not decline significantly with age.

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... transducer into the body. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  7. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... needles are used to extract a sample of cells from organs for laboratory testing. Doppler ultrasound images ... ultrasound, measures the direction and speed of blood cells as they move through vessels. The movement of ...

  8. Computer aided prognosis for cell death categorization and prediction in vivo using quantitative ultrasound and machine learning techniques.

    Science.gov (United States)

    Gangeh, M J; Hashim, A; Giles, A; Sannachi, L; Czarnota, G J

    2016-12-01

    At present, a one-size-fits-all approach is typically used for cancer therapy in patients. This is mainly because there is no current imaging-based clinical standard for the early assessment and monitoring of cancer treatment response. Here, the authors have developed, for the first time, a complete computer-aided-prognosis (CAP) system based on multiparametric quantitative ultrasound (QUS) spectroscopy methods in association with texture descriptors and advanced machine learning techniques. This system was used to noninvasively categorize and predict cell death levels in fibrosarcoma mouse tumors treated using ultrasound-stimulated microbubbles as novel endothelial-cell radiosensitizers. Sarcoma xenograft tumor-bearing mice were treated using ultrasound-stimulated microbubbles, alone or in combination with x-ray radiation therapy, as a new antivascular treatment. Therapy effects were assessed at 2-3, 24, and 72 h after treatment using a high-frequency ultrasound. Two-dimensional spectral parametric maps were generated using the power spectra of the raw radiofrequency echo signal. Subsequently, the distances between "pretreatment" and "post-treatment" scans were computed as an indication of treatment efficacy, using a kernel-based metric on textural features extracted from 2D parametric maps. A supervised learning paradigm was used to either categorize cell death levels as low, medium, or high using a classifier, or to "continuously" predict the levels of cell death using a regressor. The developed CAP system performed at a high level for the classification of cell death levels. The area under curve of the receiver operating characteristic was 0.87 for the classification of cell death levels to both low/medium and medium/high levels. Moreover, the prediction of cell death levels using the proposed CAP system achieved a good correlation (r = 0.68,  p course of therapy to enable switching to more efficacious treatments.

  9. Quantitative Measures of Mineral Supply Risk

    Science.gov (United States)

    Long, K. R.

    2009-12-01

    Almost all metals and many non-metallic minerals are traded internationally. An advantage of global mineral markets is that minerals can be obtained from the globally lowest-cost source. For example, one rare-earth element (REE) mine in China, Bayan Obo, is able to supply most of world demand for rare earth elements at a cost significantly less than its main competitors. Concentration of global supplies at a single mine raises significant political risks, illustrated by China’s recent decision to prohibit the export of some REEs and severely limit the export of others. The expected loss of REE supplies will have a significant impact on the cost and production of important national defense technologies and on alternative energy programs. Hybrid vehicles and wind-turbine generators, for example, require REEs for magnets and batteries. Compact fluorescent light bulbs use REE-based phosphors. These recent events raise the general issue of how to measure the degree of supply risk for internationally sourced minerals. Two factors, concentration of supply and political risk, must first be addressed. Concentration of supply can be measured with standard economic tools for measuring industry concentration, using countries rather than firms as the unit of analysis. There are many measures of political risk available. That of the OECD is a measure of a country’s commitment to rule-of-law and enforcement of contracts, as well as political stability. Combining these measures provides a comparative view of mineral supply risk across commodities and identifies several minerals other than REEs that could suddenly become less available. Combined with an assessment of the impact of a reduction in supply, decision makers can use these measures to prioritize risk reduction efforts.

  10. Measuring wheel/rail contact stresses using ultrasound

    OpenAIRE

    Marhsall, M.B.; Lewis, R.; Dwyer-Joyce, R.S.; Olofsson, O.; Bjorklund, S

    2004-01-01

    The investigation of contact area and pressure distribution in a wheel/rail contact is essential information required in fatigue and wear calculations to determine design life, regrinding requirements, and maintenance schedules. The aim of this work was to use ultrasound to non-destructively determine wheel/rail contact pressures. Three different contacts were investigated those resulting from; un-used, sand damaged, and worn wheel/rail specimens. \\ud \\ud A wheel/rail interface behaves like a...

  11. Quantitative Ultrasound-Assisted Extraction for Trace-Metal Determination: An Experiment for Analytical Chemistry

    Science.gov (United States)

    Lavilla, Isela; Costas, Marta; Pena-Pereira, Francisco; Gil, Sandra; Bendicho, Carlos

    2011-01-01

    Ultrasound-assisted extraction (UAE) is introduced to upper-level analytical chemistry students as a simple strategy focused on sample preparation for trace-metal determination in biological tissues. Nickel extraction in seafood samples and quantification by electrothermal atomic absorption spectrometry (ETAAS) are carried out by a team of four…

  12. Three-dimensional quantitative coronary angiography and the registration with intravascular ultrasound and optical coherence tomography

    NARCIS (Netherlands)

    Tu, Shengxian

    2012-01-01

    This thesis proposes several new algorithms including X-ray angiographic image enhancement, three-dimensional (3D) angiographic reconstruction, angiographic overlap prediction, and the co-registration of X-ray angiography with intracoronary imaging devices, such as intravascular ultrasound (IVUS) an

  13. Quantitative Ultrasound-Assisted Extraction for Trace-Metal Determination: An Experiment for Analytical Chemistry

    Science.gov (United States)

    Lavilla, Isela; Costas, Marta; Pena-Pereira, Francisco; Gil, Sandra; Bendicho, Carlos

    2011-01-01

    Ultrasound-assisted extraction (UAE) is introduced to upper-level analytical chemistry students as a simple strategy focused on sample preparation for trace-metal determination in biological tissues. Nickel extraction in seafood samples and quantification by electrothermal atomic absorption spectrometry (ETAAS) are carried out by a team of four…

  14. Quantitative Measurement of the Digital Divide

    Science.gov (United States)

    Cottrell, Roger

    2007-04-01

    Bandwidth and the Internet infrastructure are the life-blood of the world's knowledge economy, but they are often scarcest where most needed. Measuring the numbers of users of the Internet infrastructure is not easy in developing countries because many people share accounts, use corporate and academic networks, or visit the rapidly growing number of cyber cafes, telecentres and business services. Also measuring the number of users does not take into account the level of use. One valuable indicator for measuring the Internet infrastructure is the international Internet performance of a country or region. One of the major aims of the PingER project is to provide an historical archive of extensive, publicly accessible, up-to-date, measurements, analyses and reports of multiple Internet performance indicators (such as delay, loss, throughput, reachability, and jitter) between sites, countries and regions of the world. This talk will briefly describe the PingER project and then compare and contrast the Internet performance and its trends within and between countries and regions of the world. By means of extensive case studies it will also identify which regions need the greatest attention, together with their major issues and possible approaches to reducing the divide.

  15. Prospective evaluation of multiparametric ultrasound and quantitative elastosonography in the differential diagnosis of benign and malignant thyroid nodules: Preliminary experience

    Energy Technology Data Exchange (ETDEWEB)

    Cantisani, Vito, E-mail: vito.cantisani@uniroma1.it [Department of Radiology, Oncology, and Anatomy Pathology, University “La Sapienza”, Policlinico Umberto I, Rome, Itlay (Italy); D’Andrea, Vito [Department of Surgical Sciences, University “La Sapienza”, Rome (Italy); Biancari, Fausto [Department of Surgery, Oulu University Hospital, Oulu (Finland); Medvedyeva, Olena; Di Segni, Mattia; Olive, Matteo [Department of Radiology, Oncology, and Anatomy Pathology, University “La Sapienza”, Policlinico Umberto I, Rome, Itlay (Italy); Patrizi, Gregorio; Redler, Adriano; De Antoni E, Enrico [Department of Surgical Sciences, University “La Sapienza”, Rome (Italy); Masciangelo, Raffaele [Department of Hygiene and Infectious Disease, University “La Sapienza”, Rome (Italy); Frezzotti, Francesca [Department of Surgical Sciences, University “La Sapienza”, Rome (Italy); Ricci, Paolo [Department of Radiology, Oncology, and Anatomy Pathology, University “La Sapienza”, Policlinico Umberto I, Rome, Itlay (Italy)

    2012-10-15

    Purpose: To assess the clinical value of quantitative elastosonography compared with multiparametric ultrasound in differentiating the nature of thyroid nodules. Methods and materials: Ninety-seven consecutive patients (32 males, 65 females, mean age, 54 years, range 20–81 years) with thyroid nodules previously detected at color-Doppler ultrasound (CDUS), were prospectively examined with elastosonography with dedicated quantitative software (Elasto-Q, Toshiba) before surgery. Ultrasound examination and elastosonography were evaluated by two investigators in consensus. US features, color-Doppler pattern, and strain ratio value were evaluated. Sensitivity and specificity of CDUS and sono-elastography were compared using X{sup 2} test and ROC curves. Results: Sensitivity and specificity of hypoechogenicity, irregular margins or suspicious halo features, CDUS blood flow pattern, and strain ratio in the diagnosis of malignant nodules were 56.8%, 62.2%, 54.1% and 97.3% and 71.7%, 93.3%, 28.3%, and 91.7%, respectively. Elastosonography was more sensitive and specific than all ultrasonographic features in predicting malignancy of the thyroid nodules (p < 0.0001). According to elastosonographic features the lesions characterized by strain ratio ≥2 were highly likely to be of malignant nature (p < 0.0001, O.R. 396, 95%, CI: 44–3530). Conclusions: The results of the present study suggest that elastosonography with Q system is a valuable tool in the characterization of thyroid nodules and it seems to be far more accurate than CDUS. These findings as well as those of previous studies support its use in selecting patients who are candidates for surgery.

  16. Quantitative assessment of photoacoustic tomography systems integrating clinical ultrasound transducers using novel tissue-simulating phantoms

    Science.gov (United States)

    Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Pfefer, Joshua

    2015-03-01

    Photoacoustic Tomography (PAT) systems based on commercial ultrasound instruments have the benefit of dualmodality imaging, which increases their appeal from a clinical standpoint. However, factors that influence PAT system performance have not been thoroughly investigated and standardized test methods have not been established for image quality evaluation. To address these issues we have adapted phantom-based approaches from ultrasound imaging standards and implemented them to assess a PAT system developed for vascular imaging. Our system comprises a tunable near-infrared pulsed laser and a commercial ultrasound imaging system, including four interchangeable linear array clinical ultrasound transducers with varying center frequencies, acoustic bandwidths and geometries. Phantoms consisted of a customized polyvinyl chloride (PVC) plastisol gel that simulates both optical and acoustic properties of breast tissue. One phantom incorporates a sub-resolution filament array suitable for bimodal ultrasound-photoacoustic imaging, while another contains an array of hemoglobin-filled cylindrical inclusions at various depths. Key performance characteristics were evaluated, including spatial resolution, signal uniformity, contrast, and penetration depth. These characteristics were evaluated at 750 nm at radiant exposures below ANSI safety limits. Effects of transducer properties on imaging performance were evaluated. Axial and lateral resolution ranged from 0.27-0.83 mm and 0.28-1.8 mm, respectively, and penetration depths from 1.9-4.2 cm were achieved. These results demonstrate variation in PAT system performance based on clinical transducer selection, as well as the utility of realistic phantom-based test methods in performing benchtop evaluations of system performance.

  17. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Jida Xing

    2015-06-01

    Full Text Available In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared

  18. Quantitative measurements of autobiographical memory content.

    Directory of Open Access Journals (Sweden)

    Robert S Gardner

    Full Text Available Autobiographical memory (AM, subjective recollection of past experiences, is fundamental in everyday life. Nevertheless, characterization of the spontaneous occurrence of AM, as well as of the number and types of recollected details, remains limited. The CRAM (Cue-Recalled Autobiographical Memory test (http://cramtest.info adapts and combines the cue-word method with an assessment that collects counts of details recalled from different life periods. The SPAM (Spontaneous Probability of Autobiographical Memories protocol samples introspection during everyday activity, recording memory duration and frequency. These measures provide detailed, naturalistic accounts of AM content and frequency, quantifying essential dimensions of recollection. AM content (∼20 details/recollection decreased with the age of the episode, but less drastically than the probability of reporting remote compared to recent memories. AM retrieval was frequent (∼20/hour, each memory lasting ∼30 seconds. Testable hypotheses of the specific content retrieved in a fixed time from given life periods are presented.

  19. Contrast enhanced ultrasound with quantitative perfusion analysis for objective characterization of pancreatic ductal adenocarcinoma: A feasibility study.

    Science.gov (United States)

    D'Onofrio, Mirko; Canestrini, Stefano; Crosara, Stefano; De Robertis, Riccardo; Pozzi Mucelli, Roberto

    2014-03-28

    The aim of this study was to determine whether contrast enhanced ultrasound (CEUS) quantitative perfusion analysis allows an objective characterization of ductal adenocarcinoma (ADK) of the pancreas. Patients with pancreatic ADK underwent CEUS. All examinations were performed on an Acuson S2000 system (Siemens, Erlangen, Germany) after the iv administration of 2.4 mL contrast agent (SonoVue(®), Bracco, Milan, Italy). All lesions were pathologically proved. An operator manually drew different regions of interest within the tumor and the adjacent parenchyma to allow the quantitative perfusion analysis. The mean values of peak of enhancement, time to peak and ascending curve were calculated and compared using the Student's t test. The quantitative perfusion analysis was possible in all lesions. The mean values of the peak of enhancement, time to peak and ascending curve were 17.19%, 7.97 s and 159.52% s within the tumor and 33.57%, 8.89 s and 355.29% s within the adjacent parenchyma. The peak of enhancement and the ascending curve values were significantly different within the tumor and the adjacent parenchyma. Thus, CEUS allows the quantitative perfusion analysis of pancreatic ductal adenocarcinoma.

  20. Quantitatively measuring the orbital angular momentum density of light : Presentation

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2013-08-01

    Full Text Available Although many techniques are efficient at measuring optical orbital angular momentum (OAM), they do not allow one to obtain a quantitative measurement for the OAM density across an optical field and instead only measure its global OAM. Numerous...

  1. The association between bone health indicated by calcaneal quantitative ultrasound and metabolic syndrome in Malaysian men.

    Science.gov (United States)

    Chin, Kok-Yong; Ima-Nirwana, Soelaiman; Mohamed, Isa Naina; Ahmad, Fairus; Mohd Ramli, Elvy Suhana; Aminuddin, Amilia; Wan Ngah, Wan Zurinah

    2015-01-01

    Previous studies on the relationship between bone health and metabolic syndrome (MS) have revealed heterogeneous results. There are limited studies employing bone quantitative ultrasonometry in evaluating this relationship. This study aimed to determine the relationship between MS and bone health in a group of Malaysian middle-aged and elderly men using bone quantitative ultrasonometry. This cross-sectional study recruited 309 free living Chinese and Malay men aged 40 years and above residing in Klang Valley, Malaysia. Their demographic and anthropometric data were collected. Their calcaneal speed of sound (SOS) was measured using a CM-200 bone ultrasonometer. Their blood was collected for the evaluation of lipid profile, total testosterone and sex hormone-binding globulin. The joint interim MS definition was used for the classification of subjects. Multiple linear regression analysis was used to assess the association between SOS and indicators of MS and the presence of MS, with suitable adjustment for confounders. There was no significant difference in SOS value between MS and non-MS subjects (p > 0.05). The SOS values among subjects with different MS scores did not differ significantly (p > 0.05). There were no significant associations between SOS values and indicators of MS or the presence of MS (p > 0.05). The relationship between bone health and MS is not significant in Malaysian middle-aged and elderly men. A longitudinal study should be conducted to evaluate the association between bone loss and MS to confirm this finding.

  2. Transforming growth factor beta-1 (TGFB1 and peak bone mass: association between intragenic polymorphisms and quantitative ultrasound of the heel

    Directory of Open Access Journals (Sweden)

    Logan Alexander G

    2005-06-01

    Full Text Available Abstract Background Variance of peak bone mass has a substantial genetic component, as has been shown with twin studies examining quantitative measures such as bone mineral density (BMD and quantitative ultrasound (QUS. Evidence implicating single nucleotide polymorphisms (SNPs of the transforming growth factor beta-1 (TGFB1 gene is steadily accumulating. However, a comprehensive look at multiple SNPs at this locus for their association with indices of peak bone mass has not been reported. Methods A cohort of 653 healthy Caucasian females 18 to 35 years old was genotyped for seven TGFB1 SNPs. Polymorphisms were detected by restriction endonuclease digestion of amplified DNA segments. Results The frequencies of the least common allele at G-800A, C-509T, codon 10 (L10P, codon 25 (R25P, codon 263 (T263I, C861-20T, and 713-8 delC loci were 0.07, 0.33, 0.41, 0.08, 0.04, 0.25 and 0.01, respectively. A significant association was seen between QUS Stiffness Index (QUS-SI and the SNP at codon 10 and the linked promoter SNP, C-509T. This association remained significant after multiple regression was used to incorporate important clinical covariates – age, BMI, level of activity, family history, and caffeine intake – into the model. Conclusion The association of QUS-SI with -509T is consistent with a gene-dose effect, while only individuals homozygous for the codon 10P allele showed a significant increase. In this cohort of young healthy Caucasian females, the T allele at position -509 is associated with greater bone mass as measured by calcaneal ultrasound.

  3. Changes in qualitative and quantitative ultrasound assessment of the gastric antrum before and after elective caesarean section in term pregnant women: a prospective cohort study.

    Science.gov (United States)

    Rouget, C; Chassard, D; Bonnard, C; Pop, M; Desgranges, F P; Bouvet, L

    2016-11-01

    Ultrasound measurement of the antral cross-sectional area allows a quantitative estimate of gastric contents in non-pregnant adults, but this relationship may be affected by compression of the stomach exerted by the gravid uterus during pregnancy. This study aimed to assess differences in quantitative (Perlas score) and qualitative (antral cross-sectional area) ultrasound assessments of the gastric antrum performed immediately before and after caesarean section. Forty-three women having elective caesarean section performed under spinal anaesthesia were studied in the semirecumbent and semirecumbent-right lateral positions. Thirty-nine women showed no change in stomach contents using the Perlas score between the two measurement periods; four women showed a change, but by one grade only. The median (IQR [range]) antral cross-sectional area was 323 (243-495 [103-908]) mm(2) before, and 237 (165-377 [112-762]) mm(2) after, caesarean section in the semirecumbent position (p = 0.001); the comparable values in the semirecumbent-right lateral position were 418 (310-640 [161-1238]) mm(2) and 362 (280-491 [137-1231]) mm(2) (p = 0.09). The distance between the skin and the antrum, and the aorta and the antrum, decreased significantly in both positions after surgery. We suggest that our results indicate that stomach contents remain largely unchanged in women having elective caesarean section, but antral cross-sectional area decreases, especially in the semirecumbent position, related to a change in the position of the stomach within the abdomen. This implies that the relationship of antral cross-sectional area to volume of stomach contents, which has been determined for non-pregnant subjects, may not apply in term pregnant women. © 2016 The Association of Anaesthetists of Great Britain and Ireland.

  4. Discriminative ability of calcaneal quantitative ultrasound compared with dual-energy X-ray absorptiometry in men with hip or distal forearm fractures.

    Science.gov (United States)

    Cesme, Fatih; Esmaeilzadeh, Sina; Oral, Aydan

    2016-10-01

    The aim of this case-control study was to compare the discriminatory ability of bone mineral density (BMD) measurements and calcaneal quantitative ultrasound (QUS) parameters for fractures and to determine fracture thresholds for each variable in men with hip or distal forearm fractures. A total of 20 men with hip and 18 men with distal forearm fractures and 38 age-matched controls were included in this study. Dual-energy X-ray absorptiometry (DXA) BMD (spine and hip) and calcaneal QUS measurements were made. Area under the curves (AUCs) were calculated to assess fracture discriminatory power of DXA and QUS variables. Quantitative Ultrasound Index (QUI) T-score and Speed of Sound (SOS) were found to be the best parameters for the identification of hip and distal forearm fractures, respectively, with AUCs greater than those of DXA BMD and other QUS parameters. While a QUI T-score of ≤-1.18 could identify and rule out hip fracture cases with approximately 80% sensitivity and specificity, a SOS value of ≤1529.75 reached to almost 90% for ruling in and out distal forearm fractures. The discriminatory performance of calcaneal QUS variables between fractured and non-fractured men was as good as those of the DXA BMD and even better. Since men appear to sustain fractures at closer QUS variable levels than those of the DXA BMD regardless of the fracture type, it may be speculated that calcaneal QUS may be more helpful in predicting the risk of fractures when BMD alone does not demonstrate impaired bones. Level III, Study of Diagnostic Test. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  5. Ultrasound pregnancy

    Science.gov (United States)

    Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; ...

  6. Quantitative ultrasound for predicting curve progression in adolescent idiopathic scoliosis: a prospective cohort study of 294 cases followed-up beyond skeletal maturity.

    Science.gov (United States)

    Lam, Tsz Ping; Hung, Vivian Wing Yin; Yeung, Hiu Yan; Chu, Winnie Chiu Wing; Ng, Bobby Kin Wah; Lee, Kwong Man; Qin, Ling; Cheng, Jack Chun Yiu

    2013-03-01

    Adolescent idiopathic scoliosis (AIS) is prevalent among adolescents and can carry significant morbidities. We evaluated the use of quantitative ultrasound (QUS) for predicting curve progression in patients with AIS. We recruited 294 girls with AIS at a mean age of 13.4 years, and they were prospectively followed beyond skeletal maturity for curve progression. We recorded 3 calcaneal QUS measurements at baseline, namely broadband ultrasound attenuation (BUA), velocity of sound (VOS), and stiffness index (SI). Logistic regression analysis indicated that SI, age, menarchal status, and Cobb angle were significant prognostic factors to be included in the final prediction model. The adjusted odds ratio of curve progression for Z-score of SI≦0 was 2.00 (95% CI: 1.08-3.71). The area under the ROC curve was 0.831 (95% CI: 0.785-0.877). The results of this study indicate that SI was an independent and significant prognostic factor for AIS and could be considered in addition to other prognostic factors when estimating the risk for curve progression and planning treatment for patients with AIS.

  7. The Use of B-Mode Ultrasound for Measuring Subcutaneous Fat Thickness on the Upper Arms.

    Science.gov (United States)

    Weiss, Lawrence W.; Clark, Frank C.

    1985-01-01

    A study was carried out to investigate the potential use of B-mode ultrasound for measuring subcutaneous fat thickness at two arm sites. B-mode sonograms and skinfold measurements were found to be highly correlated for both men and women. (Author/MT)

  8. Measuring Bubble, Drop and Particle Sizes in Multiphase Systems with Ultrasound

    NARCIS (Netherlands)

    Cents, A.H.G.; Brilman, D.W.F.; Versteeg, G.F.; Wijnstra, P.J.; Regtien, P.P.L.

    2004-01-01

    A technique is developed for measurement of bubble, droplet and particle-size distributions in multiphase systems, based on the propagation speed and attenuation of ultrasound. The measurement of the size distribution of the dispersed phase in multiphase systems was desired to analyze the mass-trans

  9. The Use of B-Mode Ultrasound for Measuring Subcutaneous Fat Thickness on the Upper Arms.

    Science.gov (United States)

    Weiss, Lawrence W.; Clark, Frank C.

    1985-01-01

    A study was carried out to investigate the potential use of B-mode ultrasound for measuring subcutaneous fat thickness at two arm sites. B-mode sonograms and skinfold measurements were found to be highly correlated for both men and women. (Author/MT)

  10. Mechanism modeling for phase fraction measurement with ultrasound attenuation in oil–water two-phase flow

    Science.gov (United States)

    Su, Qian; Tan, Chao; Dong, Feng

    2017-03-01

    When measuring the phase fraction of oil–water two-phase flow with the ultrasound attenuation, the phase distribution and fraction have direct influence on the attenuation coefficient. Therefore, the ultrasound propagation at various phase fractions and distributions were investigated. Mechanism models describing phase fraction with the ultrasound attenuation coefficient were established by analyzing the interaction between ultrasound and two-phase flow by considering the scattering, absorption and diffusion effect. Experiments were performed to verify the theoretical analysis, and the test results gave good agreement with the theoretical analysis. When the dispersed phase fraction is low, the relationship between ultrasound attenuation coefficient and phase fraction is of monotonic linearity; at higher dispersed phase fraction, ultrasound attenuation coefficient presents an irregular response to the dispersed phase fraction. The presented mechanism models give reasonable explanations about the trend of ultrasound attenuation.

  11. Quantitative analysis of vascular heterogeneity in breast lesions using contrast-enhanced 3-D harmonic and subharmonic ultrasound imaging.

    Science.gov (United States)

    Sridharan, Anush; Eisenbrey, John R; Machado, Priscilla; Ojeda-Fournier, Haydee; Wilkes, Annina; Sevrukov, Alexander; Mattrey, Robert F; Wallace, Kirk; Chalek, Carl L; Thomenius, Kai E; Forsberg, Flemming

    2015-03-01

    Ability to visualize breast lesion vascularity and quantify the vascular heterogeneity using contrast-enhanced 3-D harmonic (HI) and subharmonic (SHI) ultrasound imaging was investigated in a clinical population. Patients (n = 134) identified with breast lesions on mammography were scanned using power Doppler imaging, contrast-enhanced 3-D HI, and 3-D SHI on a modified Logiq 9 scanner (GE Healthcare). A region of interest corresponding to ultrasound contrast agent flow was identified in 4D View (GE Medical Systems) and mapped to raw slice data to generate a map of time-intensity curves for the lesion volume. Time points corresponding to baseline, peak intensity, and washout of ultrasound contrast agent were identified and used to generate and compare vascular heterogeneity plots for malignant and benign lesions. Vascularity was observed with power Doppler imaging in 84 lesions (63 benign and 21 malignant). The 3-D HI showed flow in 8 lesions (5 benign and 3 malignant), whereas 3-D SHI visualized flow in 68 lesions (49 benign and 19 malignant). Analysis of vascular heterogeneity in the 3-D SHI volumes found benign lesions having a significant difference in vascularity between central and peripheral sections (1.71 ± 0.96 vs. 1.13 ± 0.79 dB, p < 0.001, respectively), whereas malignant lesions showed no difference (1.66 ± 1.39 vs. 1.24 ± 1.14 dB, p = 0.24), indicative of more vascular coverage. These preliminary results suggest quantitative evaluation of vascular heterogeneity in breast lesions using contrast-enhanced 3-D SHI is feasible and able to detect variations in vascularity between central and peripheral sections for benign and malignant lesions.

  12. Blood flow measurements during hemodialysis vascular access interventions - Catheter-based thermodilution or Doppler ultrasound?

    DEFF Research Database (Denmark)

    Heerwagen, Søren T; Hansen, Marc A; Schroeder, Torben V

    2012-01-01

    Purpose: To test the clinical performance of catheter-based thermodilution and Doppler ultrasound of the feeding brachial artery for blood flow measurements during hemodialysis vascular access interventions.Methods: Thirty patients with arteriovenous fistulas who underwent 46 interventions had...... by ultrasound dilution was determined within three days of the procedure. The methods were compared using regression analysis and tested for systematic bias. Results: Failure to position the thermodilutional catheter correctly was observed in 8 out of 46 (17%) pre-intervention measurements. Post...

  13. Quantitative ultrasound and bone health Ultrasonido cuantitativo y salud ósea

    Directory of Open Access Journals (Sweden)

    Karen M Knapp

    2009-01-01

    Full Text Available This review of quantiative ultrasound (QUS and bone health uses the current literature to summarise the clinical and research effectiveness of QUS. QUS has been demonstrated to have the ability to predict fracture, particularly at the hip. However, the magnitude of prediction is fracture-site, measurement-site and device dependent. The correlations between dual X-ray absorptiometry (DXA and bone mineral density (BMD are weak to moderate, resulting in different subjects being identified as being at risk of fracture by the two different methods. QUS is sensitive to age and menopause-related changes and to clinical risk factors and lifestyle factors associated with osteoporosis. Whilst a limited ability of QUS to monitor therapeutic intervention has been demonstrated, this is still an area where it's poorer precision, in comparison to DXA, results in limited applicability. Whilst DXA remains the gold standard for the diagnosis of osteoporosis, QUS may be of use for the prediction of those at risk of future fracture in areas where there is limited availability of DXA.En esta revisión sobre el Ultrasonido Cuantitativo (QUS y su aplicación en la evaluación de la salud de los huesos, se analiza detalladamente la literatura disponible para conocer su papel y efectividad en la clínica cotidiana y en los programas de investigación. El QUS ha probado ser útil para predecir fracturas, especialmente de la cadera. Sin embargo, la exactitud de la predicción depende del sitio de fractura que se desea evaluar, del sitio anatómico donde se realiza la medición y de los diferentes instrumentos. La correlación que existe entre densitometría de rayos X (DXA y QUS puede ser débil a moderada, porque ambos métodos determinan diferentes componentes de la masa ósea relacionados con la presentación de las fracturas. El resultado del QUS como el del DXA también es sensible a la edad, cambios relacionados con la menopausia, a factores de riesgo clínicos y de

  14. Comparison of two- and three-dimensional quantitative coronary angiography to intravascular ultrasound in the assessment of intermediate left main stenosis.

    Science.gov (United States)

    Porto, Italo; Dato, Ilaria; Todaro, Daniel; Calabrese, Michele; Rigattieri, Stefano; Leone, Antonio Maria; Niccoli, Giampaolo; Burzotta, Francesco; Trani, Carlo; Crea, Filippo

    2012-06-01

    Angiographic evaluation of intermediate left main coronary artery stenosis (LMS) is often limited. Three-dimensional (3D) quantitative coronary angiography has recently developed to overcome 2-dimensional (2D) quantitative coronary angiographic (QCA) limitations. In patients with angiographically intermediate LMS, we investigated whether 3D quantitative coronary angiography was superior to 2D quantitative coronary angiography in predicting the presence of a significant LMS, defined as a minimum luminal area <6 mm(2) at intravascular ultrasound (IVUS). 2D and 3D quantitative coronary angiography were compared in their measurements of minimum luminal area, percent area stenosis, minimum luminal diameter, and percent diameter stenosis and in their prediction of an IVUS minimum luminal area <6 mm(2). In total 58 target lesions were interrogated, 25 (43%) of which had an IVUS minimum luminal area <6 mm(2). Correlation between 3D-QCA minimum luminal area and IVUS minimum luminal area was stronger than the correlation between 2D-QCA minimum luminal area (or minimum luminal diameter) and IVUS minimum luminal area (R = 0.67, p = 0.0001, and R = 0.40, p = 0.001, respectively, p = 0.04 for comparison). To predict IVUS minimum luminal area <6 mm(2), the most accurate 2D-QCA measurement was minimum luminal diameter (area under curve 0.81, cutoff 2.2 mm, p = 0.0001), and the most accurate 3D-QCA measurement was minimum luminal area (area under curve 0.86, cutoff 5.6 mm(2), p = 0.0001). 2D-QCA percent diameter stenosis did not significantly predict IVUS minimum luminal area <6 mm(2) (area under curve 0.56, cutoff 38%, p = 0.45). In conclusion, the accuracy of quantitative coronary angiography in predicting LM IVUS minimum luminal area <6 mm(2) is limited. When IVUS is not available or contraindicated, 3D quantitative coronary angiography may assist in the evaluation of intermediate LMS. Among 2D-QCA parameters, minimum luminal diameter is more accurate than percent diameter

  15. Proopiomelanocortin gene polymorphisms and its association with meat quality traits by ultrasound measurement in Chinese cattle.

    Science.gov (United States)

    Liu, Yongfeng; Zan, Linsen; Li, Linqiang; Xin, Yaping

    2013-10-15

    Ultrasound technology was used to measure live animal meat traits instead of true carcass meat traits for beef production and cattle breeding by an increasing number of institutions. In this study, we analyzed the association between genetic polymorphisms of proopiomelanocortin (POMC) and ultrasound measurement traits in Chinese cattle. Using direct DNA sequencing in 322 individuals of 7 different cattle subpopulation, 7 SNPs were identified for genotyping within 790bp region of intron 2 and exon 3 of POMC. 6586 T>G in intron 2 and 6769 C>T and 7216 C>T in exon 3 were significantly associated with ultrasound backfat thickness (UBF) (PT, 6706 T>C, 6796 C>T and 6810 C>T in exon 3 were significantly associated with ULMA (Pmeat in Chinese cattle breeding program. Following validation in other populations and breeds, these markers could be incorporated into breeding programs to increase the rate of improvement in carcass and meat quality traits.

  16. Quantitative imaging of young's modulus of soft tissues from ultrasound water jet indentation: a finite element study.

    Science.gov (United States)

    Lu, Min-Hua; Mao, Rui; Lu, Yin; Liu, Zheng; Wang, Tian-Fu; Chen, Si-Ping

    2012-01-01

    Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young's modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson's ratio using Hayes' equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes' equation has been derived by introducing a new scaling factor which is dependent on Poisson's ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue), and deformation ratio d/h. With this model, the Young's modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%.

  17. Quantitative Imaging of Young’s Modulus of Soft Tissues from Ultrasound Water Jet Indentation: A Finite Element Study

    Directory of Open Access Journals (Sweden)

    Min-Hua Lu

    2012-01-01

    Full Text Available Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young’s modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson’s ratio using Hayes’ equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes’ equation has been derived by introducing a new scaling factor which is dependent on Poisson’s ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue, and deformation ratio d/h. With this model, the Young’s modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%.

  18. Measurement Invariance: A Foundational Principle for Quantitative Theory Building

    Science.gov (United States)

    Nimon, Kim; Reio, Thomas G., Jr.

    2011-01-01

    This article describes why measurement invariance is a critical issue to quantitative theory building within the field of human resource development. Readers will learn what measurement invariance is and how to test for its presence using techniques that are accessible to applied researchers. Using data from a LibQUAL+[TM] study of user…

  19. Qualitative, quantitative and combination score systems in differential diagnosis of breast lesions by contrast-enhanced ultrasound.

    Science.gov (United States)

    Wang, YongMei; Fan, Wei; Zhao, Song; Zhang, Kai; Zhang, Li; Zhang, Ping; Ma, Rong

    2016-01-01

    To assess the feasibility of score systems in differential diagnosis of breast lesions by contrast-enhanced ultrasound (CEUS). CEUS was performed in 121 patients with 127 breast lesions by Philips iU22 with Sonovue as contrast agent. Pearson Chi-square χ(2) test, binary logistic regression analysis and Student's t-test are used to identify significant CEUS parameters in differential diagnosis. Based on these significant CEUS parameters, qualitative, quantitative and combination score systems were built by scoring 1 for benign characteristic and scoring 2 for malignant characteristic. Receiver operating characteristic (ROC) curve was applied to evaluate the diagnostic efficacy of different analytical methods. Pathological results showed 41 benign and 86 malignant lesions. Qualitative analysis and logistic regression analysis showed that there are significant differences in enhancement degree, enhancement order, internal homogeneity, enhancement margin, surrounding vessels and enlargement of diameters (PQuantitative analysis indicated that malignant lesions tended to show higher peak intensity (PI), larger area under the curve (AUC) and shorter time to peak (TTP) than benign ones (PQualitative score systems showed higher diagnostic efficacy than single quantitative CEUS parameters. The corresponding area under the ROC curve for qualitative, quantitative and combination score systems were 0.897, 0.716 and 0.903 respectively. Z test showed that area under the ROC curve of quantitative score system was statistically smaller than that of other score systems. Quantitative score system helps little in improving the diagnostic efficacy of CEUS. While qualitative score system improves the performance of CEUS greatly in discrimination of benign and malignant breast lesions. The application of qualitative could develop the diagnostic performance of CEUS which is clinically promising. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Investigation into the quantitative and qualitative characteristics of choroidal melanoma through magnetic resonance imaging and B-scan ultrasound.

    Science.gov (United States)

    Papayiannis, Vassilis; Tsaousis, Konstantinos T; Kouskouras, Constantinos A; Haritanti, Afroditi; Diakonis, Vasilios F; Tsinopoulos, Ioannis T

    2017-01-01

    To investigate the homogeneity and vascularity of choroidal melanoma through magnetic resonance imaging (MRI) and brightness modulation (B-mode) ultrasound scan and their correlation with dimensions of tumor, as well as to measure the sensitivity of both modalities in retinal detachment (RD) detection. This retrospective chart review included patients diagnosed with choroidal melanoma. All these patients underwent MRI scans using T2-weighted (T2-WI) and T1-weighted (T1-WI) sequences, before and after an intravenous injection of paramagnetic contrast material. The patients were also examined using a B-mode ultrasound scan, and the results from both modalities were compared (tumor homogeneity, tumor height, tumor base diameter, and tumor vascularity). Forty-two patients (mean age=65.33±12.51 years) with choroidal melanoma were included in the study. Homogeneity was confirmed in 16 patients through ultrasound scan, in 19 patients through T1-WI sequence, in 21 patients through T2-WI sequence, and in 25 patients through T1-WI sequence + contrast (gadolinium). Patients with homogenous tumors presented with lower (P=0.0045) mean height than that of those with nonhomogenous tumors, whereas no statistically significant difference was found for base diameter measurements (P=0.056). Patients with tumors of high vascularity presented with greater mean height (P=0.000638) and greater mean base diameter compared with those with tumors of low vascularity (P=0.019543). RD was detected in 26 patients through T1-WI sequence, in 13 patients through T2-WI sequence, in 26 patients through T1-WI sequence + contrast, and in 32 patients through ultrasound scan, which proved to be the most sensitive modality. The height of choroidal melanoma was positively correlated with tumor's homogeneity. Melanomas of greater height were found to be less homogenous, due to increased degeneration and higher occurrence of intratumoral hemorrhage. In addition, choroidal melanoma's height was also

  1. The cardiac cycle is a major contributor to variability in size measurements of abdominal aortic aneurysms by ultrasound

    DEFF Research Database (Denmark)

    Grøndal, Nikolaj Fibiger; Bramsen, Morten; Thomsen, Marie Dahl

    2012-01-01

    The objective of the study was to evaluate the impact of the cardiac cycle on ultrasound measurements of abdominal aortic aneurysm (AAA) diameters.......The objective of the study was to evaluate the impact of the cardiac cycle on ultrasound measurements of abdominal aortic aneurysm (AAA) diameters....

  2. Is Quantitative HBsAg Measurement a Reliable Substitute for HBV DNA Quantitation?

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Mahdavi

    2015-07-01

    Conclusion: There are many factors affecting the correlation between serum HBV DNA copy number and HBsAg level such as genotype of HBV virus, phase of infection, methods of measurement, HBeAg status, and drug and types of treatment procedures. Therefore, these factors should be considered in further studies dealing with the correlation between quantitative HBV DNA and HBsAg tests.

  3. Quantitative ultrasound venous valve movement: early diagnosis of deep vein thrombosis

    Science.gov (United States)

    Muhd Suberi, Anis Azwani; Wan Zakaria, Wan Nurshazwani; Tomari, Razali; Ibrahim, Nabilah

    2016-07-01

    The purpose of this paper is to provide an in-depth analysis of computer aided system for the early diagnosis of Deep Vein Thrombosis (DVT). Normally, patients are diagnosed with DVT through ultrasound examination after they have a serious complication. Thus, this study proposes a new approach to reduce the risk of recurrent DVT by tracking the venous valve movement behaviour. Inspired by image processing technology, several image processing methods namely, image enhancement, segmentation and morphological have been implemented to improve the image quality for further tracking procedure. In segmentation, Otsu thresholding provides a significant result in segmenting valve structure. Subsequently, morphological dilation method is able to enhance the region shape of the valve distinctly and precisely. Lastly, image subtraction method is presented and evaluated to track the valve movement. Based on the experimental results the normal range of valve velocity lies within the range of blood flow velocity (Vb) and occasionally may result in higher values.

  4. STEREOCHEMICAL ASPECTS OF HYDRATION OF CARBOHYDRATES IN AQUEOUS-SOLUTIONS .3. DENSITY AND ULTRASOUND MEASUREMENTS

    NARCIS (Netherlands)

    GALEMA, SA; HOILAND, H

    1991-01-01

    Density and ultrasound measurements have been performed in aqueous solutions of pentoses, hexoses, methylpyranosides, and disaccharides as a function of molality of carbohydrate (0-0.3 mol kg-1). Partial molar volumes, partial molar isentropic compressibilities, and hydration numbers have been calcu

  5. Measurement of central corneal thickness using ultrasound pachymetry and Orbscan II in normal eyes

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Sadoughi

    2015-01-01

    Conclusion: Orbscan II has good correlation with ultrasound pachymetry for measurement of CCT in normal eyes; however Orbscan II should not be used to evaluate corneal thickness before keratorefractive surgeries, as it tends to overestimate corneal thickness and may result in undesirable, low residual stromal thickness.

  6. A Multidimensional Investigation of Children's /r/ Productions: Perceptual, Ultrasound, and Acoustic Measures

    Science.gov (United States)

    Klein, Harriet B.; McAllister Byun, Tara; Davidson, Lisa; Grigos, Maria I.

    2013-01-01

    Purpose: This study explored relationships among perceptual, ultrasound, and acoustic measurements of children's correct and misarticulated /r/ sounds. Longitudinal data documenting changes across these parameters were collected from 2 children who acquired /r/ over a period of intervention and were compared with data from children with typical…

  7. STEREOCHEMICAL ASPECTS OF HYDRATION OF CARBOHYDRATES IN AQUEOUS-SOLUTIONS .3. DENSITY AND ULTRASOUND MEASUREMENTS

    NARCIS (Netherlands)

    GALEMA, SA; HOILAND, H

    1991-01-01

    Density and ultrasound measurements have been performed in aqueous solutions of pentoses, hexoses, methylpyranosides, and disaccharides as a function of molality of carbohydrate (0-0.3 mol kg-1). Partial molar volumes, partial molar isentropic compressibilities, and hydration numbers have been

  8. Validation of Navigation Ultrasound for Clavicular Length Measurement

    DEFF Research Database (Denmark)

    Høj, Anders Thorsmark; Villa, Chiara; Christensen, Ole M

    2017-01-01

    Accurate clavicular length measurement is considered important for the selection of patients requiring surgical treatment after a midclavicular fracture. As radiographic length measurements can be inaccurate to varying degrees, new measurement methods are needed. Use of novel technology, navigati...

  9. Exploration Analysis of Carbon Dioxide Levels and Ultrasound Measures of the Eye During ISS Missions

    Science.gov (United States)

    Young, M.; Mason, S.; Schaefer, C.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Coble, C.; Gruschkus, S.; Law, J.; Alexander, D.; hide

    2016-01-01

    Enhanced screening for the Visual Impairment/Intracranial Pressure (VIIP) Syndrome, including in-flight ultrasound, was implemented in 2010 to better characterize the changes in vision observed in some long-duration crewmembers. Suggested possible risk factors for VIIP include cardiovascular changes, diet, anatomical and genetic factors, and environmental conditions. As a potent vasodilator, carbon dioxide (CO (sub 2)), which is chronically elevated on the International Space Station (ISS) relative to typical indoor and outdoor ambient levels on Earth, seems a plausible contributor to VIIP. In an effort to understand the possible associations between CO (sub 2) and VIIP, this study analyzes the relationship between ambient CO (sub 2) levels on ISS and ultrasound measures of the eye obtained from ISS fliers. CO (sub 2) measurements will be pulled directly from Operational Data Reduction Complex for the Lab and Node 3 major constituent analyzers (MCAs) on ISS or from sensors located in the European Columbus module, as available. CO (sub 2) measures between ultrasound sessions will be summarized using standard time series class metrics in MATLAB including time-weighted means and variances. Cumulative CO (sub 2) exposure metrics will also be developed. Regression analyses will be used to quantify the relationships between the CO (sub 2) metrics and specific ultrasound measures. Generalized estimating equations will adjust for the repeated measures within individuals. Multiple imputation techniques will be used to adjust for any possible biases in missing data for either CO (sub 2) or ultrasound measures. These analyses will elucidate the possible relationship between CO (sub 2) and changes in vision and also inform future analysis of inflight VIIP data.

  10. Quantitative assessment of the supraspinatus tendon on MRI using T2/T2* mapping and shear-wave ultrasound elastography: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Krepkin, Konstantin; Adler, Ronald S.; Gyftopoulos, Soterios [NYU Langone Medical Center/Hospital for Joint Diseases, Department of Radiology, New York, NY (United States); Bruno, Mary; Raya, Jose G. [NYU Langone Medical Center, Center for Biomedical Imaging, Department of Radiology, New York, NY (United States)

    2017-02-15

    To determine whether there is an association between T2/T2* mapping and supraspinatus tendon mechanical properties as assessed by shear-wave ultrasound elastography (SWE). This HIPAA-compliant prospective pilot study received approval from our hospital's institutional review board. Eight patients (3 males/5 females; age range 44-72 years) and nine shoulders underwent conventional shoulder MRI, T2/T2* mapping on a 3-T scanner, and SWE. Two musculoskeletal radiologists reviewed the MRI examinations in consensus for evidence of supraspinatus tendon pathology, with tear size measured for full-thickness tears. T2/T2* values and ultrasound shear-wave velocities (SWV) were calculated in three corresponding equidistant regions of interest (ROIs) within the insertional 1-2 cm of the supraspinatus tendon (medial, middle, lateral). Pearson correlation coefficients between T2/T2* values and SWV, as well as among T2, T2*, SWV and tear size, were calculated. There was a significant negative correlation between T2* and SWV in the lateral ROI (r = -0.86, p = 0.013) and overall mean ROI (r = -0.90, p = 0.006). There was significant positive correlation between T2 and measures of tear size in the lateral and mean ROIs (r range 0.71-0.77, p range 0.016-0.034). There was significant negative correlation between SWV and tear size in the middle and mean ROIs (r range -0.79-0.68, p range 0.011-0.046). Our pilot study demonstrated a potential relationship between T2* values and shear wave velocity values in the supraspinatus tendon, a finding that could lead to an improved, more quantitative evaluation of the rotator cuff tendons. (orig.)

  11. Quantitative assessment of the supraspinatus tendon on MRI using T2/T2* mapping and shear-wave ultrasound elastography: a pilot study.

    Science.gov (United States)

    Krepkin, Konstantin; Bruno, Mary; Raya, José G; Adler, Ronald S; Gyftopoulos, Soterios

    2017-02-01

    To determine whether there is an association between T2/T2* mapping and supraspinatus tendon mechanical properties as assessed by shear-wave ultrasound elastography (SWE). This HIPAA-compliant prospective pilot study received approval from our hospital's institutional review board. Eight patients (3 males/5 females; age range 44-72 years) and nine shoulders underwent conventional shoulder MRI, T2/T2* mapping on a 3-T scanner, and SWE. Two musculoskeletal radiologists reviewed the MRI examinations in consensus for evidence of supraspinatus tendon pathology, with tear size measured for full-thickness tears. T2/T2* values and ultrasound shear-wave velocities (SWV) were calculated in three corresponding equidistant regions of interest (ROIs) within the insertional 1-2 cm of the supraspinatus tendon (medial, middle, lateral). Pearson correlation coefficients between T2/T2* values and SWV, as well as among T2, T2*, SWV and tear size, were calculated. There was a significant negative correlation between T2* and SWV in the lateral ROI (r = -0.86, p = 0.013) and overall mean ROI (r = -0.90, p = 0.006). There was significant positive correlation between T2 and measures of tear size in the lateral and mean ROIs (r range 0.71-0.77, p range 0.016-0.034). There was significant negative correlation between SWV and tear size in the middle and mean ROIs (r range -0.79--0.68, p range 0.011-0.046). Our pilot study demonstrated a potential relationship between T2* values and shear wave velocity values in the supraspinatus tendon, a finding that could lead to an improved, more quantitative evaluation of the rotator cuff tendons.

  12. Quantitative assessment of pressure sore generation and healing through numerical analysis of high-frequency ultrasound images

    Directory of Open Access Journals (Sweden)

    Sahar Moghimi, MS

    2010-04-01

    Full Text Available This article focuses on the development of a method to quantitatively assess the healing process of artificially induced pressure sores using high-frequency (20 MHz ultrasound images. We induced sores in guinea pigs and monitored predefined regions on days 3, 7, 14, and 21 after sore generation. We extracted relevant parameters regarding the tissue echographic structure and attenuation properties. We examined tissue healing by defining a healing function that used the extracted parameters. We verified the significance of the extracted features by using analysis of variance and multiple comparison tests. The features displayed ascending/descending behavior during wound generation and reverse behavior during healing. We optimized the parameters of our healing function by using a pattern search method. We tested the efficiency of the optimized values by calculating the healing function value on assessment days and then comparing these results with the expected pattern of changes in the tissue conditions after removing the applied pressure. The results of this study suggest that the methodology developed may be a viable tool for quantitative assessment of pressure sores during their early generation as well as during healing stages.

  13. Quantitative assessment of pressure sore generation and healing through numerical analysis of high-frequency ultrasound images.

    Science.gov (United States)

    Moghimi, Sahar; Miran Baygi, Mohammad Hossein; Torkaman, Giti; Mahloojifar, Ali

    2010-01-01

    Abstract-This article focuses on the development of a method to quantitatively assess the healing process of artificially induced pressure sores using high-frequency (20 MHz) ultrasound images. We induced sores in guinea pigs and monitored predefined regions on days 3, 7, 14, and 21 after sore generation. We extracted relevant parameters regarding the tissue echographic structure and attenuation properties. We examined tissue healing by defining a healing function that used the extracted parameters. We verified the significance of the extracted features by using analysis of variance and multiple comparison tests. The features displayed ascending/descending behavior during wound generation and reverse behavior during healing. We optimized the parameters of our healing function by using a pattern search method. We tested the efficiency of the optimized values by calculating the healing function value on assessment days and then comparing these results with the expected pattern of changes in the tissue conditions after removing the applied pressure. The results of this study suggest that the methodology developed may be a viable tool for quantitative assessment of pressure sores during their early generation as well as during healing stages.

  14. Quadratic elongation: A quantitative measure of distortion in coordination polyhedra

    Science.gov (United States)

    Robinson, Kelly F.; Gibbs, G.V.; Ribbe, P.H.

    1971-01-01

    Quadratic elongation and the variance of bond angles are linearly correlated for distorted octahedral and tetrahedral coordination complexes, both of which show variations in bond length and bond angle. The quadratic elonga tion is dimensionless, giving a quantitative measure of polyhedral distortion which is independent of the effective size of the polyhedron.

  15. Quantitative Measurement of Trans-Fats by Infrared Spectroscopy

    Science.gov (United States)

    Walker, Edward B.; Davies, Don R.; Campbell, Mike

    2007-01-01

    Trans-fat is a general term, which is mainly used to describe the various trans geometric isomers present in unsaturated fatty acids. Various techniques are now used for a quantitative measurement of the amount of trans-fats present in foods and cooking oil.

  16. Quantitative Measurement of Trans-Fats by Infrared Spectroscopy

    Science.gov (United States)

    Walker, Edward B.; Davies, Don R.; Campbell, Mike

    2007-01-01

    Trans-fat is a general term, which is mainly used to describe the various trans geometric isomers present in unsaturated fatty acids. Various techniques are now used for a quantitative measurement of the amount of trans-fats present in foods and cooking oil.

  17. Quantitative analysis of ultrasound contrast flow behavior in carotid plaque neovasculature.

    Science.gov (United States)

    Hoogi, Assaf; Akkus, Zeynettin; van den Oord, Stijn C H; ten Kate, Gerrit L; Schinkel, Arend F L; Bosch, Johan G; de Jong, Nico; Adam, Dan; van der Steen, Antonius F W

    2012-12-01

    Intraplaque neovascularization is considered as an important indication for plaque vulnerability. We propose a semiautomatic algorithm for quantification of neovasculature, thus, enabling assessment of plaque vulnerability. The algorithm detects and tracks contrast spots using multidimensional dynamic programming. Classification of contrast tracks into blood vessels and artifacts was performed. The results were compared with manual tracking, visual classification and maximal intensity projection. In 28 plaques, 97% of the contrast spots were detected. In 89% of the objects, the automatic tracking determined the contrast motion with an average distance of less than 0.5 mm from the manual marking. Furthermore, 75% were correctly classified into artifacts and vessels. The automated neovascularization grading agreed within 1 grade with visual analysis in 91% of the cases, which was comparable to the interobserver variability of visual grading. These results show that the method can successfully quantify features that are linked to vulnerability of the carotid plaque. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  18. Non-invasive Measurement of Pressure Gradients in Pulsatile Flow using Ultrasound

    DEFF Research Database (Denmark)

    Olesen, Jacob Bjerring; Traberg, Marie Sand; Pihl, Michael Johannes

    2013-01-01

    approach. Pressure gradients are calculated from the measured velocity fields using the Navier-Stokes equation. Velocity fields are measured during constant and pulsating flow on a carotid bifurcation phantom and on a common carotid artery in-vivo. Scanning is performed with a 5 MHz BK8670 linear......This paper demonstrates how pressure gradients in a pulsatile flow environment can be measured non-invasively using ultrasound. The proposed method relies on vector velocity fields acquired from ultrasound data. 2-D flow data are acquired at 18-23 frames/sec using the Transverse Oscillation...... transducer using a BK Medical 2202 UltraView Pro Focus scanner. The calculated pressure gradients are validated through a finite element simulation of the constant flow model. The geometry of the flow simulation model is reproduced using MRI data, thereby providing identical flow domains in measurement...

  19. Measurement of temperature decrease caused by blood flow in focused ultrasound irradiation by thermal imaging method

    Science.gov (United States)

    Tsuchiya, Takenobu; Hatano, Yuichi; Mori, Yashunori; Shen, Rakushin; Endoh, Nobuyuki

    2016-07-01

    In this study, to estimate the local temperature changes caused by a thick blood vessel, the temperature distribution in a tissue phantom with a thick blood vessel during focused ultrasound irradiation was measured by a thermal imaging method. The blood flow rate in the simulated blood vessel was varied and the relationship between flow rate and temperature decrease was examined. The phantom using the thermal imaging method is divided into two parts, and the increases in temperature distribution as a function of blood flow rate are measured using a thermocamera under constant ultrasound irradiation. The irradiation conditions of ultrasound waves were a central frequency of 1 MHz, a wave number length of 200 cycles, and a duty ratio of 0.2. The irradiation duration was 5 min, and the ultrasound intensity I SPTA was 36 W/cm2. The amount of temperature decrease caused by the cooling effect of blood flow increased with the blood flow rate and it became constant at a certain threshold of blood flow rate. The threshold of blood flow rate is about 250 ml/min.

  20. Measurement of Central Corneal Thickness Using Ultrasound Pachymetry and Orbscan II in Normal Eyes

    Science.gov (United States)

    Sadoughi, Mohammad Mehdi; Einollahi, Bahram; Einollahi, Neda; Rezaei, Javad; Roshandel, Danial; Feizi, Sepehr

    2015-01-01

    Purpose: To compare ultrasound pachymetry and Orbscan II for measurement of central corneal thickness (CCT) in normal eyes. Methods: The current study was performed at Labbafinejad Medical Center (LMC), Tehran, Iran. Three hundred eyes from 150 healthy individuals referred for keratorefractive surgery were assessed first by Orbscan II and then by ultrasound pachymetry, and CCT values were recorded and compared. Results: Overall, Orbscan II overestimated CCT as compared to ultrasound pachymetry by about 2.4% (mean values 547.6 ± 34.7 versus 534.8 ± 34.7, respectively, P < 0.001). The difference was more significant when CCT was less than 500 microns (mean values 493.2 ± 16.9 versus 479.9 ± 15.6, mean overestimation: 2.6%, P < 0.001). There was good linear correlation between the two methods (Pearson's correlation r = 0.968, P < 0.0001). Conclusion: Orbscan II has good correlation with ultrasound pachymetry for measurement of CCT in normal eyes; however Orbscan II should not be used to evaluate corneal thickness before keratorefractive surgeries, as it tends to overestimate corneal thickness and may result in undesirable, low residual stromal thickness. PMID:26005545

  1. Time-resolved measurement of bubble cavitation by using power Doppler ultrasound image

    Science.gov (United States)

    Koda, Ren; Izumi, Yosuke; Nagai, Hayato; Yamakoshi, Yoshiki

    2017-04-01

    In this study, a novel measurement method for a secondary ultrasound wave irradiated by microbubble cavitation is proposed. High-intensity ultrasound (h-US, 1.0–1.5 MPa), which produces bubble cavitation, is irradiated with a fixed time delay after introducing imaging US, whose frequency is different from that of the h-US. The bubble cavitation signal (BCS) is detected by the signal-processing unit of an ultrasound power Doppler imaging instrument. By this method, both a spatially resolved bubble image (S-image) and the temporal transition of the BCS (T-image) are monitored simultaneously. A feature of the method is that the BCS is observed in situ with sub-µs time resolution. The accuracy of the method is evaluated and it is found that the maximum deviation of the amplitude of the simulated BCS is 4.80%. This method is applied to measure the BCS of ultrasound contrast agent microbubbles. As a result, the dependence of the inherent temporal transition of the BCS on the sound pressure of the h-US (0.6–1.2 MPa) is observed.

  2. Quantitative Ultrasound for Staging of Hepatic Steatosis in Patients on Home Parenteral Nutrition Validated with Magnetic Resonance Spectroscopy: A Feasibility Study.

    Science.gov (United States)

    Weijers, Gerrit; Wanten, Geert; Thijssen, Johan M; van der Graaf, Marinette; de Korte, Chris L

    2016-03-01

    Patients on home parenteral nutrition are at risk for developing liver dysfunction, which is due partly to the accumulation of lipids in the liver (steatosis) and may progress to end-stage liver disease with overt liver failure. Therefore, a timely diagnosis with easy access to repeated assessment of the degree of liver steatosis is of great importance. A pilot study was performed in 14 patients on long-term home parenteral nutrition using the computer-aided ultrasound method. Ultrasound radio frequency data were acquired using a phased array transducer and were converted into conventional B-mode images. All patients were subjected to proton magnetic resonance spectroscopy measurement of liver fat content for reference. Computer-aided ultrasound parameters similar to those in a previous validation study in cows revealed significant correlations with fat content measured by magnetic resonance spectroscopy. The most significant parameters were the residual attenuation coefficient (R = 0.95, p ultrasound for staging of hepatic steatosis.

  3. The age-related advancement of arterial disease measured by Doppler ultrasound diastolic flow analysis.

    Science.gov (United States)

    Terenzi, T; Gallagher, D; DeMeersman, R; Beadle, E; Muller, D

    1993-10-01

    To quantify by A-mode Doppler sonography the age-related progression of arterial disease so that age dependent normal values may be established for the screening Doppler peripheral arterial exam. Arterial distensibility was assessed by A-mode Doppler diastolic flow analysis as a measure of atherogenesis. These values will increase the sensitivity and decrease the incidence of false-positive results when the Doppler exam is utilized to differentially diagnosis vascular and sciatic neurogenic claudication. The relationship between age and results from the standard ankle/arm index ultrasound pneumatic cuff examination was also analyzed. A two by three analysis of variance with orthogonal Helmert contrast codes and simple linear regression analysis was utilized for this cross-sectionally designed investigation. The dependent measures of diastolic flow analysis and ankle/arm pressure index were obtained within three nested successively increasing age groups. Chiropractic office. Studied were a total of 90 sedentary nonsmoking subjects, aged 23-79 yr, all of whom had normally accepted levels of serum glucose, cholesterol and blood pressure. Subjects were screened for evidence of aortic coarctation, myocardial infarction, tachyarrhythmia, aortic valve stenosis, mitral prolapse, hypertension, hypercholesterolemia, diabetes and peripheral occlusive arterial disease. Anthropometric measurements and percent body fat were obtained. A predictive oxygen consumption bike ergometer test was performed to obtain aerobic capacity. The commonly utilized standard ankle/arm index ultrasound pneumatic cuff examination and arterial diastolic flow analysis were performed with A-mode Doppler ultrasound on all subjects. These results demonstrate that a significant inverse linear relationship exists between aging and arterial compliance (p < .0001) in our population. Diastolic flow analysis had a greater sensitivity to arterial disease than the standard ankle/arm index ultrasound pneumatic

  4. Ultrasound Estimated Bladder Weight and Measurement of Bladder Wall Thickness-Useful Noninvasive Methods for Assessing the Lower Urinary Tract?

    NARCIS (Netherlands)

    E. Bright; M. Oelke; A. Tubaro; P. Abrams

    2010-01-01

    Purpose: In the last decade interest has arisen in the use of ultrasound derived measurements of bladder wall thickness, detrusor wall thickness and ultrasound estimated bladder weight as potential diagnostic tools for conditions known to induce detrusor hypertrophy. However, to date such measuremen

  5. Measurement of anterior and posterior circulation flow contributions to cerebral blood flow. An ultrasound-derived volumetric flow analysis.

    Science.gov (United States)

    Boyajian, R A; Schwend, R B; Wolfe, M M; Bickerton, R E; Otis, S M

    1995-01-01

    Ultrasound-derived volumetric flow analysis may be useful in answering questions of basic physiological interest in the cerebrovascular circulation. Using this technique, the authors have sought to describe quantitatively the complete concurrent flow relations among all four arteries supplying the brain. The aim of this study of normal subjects was to determine the relative flow contributions of the anterior (internal carotid arteries) and posterior (vertebral arteries) cerebral circulation. Comparisons between the observed and theoretically expected anterior and posterior flow distribution would provide an opportunity to assess traditional rheological conceptions in vivo. Pulsed color Doppler ultrasonography was used to measure mean flow rates in the internal carotid and vertebral arteries in 21 normal adults. The anterior circulation (internal carotid arteries bilaterally) carried 82% of the brain's blood supply and comprised 67% of the total vascular cross-sectional area. These values demonstrate precise concordance between observations in vivo and the theoretically derived (Hagen-Poiseuille) expected flow distribution. These cerebrovascular findings support the traditional conception of macroscopic blood flow. Further studies using ultrasound-derived volumetric analysis of the brain's arterial flow relations may illuminate the vascular pathophysiology underlying aging, cerebral ischemia, and dementias.

  6. In Vivo Quantitative Ultrasound Image Analysis of Femoral Subchondral Bone in Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Jana Podlipská

    2013-01-01

    Full Text Available A potential of quantitative noninvasive knee ultrasonography (US for detecting changes in femoral subchondral bone related to knee osteoarthritis (OA was investigated. Thirty-nine patients referred to a knee arthroscopy underwent dynamic noninvasive US examination of the knee joint. The subchondral bone was semiautomatically segmented from representative US images of femoral medial and lateral condyles and intercondylar notch area. Subsequently, the normalized mean gray-level intensity profile, starting from the cartilage-bone interface and extending to the subchondral bone depth of ~1.7 mm, was calculated. The obtained profile was divided into 5 depth levels and the mean of each level, as well as the slope of the profile within the first two levels, was calculated. The US quantitative data were compared with the arthroscopic Noyes’ grading and radiographic Kellgren-Lawrence (K-L grading. Qualitatively, an increase in relative subchondral bone US gray-level values was observed as OA progressed. Statistically significant correlations were observed between normalized US mean intensity or intensity slope especially in subchondral bone depth level 2 and K-L grading (r=0.600, P<0.001; r=0.486, P=0.006, resp. or femoral arthroscopic scoring (r=0.332, P=0.039; r=0.335, P=0.037, resp.. This novel quantitative noninvasive US analysis technique is promising for detection of femoral subchondral bone changes in knee OA.

  7. Quantitative assessment on the orientation and distribution of carbon fibers in a conductive polymer composite using high-frequency ultrasound.

    Science.gov (United States)

    Lin, Yi-Hsun; Huang, Chih-Chung; Wang, Shyh-Hau

    2012-05-01

    Conductive polymer composites, typically fabricated from a mix of conductive fillers and a polymer substrate, are commonly applied as bipolar plates in a fuel cell stack. Electrical conductivity is a crucial property that greatly depends on the distribution and orientation of the fillers. In this study, a 50-MHz ultrasound imaging system and analysis techniques capable of nondestructively assessing the properties of carbon fibers (CFs) in conductive polymer composites were developed. Composite materials containing a mix of polycarbonate substrates and 0 to 0.3 wt% of CFs were prepared using an injection molding technique. Ultrasonic A-line signals and C-scan images were acquired from each composite sample in regions at a depth of 0.15 mm beneath the sample surface (region A) and those at a depth of 0.3 mm (region B). The integrated backscatter (IB) and the Nakagami statistical parameter were calculated to quantitatively assess the samples. The area ratio, defined as the percentage of areas composed of CF images normalized by that of the whole C-scan image, was applied to further quantify the orientation of CFs perpendicular to the sample surface. Corresponding to the increase in CF concentrations from 0.1 to 0.3 wt%, the average IB and Nakagami parameter (m) of the composite samples increased from -78.10 ± 2.20 (mean ± standard deviation) to -72.66 ± 1.40 dB and from 0.024 ± 0.012 to 0.048 ± 0.011, respectively. The corresponding area ratios were respectively estimated to be 0.78 ± 0.35%, 2.33 ± 0.66%, and 2.20 ± 0.60% in region A of the samples; those of CFs with a perpendicular orientation were 0.04 ± 0.03%, 0.08 ± 0.02%, and 0.12 ± 0.05%. The area ratios in region B of the samples were calculated to be 1.19 ± 0.54%, 2.81 ± 0.42%, and 2.64 ± 0.76%, and those of CFs with a perpendicular orientation were 0.07 ± 0.04%, 0.12 ± 0.04%, and 0.14 ± 0.03%. According to the results of the orientations and ultrasonic images, CFs tended to distribute more

  8. Third trimester ultrasound soft-tissue measurements accurately predicts macrosomia.

    Science.gov (United States)

    Maruotti, Giuseppe Maria; Saccone, Gabriele; Martinelli, Pasquale

    2017-04-01

    To evaluate the accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia. Electronic databases were searched from their inception until September 2015 with no limit for language. We included only studies assessing the accuracy of sonographic measurements of fetal soft tissue in the abdomen or thigh in the prediction of macrosomia  ≥34 weeks of gestation. The primary outcome was the accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia. We generated the forest plot for the pooled sensitivity and specificity with 95% confidence interval (CI). Additionally, summary receiver-operating characteristics (ROC) curves were plotted and the area under the curve (AUC) was also computed to evaluate the overall performance of the diagnostic test accuracy. Three studies, including 287 singleton gestations, were analyzed. The pooled sensitivity of sonographic measurements of abdominal or thigh fetal soft tissue in the prediction of macrosomia was 80% (95% CI: 66-89%) and the pooled specificity was 95% (95% CI: 91-97%). The AUC for diagnostic accuracy of sonographic measurements of fetal soft tissue in the prediction of macrosomia was 0.92 and suggested high diagnostic accuracy. Third-trimester sonographic measurements of fetal soft tissue after 34 weeks may help to detect macrosomia with a high degree of accuracy. The pooled detection rate was 80%. A standardization of measurements criteria, reproducibility, building reference charts of fetal subcutaneous tissue and large studies to assess the optimal cutoff of fetal adipose thickness are necessary before the introduction of fetal soft-tissue markers in the clinical practice.

  9. Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound

    Science.gov (United States)

    Hargens, A. R.

    1998-01-01

    Prevention of secondary brain injuries following head can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop (PPLL) devise, which was developed and patented, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year one studies involved instrument improvements and measurement of altered intracranial distance with altered ICP in fresh cadavera. Our software was improved to facilitate future studies of normal subjects and trauma patients. Our bench studies proved that PPLL output correlated highly with changes in path length across a model cranium. Cadaveric studies demonstrated excellent compact, noninvasive devise for monitoring changes in intracranial distance may aid in the early detection of elevated ICP, decreasing risk of secondary brain injury and infection, and returning head-injured patients to duty.

  10. Bone mineral density, quantitative ultrasound parameters and bone metabolism in postmenopausal women with depression.

    Science.gov (United States)

    Atteritano, Marco; Lasco, Antonino; Mazzaferro, Susanna; Macrì, Ida; Catalano, Antonino; Santangelo, Antonino; Bagnato, Gianluca; Bagnato, Gianfilippo; Frisina, Nicola

    2013-09-01

    Low bone mineral density, which increases the risk of stress fragility fractures, is a frequent, often persistent finding in patients with major depressive disorder (MDD). The clinical association between major depressive disorder and osteopenia is still unclear, although several factors are associated with a loss of bone mass. The aim of our study, therefore, was to evaluate bone mineral density and bone metabolism in patients with MDD. Bone mineral density was evaluated in fifty postmenopausal women with MDD, and in 50 matched postmenopausal control women by dual-energy X-ray absorptiometry of the lumbar spine and femur, and by ultrasonography of the calcaneus and phalanges. Serum levels of 25-hydroxivitamin D, parathyroid hormone, Osteoprotegerin/Receptor Activator for Nuclear Factor κB Ligand ratio, bone turnover markers, serum and urinary cortisol were examined. Bone mineral density of the lumbar spine (BMD: 0.72 ± 0.06 vs. 0.82 ± 0.09 g/cm(2), p < 0.001), femoral neck (BMD: 0.58 ± 0.04 vs. 0.71 ± 0.07 g/cm(2), p < 0.001) and total femur (BMD 0.66 ± 0.09 vs. 0.54 ± 0.06 g/cm(2), p < 0.001); and ultrasound parameters at calcaneus (SI: 81.30 ± 6.10 vs. 93.80 ± 7.10, p < 0.001) and phalanges (AD-SOS: 1915.00 ± 37.70 vs. 2020.88 ± 39.46, p < 0.001; BTT : 1.30 ± 0.8 vs. 1.45 ± 0.9, p < 0.001) are significantly lower in patients with MDD compared with controls. Moreover bone turnover markers, parathyroid hormone levels and Receptor Activator for Nuclear Factor κB Ligand are significantly higher in MDD patients compared with controls, while serum levels of 25-hydroxivitamin D and osteoprotegerin are significantly lower. There are no differences in urinary excretion and serum cortisol between groups. Postmenopausal women with depressive disorder have an elevated risk for osteoporosis. Our data suggest that a high level of parathyroid hormone may play a role in the pathogenetic process underlying osteopenia in these patients.

  11. Hybrid Segmentation of Vessels and Automated Flow Measures in In-Vivo Ultrasound Imaging

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Martins, Bo; Hansen, Kristoffer Lindskov

    2016-01-01

    expert segmentations. The flowrig results also demonstrated that the PSVs measured from VFI had a mean relative error of 14.5% in comparison with the actual PSVs. The error for the PSVs measured from spectral Doppler was 29.5%, indicating that VFI is 15% more precise than spectral Doppler in PSV...... method implements automated VFI flow measures such as peak systolic velocity (PSV) and volume flow. An evaluation of the performance of the segmentation algorithm relative to expert manual segmentation of 60 frames randomly chosen from 6 ultrasound sequences (10 frame randomly chosen from each sequence...... measurement....

  12. Limited Accuracy of Colour Doppler Ultrasound Dynamic Tissue Perfusion Measurement in Diabetic Adults

    Science.gov (United States)

    Stoperka, Felix; Karger, Claudia

    2016-01-01

    Dynamic tissue perfusion measurement (DTPM) is a pre-described and available method in pediatric ultrasound to quantify tissue perfusion in renal Doppler ultrasound by particular video analysis software. This study evaluates DTPM during single and between repeated visits after 6 months, calibrates repeated DTPM within different region of interest (ROI) and compares DTPM with kidney function markers in adult patients with early diabetic nephropathy (n = 17). During repeated measurements, no association of readings at the same patients in the same (n = 3 readings) as well as repeated visit (n = 2 visits) could be retrieved. No association between DTPM, MDRD-GFR, albuminuria, age and duration of diabetes was observed. These negative results are presumably related to inconsistency of DTPM due to non-fixed ROI position as could be shown in calibrating series. Further development of the method should be performed to enable reproducible DTPM readings in adults. PMID:28033403

  13. Carotid Artery Segmentation in Ultrasound Images and Measurement of Intima-Media Thickness

    Directory of Open Access Journals (Sweden)

    Vaishali Naik

    2013-01-01

    Full Text Available Background. The segmentation of the common carotid artery (CCA wall is imperative for the determination of the intima-media thickness (IMT on B-mode ultrasound (US images. The IMT is considered an important indicator in the evaluation of the risk for the development of atherosclerosis. In this paper, authors have discussed the relevance of measurements in clinical practices and the challenges that one has to face while approaching the segmentation of carotid artery on ultrasound images. The paper presents an overall review of commonly used methods for the CCA segmentation and IMT measurement along with the different performance metrics that have been proposed and used for performance validation. Summary and future directions are given in the conclusion.

  14. Accurate acoustic power measurement for low-intensity focused ultrasound using focal axial vibration velocity

    Science.gov (United States)

    Tao, Chenyang; Guo, Gepu; Ma, Qingyu; Tu, Juan; Zhang, Dong; Hu, Jimin

    2017-07-01

    Low-intensity focused ultrasound is a form of therapy that can have reversible acoustothermal effects on biological tissue, depending on the exposure parameters. The acoustic power (AP) should be chosen with caution for the sake of safety. To recover the energy of counteracted radial vibrations at the focal point, an accurate AP measurement method using the focal axial vibration velocity (FAVV) is proposed in explicit formulae and is demonstrated experimentally using a laser vibrometer. The experimental APs for two transducers agree well with theoretical calculations and numerical simulations, showing that AP is proportional to the square of the FAVV, with a fixed power gain determined by the physical parameters of the transducers. The favorable results suggest that the FAVV can be used as a valuable parameter for non-contact AP measurement, providing a new strategy for accurate power control for low-intensity focused ultrasound in biomedical engineering.

  15. Visual and quantitative evaluation of selected image combination schemes in ultrasound spatial compound scanning

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Jensen, M.S.; Jespersen, S.K.

    2004-01-01

    Multi-angle spatial compound images are normally generated by averaging the recorded single-angle images (SAIs). To exploit possible advantages associated with alternative combination schemes, this paper investigates both the effect of number of angles (Ntheta) as well as operator (mean, median......, mean-excluding-maximum (mem), root-mean-square (rms), geometric mean and maximum) on image quality (tissue delineation and artifacts), speckle signal-to-noise ratio (SNRs) and contrast. The evaluation is based on in vitro SAI (+/-21degrees in steps of Deltatheta = 7degrees) of formalin fixed porcine...... tissue containing adipose, connective and muscular tissue. Image quality increased with number of angles up to +/-14degrees after which the improvements became debatable. The mem and median operators, which try to render the images more quantitatively correct by suppressing strong echoes from specular...

  16. Digital X-ray radiogrammetry better identifies osteoarthritis patients with a low bone mineral density than quantitative ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Goerres, Gerhard W. [University Hospital Zurich, Institute of Diagnostic Radiology, Department of Medical Radiology, Zurich (Switzerland); University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); Frey, Diana; Studer, Annina; Hauser, Dagmar; Zilic, Nathalie [University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); Hany, Thomas F. [University Hospital Zurich, Institute of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Seifert, Burkhardt [University of Zurich, Department of Biostatistics, Zurich (Switzerland); Haeuselmann, Hans J. [Center for Rheumatology and Bone Disease, Klinik im Park, Zurich (Switzerland); Michel, Beat A.; Uebelhart, Daniel [University Hospital Zurich, Osteoporosis Center, Zurich (Switzerland); University Hospital Zurich, Department of Rheumatology and Institute of Physical Medicine, Zurich (Switzerland); Hans, Didier [University Hospital Geneva, Division of Nuclear Medicine, Geneva (Switzerland)

    2007-04-15

    This study assessed the ability of quantitative ultrasound (QUS) and digital X-ray radiogrammetry (DXR) to identify osteopenia and osteoporosis in patients with knee osteoarthritis (OA). One hundred and sixty-one patients with painful knee OA (81 men, 80 women; age 62.6{+-}9.2 years, range 40-82 years) were included in this cross-sectional study and underwent dual-energy X-ray absorptiometry (DXA) of both hips and the lumbar spine, QUS of the phalanges and calcanei of both hands and heels, and DXR using radiographs of both hands. Unpaired t-test, Mann-Whitney U test, ROC analysis and Spearman's rank correlation were used for comparisons and correlation of methods. Using DXA as the reference standard, we defined a low bone mineral density (BMD) as a T-score {<=}-1.0 at the lumbar spine or proximal femur. In contrast to phalangeal or calcaneal QUS, DXR was able to discriminate patients with a low BMD at the lumbar spine (p<0.0001) or hips (p<0.0001). ROC analysis showed that DXR had an acceptable predictive power in identifying OA patients a low hip BMD (sensitivity 70%, specificity 71%). Therefore, DXR used as a screening tool could help in identifying patients with knee OA for DXA. (orig.)

  17. Cranial Ultrasound/Head Ultrasound

    Science.gov (United States)

    ... sickle cell disease. It is also used to measure conditions affecting blood flow to and within the brain, such as: Stenosis : ... saved. Doppler ultrasound, a special application of ultrasound, measures ... represent the flow of blood through the blood vessels. top of ...

  18. Colonic wall thickness measured by ultrasound: striking differences in patients with cystic fibrosis versus healthy controls.

    OpenAIRE

    1997-01-01

    BACKGROUND: Colonic strictures represent an advanced stage of fibrosing colonopathy in patients with cystic fibrosis. AIMS: To clarify whether ultrasonography can identify patients with an early stage of fibrosing colonopathy and to determine clinical factors that influence bowel wall thickening. PATIENTS: Ninety patients with cystic fibrosis, median age 10 years, and 46 healthy controls, median age 13 years, were investigated. METHODS: Bowel wall thickness was measured by ultrasound in a pro...

  19. Exploratory Analysis of Carbon Dioxide Levels and Ultrasound Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Young, M.; Mason, S.; Coble, C.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Law. J.; Alexander, D.; Ryder, V. Myers; hide

    2016-01-01

    Carbon dioxide (CO2) levels on ISS have typically averaged 2.3 to 5.3mm Hg, with large fluctuations occurring over periods of hours and days. CO2 has effects on cerebral vascular tone, resulting in vasodilation and alteration of cerebral blood flow(CBF). Increased CBF leads to elevated intracranial pressure(ICP), which is a factor leading to visual disturbance, headaches, and other central nervous system symptoms. Ultrasound of the optic nerve provides a surrogate measurement of ICP. Inflight ultrasounds were implemented as an enhanced screening tool for the Visual Impairment/Intracranial Pressure (VIIP) Syndrome. This analysis examines the relationships between ambient CO2 levels on ISS and ultrasound measures of the eye in an effort to understand how CO2 may be associated with VIIP and to inform future analysis of inflight VIIP data. Results as shown in Figure2, there was a large timeframe where CO2 readings were removed due to sensor fault errors(see Limitations), from June 2011 to January 2012. After extensive cleaning of the CO2 data, metrics for all of the data were calculated (Table2). Preliminary analyses showed possible associations between variability measures of CO2 and AP diameter (Figure3),and average CO2 exposure and ONSD(Figure4). Adjustments for multiple comparisons were not made due to the exploratory nature of the analysis.

  20. Duplex ultrasound

    Science.gov (United States)

    Vascular ultrasound; Peripheral vascular ultrasound ... A duplex ultrasound combines: Traditional ultrasound: This uses sound waves that bounce off blood vessels to create pictures. Doppler ultrasound: This ...

  1. Quantification of ultrasound correlation-based flow velocity mapping and edge velocity gradient measurement.

    Science.gov (United States)

    Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F

    2013-10-01

    This study investigated the use of ultrasound speckle decorrelation- and correlation-based lateral speckle-tracking methods for transverse and longitudinal blood velocity profile measurement, respectively. By studying the blood velocity gradient at the vessel wall, vascular wall shear stress, which is important in vascular physiology as well as the pathophysiologic mechanisms of vascular diseases, can be obtained. Decorrelation-based blood velocity profile measurement transverse to the flow direction is a novel approach, which provides advantages for vascular wall shear stress measurement over longitudinal blood velocity measurement methods. Blood flow velocity profiles are obtained from measurements of frame-to-frame decorrelation. In this research, both decorrelation and lateral speckle-tracking flow estimation methods were compared with Poiseuille theory over physiologic flows ranging from 50 to 1000 mm/s. The decorrelation flow velocity measurement method demonstrated more accurate prediction of the flow velocity gradient at the wall edge than the correlation-based lateral speckle-tracking method. The novelty of this study is that speckle decorrelation-based flow velocity measurements determine the blood velocity across a vessel. In addition, speckle decorrelation-based flow velocity measurements have higher axial spatial resolution than Doppler ultrasound measurements to enable more accurate measurement of blood velocity near a vessel wall and determine the physiologically important wall shear.

  2. Central Corneal Thickness Measurement by Ultrasound versus Orbscan II

    Directory of Open Access Journals (Sweden)

    Amir Faramarzi

    2008-12-01

    Full Text Available

    PURPOSE: To compare Orbscan II and ultrasonic pachymetry for measurement of central corneal thickness (CCT in eyes scheduled for keratorefractive surgery. METHODS: CCT was measured using Orbscan II (Bausch & Lomb, USA and then by ultrasonic pachymetry (Tomey SP-3000, Tomey Ltd, Japan in 100 eyes of 100 patients with no history of ocular surgery scheduled for excimer laser refractive surgery. RESULTS: Mean CCT was 544.7±35.5 (range 453-637 µm by ultrasonic pachymetry versus 546.9±41.6 (range 435-648 µm measured by Orbscan II applying an acoustic factor of 0.92 (P=0.14. The standard deviation of measurements was greater with Orbscan pachymetry but the difference was not statistically significant. CONCLUSION: CCT measurements by Orbscan II (applying an acoustic factor and by ultrasonic pachymetry are not significantly different; however, when CCT readings by Orbscan II are in the lower range, it is advisable to recheck the measurements using ultrasonic pachymetry.

  1. Ultrasound Velocity Measurements in High-Chromium Steel Under Plastic Deformation

    Science.gov (United States)

    Lunev, Aleksey; Bochkareva, Anna; Barannikova, Svetlana; Zuev, Lev

    2016-04-01

    In the present study, the variation of the propagation velocity of ultrasound in the plastic deformation of corrosion-resistant high-chromium steel 40X13 with ferrite-carbide (delivery status), martensitic (quenched) and sorbitol (after high-temperature tempering) structures have beem studied/ It is found that each state shows its view of the loading curve. In the delivery state diagram loading is substantially parabolic throughout, while in the martensitic state contains only linear strain hardening step and in the sorbitol state the plastic flow curve is three-step. The velocity of ultrasonic surface waves (Rayleigh waves) was measured simultaneously with the registration of the loading curve in the investigated steel in tension. It is shown that the dependence of the velocity of ultrasound in active loading is determined by the law of plastic flow, that is, the staging of the corresponding diagram of loading. Structural state of the investigated steel is not only changing the type of the deformation curve under uniaxial tension, but also changes the nature of ultrasound speed of deformation.

  2. [Precision of arthroscopic surgeons using ultrasound for the first time to measure tendon structures].

    Science.gov (United States)

    Erquicia, J I; Tey, M; Doreste, J L; Monllau, J C; Centenera, J M; Altisench, J M

    2016-01-01

    The precision of a group of arthroscopic surgeons using ultrasound for the first time was assessed when measuring shoulder and hip tendon structures. Twenty-two students and 3 professors participated in a one-day theoretical-practical course. Two measurement rounds were conducted, during which each student identified the greater and lesser axes and the cross-sectional area of the biceps tendon, the supraspinous depth, as well as the lesser and greater axes and the cross-sectional area of the iliac psoas. The mean of the two measurements made by each of the course professors was considered as the reference value. When the 2 measurements made by each of the students of each of the structures were assessed, no significant correlation was found in any of the cases, with a p 0.05. With the exception of the cross-sectional area of the biceps, where there was a significant undersizing of the structure, in the remaining 7 measurements a marked trend to oversize the structures was seen in both the first and second measurements, with a high statistical significance (p 0.05). Ultrasound is a useful method through which arthroscopic surgeons can identify structures. However, the marked trend to oversize structures compared to the reference values leads to think that the training courses and the daily practice are essential to improve the method.

  3. Pulse-echo ultrasound transit time spectroscopy: A comparison of experimental measurement and simulation prediction.

    Science.gov (United States)

    Wille, Marie-Luise; Almualimi, Majdi A; Langton, Christian M

    2016-01-01

    Considering ultrasound propagation through complex composite media as an array of parallel sonic rays, a comparison of computer-simulated prediction with experimental data has previously been reported for transmission mode (where one transducer serves as transmitter, the other as receiver) in a series of 10 acrylic step-wedge samples, immersed in water, exhibiting varying degrees of transit time inhomogeneity. In this study, the same samples were used but in pulse-echo mode, where the same ultrasound transducer served as both transmitter and receiver, detecting both 'primary' (internal sample interface) and 'secondary' (external sample interface) echoes. A transit time spectrum was derived, describing the proportion of sonic rays with a particular transit time. A computer simulation was performed to predict the transit time and amplitude of various echoes created, and compared with experimental data. Applying an amplitude-tolerance analysis, 91.7% ± 3.7% of the simulated data were within ±1 standard deviation of the experimentally measured amplitude-time data. Correlation of predicted and experimental transit time spectra provided coefficients of determination (R(2)%) ranging from 100.0% to 96.8% for the various samples tested. The results acquired from this study provide good evidence for the concept of parallel sonic rays. Furthermore, deconvolution of experimental input and output signals has been shown to provide an effective method to identify echoes otherwise lost due to phase cancellation. Potential applications of pulse-echo ultrasound transit time spectroscopy include improvement of ultrasound image fidelity by improving spatial resolution and reducing phase interference artefacts.

  4. Bone mass status of school-aged children in Taiwan assessed by quantitative ultrasound: the Nutrition and Health Survey in Taiwan Elementary School Children (NAHSIT Children 2001-2002).

    Science.gov (United States)

    Lin, Yi-Chin; Tu, Su-Hao; Pan, Wen-Harn L

    2007-01-01

    Bone health status in childhood and adolescence may be important factors influencing the attainment of peak bone mass. The Nutrition and Health Survey in Taiwan Elementary School Children 2000-2001 was carried out to evaluate the overall nutrition and health status of school children aged between 6 and 13 years. The survey was conducted using a multi-stage complex sampling scheme. Townships and city districts in Taiwan were classified into 13 strata. Bone mass measured as broadband ultrasound attenuation was taken at heel by quantitative ultrasound bone densitometry. A total of 1164 boys and 1016 girls who had complete physical examination data with ultrasound bone scan were included in the current analysis. There were no apparent differences in BUA across all strata for both genders. In both boys and girls, age, height, body weight, BMI, and intake frequencies of vegetables and fruits/juices were significantly related to BUA. Results of multivariate regression showed that age (beta=1.36, p=0.0002) and body weight (beta=0.40, pvariables on BUA in boys and girls may be in part due to the development of puberty. It would be necessary to include levels of physical activity in future analyses for better understanding factors influencing the development of peak bone mass in Taiwanese children.

  5. Quantitative measures for assessment of the hydraulic excavator digging efficiency

    Institute of Scientific and Technical Information of China (English)

    Dragoslav JANOSEVIC; Rosen MITREV; Boban ANDJELKOVIC; Plamen PETROV

    2012-01-01

    In this paper,quantitative measures for the assessment of the hydraulic excavator digging efficiency are proposed and developed.The following factors are considered: (a) boundary digging forces allowed for by the stability of an excavator,(b) boundary digging forces enabled by the driving mechanisms of the excavator,(c) factors taking into consideration the digging position in the working range of an excavator,and (d) sign and direction of potential digging resistive force.A corrected digging force is defined and a mathematical model of kinematic chain and drive mechanisms of a five-member excavator configuration was developed comprising: an undercarriage,a rotational platform and an attachment with boom,stick,and bucket.On the basis of the mathematical model of the excavator,software was developed for computation and detailed analysis of the digging forces in the entire workspace of the excavator.By using the developed software,the analysis of boundary digging forces is conducted and the corrected digging force is determined for two models of hydraulic excavators of the same mass (around 17000 kg) with identical kinematic chain parameters but with different parameters of manipulator driving mechanisms.The results of the analysis show that the proposed set of quantitative measures can be used for assessment of the digging efficiency of existing excavator models and to serve as an optimization criterion in the synthesis of manipulator driving mechanisms of new excavator models.

  6. Quantitative Thermochemical Measurements in High-Pressure Gaseous Combustion

    Science.gov (United States)

    Kojima, Jun J.; Fischer, David G.

    2012-01-01

    We present our strategic experiment and thermochemical analyses on combustion flow using a subframe burst gating (SBG) Raman spectroscopy. This unconventional laser diagnostic technique has promising ability to enhance accuracy of the quantitative scalar measurements in a point-wise single-shot fashion. In the presentation, we briefly describe an experimental methodology that generates transferable calibration standard for the routine implementation of the diagnostics in hydrocarbon flames. The diagnostic technology was applied to simultaneous measurements of temperature and chemical species in a swirl-stabilized turbulent flame with gaseous methane fuel at elevated pressure (17 atm). Statistical analyses of the space-/time-resolved thermochemical data provide insights into the nature of the mixing process and it impact on the subsequent combustion process in the model combustor.

  7. Design and implementation of a smartphone-based portable ultrasound pulsed-wave Doppler device for blood flow measurement.

    Science.gov (United States)

    Huang, Chih-Chung; Lee, Po-Yang; Chen, Pay-Yu; Liu, Ting-Yu

    2012-01-01

    Blood flow measurement using Doppler ultrasound has become a useful tool for diagnosing cardiovascular diseases and as a physiological monitor. Recently, pocket-sized ultrasound scanners have been introduced for portable diagnosis. The present paper reports the implementation of a portable ultrasound pulsed-wave (PW) Doppler flowmeter using a smartphone. A 10-MHz ultrasonic surface transducer was designed for the dynamic monitoring of blood flow velocity. The directional baseband Doppler shift signals were obtained using a portable analog circuit system. After hardware processing, the Doppler signals were fed directly to a smartphone for Doppler spectrogram analysis and display in real time. To the best of our knowledge, this is the first report of the use of this system for medical ultrasound Doppler signal processing. A Couette flow phantom, consisting of two parallel disks with a 2-mm gap, was used to evaluate and calibrate the device. Doppler spectrograms of porcine blood flow were measured using this stand-alone portable device under the pulsatile condition. Subsequently, in vivo portable system verification was performed by measuring the arterial blood flow of a rat and comparing the results with the measurement from a commercial ultrasound duplex scanner. All of the results demonstrated the potential for using a smartphone as a novel embedded system for portable medical ultrasound applications. © 2012 IEEE

  8. Quantitative Assessment of Variational Surface Reconstruction from Sparse Point Clouds in Freehand 3D Ultrasound Imaging during Image-Guided Tumor Ablation

    Directory of Open Access Journals (Sweden)

    Shuangcheng Deng

    2016-04-01

    Full Text Available Surface reconstruction for freehand 3D ultrasound is used to provide 3D visualization of a VOI (volume of interest during image-guided tumor ablation surgery. This is a challenge because the recorded 2D B-scans are not only sparse but also non-parallel. To solve this issue, we established a framework to reconstruct the surface of freehand 3D ultrasound imaging in 2011. The key technique for surface reconstruction in that framework is based on variational interpolation presented by Greg Turk for shape transformation and is named Variational Surface Reconstruction (VSR. The main goal of this paper is to evaluate the quality of surface reconstructions, especially when the input data are extremely sparse point clouds from freehand 3D ultrasound imaging, using four methods: Ball Pivoting, Power Crust, Poisson, and VSR. Four experiments are conducted, and quantitative metrics, such as the Hausdorff distance, are introduced for quantitative assessment. The experiment results show that the performance of the proposed VSR method is the best of the four methods at reconstructing surface from sparse data. The VSR method can produce a close approximation to the original surface from as few as two contours, whereas the other three methods fail to do so. The experiment results also illustrate that the reproducibility of the VSR method is the best of the four methods.

  9. Automatic segmentation and measurements of gestational sac using static B-mode ultrasound images

    Science.gov (United States)

    Ibrahim, Dheyaa Ahmed; Al-Assam, Hisham; Du, Hongbo; Farren, Jessica; Al-karawi, Dhurgham; Bourne, Tom; Jassim, Sabah

    2016-05-01

    Ultrasound imagery has been widely used for medical diagnoses. Ultrasound scanning is safe and non-invasive, and hence used throughout pregnancy for monitoring growth. In the first trimester, an important measurement is that of the Gestation Sac (GS). The task of measuring the GS size from an ultrasound image is done manually by a Gynecologist. This paper presents a new approach to automatically segment a GS from a static B-mode image by exploiting its geometric features for early identification of miscarriage cases. To accurately locate the GS in the image, the proposed solution uses wavelet transform to suppress the speckle noise by eliminating the high-frequency sub-bands and prepare an enhanced image. This is followed by a segmentation step that isolates the GS through the several stages. First, the mean value is used as a threshold to binarise the image, followed by filtering unwanted objects based on their circularity, size and mean of greyscale. The mean value of each object is then used to further select candidate objects. A Region Growing technique is applied as a post-processing to finally identify the GS. We evaluated the effectiveness of the proposed solution by firstly comparing the automatic size measurements of the segmented GS against the manual measurements, and then integrating the proposed segmentation solution into a classification framework for identifying miscarriage cases and pregnancy of unknown viability (PUV). Both test results demonstrate that the proposed method is effective in segmentation the GS and classifying the outcomes with high level accuracy (sensitivity (miscarriage) of 100% and specificity (PUV) of 99.87%).

  10. Techniques and evaluation from a cross-platform imaging comparison of quantitative ultrasound parameters in an in vivo rodent fibroadenoma model.

    Science.gov (United States)

    Wirtzfeld, Lauren A; Nam, Kibo; Labyed, Yassin; Ghoshal, Goutam; Haak, Alexander; Sen-Gupta, Ellora; He, Zhi; Hirtz, Nathaniel R; Miller, Rita J; Sarwate, Sandhya; Simpson, Douglas G; Zagzebski, James A; Bigelow, Timothy A; Oelze, Michael; Hall, Timothy J; O'Brien, William D

    2013-07-01

    This contribution demonstrates that quantitative ultrasound (QUS) capabilities are platform independent, using an in vivo model. Frequency-dependent attenuation estimates, backscatter coefficient, and effective scatterer diameter estimates are shown to be comparable across four different ultrasound imaging systems with varied processing techniques. The backscatter coefficient (BSC) is a fundamental material property from which several QUS parameters are estimated; therefore, consistent BSC estimates among different systems must be demonstrated. This study is an intercomparison of BSC estimates acquired by three research groups (UIUC, UW, ISU) from four in vivo spontaneous rat mammary fibroadenomas using three clinical array systems and a single-element laboratory scanner system. Because of their highly variable backscatter properties, fibroadenomas provided an extreme test case for BSC analysis, and the comparison is across systems for each tumor, not across the highly heterogeneous tumors. RF echo data spanning the 1 to 12 MHz frequency range were acquired in three dimensions from all animals using each system. Each research group processed their RF data independently, and the resulting attenuation, BSC, and effective scatterer diameter (ESD) estimates were compared. The attenuation estimates across all systems showed the same trends and consistently fit the power-law dependence on frequency. BSCs varied among the multiple slices of data acquired by each transducer, with variations between transducers being of a similar magnitude as those from slice to slice. Variation between BSC estimates was assessed via functional signal-to-noise ratios derived from backscatter data. These functional signal-to-noise ratios indicated that BSC versus frequency variations between systems ranged from negligible compared with the noise level to roughly twice the noise level. The corresponding functional analysis of variance (fANOVA) indicated statistically significant differences

  11. Attenuation measuring ultrasound shearwave elastography and in vivo application in post-transplant liver patients

    Science.gov (United States)

    Nenadic, Ivan Z.; Qiang, Bo; Urban, Matthew W.; Zhao, Heng; Sanchez, William; Greenleaf, James F.; Chen, Shigao

    2017-01-01

    Ultrasound and magnetic resonance elastography techniques are used to assess mechanical properties of soft tissues. Tissue stiffness is related to various pathologies such as fibrosis, loss of compliance, and cancer. One way to perform elastography is measuring shear wave velocity of propagating waves in tissue induced by intrinsic motion or an external source of vibration, and relating the shear wave velocity to tissue elasticity. All tissues are inherently viscoelastic and ignoring viscosity biases the velocity-based estimates of elasticity and ignores a potentially important parameter of tissue health. We present attenuation measuring ultrasound shearwave elastography (AMUSE), a technique that independently measures both shear wave velocity and attenuation in tissue and therefore allows characterization of viscoelasticity without using a rheological model. The theoretical basis for AMUSE is first derived and validated in finite element simulations. AMUSE is validated against the traditional methods for assessing shear wave velocity (phase gradient) and attenuation (amplitude decay) in tissue mimicking phantoms and excised tissue. The results agreed within one standard deviation. AMUSE was used to measure shear wave velocity and attenuation in 15 transplanted livers in patients with potential acute rejection, and the results were compared with the biopsy findings in a preliminary study. The comparison showed excellent agreement and suggests that AMUSE can be used to separate transplanted livers with acute rejection from livers with no rejection.

  12. Automated kidney morphology measurements from ultrasound images using texture and edge analysis

    Science.gov (United States)

    Ravishankar, Hariharan; Annangi, Pavan; Washburn, Michael; Lanning, Justin

    2016-04-01

    In a typical ultrasound scan, a sonographer measures Kidney morphology to assess renal abnormalities. Kidney morphology can also help to discriminate between chronic and acute kidney failure. The caliper placements and volume measurements are often time consuming and an automated solution will help to improve accuracy, repeatability and throughput. In this work, we developed an automated Kidney morphology measurement solution from long axis Ultrasound scans. Automated kidney segmentation is challenging due to wide variability in kidney shape, size, weak contrast of the kidney boundaries and presence of strong edges like diaphragm, fat layers. To address the challenges and be able to accurately localize and detect kidney regions, we present a two-step algorithm that makes use of edge and texture information in combination with anatomical cues. First, we use an edge analysis technique to localize kidney region by matching the edge map with predefined templates. To accurately estimate the kidney morphology, we use textural information in a machine learning algorithm framework using Haar features and Gradient boosting classifier. We have tested the algorithm on 45 unseen cases and the performance against ground truth is measured by computing Dice overlap, % error in major and minor axis of kidney. The algorithm shows successful performance on 80% cases.

  13. Fetal growth and air pollution - A study on ultrasound and birth measures.

    Science.gov (United States)

    Malmqvist, Ebba; Liew, Zeyan; Källén, Karin; Rignell-Hydbom, Anna; Rittner, Ralf; Rylander, Lars; Ritz, Beate

    2017-01-01

    Air pollution has been suggested to affect fetal growth, but more data is needed to assess the timing of exposure effects by using ultrasound measures. It is also important to study effects in low exposure areas to assess eventual thresholds of effects. The MAPSS (Maternal Air Pollution in Southern Sweden) cohort consists of linked registry data for around 48,000 pregnancies from an ultrasound database, birth registry and exposure data based on residential addresses. Measures of air pollution exposure were obtained through dispersion modelling with input data from an emissions database (NOx) with high resolution (100-500m grids). Air pollution effects were assessed with linear regressions for the following endpoints; biparietal diameter, femur length, abdominal diameter and estimated fetal weight measured in late pregnancy and birth weight and head circumference measured at birth. We estimated negative effects for NOx; in the adjusted analyses the decrease of abdominal diameter and femur length were -0.10 (-0.17, -0.03) and -0.13 (-0.17, -0.01)mm, respectively, per 10µg/m(3) increment of NOx. We also estimated an effect of NOx-exposures on birth weight by reducing birth weight by 9g per 10µg/m(3) increment of NOx. We estimated small but statistically significant effects of air pollution on late fetal and birth size and reduced fetal growth late in pregnancy in a geographic area with levels below current WHO air quality guidelines.

  14. Accuracy of electrocardiographic-gated versus nongated volumetric intravascular ultrasound measurements of coronary arterial narrowing

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per

    2007-01-01

    Intravascular ultrasound (IVUS) allows precise measurements of plaque plus media (P+M) volume and neointimal hyperplasia after coronary artery stenting. Conventional IVUS volumetric analysis is performed mostly without electrocardiographically gated acquisition, and the IVUS images are selected...... in changes between 2 electrocardiographically gated and 2 nongated pullbacks (lumen: 0.37 +/- 1.76 vs -0.23 +/- 2.32 mm(3), p = NS; EEM: 0.25 +/- 3.22 vs -0.94 +/- 4.27 mm(3), p = NS; P+M: -0.18 +/- 3.42 vs -0.74 +/- 3.88 mm(3), p = NS). In conclusion, in moderate atherosclerotic or stented coronary arteries...

  15. DXA测量BMD与超声测量SOS的比较%Comparison between SOS of quantitative ultrasound and BMD meas ured by DXA in diagnostic value of osteoporosis

    Institute of Scientific and Technical Information of China (English)

    安珍; 杨定焯; 王文志; 张祖君; 姜光瑶

    2001-01-01

    目的 本文通过对同一个人的跟骨超声声速(SOS)测量与双能X线吸收法测量腰2- 4,股骨近端骨密度(BMD)的临床对比来评价超声骨密度仪测量跟骨的SOS对诊断骨质疏松症 的敏感性和与DXA测量BMD的相关性。方法 对523名8~87岁健康人群同时采用DXA测量L2-4,股骨近端(N eck,Ward三角,Troch)BMD和超声骨密度仪测量左跟骨SOS值并进行相关分析。对1006名3~8 7岁健康人群测量左右跟骨的SOS值。结果 SOS与DXA测量BMD的骨峰值(PBM)均出现在20~39岁,SOS的PBM男性 为(1542.83±27.44)m/s,女性为(1531.02±29.96)m/s。40岁以后随着年龄的增加,二 者均逐渐下降。健康成人中BMD与SOS的相关系数为0.3~0.6,骨质疏松患者BMD与SOS的相 关系数(r=0.16~0.39)较健康人(r=0.33~0.61)低。左右足跟SOS无显著差异 ,DXA的BMD与SOS诊断骨质疏松症(OP)的符合率为60%。结论 DXA测量BMD与超声SOS为中等相关。建议在单独使用超声骨密度仪测 量SOS来诊断OP时,应当参照临床症状和X线的检查全面考虑,以免造成漏诊或误诊。%Dual energy x-ray absorptiometry(DXA) is a method o f measur ing the material properties of bone, that is, bone mineral density(BMD), whereas the quantitative ultrasound(QUS) is a method of assessing the mechanical proper ties of bone by the reflection and attenuation of ultrasound. We evaluated the s ensitivity of ultrasound in measuring bone mass by comparing with dual energy x -ray absorptiometry. BMD at lumbar spine and proximal part of the femur was mea sured by DXA and SOS at calcaneus by QUS in 892 subjects of 3 to 87 years in Chengdu. The results showed that SOS peaked at the age of 20 and declined with aging. The peak SOS was (1542.83±27.44)m/s in males and (1531.02±28.96)m/s in females. The correlation coefficients between SOS and BMD were 0.12~0.21 in children and 0.3~0.6 in adults, respectively. The homogeneity rate of the

  16. Quantitative correlational study of microbubble-enhanced ultrasound imaging and magnetic resonance imaging of glioma and early response to radiotherapy in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chen [Department of Ultrasound, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022 (China); Lee, Dong-Hoon; Zhang, Kai; Li, Wenxiao; Zhou, Jinyuan [Division of MR Research, Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287 (United States); Mangraviti, Antonella; Tyler, Betty [Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287 (United States); Su, Lin; Zhang, Yin; Zhang, Bin; Wong, John; Wang, Ken Kang-Hsin; Velarde, Esteban; Ding, Kai, E-mail: kding1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21231 (United States)

    2015-08-15

    Purpose: Radiotherapy remains a major treatment method for malignant tumors. Magnetic resonance imaging (MRI) is the standard modality for assessing glioma treatment response in the clinic. Compared to MRI, ultrasound imaging is low-cost and portable and can be used during intraoperative procedures. The purpose of this study was to quantitatively compare contrast-enhanced ultrasound (CEUS) imaging and MRI of irradiated gliomas in rats and to determine which quantitative ultrasound imaging parameters can be used for the assessment of early response to radiation in glioma. Methods: Thirteen nude rats with U87 glioma were used. A small thinned skull window preparation was performed to facilitate ultrasound imaging and mimic intraoperative procedures. Both CEUS and MRI with structural, functional, and molecular imaging parameters were performed at preradiation and at 1 day and 4 days postradiation. Statistical analysis was performed to determine the correlations between MRI and CEUS parameters and the changes between pre- and postradiation imaging. Results: Area under the curve (AUC) in CEUS showed significant difference between preradiation and 4 days postradiation, along with four MRI parameters, T{sub 2}, apparent diffusion coefficient, cerebral blood flow, and amide proton transfer-weighted (APTw) (all p < 0.05). The APTw signal was correlated with three CEUS parameters, rise time (r = − 0.527, p < 0.05), time to peak (r = − 0.501, p < 0.05), and perfusion index (r = 458, p < 0.05). Cerebral blood flow was correlated with rise time (r = − 0.589, p < 0.01) and time to peak (r = − 0.543, p < 0.05). Conclusions: MRI can be used for the assessment of radiotherapy treatment response and CEUS with AUC as a new technique and can also be one of the assessment methods for early response to radiation in glioma.

  17. Quantitative correlational study of microbubble-enhanced ultrasound imaging and magnetic resonance imaging of glioma and early response to radiotherapy in a rat model.

    Science.gov (United States)

    Yang, Chen; Lee, Dong-Hoon; Mangraviti, Antonella; Su, Lin; Zhang, Kai; Zhang, Yin; Zhang, Bin; Li, Wenxiao; Tyler, Betty; Wong, John; Wang, Ken Kang-Hsin; Velarde, Esteban; Zhou, Jinyuan; Ding, Kai

    2015-08-01

    Radiotherapy remains a major treatment method for malignant tumors. Magnetic resonance imaging (MRI) is the standard modality for assessing glioma treatment response in the clinic. Compared to MRI, ultrasound imaging is low-cost and portable and can be used during intraoperative procedures. The purpose of this study was to quantitatively compare contrast-enhanced ultrasound (CEUS) imaging and MRI of irradiated gliomas in rats and to determine which quantitative ultrasound imaging parameters can be used for the assessment of early response to radiation in glioma. Thirteen nude rats with U87 glioma were used. A small thinned skull window preparation was performed to facilitate ultrasound imaging and mimic intraoperative procedures. Both CEUS and MRI with structural, functional, and molecular imaging parameters were performed at preradiation and at 1 day and 4 days postradiation. Statistical analysis was performed to determine the correlations between MRI and CEUS parameters and the changes between pre- and postradiation imaging. Area under the curve (AUC) in CEUS showed significant difference between preradiation and 4 days postradiation, along with four MRI parameters, T2, apparent diffusion coefficient, cerebral blood flow, and amide proton transfer-weighted (APTw) (all p correlated with three CEUS parameters, rise time (r = - 0.527, p correlated with rise time (r = - 0.589, p < 0.01) and time to peak (r = - 0.543, p < 0.05). MRI can be used for the assessment of radiotherapy treatment response and CEUS with AUC as a new technique and can also be one of the assessment methods for early response to radiation in glioma.

  18. A passive quantitative measurement of airway resistance using depth data.

    Science.gov (United States)

    Ostadabbas, Sarah; Bulach, Christoph; Ku, David N; Anderson, Larry J; Ghovanloo, Maysam

    2014-01-01

    The Respiratory Syncytial Virus (RSV) is the most common cause of serious lower respiratory tract infections in infants and young children. RSV often causes increased airway resistance, clinically detected as wheezing by chest auscultation. In this disease, expiratory flows are significantly reduced due to the high resistance in patient's airway passages. A quantitative method for measuring resistance can have a great benefit to diagnosis and management of children with RSV infections as well as with other lung diseases. Airway resistance is defined as the lung pressure divided by the airflow. In this paper, we propose a method to quantify resistance through a simple, non-contact measurement of chest volume that can act as a surrogate measure of the lung pressure and volumetric airflow. We used depth data collected by a Microsoft Kinect camera for the measurement of the lung volume over time. In our experimentation, breathing through a number of plastic straws induced different airway resistances. For a standard spirometry test, our volume/flow estimation using Kinect showed strong correlation with the flow data collected by a commercially-available spirometer (five subjects, each performing 20 breathing trials, correlation coefficient = 0.88, with 95% confidence interval). As the number of straws decreased, emulating a higher airway obstruction, our algorithm was sufficient to distinguish between several levels of airway resistance.

  19. Measurement of quantitative viscoelasticity of bovine corneas based on lamb wave dispersion properties.

    Science.gov (United States)

    Zhang, Xinyu; Yin, Yin; Guo, Yanrong; Fan, Ning; Lin, Haoming; Liu, Fulong; Diao, Xianfen; Dong, Changfeng; Chen, Xin; Wang, Tianfu; Chen, Siping

    2015-05-01

    The viscoelastic properties of the human cornea can provide valuable information for clinical applications such as the early detection of corneal diseases, better management of corneal surgery and treatment and more accurate measurement of intra-ocular pressure. However, few techniques are capable of quantitatively and non-destructively assessing corneal biomechanics in vivo. The cornea can be regarded as a thin plate in which the vibration induced by an external vibrator propagates as a Lamb wave, the properties of which depend on the thickness and biomechanics of the tissue. In this study, pulses of ultrasound radiation force with a repetition frequency of 100 or 200 Hz were applied to the apex of corneas, and the linear-array transducer of a SonixRP system was used to track the tissue motion in the radial direction. Shear elasticity and viscosity were estimated from the phase velocities of the A0 Lamb waves. To assess the effectiveness of the method, some of the corneas were subjected to collagen cross-linking treatment, and the changes in mechanical properties were validated with a tensile test. The results indicated that the shear modulus was 137 ± 37 kPa and the shear viscosity was 3.01 ± 2.45 mPa · s for the group of untreated corneas and 1145 ± 267 kPa and was 0.16 ± 0.11 mPa · s for the treated group, respectively, implying a significant increase in elasticity and a significant decrease in viscosity after collagen cross-linking treatment. This result is in agreement with the results of the mechanical tensile test and with reports in the literature. This initial investigation illustrated the ability of this ultrasound-based method, which uses the velocity dispersion of low-frequency A0 Lamb waves, to quantitatively assess both the elasticity and viscosity of corneas. Future studies could discover ways to optimize this system and to determine the feasibility of using this method in clinical situations.

  20. Developing quantitative tools for measuring aspects of prisonization

    DEFF Research Database (Denmark)

    Kjær Minke, Linda

    2013-01-01

    The article describes and discusses the preparation and completion of a quantitative study among prison officers and prisoners.......The article describes and discusses the preparation and completion of a quantitative study among prison officers and prisoners....

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... the prostate is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any ... size with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate ...

  2. Prostate Ultrasound

    Medline Plus

    Full Text Available ... prostate is enlarged, also known as benign prostatic hyperplasia (BPH) , with measurements acquired as needed for any ... with caption Related Articles and Media Benign Prostatic Hyperplasia (BPH) Prostate Cancer Ultrasound- and MRI-Guided Prostate ...

  3. A novel semi-quantitative method for measuring tissue bleeding.

    Science.gov (United States)

    Vukcevic, G; Volarevic, V; Raicevic, S; Tanaskovic, I; Milicic, B; Vulovic, T; Arsenijevic, S

    2014-03-01

    In this study, we describe a new semi-quantitative method for measuring the extent of bleeding in pathohistological tissue samples. To test our novel method, we recruited 120 female patients in their first trimester of pregnancy and divided them into three groups of 40. Group I was the control group, in which no dilation was applied. Group II was an experimental group, in which dilation was performed using classical mechanical dilators. Group III was also an experimental group, in which dilation was performed using a hydraulic dilator. Tissue samples were taken from the patients' cervical canals using a Novak's probe via energetic single-step curettage prior to any dilation in Group I and after dilation in Groups II and III. After the tissue samples were prepared, light microscopy was used to obtain microphotographs at 100x magnification. The surfaces affected by bleeding were measured in the microphotographs using the Autodesk AutoCAD 2009 program and its "polylines" function. The lines were used to mark the area around the entire sample (marked A) and to create "polyline" areas around each bleeding area on the sample (marked B). The percentage of the total area affected by bleeding was calculated using the formula: N = Bt x 100 / At where N is the percentage (%) of the tissue sample surface affected by bleeding, At (A total) is the sum of the surfaces of all of the tissue samples and Bt (B total) is the sum of all the surfaces affected by bleeding in all of the tissue samples. This novel semi-quantitative method utilizes the Autodesk AutoCAD 2009 program, which is simple to use and widely available, thereby offering a new, objective and precise approach to estimate the extent of bleeding in tissue samples.

  4. Properties of Ultrasound Probes

    OpenAIRE

    Rusina, M.

    2015-01-01

    This work deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. In this work there are described the possibility of measuring the spatial resolution, sensitivity of the probe and measuring the length of the dead zone. Ultrasound phantom ATS Multi Purpose Phantom Type 539 was used for measurements.

  5. MR guided focused ultrasound: technical acceptance measures for a clinical system

    Energy Technology Data Exchange (ETDEWEB)

    Gorny, K R; Hangiandreou, N J; Hesley, G K; Gostout, B S; McGee, K P; Felmlee, J P [Department of Radiology, Mayo Clinic, Rochester, MN 55905 (United States)

    2006-06-21

    Magnetic resonance (MR) guided focused ultrasound (MRgFUS) is a hybrid technique which offers efficient and safe focused ultrasound (FUS) treatments of uterine fibroids under MR guidance and monitoring. As a therapy device, MRgFUS requires systematic testing over a wide range of operational parameters prior to use in the clinical environment. We present technical acceptance tests and data for the first clinical MRgFUS system, ExAblate (registered) 2000 (InSightec Inc., Haifa, Israel), that has been FDA approved for treating uterine fibroids. These tests characterize MRgFUS by employing MR temperature measurements in tissue mimicking phantoms. The coronal scan plane is empirically demonstrated to be most reliable for measuring temperature elevations resulting from high intensity ultrasound (US) pulses ('sonications') and shows high sensitivity to changes in sonication parameters. Temperatures measured in the coronal plane were used as a measure of US energy deposited within the focal spot for a range of sonication parameters used in clinical treatments: spot type, spot length, output power, sonication duration, US frequency, and depth of sonication. In addition, MR images acquired during sonications were used to measure effective diameters and lengths of available sonication spot types and lengths. At a constant 60 W output power, the effective spot type diameters were measured to vary between 4.7 {+-} 0.3 mm and 6.6 {+-} 0.4 mm; treatment temperatures were found to decrease with increasing spot diameter. Prescribing different spot lengths was found to have no effect on the measured length or on measured temperatures. Tests of MRgFUS positioning accuracy determined errors in the direction parallel to the propagation of the US beam to be significantly greater than those in the perpendicular direction; most sonication spots were erroneously positioned towards the FUS transducer. The tests reported here have been demonstrated to be sufficiently sensitive to

  6. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... specific content. Related Articles and Media Sonohysterography Ultrasound - Abdomen Children's (Pediatric) Ultrasound - Abdomen Obstetric Ultrasound Ultrasound - Prostate Kidney and ...

  7. A novel method for measuring anterior segment area of the eye on ultrasound biomicroscopic images using photoshop.

    Directory of Open Access Journals (Sweden)

    Zhonghao Wang

    Full Text Available To describe a novel method for quantitative measurement of area parameters in ocular anterior segment ultrasound biomicroscopy (UBM images using Photoshop software and to assess its intraobserver and interobserver reproducibility.Twenty healthy volunteers with wide angles and twenty patients with narrow or closed angles were consecutively recruited. UBM images were obtained and analyzed using Photoshop software by two physicians with different-level training on two occasions. Borders of anterior segment structures including cornea, iris, lens, and zonules in the UBM image were semi-automatically defined by the Magnetic Lasso Tool in the Photoshop software according to the pixel contrast and modified by the observers. Anterior chamber area (ACA, posterior chamber area (PCA, iris cross-section area (ICA and angle recess area (ARA were drawn and measured. The intraobserver and interobserver reproducibilities of the anterior segment area parameters and scleral spur location were assessed by limits of agreement, coefficient of variation (CV, and intraclass correlation coefficient (ICC.All of the parameters were successfully measured by Photoshop. The intraobserver and interobserver reproducibilities of ACA, PCA, and ICA were good, with no more than 5% CV and more than 0.95 ICC, while the CVs of ARA were within 20%. The intraobserver and interobserver reproducibilities for defining the spur location were more than 0.97 ICCs. Although the operating times for both observers were less than 3 minutes per image, there was significant difference in the measuring time between two observers with different levels of training (p<0.001.Measurements of ocular anterior segment areas on UBM images by Photoshop showed good intraobserver and interobserver reproducibilties. The methodology was easy to adopt and effective in measuring.

  8. Brachial artery vasomotion and transducer pressure effect on measurements by active contour segmentation on ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Theodore W.; Sultan, Laith R.; Sehgal, Chandra M., E-mail: sehgalc@uphs.upenn.edu [Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Reamer, Courtney B.; Mohler, Emile R. [Department of Medicine, Division of Cardiovascular Medicine, Section of Vascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2014-02-15

    Purpose: To use feed-forward active contours (snakes) to track and measure brachial artery vasomotion on ultrasound images recorded in both transverse and longitudinal views; and to compare the algorithm's performance in each view. Methods: Longitudinal and transverse view ultrasound image sequences of 45 brachial arteries were segmented by feed-forward active contour (FFAC). The segmented regions were used to measure vasomotion artery diameter, cross-sectional area, and distention both as peak-to-peak diameter and as area. ECG waveforms were also simultaneously extracted frame-by-frame by thresholding a running finite-difference image between consecutive images. The arterial and ECG waveforms were compared as they traced each phase of the cardiac cycle. Results: FFAC successfully segmented arteries in longitudinal and transverse views in all 45 cases. The automated analysis took significantly less time than manual tracing, but produced superior, well-behaved arterial waveforms. Automated arterial measurements also had lower interobserver variability as measured by correlation, difference in mean values, and coefficient of variation. Although FFAC successfully segmented both the longitudinal and transverse images, transverse measurements were less variable. The cross-sectional area computed from the longitudinal images was 27% lower than the area measured from transverse images, possibly due to the compression of the artery along the image depth by transducer pressure. Conclusions: FFAC is a robust and sensitive vasomotion segmentation algorithm in both transverse and longitudinal views. Transverse imaging may offer advantages over longitudinal imaging: transverse measurements are more consistent, possibly because the method is less sensitive to variations in transducer pressure during imaging.

  9. Decrease of uteroplacental blood flow after feticide during second-trimester pregnancy termination with complete placenta previa: quantitative analysis using contrast-enhanced ultrasound imaging.

    Science.gov (United States)

    Poret-Bazin, H; Simon, E G; Bleuzen, A; Dujardin, P A; Patat, F; Perrotin, F

    2013-11-01

    Contrast enhanced ultrasound (CEUS) was used to quantify the dynamic changes in uteroplacental blood flow before and after the interruption of fetal villus circulation resulting from feticide during a second trimester pregnancy termination in a patient with complete placenta previa. Quantitative analysis was performed on time-intensity curves acquired 24 h before and 48 h and 120 h after feticide and demonstrated the persistence of utero-placental blood flow with a progressive and two-step reduction in intervillous space and uteroplacental blood flow. Our results suggest that placental blood flow reduction after interruption of fetal circulation is a progressive and delayed mechanism.

  10. Competitive Swimming and Handball Participation Have a Positive Influence on Bone Parameters as Assessed by Phalangeal Quantitative Ultrasound in Female Adolescents.

    Science.gov (United States)

    Krahenbuhl, Tathyane; Gonçalves, Ezequiel M; Guimarães, Roseane Fatima; Guerra-Junior, Gil; Barros-Filho, Antonio

    2016-08-01

    To examine the influence of participation in competitive sports on bone parameters, as assessed by quantitative ultrasound (QUS) of the phalanges in female adolescents. Female adolescents (n = 329, 13.0-16.7 years old) were classified into handball (n = 55), swimming (n = 49) and control (n = 225) groups. QUS was used to evaluate the amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT), and their z-scores (zAD-SoS and zBTT) were calculated. Anthropometric measurements and Tanner's stages were also obtained. Swimmers had higher AD-SoS (2089 ± 43.8 m/s) and zAD-SoS (0.47 ± 0.8) than controls (2060 ± 54.0 m/s; 0.09 ± 1.0; both p ≤ .05) and both groups of athletes had higher BTT (handball: 1.44 ± 0.2 μs; swimming: 1.45 ± 0.2) and zBTT (handball: 0.71 ± 0.8; swimming: 0.72 ± 1.1) than the control group (1.37 ± 0.2 μs; 0.32 ± 0.9; all p ≤ .05). Swimmers had a higher total training time (TTT: 52.5 ± 27.6 months) and frequency of training per week (FT: 5.38 ± 0.1) compared with the handball group (35.9 ± 18.1; 3.32 ± 0.8; p ≤ .05). zAD-SoS, BTT and zBTT were positively correlated with FT, while BTT and zBTT showed a positive correlation with TTT. Sports practice influences bone parameters and higher bone parameter values are related to the amount of time and frequency of weekly training. The differences in phalangeal QUS parameters are independent of the impact of weight-bearing exercise.

  11. 3-D Ultrasound Imaging Performance of a Row-Column Addressed 2-D Array Transducer: A Measurement Study

    DEFF Research Database (Denmark)

    Rasmussen, Morten Fischer; Jensen, Jørgen Arendt

    2013-01-01

    A real-time 3-D ultrasound measurement using only 32 elements and 32 emissions is presented. The imaging quality is compared to a conventionally fully addressed array using 1024 elements and 256 emissions. The main-lobe of the measured line spread function is almost identical, but the side-lobe l...... ultrasound probe made by Vermon S.A....... is 510% larger than when row-column addressing the array. The cyst radius needed to achieve -20 dB intensity in the cyst is 396% larger for the fully addressed array compared to the row-column addressed array. The measurements were made using the experimental ultrasound scanner SARUS and a 32x32 element...

  12. Sooting turbulent jet flame: characterization and quantitative soot measurements

    Science.gov (United States)

    Köhler, M.; Geigle, K. P.; Meier, W.; Crosland, B. M.; Thomson, K. A.; Smallwood, G. J.

    2011-08-01

    Computational fluid dynamics (CFD) modelers require high-quality experimental data sets for validation of their numerical tools. Preferred features for numerical simulations of a sooting, turbulent test case flame are simplicity (no pilot flame), well-defined boundary conditions, and sufficient soot production. This paper proposes a non-premixed C2H4/air turbulent jet flame to fill this role and presents an extensive database for soot model validation. The sooting turbulent jet flame has a total visible flame length of approximately 400 mm and a fuel-jet Reynolds number of 10,000. The flame has a measured lift-off height of 26 mm which acts as a sensitive marker for CFD model validation, while this novel compiled experimental database of soot properties, temperature and velocity maps are useful for the validation of kinetic soot models and numerical flame simulations. Due to the relatively simple burner design which produces a flame with sufficient soot concentration while meeting modelers' needs with respect to boundary conditions and flame specifications as well as the present lack of a sooting "standard flame", this flame is suggested as a new reference turbulent sooting flame. The flame characterization presented here involved a variety of optical diagnostics including quantitative 2D laser-induced incandescence (2D-LII), shifted-vibrational coherent anti-Stokes Raman spectroscopy (SV-CARS), and particle image velocimetry (PIV). Producing an accurate and comprehensive characterization of a transient sooting flame was challenging and required optimization of these diagnostics. In this respect, we present the first simultaneous, instantaneous PIV, and LII measurements in a heavily sooting flame environment. Simultaneous soot and flow field measurements can provide new insights into the interaction between a turbulent vortex and flame chemistry, especially since soot structures in turbulent flames are known to be small and often treated in a statistical manner.

  13. Influence of lung injury on cardiac output measurement using transpulmonary ultrasound dilution: a validation study in neonatal lambs

    NARCIS (Netherlands)

    Vrancken, S.L.A.G.; Boode, W.P. de; Hopman, J.C.W.; Looijen-Salamon, M.G.; Liem, K.D.; Heijst, A.F. van

    2012-01-01

    BACKGROUND: /st> Transpulmonary ultrasound dilution (TPUD) is a promising method for cardiac output (CO) measurement in severely ill neonates. The incidence of lung injury in this population is high, which might influence CO measurement using TPUD because of altered lung perfusion. We evaluated t

  14. Characterization of fetal growth by repeated ultrasound measurements in the wild guinea pig (Cavia aperea).

    Science.gov (United States)

    Schumann, K; Guenther, A; Göritz, F; Jewgenow, K

    2014-08-01

    Fetal growth during pregnancy has previously been studied in the domesticated guinea pig (Cavia aperea f. porcellus) after dissecting pregnant females, but there are no studies describing the fetal growth in their wild progenitor, the wild guinea pig (C aperea). In this study, 50 pregnancies of wild guinea pig sows were investigated using modern ultrasound technique. The two most common fetal growth parameters (biparietal diameter [BPD] and crown-rump-length [CRL]) and uterine position were measured. Data revealed similar fetal growth patterns in the wild guinea pig and domesticated guinea pig in the investigated gestation period, although they differ in reproductive milestones such as gestation length (average duration of pregnancy 68 days), average birth weight, and litter mass. In this study, pregnancy lasted on average 60.2 days with a variance of less than a day (0.96 days). The measured fetal growth parameters are strongly correlated with each (R = 0.91; P guinea pig.

  15. Photoacoustic clutter reduction by inversion of a linear scatter model using plane wave ultrasound measurements.

    Science.gov (United States)

    Schwab, Hans-Martin; Beckmann, Martin F; Schmitz, Georg

    2016-04-01

    Photoacoustic imaging aims to visualize light absorption properties of biological tissue by receiving a sound wave that is generated inside the observed object as a result of the photoacoustic effect. In clinical applications, the strong light absorption in human skin is a major problem. When high amplitude photoacoustic waves that originate from skin absorption propagate into the tissue, they are reflected back by acoustical scatterers and the reflections contribute to the received signal. The artifacts associated with these reflected waves are referred to as clutter or skin echo and limit the applicability of photoacoustic imaging for medical applications severely. This study seeks to exploit the acoustic tissue information gained by plane wave ultrasound measurements with a linear array in order to correct for reflections in the photoacoustic image. By deriving a theory for clutter waves in k-space and a matching inversion approach, photoacoustic measurements compensated for clutter are shown to be recovered.

  16. MODELLING OF EXTRINSIC FIBER OPTIC SAGNAC ULTRASOUND INTERFEROMETER USED FOR DISPLACEMENT MEASUREMENTS

    Directory of Open Access Journals (Sweden)

    S. BENHAMIDA

    2012-06-01

    Full Text Available Ultrasonic waves are used extensively in nondestructive testing both for characterization of material properties, in this paper, we describe a fiber optic sensor suitable for detection of ultrasonic waves. This sensor is based on an extrinsic fiber optic sagnac interferometer. The proposed sensor model can act as a conventional in-phase detector or as a narrowband detector. In this study we use methods interference of ultrasonic waves between the source of ultrasonic waves and the object under investigation is exploited. The main advantages of the proposed sensor are the ability to detect ultrasonic waves on the surface; this sensor possesses higher sensitivity and accuracy than the pulse method. The cavity resonator was very successfully used for measurement of small ultrasound velocity changes. The ultrasonic interferometric technique based on phase-locked loop is the most suitable for measurements of small displacements. This method ensures the highest sensitivity and accuracy.

  17. What is the value of ultrasound soft tissue measurements in the prediction of abnormal fetal growth?

    LENUS (Irish Health Repository)

    Farah, N

    2012-02-01

    Abnormal fetal growth increases the complications of pregnancy not only for the baby but also for the mother. Growth abnormalities also have lifelong consequences. These babies are at increased risk of insulin resistance, diabetes and hypertension later in life. It is important to identify these babies antenatally to optimise their clinical care. Although used extensively antenatally to monitor fetal growth, ultrasound has its limitations. Despite the use of more than 50 different formulae to estimate fetal weight, their performance has been poor at the extremes of fetal weight. Over the past 20 years there has been emerging interest in studying fetal soft tissue measurements to improve detection of growth abnormalities. This review paper outlines the value of soft tissue measurements in identifying fetal growth abnormalities, in estimating fetal weight and in managing diabetes mellitus in pregnancy.

  18. Ultrasound measurements in the spinel compound GeCo{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Sasame, H [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Yoshimoto, H [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Takahashi, Y [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Watanabe, T [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Takase, K [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Takano, Y [Nihon University, Chiyoda-ku, 101-8308 Tokyo (Japan); Hara, S [AIST, Tsukuba, 305-8568 Ibaraki (Japan); Ikeda, Si [AIST, Tsukuba, 305-8568 Ibaraki (Japan)

    2007-12-15

    Elastic properties of the spinel compound GeCo{sub 2}O{sub 4} were investigated by the ultrasound velocity measurements in the single crystal. Absence of the elastic softening in (C{sub 11}- C{sub 12})/2 in the paramagnetic state suggests the Jahn-Teller inactive character of Co{sup 2+}, despite the presence of the orbital degree of freedom. The pronounced C{sub 44} anomaly in the paramagnetic state near T{sub N} alternatively suggests that the ultrasound dominantly couple to the exchange interactions among Co{sup 2+} ions by the exchange striction effect. The present results conclude that Co{sup 2+} adopts the high spin state in this substance. In the antiferromagnetic phase, new elastic anomalies were observed only in (C{sub 11}- C{sub 12})/2 implying the occurrence of the magnetic transitions triggered by the exchange interactions within the Co{sup 2+} bonds along [110] directions.

  19. Development of a thermal test object for the measurement of ultrasound intracavity transducer self-heating.

    Science.gov (United States)

    Killingback, Alban L T; Newey, Valentine R; El-Brawany, Mohamed A; Nassiri, Dariush K

    2008-12-01

    The elevated surface temperature of diagnostic ultrasound transducers imposes an important limitation to their safe use in clinical situations. Moreover, particular care should be taken if transvaginal transducers are to be used during routine scans in the first few weeks of pregnancy as the transducer surface can be very close to embryonic/fetal tissues. Published results have shown that the heating of tissue due to transducer self-heating can equal and often exceed the acoustic heating contribution. In this article, we report the development of a portable self contained thermal test object (TTO) capable of assessing the self-heating of intracavity diagnostic ultrasound transducers. The thermal conductivity and volumetric heat capacity of the tissue mimicking material (TMM) used in the TTO were measured, yielding values of (0.56 +/- 0.01) W m(-1) K(-1) and (3.5 +/- 0.8) MJ m(-3) K(-1). The speed of sound of the TMM was measured as 1540 m s(-1) and the attenuation over a frequency range of 2 to 10 MHz was found to be (0.50 +/- 0.01) dB cm(-1) MHz(-1). These results are in excellent agreement with the International Electrotechnical Commission (IEC 60601-2-37) requirements and the previously published properties of biological soft tissue. The temperature stability and uniformity, and suitability of the TTO for the measurement of transducer self-heating were tested and found to be satisfactory. The TTO reached a stable temperature of 37 degrees C in 3 h and the spatial variation in temperature was less than +/- 0.2 degrees C. Lastly, transducer self-heating measurements from a transvaginal transducer exceeded the IEC temperature limit of 43 degrees C in less than 5 min and the temperature reached after 30 min was 47.3 degrees C.

  20. A Framework for Mixing Methods in Quantitative Measurement Development, Validation, and Revision: A Case Study

    Science.gov (United States)

    Luyt, Russell

    2012-01-01

    A framework for quantitative measurement development, validation, and revision that incorporates both qualitative and quantitative methods is introduced. It extends and adapts Adcock and Collier's work, and thus, facilitates understanding of quantitative measurement development, validation, and revision as an integrated and cyclical set of…

  1. A Framework for Mixing Methods in Quantitative Measurement Development, Validation, and Revision: A Case Study

    Science.gov (United States)

    Luyt, Russell

    2012-01-01

    A framework for quantitative measurement development, validation, and revision that incorporates both qualitative and quantitative methods is introduced. It extends and adapts Adcock and Collier's work, and thus, facilitates understanding of quantitative measurement development, validation, and revision as an integrated and cyclical set of…

  2. Application of Quantitative Measures for Analysing Aircraft Handling Qualities

    Directory of Open Access Journals (Sweden)

    Archana Hebbar

    2016-01-01

    Full Text Available The ease and precision with which pilot is able to handle the designated task determines the aircraft’s handling qualities. Accordingly, the most common methodology for determining aircraft’s handling qualities is through pilot opinions or through questionnaires. These subjective means of analysis is not reliable as the sole source of judgments. Quantitative metrics to analyse the task difficulty based on pilot’s performance, supplemented with subjective decision, can provide better insight into pilot workload levels and in turn the aircraft’s handling qualities. The application of few objective performance measurement techniques to flight data of a high performance fighter aircraft is discussed. Pilot/aircraft’s performance under different configurations is analysed. Analysis results show that pilots usually tend to give more priority to pitch axis in case of dual axis tracking task. And pilots are therefore more aggressive in accomplishing pitch axis tracking task than in roll. Workload assessments were also performed by comparing the results of single axis tracking experiments conducted using a high fidelity flight simulator with the flight data. It is seen that pilot’s aggressiveness levels in controlling the roll control inceptor is significantly less, with improved tracking accuracy when exercised as the primary task.Defence Science Journal, Vol. 66, No. 1, January 2016, pp. 03-10, DOI: http://dx.doi.org/10.14429/dsj.66.9196

  3. Quantitative evaluation of the structure and function of the common carotid artery in hypertriglyceridemic subjects using ultrasound radiofrequency-data technology

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Hai-Jun, E-mail: danhaijun@163.com [Department of Physical Examination, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei (China); Wang, Yan [Department of Ultrasound in Medicine, Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, Shanghai 200233 (China); Sha, Hai-Jing [Second Department of Geriatrics, The Central Hospital of Handan, Handan 056001, Hebei (China); Wen, Shu-Bin [Department of Physical Examination, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei (China)

    2012-11-15

    Assessment of the properties of blood-vessel walls by ultrasound radiofrequency (RF)-data technology is an innovative technique. We quantitatively evaluated the intima-media thickness (IMT) and arterial elasticity of the common carotid artery (CCA) in asymptomatic subjects with hypertriglyceridemia (HTG) using RF-data technology. Thirty HTG subjects and 30 matched controls were enrolled in the study. The common carotid arterial systolic diameter, diastolic diameter, IMT, carotid distensibility (CD), local pulse wave velocity (PWV{beta}), and stiffness ({beta}) were compared between the two groups, as was the correlation between triglyceride level and the parameters mentioned above. The HTG group had significantly higher values of CCA-IMT compared with the control group (p < 0.001). There were significant differences between the HTG group and controls in terms of higher values of PWV{beta} and {beta}, and lower values of CD (all p < 0.05). No difference was observed in terms of the systolic and diastolic diameter of the CCA (p > 0.05). The level of triglycerides had significant positive correlations with CCA-IMT (r = 0.493, p < 0.001), whereas significant correlations with CD, PWV{beta}, and {beta} were not observed in the HTG group. Ultrasound RF-data technology can be used to non-invasively and quantitatively detect the change in the structure and function of the CCA in asymptomatic HTG subjects for evaluating preclinical atherosclerosis.

  4. Reliability of ultrasound thickness measurement of the abdominal muscles during clinical isometric endurance tests.

    Science.gov (United States)

    ShahAli, Shabnam; Arab, Amir Massoud; Talebian, Saeed; Ebrahimi, Esmaeil; Bahmani, Andia; Karimi, Noureddin; Nabavi, Hoda

    2015-07-01

    The study was designed to evaluate the intra-examiner reliability of ultrasound (US) thickness measurement of abdominal muscles activity when supine lying and during two isometric endurance tests in subjects with and without Low back pain (LBP). A total of 19 women (9 with LBP, 10 without LBP) participated in the study. Within-day reliability of the US thickness measurements at supine lying and the two isometric endurance tests were assessed in all subjects. The intra-class correlation coefficient (ICC) was used to assess the relative reliability of thickness measurement. The standard error of measurement (SEM), minimal detectable change (MDC) and the coefficient of variation (CV) were used to evaluate the absolute reliability. Results indicated high ICC scores (0.73-0.99) and also small SEM and MDC scores for within-day reliability assessment. The Bland-Altman plots of agreement in US measurement of the abdominal muscles during the two isometric endurance tests demonstrated that 95% of the observations fall between the limits of agreement for test and retest measurements. Together the results indicate high intra-tester reliability for the US measurement of the thickness of abdominal muscles in all the positions tested. According to the study's findings, US imaging can be used as a reliable method for assessment of abdominal muscles activity in supine lying and the two isometric endurance tests employed, in participants with and without LBP.

  5. Obstetrical Ultrasound

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Obstetric Ultrasound Obstetric ultrasound uses sound waves to produce pictures ... limitations of Obstetrical Ultrasound Imaging? What is Obstetrical Ultrasound Imaging? Ultrasound is safe and painless, and produces ...

  6. Prostate Ultrasound

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves ... the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and ...

  7. Musculoskeletal Ultrasound

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Musculoskeletal Ultrasound imaging uses sound waves to produce ... Ultrasound Imaging of the Musculoskeletal System? What is Ultrasound Imaging of the Musculoskeletal System? Ultrasound is safe ...

  8. Ultrasound - Scrotum

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Scrotum Ultrasound imaging of the scrotum uses sound ... of Ultrasound Imaging of the Scrotum? What is Ultrasound Imaging of the Scrotum? Ultrasound imaging of the ...

  9. Ultrasound -- Vascular

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate ... the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces pictures ...

  10. Hip Ultrasound

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Hip Ultrasound Hip ultrasound uses sound waves to produce pictures ... of Ultrasound Imaging of the Hip? What is Ultrasound Imaging of the Hip? Ultrasound images of the ...

  11. Ultrasound -- Vascular

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Vascular Vascular ultrasound uses sound waves to evaluate the ... are the limitations of Vascular Ultrasound? What is Vascular Ultrasound? Ultrasound is safe and painless, and produces ...

  12. Feasibility of coded vibration in a vibro-ultrasound system for tissue elasticity measurement.

    Science.gov (United States)

    Zhao, Jinxin; Wang, Yuanyuan; Yu, Jinhua; Li, Tianjie; Zheng, Yong-Ping

    2016-07-01

    The ability of various methods for elasticity measurement and imaging is hampered by the vibration amplitude on biological tissues. Based on the inference that coded excitation will improve the performance of the cross-correlation function of the tissue displacement waves, the idea of exerting encoded external vibration on tested samples for measuring its elasticity is proposed. It was implemented by integrating a programmable vibration generation function into a customized vibro-ultrasound system to generate Barker coded vibration for elasticity measurement. Experiments were conducted on silicone phantoms and porcine muscles. The results showed that coded excitation of the vibration enhanced the accuracy and robustness of the elasticity measurement especially in low signal-to-noise ratio scenarios. In the phantom study, the measured shear modulus values with coded vibration had an R(2 )= 0.993 linear correlation to that of referenced indentation, while for single-cycle pulse the R(2) decreased to 0.987. In porcine muscle study, the coded vibration also obtained a shear modulus value which is more accurate than the single-cycle pulse by 0.16 kPa and 0.33 kPa at two different depths. These results demonstrated the feasibility and potentiality of the coded vibration for enhancing the quality of elasticity measurement and imaging.

  13. Ultrasound measurement of the corpus callosum and neural development of premature infants.

    Science.gov (United States)

    Liu, Fang; Cao, Shikao; Liu, Jiaoran; Du, Zhifang; Guo, Zhimei; Ren, Changjun

    2013-09-15

    Length and thickness of 152 corpus callosa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus callosum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus callosum length as well as thickness of the genu and splenium increased with tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus callosum velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus callosum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose gestational age was 34 weeks or less. Corpus callosum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus callosum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus callosum growth in premature infants is associated with neurobehavioral development during the early extrauterine stage.

  14. Ultrasound measures of supraspinatus tendon thickness and acromiohumeral distance in rotator cuff tendinopathy are reliable.

    Science.gov (United States)

    McCreesh, Karen M; Anjum, Shakeel; Crotty, James M; Lewis, Jeremy S

    2016-01-01

    Rotator cuff (RC) tendinopathy has been widely ascribed to impingement of the supraspinatus tendon (SsT) in the subacromial space, measured as the acromiohumeral distance (AHD). Ultrasound (US) is suitable for measuring AHD and SsT thickness, but few reliability studies have been carried out in symptomatic populations, and interrater reliability is unconfirmed. This study aimed to examine the intrarater and interrater reliability of US measurements of AHD and SsT thickness in asymptomatic control subjects and patients with RC tendinopathy. Seventy participants were recruited and grouped as healthy controls (n = 25) and RC tendinopathy (n = 45). Repeated US measurements of AHD and SsT thickness were obtained by one rater in both groups and by two raters in the RC tendinopathy group. Intrarater and interrater reliability coefficients were excellent for both measurements (intraclass correlation > 0.92), but the intrarater reliability was superior. The minimal detectable change values in the symptomatic group were 0.7 mm for AHD and 0.6 mm for SsT thickness for a single experienced examiner; the values rose to 1.2 mm and 1.3 mm, respectively, for the pair of examiners. The results support the reliability of US for the measurement of AHD and SsT thickness in patients with symptomatic RC tendinopathy and provide minimal detectable change values for use in future research studies. © 2015 Wiley Periodicals, Inc.

  15. Ultrasound-based measurement of liquid-layer thickness: A novel time-domain approach

    Science.gov (United States)

    Praher, Bernhard; Steinbichler, Georg

    2017-01-01

    Measuring the thickness of a thin liquid layer between two solid materials is important when the adequate separation of metallic parts by a lubricant film (e.g., in bearings or mechanical seals) is to be assessed. The challenge in using ultrasound-based systems for such measurements is that the signal from the liquid layer is a superposition of multiple reflections. We have developed an algorithm for reconstructing this superimposed signal in the time domain. By comparing simulated and measured signals, the time-of-flight of the ultrasonic pulse in a layer can be estimated. With the longitudinal sound velocity known, the layer thickness can then be calculated. In laboratory measurements, we validate successfully (maximum relative error 4.9%) our algorithm for layer thicknesses ranging from 30 μm to 200 μm. Furthermore, we tested our method in the high-temperature environment of polymer processing by measuring the clearance between screw and barrel in the plasticisation unit of an injection moulding machine. The results of such measurements can indicate (i) the wear status of the tribo-mechanical screw-barrel system and (ii) unsuitable process conditions.

  16. Medical Ultrasound Imaging.

    Science.gov (United States)

    Hughes, Stephen

    2001-01-01

    Explains the basic principles of ultrasound using everyday physics. Topics include the generation of ultrasound, basic interactions with material, and the measurement of blood flow using the Doppler effect. (Author/MM)

  17. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... may also be saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  18. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of blood cells as ... tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure ...

  19. Fully automated software for quantitative measurements of mitochondrial morphology.

    Science.gov (United States)

    McClatchey, P Mason; Keller, Amy C; Bouchard, Ron; Knaub, Leslie A; Reusch, Jane E B

    2016-01-01

    Mitochondria undergo dynamic changes in morphology in order to adapt to changes in nutrient and oxygen availability, communicate with the nucleus, and modulate intracellular calcium dynamics. Many recent papers have been published assessing mitochondrial morphology endpoints. Although these studies have yielded valuable insights, contemporary assessment of mitochondrial morphology is typically subjective and qualitative, precluding direct comparison of outcomes between different studies and likely missing many subtle effects. In this paper, we describe a novel software technique for measuring the average length, average width, spatial density, and intracellular localization of mitochondria from a fluorescent microscope image. This method was applied to distinguish baseline characteristics of Human Umbilical Vein Endothelial Cells (HUVECs), primary Goto-Kakizaki rat aortic smooth muscle cells (GK SMCs), primary Wistar rat aortic smooth muscle cells (Wistar SMCs), and SH-SY5Ys (human neuroblastoma cell line). Consistent with direct observation, our algorithms found SH-SY5Ys to have the greatest mitochondrial density, while HUVECs were found to have the longest mitochondria. Mitochondrial morphology responses to temperature, nutrient, and oxidative stressors were characterized to test algorithm performance. Large morphology changes recorded by the software agreed with direct observation, and subtle but consistent morphology changes were found that would not otherwise have been detected. Endpoints were consistent between experimental repetitions (R=0.93 for length, R=0.93 for width, R=0.89 for spatial density, and R=0.74 for localization), and maintained reasonable agreement even when compared to images taken with compromised microscope resolution or in an alternate imaging plane. These results indicate that the automated software described herein allows quantitative and objective characterization of mitochondrial morphology from fluorescent microscope images.

  20. Quantitative measurement of endogenous amino acid absorption in unanaesthetized pigs.

    Science.gov (United States)

    Rerat, A; Vaissade, P; Vaugelade, P

    1988-06-01

    The present experiment was carried out with 11 pigs (mean body weight: 53.9 +/- 1.3 kg) fitted with permanent catheters in the portal vein and carotid artery and with an electromagnetic flow probe around the portal vein. They were each subjected to 2 or 3 trials at 3 to 4-day intervals. During each trial the animals received after a previous fasting of 20 h a given amount of a protein-free diet (200 to 1200 g). The blood was collected either continuously for a quantitative determination of amino nitrogen, reducing sugars, urea and ammonia (number of meals 12, mean intake: 727 +/- 60 g) or discontinuously every 30 min between 0 and 8 h after the meal for amino acid analysis (number of meals 8; mean intake 709 +/- 105 g). A rather constant appearance (2 g/h) of amino acids in the portal blood was observed throughout the postprandial period. The intestinal absorption of each amino acid was however variable and represented between 10 and 50% of the daily requirements of the animal during the measuring period (8 h). Glutamine and to a less extent glutamic acid were exceptions as they were taken up by the gut wall from the arterial blood. There was also a marked synthesis of ornithine and citrulline by the latter. Because of the low blood level of urea, there were no apparent exchanges of urea between the blood and the intestine; in contrast, the ammonia absorption represented about 70% of that observed after ingestion of normal protein diets. Most amino acids are largely taken up by the liver and peripheral tissues, but in the case of alanine the syntheses exceed the uptake.

  1. Reliability and Validity of Ultrasound Cross Sectional Area Measurements for Long-Duration Spaceflight

    Science.gov (United States)

    Scott, Jessica M.; Martin, David S.; Cunningham, David; Matz, Timothy; Caine, Timothy; Hackney, Kyle J.; Arzeno, Natalia; Ploutz-Snyder, Lori

    2010-01-01

    Limb muscle atrophy and the accompanying decline in function can adversely affect the performance of astronauts during mission-related activities and upon re-ambulation in a gravitational environment. Previous characterization of space flight-induced muscle atrophy has been performed using pre and post flight magnetic resonance imaging (MRI). In addition to being costly and time consuming, MRI is an impractical methodology for assessing in-flight changes in muscle size. Given the mobility of ultrasound (US) equipment, it may be more feasible to evaluate changes in muscle size using this technique. PURPOSE: To examine the reliability and validity of using a customized template to acquire panoramic ultrasound (US) images for determining quadriceps and gastrocnemius anatomical cross sectional area (CSA). METHODS: Vastus lateralis (VL), rectus femoris (RF), medial gastrocnemius (MG), and lateral gastrocnemius (LG) CSA were assessed in 10 healthy individuals (36+/-2 yrs) using US and MRI. Panoramic US images were acquired by 2 sonographers using a customized template placed on the thigh and calf and analyzed by the same 2 sonographers (CX50 Philips). MRI images of the leg were acquired while subjects were supine in a 1.5T scanner (Signa Horizon LX, General Electric) and were analyzed by 3 trained investigators. The average of the 2 US and 3 MRI values were used for validity analysis. RESULTS: High inter-experimenter reliability was found for both the US template and MRI analysis as coefficients of variation across muscles ranged from 2.4 to 4.1% and 2.8 to 3.8%, respectively. Significant correlations were found between US and MRI CSA measures (VL, r = 0.85; RF, r = 0.60; MG, r = 0.86; LG, r = 0.73; p muscles. CONCLUSION: The present results indicate that utilizing a customized US template provides reliable measures of leg muscle CSA, and thus could be used to characterize changes in muscle CSA both in flight and on the ground.

  2. Combinatorial and probabilistic fusion of noisy correlation measurements for untracked freehand 3-D ultrasound.

    Science.gov (United States)

    Laporte, Catherine; Arbel, Tal

    2008-01-01

    In freehand 3-D ultrasound (US), the relative positions of US images are usually measured using a position tracking device despite its cumbersome nature. The probe trajectory can instead be estimated from image data, using registration techniques to recover in-plane motion and speckle decorrelation to recover out-of-plane transformations. The relationship between speckle decorrelation and elevational separation is typically represented by a single curve, estimated from calibration data. Distances read off such a curve are corrupted by bias and uncertainty, and only provide an absolute estimate of elevational displacement. This paper presents a probabilistic model of the relationship between correlation measurements and elevational separation. This representation captures the skewed distribution of distance estimates based on high correlations and the uncertainties attached to each measurement. Multiple redundant correlation measurements can then be integrated within a maximum likelihood estimation framework. This paper also introduces a new method based on the traveling salesman problem for resolving sign ambiguities in data sets resulting from nonmonotonic probe motion and frame intersections. Experiments with real and synthetic US data show that by combining these new methods, out-of-plane US probe motion is recovered with improved accuracy over baseline methods using a deterministic model and fewer measurements.

  3. Quantitative analysis of sensor for pressure waveform measurement

    Directory of Open Access Journals (Sweden)

    Tyan Chu-Chang

    2010-01-01

    Full Text Available Abstract Background Arterial pressure waveforms contain important diagnostic and physiological information since their contour depends on a healthy cardiovascular system 1. A sensor was placed at the measured artery and some contact pressure was used to measure the pressure waveform. However, where is the location of the sensor just about enough to detect a complete pressure waveform for the diagnosis? How much contact pressure is needed over the pulse point? These two problems still remain unresolved. Method In this study, we propose a quantitative analysis to evaluate the pressure waveform for locating the position and applying the appropriate force between the sensor and the radial artery. The two-axis mechanism and the modified sensor have been designed to estimate the radial arterial width and detect the contact pressure. The template matching method was used to analyze the pressure waveform. In the X-axis scan, we found that the arterial diameter changed waveform (ADCW and the pressure waveform would change from small to large and then back to small again when the sensor was moved across the radial artery. In the Z-axis scan, we also found that the ADCW and the pressure waveform would change from small to large and then back to small again when the applied contact pressure continuously increased. Results In the X-axis scan, the template correlation coefficients of the left and right boundaries of the radial arterial width were 0.987 ± 0.016 and 0.978 ± 0.028, respectively. In the Z-axis scan, when the excessive contact pressure was more than 100 mm Hg, the template correlation was below 0.983. In applying force, when using the maximum amplitude as the criteria level, the lower contact pressure (r = 0.988 ± 0.004 was better than the higher contact pressure (r = 0.976 ± 0.012. Conclusions Although, the optimal detective position has to be close to the middle of the radial arterial, the pressure waveform also has a good completeness with

  4. Quantitation of and measurements utilizing the sphenoid ridge.

    Science.gov (United States)

    Tubbs, R Shane; Salter, E George; Oakes, W Jerry

    2007-03-01

    The sphenoid ridge (posterior aspect of the lesser wings) is encountered in many intracranial procedures. Increased knowledge of its morphology and relationships is, therefore, of importance to the neurosurgeon and clinician who appreciate imaging of this anatomical region. We have quantitated this part of the sphenoid bone in dry human skulls (35) and made cadaveric (15) measurements between its parts and surrounding neuroanatomical structures in all three cranial fossae. The length of the left and right lesser wings was on average 4.2 and 4 cm, respectively. The mean widths of this bony part at its midline, midpoint, and lateral point (crista alaris) were 1.5 cm, 2.0 cm, and 2 mm, respectively. From the crista alaris the mean distances to the crista galli, V3 at its exit through the foramen ovale, entrance of the occulomotor nerve into the cavernous sinus, middle meningeal artery at its emergence from the foramen spinosum, and the facial and vestibulocochlear nerves at the internal auditory meatus were 4.9, 4.5, 5, 4.7, and 6.1 cm, respectively. From the midpoint of the lesser wing, the mean distances to the crista galli, V3 at its exit through the foramen ovale, entrance of the occulomotor nerve into the cavernous sinus, middle meningeal artery at its emergence from the foramen spinosum, and the facial and vestibulocochlear nerves at the internal auditory meatus were 4.2, 2.9, 3, 3.4, and 4.7 cm, respectively. From the anterior clinoid process of the lesser wing, the mean distances to the crista galli, V3 at its exit through the foramen ovale, entrance of the oculomotor nerve into the cavernous sinus, middle meningeal artery at its emergence from the foramen spinosum, and the facial and vestibulocochlear nerves at the internal auditory meatus were 4.3, 2.8, 1, 3.3, and 4.1 cm, respectively. Additional measurements between the parts of the sphenoid ridge and surrounding anatomical structures may assist the surgeon who operates in this region or the clinician who

  5. Ultrasound transducer shape has no effect on measurements of lumbar multifidus muscle size.

    Science.gov (United States)

    Worsley, Peter R; Smith, Nicholas; Warner, Martin B; Stokes, Maria

    2012-04-01

    Evidence is currently lacking for guidance on ultrasound transducer configuration (shape) when imaging muscle to measure its size. This study compared measurements made of lumbar multifidus on images obtained using curvilinear and linear transducers. Fifteen asymptomatic males (aged 21-32 years) had their right lumbar multifidus imaged at L3. Two transverse images were taken with two transducers (5 MHz curvilinear and 6 MHz linear), and linear and cross-sectional area (CSA) measurements were made off-line. Reliability of image interpretation was shown using intra-class correlation coefficients (0.78-0.99). Muscle measurements were compared between transducers using Bland and Altman plots and paired t-tests. Relationships between CSA and linear measurements were examined using Pearson's Correlation Coefficients. There were no significant differences (p > 0.05) in the measurements of the two transducers. Thickness and CSA measurements had small differences between transducers, with mean differences of 0.01 cm (SDdiff = 0.21 cm) and 0.03 cm(2) (SDdiff = 0.58 cm(2)) respectively. Width measures had a mean difference of 0.14 cm, with the linear transducer giving larger measures. Significant correlations (p transducers (r = 0.78-0.89). Measurements of multifidus at L3 were not influenced by the configuration of transducers of similar frequency. For the purposes of image interpretation, the curvilinear transducer produced better definition of the lateral muscle border, suggesting it as the preferable transducer for imaging lumbar multifidus. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Diagnosis of Parathyroid Adenoma Detected during Thyroid Ultrasound: The Role of Parathormone Measurement in Fine-Needle Aspiration Washout

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sung Soo; Kim, Eun Kyung; Kwak, Jin Young; Kim, Min Jung [Severance Hospital, Yonsei University, College of Medicine, Seoul (Korea, Republic of)

    2009-03-15

    With the widespread use of thyroid ultrasound, the detection rate of parathyroid incidentalomas as well as thyroid nodules has been on the increase. The differentiation between thyroid nodules and parathyroid nodules is occasionally difficult due to considerable overlap in terms of the sonographic findings. A case of parathyroid adenoma diagnosed with a measured parathyroid hormone level after fine needle aspiration washout is presented

  7. Validation of the Measurement of Intra-abdominal Fat Between Ultrasound and CT Scan in Women with Obesity and Infertility

    NARCIS (Netherlands)

    Kuchenbecker, Walter K. H.; Groen, Henk; Pel, Heleen; Bolster, Johanna H. T.; Wolffenbuttel, Bruce H. R.; Land, Jolande A.; Hoek, Annemieke; Corpeleijn, Eva

    2014-01-01

    Objective: To compare the means and changes over time of intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured by abdominal ultrasound (US) and computerized tomography (CT). Design and Methods: Prospective cohort study of 53 women with obesity and infertility undergoing a lifestyle

  8. Measurement of tibial nerve excursion during ankle joint dorsiflexion in a weight-bearing position with ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Carroll Matthew

    2012-03-01

    Full Text Available Abstract Background The ability of peripheral nerves to stretch and slide is thought to be of paramount importance to maintain ideal neural function. Excursion in peripheral nerves such as the tibial can be measured by analysis of ultrasound images. The aim of this study was to assess the degree of longitudinal tibial nerve excursion as the ankle moved from plantar flexion to dorsiflexion in a standardised weight-bearing position. The reliability of ultrasound imaging to measure tibial nerve excursion was also quantified. Methods The tibial nerve was imaged over two separate sessions in sixteen asymptomatic participants in a weight-bearing position. Longitudinal nerve excursion was calculated from a three-second video loop captured by ultrasound imaging using frame-by-frame cross-correlation analysis. Intraclass correlation coefficients (ICC with 95% confidence intervals (CI were used to assess the intra-rater reliability. Standard error of the measurement (SEM and smallest real difference (SRD were calculated to assess measurement error. Results Mean nerve excursion was 2.99 mm SEM ± 0.22 mm. The SRD was 0.84 mm for session 1 and 0.66 mm for session 2. Intra-rater reliability was excellent with an ICC = 0.93. Conclusions Assessment of real-time ultrasound images of the tibial nerve via frame-by-frame cross-correlation analysis is a reliable non-invasive technique to assess longitudinal nerve excursion. The relationship between foot posture and nerve excursion can be further investigated.

  9. Validation of the Measurement of Intra-abdominal Fat Between Ultrasound and CT Scan in Women with Obesity and Infertility

    NARCIS (Netherlands)

    Kuchenbecker, Walter K. H.; Groen, Henk; Pel, Heleen; Bolster, Johanna H. T.; Wolffenbuttel, Bruce H. R.; Land, Jolande A.; Hoek, Annemieke; Corpeleijn, Eva

    Objective: To compare the means and changes over time of intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured by abdominal ultrasound (US) and computerized tomography (CT). Design and Methods: Prospective cohort study of 53 women with obesity and infertility undergoing a lifestyle

  10. Three-dimensional ultrasound improves the accuracy of diameter measurement of the residual sac in EVAR patients

    DEFF Research Database (Denmark)

    Bredahl, Kim; Taudorf, M; Long, A

    2013-01-01

    Discrepancy between maximum diameters obtained with two-dimensional ultrasound and computed tomography (CT) after endovascular aneurysm repair (EVAR) is well known. The maximal diameter is ideally measured perpendicular to the centerline, a methodology so far only feasible with three-dimensional ...

  11. Evaluation of the ultrasound reproducibility as a method to measure the subcutaneous tissue of the nasal tip

    Directory of Open Access Journals (Sweden)

    Naves, Marcell de Melo

    2011-07-01

    Full Text Available Introduction: The previous evaluation of the patient's anatomy is crucial to achieve a sharp nasal tip in a rhinoplasty. The thickness of the subcutaneous tissue is indispensable for the esthetical harmony of the area. Techniques to measure such structures on the patient 'in vivo' are not found in literature. Objective: Evaluate the inter-observer inconsistency of the ultrasound method to measure the thickness of the subcutaneous tissue of the nasal tip by way of an ultrasound. Method: 47 volunteers were submitted to a nasal tip ultrasound performed by two radiology specialists, who used the same exam technique with a linear electronic transducer at a frequency between 5 and 9 MHz. The thickness of the subcutaneous tissue was evaluated by measuring the point with the highest protrusion of the largest alar cartilage dome towards skin. Prospective study. Results: The measurement averages of the subcutaneous tissue of the nasal tip achieved by the examiners did not show statistically significant differences (p = 0.5303. When analyzing the reproducibility between examiners, an interclass 'r'correlation coefficient (Pearson 0.9333, i.e., an excellent inter-observer reproducibility was found. Conclusion: The ultrasound proved to be reproducible and examiners satisfactorily agree about evaluating the thickness of the subcutaneous tissue of the skin, thus helping the surgeon perform the pre-surgical analysis and find the best surgical technique for each case.

  12. Quantitative measure for the "nakedness" of fluoride ion sources.

    Science.gov (United States)

    Christe, Karl O; Jenkins, H Donald Brooke

    2003-08-01

    A quantitative measure for the donor strength or "nakedness" of fluoride ion donors is presented. It is based on the free energy change associated with the transfer of a fluoride ion from the donor to a given acceptor molecule. Born-Haber cycle calculations were used to calculate both the free energy and the enthalpy change for this process. The enthalpy change is given by the sum of the fluoride ion affinity of the acceptor (as defined in strict thermodynamic convention) and the lattice energy difference (DeltaU(POT)) between the fluoride ion donor and the salt formed with the acceptor. Because, for a given acceptor, the fluoride affinity has a constant value, the relative enthalpy (and also the corresponding free energy) changes are governed exclusively by the lattice energy differences. In this study, BF(3), PF(5), AsF(5), and SbF(5) were used as the acceptors, and the following seven fluoride ion donors were evaluated: CsF, N(CH(3))(4)F (TMAF), N-methylurotropinium fluoride (MUF), hexamethylguanidinium fluoride (HMGF), hexamethylpiperidinium fluoride (HMPF), N,N,N-trimethyl-1-adamantylammonium fluoride (TMAAF), and hexakis(dimethylamino)phosphazenium fluoride (HDMAPF). Smooth relationships between the enthalpy changes and the molar volumes of the donor cations were found which asymptotically approach constant values for infinitely large cations. Whereas CsF is a relatively poor F(-) donor [(U(POT)(CsF) - U(POT)(CsSbF(6))) = 213 kJ mol(-)(1)], when compared to N(CH(3))(4)F [(U(POT)(TMAF) - U(POT)(TMASbF(6))) = 69 kJ mol(-)(1)], a 4 times larger cation (phosphazenium salt) and an infinitely large cation are required to decrease DeltaU(POT) to 17 and 0 kJ mol(-)(1), respectively. These results clearly demonstrate that very little is gained by increasing the cation size past a certain level and that secondary factors, such as chemical and physical properties, become overriding considerations.

  13. Exploratory Analysis of Carbon Dioxide Levels, Ultrasound and Optical Coherence Tomography Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Young, M.; Mason, S.; Coble, C.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Patel, N.; Gibson, C.; Alexander, D.; Van Baalen, M.

    2017-01-01

    Enhanced screening for the Visual Impairment/Intracranial Pressure (VIIP) syndrome has been implemented to better characterize the ocular and vision changes observed in some long-duration crewmembers. This includes implementation of in-flight ultrasound in 2010 and optical coherence tomography (OCT) in 2013. Potential risk factors for VIIP include cardiovascular health, diet, anatomical and genetic factors, and environmental conditions. Carbon dioxide (CO2), a potent vasodilator, is chronically elevated on the International Space Station (ISS) relative to ambient levels on Earth, and is a plausible risk factor for VIIP. In an effort to understand the possible associations between CO2 and VIIP, this study explores the relationship of ambient CO2 levels on ISS compared to inflight ultrasound and OCT measures of the eye obtained from ISS crewmembers. CO2 measurements were aggregated from Operational Data Reduction Complex and Node 3 major constituent analyzers (MCAs) on ISS or from sensors located in the European Columbus module, as available. CO2 levels in the periods between each ultrasound and OCT session are summarized using timeseries metrics, including time-weighted means and variances. Partial least squares regression analyses are used to quantify the complex relationship between specific ultrasound and OCT measures and the CO2 metrics simulataneously. These analyses will enhance our understanding of the possible associations between CO2 levels and structural changes to the eye which will in turn inform future analysis of inflight VIIP data.

  14. A real-time measure of cavitation induced tissue disruption by ultrasound imaging backscatter reduction.

    Science.gov (United States)

    Hall, Timothy L; Fowlkes, J Brian; Cain, Charles A

    2007-03-01

    A feedback method for obtaining real-time information on the mechanical disruption of tissue through ultrasound cavitation is presented. This method is based on a substantial reduction in ultrasound imaging backscatter from the target volume as the tissue structure is broken down. Ex-vivo samples of porcine liver were exposed to successive high-intensity ultrasound pulses at a low duty cycle to induce mechanical disruption of tissue parenchyma through cavitation (referred to as histotripsy). At the conclusion of treatment, B-scan imaging backscatter was observed to have decreased by 22.4 +/- 2.3 dB in the target location. Treated samples of tissue were found to contain disrupted tissue corresponding to the imaged hypoechoic volume with no remaining discernable structure and a sharp boundary. The observed, substantial backscatter reduction may be an effective feedback mechanism for assessing treatment efficacy in ultrasound surgery using pulsed ultrasound to create cavitation.

  15. Body composition in sport: a comparison of a novel ultrasound imaging technique to measure subcutaneous fat tissue compared with skinfold measurement.

    Science.gov (United States)

    Müller, Wolfram; Horn, Martin; Fürhapter-Rieger, Alfred; Kainz, Philipp; Kröpfl, Julia M; Maughan, Ronald J; Ahammer, Helmut

    2013-11-01

    Extremely low weight and rapid changes in weight and body composition have become major concerns in many sports, but sufficiently accurate field methods for body composition assessment in athletes are missing. This study aimed to explore the use of ultrasound methods for assessment of body fat content in athletes. 19 female athletes (stature: 1.67(± 0.06) m, weight: 59.6(± 7.6) kg; age: 19.5(± 3.3) years) were investigated by three observers using a novel ultrasound method for thickness measurement of uncompressed subcutaneous adipose tissue and of embedded structures. Two observers also measured skinfold thickness at eight International Society for the Advancement of Kinanthrometry (ISAK) sites; mean skinfold values were compared to mean subcutaneous adipose tissue thicknesses measured by ultrasound. Interobserver reliability of imaging and evaluation obtained by this ultrasound technique: intraclass correlation coefficient ICC=0.968 (95% CI 0.957 to 0.977); evaluation of given images: ICC=0.997 (0.993 to 0.999). Skinfold compared to ultrasound thickness showed that compressibility of subcutaneous adipose tissue depends largely on the site and the person: regression slopes ranged from 0.61 (biceps) to 1.59 (thigh) and CIs were large. Limits of agreement ranged from 2.6 to 8.6 mm. Regression lines did not intercept the skinfold axis at zero because of the skin thickness being included in the skinfold. The four ISAK trunk sites caused ultrasound imaging problems in 13 of 152 sites (8 ISAK sites, 19 athletes). The ultrasound method allows measurement of uncompressed subcutaneous adipose tissue thickness with an accuracy of 0.1-0.5 mm, depending on the probe frequency. Compressibility of the skinfold depends on the anatomical site, and skin thickness varies by a factor of two. This inevitably limits the skinfold methods for body fat estimation. Ultrasound accuracy for subcutaneous adipose tissue measurement is limited by the plasticity of fat and furrowed tissue

  16. Beyond Math Skills: Measuring Quantitative Reasoning in Context

    Science.gov (United States)

    Grawe, Nathan D.

    2011-01-01

    It might be argued that quantitative and qualitative analyses are merely two alternative reflections of an overarching critical thinking. For instance, just as instructors of numeracy warn their charges to consider the construction of variables, teachers of qualitative approaches caution students to define terms. Similarly, an advocate of…

  17. Common fetal measurements: A comparison between ultrasound and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Parkar, Anagha P. (Dept. of Radiology, Haukeland Univ. Hospital, Bergen (Norway)); Olsen, Oeystein E.; Rosendahl, Karen (Diagnostic Radiology, Great Ormond Street Hospital for Children, London (United Kingdom)), e-mail: rosenk@gosh.nhs.uk; Gjelland, Knut; Kiserud, Torvid (Fetal Medicine Unit, Dept. of Obstetrics and Gynecology, Haukeland Univ. Hospital, Bergen (Norway))

    2010-01-15

    Background: Ultrasound has been the method of choice for antenatal fetal assessment for the past three decades; however, problems may arise in cases of oligohydramnion, unfavorable position of the fetus, and maternal obesity. Purpose: To compare ultrasound (US) and magnetic resonance imaging (MRI) for common fetal measurements at 19-30 weeks' gestation, and to assess the effect of high maternal body-mass index (BMI). Material and Methods: 59 low-risk singleton pregnancies were enrolled in a prospective blinded cross-sectional study. In a first session, an experienced obstetrician used a high-resolution US technique and in a second session on the same day MRI was used to measure biparietal diameter (BPD), head circumference (HC), mean abdominal diameter (MAD), abdominal circumference (AC), and femur length (FL). Inter- and intraobserver and intermodality variability was determined using Bland-Altman plots. The effect of maternal BMI was assessed using Spearman's statistics. Results: A total of 45 women aged 19-43 years (median 29 years) attended both US and MRI at median 22 weeks' gestation. The mean differences between US and MRI were 1.6 mm for HC (95% confidence interval [CI] -1.0, 4.3 mm), 1 mm for AC (95% CI -0.2, 4.0 mm), 0.2 mm for MAD (95% CI -0.7, 1.2 mm), 2.2 mm for BPD (95% CI 1.7, 2.7 mm), and 4.6 mm for FL (95% CI 2.9, 6.4 mm). Maternal BMI did not affect the results (Spearman' rho 0.054-0.277; P=NS). The intraobserver agreement for all MRI measurements was acceptable, except for FL, while the interobserver agreement was poor. Conclusion: There was good agreement between US and MRI for common fetal measurements, but not for all (i.e., BPD and particularly FL). MRI had a poor interobserver agreement, underscoring the need for technical refinement and reference ranges specifically established for MRI

  18. Serial Measurements of Splanchnic Vein Diameters in RatsUsing High-Frequency Ultrasound

    Directory of Open Access Journals (Sweden)

    Bridget M Seitz

    2016-05-01

    Full Text Available The purpose of this study was to investigate serial ultrasound imaging in rats as a fully non-invasive method to 1 quantify the diameters of splanchnic veins in real time as an indirect surrogate for the capacitance function of those veins, and 2 assess the effects of drugs on venous dimensions. A 21 MHz probe was used on anesthetized male Sprague-Dawley rats to collect images containing the portal vein (PV, superior mesenteric vein (SMV, abdominal inferior vena cava (IVC, and splenic vein (SpV; used as a landmark in timed studies and the abdominal aorta (AA. Stable landmarks were established that allowed reproducible quantification of cross-sectional diameters within an animal. The average diameters of vessels measured every 5 minutes over 45 minutes remained within 0.75±0.15% (PV, 0.2±0.09% (SMV, 0.5±0.12% (IVC and 0.38±0.06% (AA of baseline (PV: 2.0±0.12 mm; SMV: 1.7±0.04 mm; IVC: 3.2±0.1 mm; AA: 2.3±0.14 mm. The maximal effects of the vasodilator sodium nitroprusside (SNP; 2 mg/kg, i.v. bolus on venous diameters were determined 5 minutes post SNP bolus; the diameters of all noted veins were significantly increased by sodium nitroprusside, while mean arterial pressure decreased 29±4 mmHg. By contrast, administration of the venoconstrictor sarafotoxin (S6c; 5 ng/kg, i.v. bolus significantly decreased PV and SpV, but not IVC, SMV or AA, diameters 5 minutes post S6c bolus; mean arterial pressure increased by 6±2 mmHg. In order to determine if resting splanchnic vein diameters were stable over much longer periods of time, vessel diameters were measured every two weeks for 8 weeks. Measurements were found to be highly reproducible within animals over this time period. Finally, to evaluate the utility of vein imaging in a chronic condition, images were acquired from 4-week deoxycorticosterone acetate salt (DOCA-salt hypertensive and normotensive (SHAM control rats. All vessel diameters increased from baseline while mean arterial pressure

  19. Measurement of viscoelastic properties of in vivo swine myocardium using lamb wave dispersion ultrasound vibrometry (LDUV).

    Science.gov (United States)

    Urban, Matthew W; Pislaru, Cristina; Nenadic, Ivan Z; Kinnick, Randall R; Greenleaf, James F

    2013-02-01

    Viscoelastic properties of the myocardium are important for normal cardiac function and may be altered by disease. Thus, quantification of these properties may aid with evaluation of the health of the heart. Lamb wave dispersion ultrasound vibrometry (LDUV) is a shear wave-based method that uses wave velocity dispersion to measure the underlying viscoelastic material properties of soft tissue with plate-like geometries. We tested this method in eight pigs in an open-chest preparation. A mechanical actuator was used to create harmonic, propagating mechanical waves in the myocardial wall. The motion was tracked using a high frame rate acquisition sequence, typically 2500 Hz. The velocities of wave propagation were measured over the 50-400 Hz frequency range in 50 Hz increments. Data were acquired over several cardiac cycles. Dispersion curves were fit with a viscoelastic, anti-symmetric Lamb wave model to obtain estimates of the shear elasticity, μ(1), and viscosity, μ(2) as defined by the Kelvin-Voigt rheological model. The sensitivity of the Lamb wave model was also studied using simulated data. We demonstrated that wave velocity measurements and Lamb wave theory allow one to estimate the variation of viscoelastic moduli of the myocardial walls in vivo throughout the course of the cardiac cycle.

  20. Acoustic power measurement of high-intensity focused ultrasound transducer using a pressure sensor.

    Science.gov (United States)

    Zhou, Yufeng

    2015-03-01

    The acoustic power of high-intensity focused ultrasound (HIFU) is an important parameter that should be measured prior to each treatment to guarantee effective and safe outcomes. A new calibration technique was developed that involves estimating the pressure distribution, calculating the acoustic power using an underwater pressure blast sensor, and compensating the contribution of harmonics to the acoustic power. The output of a clinical extracorporeal HIFU system (center frequency of ~1 MHz, p+ = 2.5-57.2 MPa, p(-) = -1.8 to -13.9 MPa, I(SPPA) = 513-22,940 W/cm(2), -6 dB size of 1.6 × 10 mm: lateral × axial) was measured using this approach and then compared with that obtained using a radiation force balance. Similarities were found between each method at acoustic power ranging from 18.2 W to 912 W with an electrical-to-acoustic conversion efficiency of ~42%. The proposed method has advantages of low weight, smaller size, high sensitivity, quick response, high signal-to-noise ratio (especially at low power output), robust performance, and easy operation of HIFU exposimetry measurement.

  1. Prostate Ultrasound

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. Prostate ultrasound, also called transrectal ultrasound, provides ...

  2. Ultrasound measurement of the corpus callosum and neural development of premature infants*

    Institute of Scientific and Technical Information of China (English)

    Fang Liu; Shikao Cao; Jiaoran Liu; Zhifang Du; Zhimei Guo; Changjun Ren

    2013-01-01

    Length and thickness of 152 corpus cal osa were measured in neonates within 24 hours of birth. Using ultrasonic diagnostic equipment with a neonatal brain-specific probe, corpus cal osum length and thickness of the genu, body, and splenium were measured on the standard mid-sagittal plane, and the anteroposterior diameter of the genu was measured in the coronal plane. Results showed that corpus cal osum length as wel as thickness of the genu and splenium increased with gesta-tional age and birth weight, while other measures did not. These three factors on the standard mid-sagittal plane are therefore likely to be suitable for real-time evaluation of corpus cal osum de-velopment in premature infants using cranial ultrasound. Further analysis revealed that thickness of the body and splenium and the anteroposterior diameter of the genu were greater in male infants than in female infants, suggesting that there are sex differences in corpus cal osum size during the neonatal period. A second set of measurements were taken from 40 premature infants whose ges-tational age was 34 weeks or less. Corpus cal osum measurements were corrected to a gestational age of 40 weeks, and infants were grouped for analysis depending on the outcome of a neonatal behavioral neurological assessment. Compared with infants with a normal neurological assessment, corpus cal osum length and genu and splenium thicknesses were less in those with abnormalities, indicating that corpus cal osum growth in premature infants is associated with neurobehavioral de-velopment during the early extrauterine stage.

  3. Usefulness of calcaneal quantitative ultrasound stiffness for the evaluation of bone health in HIV-1-infected subjects: comparison with dual X-ray absorptiometry

    Directory of Open Access Journals (Sweden)

    Fantauzzi A

    2016-05-01

    Full Text Available Alessandra Fantauzzi,1 Marco Floridia,2 Fabrizio Ceci,3 Francesco Cacciatore,4 Vincenzo Vullo,5 Ivano Mezzaroma1 1Department of Clinical Medicine, Sapienza – University of Rome, 2Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità (ISS, 3Department of Cellular Biotechnologies and Hematology, Sapienza University of Rome, Rome, 4U.O. of Cardiac Rehabilitation, Fondazione Salvatore Maugeri, IRCCS, Istituto di Telese Terme, Benevento, 5Department of Public Health and Infectious Diseases, Sapienza – University of Rome, Rome, Italy Objectives: With the development of effective treatments and the resulting increase in life expectancy, bone mineral density (BMD alteration has emerged as an important comorbidity in human immunodeficiency virus type-1 (HIV-1-infected individuals. The potential contributors to the pathogenesis of osteopenia/osteoporosis include a higher prevalence of risk factors, combined antiretroviral therapy (cART-exposure, HIV-1 itself and chronic immune activation/inflammation. Dual-energy X-ray absorptiometry (DXA is the “gold standard” technique for assessing bone status in HIV-1 population. Methods: We conducted a cross-sectional study to investigate bone mineral status in a group of 158 HIV-1-infected subjects. The primary endpoint was the feasibility of calcaneal quantitative ultrasound (QUS as a screening tool for BMD. All subjects were receiving stable cART and were virologically suppressed (HIV-RNA <37 copies/mL from at least 12 months. Calcaneal QUS parameters were analyzed to obtain information on bone mass and microarchitecture. The results were compared with those obtained by DXA. Results: No correlations were found between DXA/QUS parameters and demographic or HIV-1-specific characteristics, also including cART strategies. In the univariate analyses BMD, QUS indexes, and Fracture Risk Assessment Tool scores conversely showed significant associations with one or more

  4. Prevalence of low bone health using quantitative ultrasound in Indian women aged 41-60 years: Its association with nutrition and other related risk factors.

    Science.gov (United States)

    Shenoy, Shweta; Chawla, Jasmine Kaur; Gupta, Swati; Sandhu, Jaspal Singh

    2017-02-02

    The purpose of this study was to find the prevalence of low bone health conditions and assess associated nutritional and other risk factors in Indian women aged 41-60 years. A total of 1,911 women participated in this cross-sectional study. Bone health was assessed using an Omnisense multisite quantitative ultrasound bone densitometer on two sites (radius and tibia). Crude prevalence of osteopenia and osteoporosis was found to be 30.09% and 19.89%, respectively. The Indian women were deficient in a majority of nutrients. Postmenopause, hysterectomy, hyperthyroid, hypothyroid, hypertension, low physical activity, low sun exposure, high stress levels, and low calcium levels were found to be independent risk factors of low bone health.

  5. Quantitative measurement of mixtures by terahertz time-domain spectroscopy

    Indian Academy of Sciences (India)

    Guifeng Liu; Zengyan Zhang; Shihua Ma; Hongwei Zhao; Xiaojing Ma; Wenfeng Wang

    2009-07-01

    Terahertz time-domain spectroscopy (THz-TDS) was applied for quantitatively analysing a series of binary mixtures and a ternary mixture. Binary mixtures having different weight ratios of two components, -aminophenol and m-nitroaniline, were investigated by THz-TDS in the range of 0.3 to 1.5 THz, and it was found that the absorption coefficients of the components in each mixture were linearly proportional to their concentrations in the mixture. The results from analysis were in agreement with actual values with a relative error of less than 7%. The quantitative method will help in the detection of illegal drugs, poisons and dangerous materials that are wrapped or mixed with other materials.

  6. Intra- and interobserver reliability of quantitative ultrasound measurement of the plantar fascia

    DEFF Research Database (Denmark)

    Skovdal Rathleff, Michael; Mølgaard, Carsten; Olesen, Jens Lykkegaard

    2011-01-01

    Colorectal cancer (CRC) is one of the leading causes of cancer deaths. Twenty-five percent of the patients radically treated for a stage II CRC (no lymph node or distant metastasis) later develop recurrence and dies from the disease. MicroRNAs (miRNAs) are aberrantly expressed or mutated in human...

  7. Effects of plasma magnesium and prolactin on quantitative ultrasound measurements of heel bone among schizophrenic patients

    Directory of Open Access Journals (Sweden)

    Renn Jenn-Huei

    2010-02-01

    Full Text Available Abstract Background Osteoporosis is a bone disease that can reduce both bone mass and bone strength. It can cause serious fractures of bones, along with causing significant and even devastating physical, psychological and financial consequences for patients and their family members. Many reports have revealed that the prevalence of decreased bone density is higher in schizophrenic patients than in the non-psychological diseased population. The previous report of our group revealed that chronic schizophrenia patients have poorer BUA levels since they were young as compared to the general community population. Hyperprolactinemia and antipsychotics are reported to be among the risk factors for osteoporosis in chronic schizophrenic patients. Methods 93 schizophrenic patients with severely poor adjusted BUA values and 93 age and gender matched patients with normal adjusted BUA values from a previous survey study were selected. Data were collected via questionnaires and via reviews of antipsychotic medications. Blood samples were drawn, and serum levels of prolactin, estradiol, testosterone, magnesium, calcium, phosphate, osteocalcin, Cross-linked N-teleopeptide of type I collagen (NTX, thyroid hormone and parathyroid hormone were checked. The association between BUA levels and serum levels of the above items, along with the type of received antipsychotic medication, was evaluated. Results There was no significant association found between reduced BUA levels and serum prolactin, calcium, phosphate, osteocalcin, NTX, thyroid stimulating hormone and parathyroid hormone levels. There was also no association between BUA levels and types of currently received antipsychotics. There was no association between BUA levels and menstruation condition in female patients. Hypermagnesemia had a borderline association with classical and combined (classical and atypical antipsychotic medications in male patients. Nevertheless, hypermagnesemia is a significant protective factor of reduced BUA levels in female patients. Hyperprolactinemia had a significant association with classical and combined antipsychotic medications in female patients. Hyperprolactinemia, however, provides a protective effect on reduced BUA levels in male patients. There was no significant association found between serum prolactin level and the type of antipsychotic medication received. Conclusions The results of this study are in contrast with literature that has reported an association between bone mass and serum prolactin levels, serum magnesium levels and type of received antipsychotics. Further study to investigate the pathophysiological process and the association between bone mass and serum prolactin level, serum magnesium level and specific antipsychotics is necessary.

  8. Quantitative method of measuring cancer cell urokinase and metastatic potential

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    1993-01-01

    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated urokinase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  9. The skin-to-calyx distance measured by renal ct scan and ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Chen Jen; Mazzucchi, Eduardo; Payão, Fabio; Gomes, Andrea Cavalanti; Baroni, Ronaldo Hueb; Torricelli, Fabio Cesar; Vicentini, Fabio Carvalho; Srougi, Miguel [Hospital das Clínicas, University of Sao Paulo Medical School, Sao Paulo, SP (Brazil)

    2014-03-15

    Purpose: We developed a stereotactic device to guide the puncture for percutaneous nephrolithotripsy, which uses the distance from the target calyx to its perpendicular point on skin (SCD) to calculate the needle´s entry angle. This study seeks to validate the use of measurements obtained by ultrasound (US) and computerized tomography (CT) for needle´s entry angle calculation and to study factors that may interfere in this procedure. Materials and Methods: Height, weight, abdominal circumference, CT of the urinary tract in dorsal decubitus (DD) and ventral decubitus (VD), and US of the kidneys in VD were obtained from thirty-five renal calculi patients. SCD obtained were compared and correlated with body-mass index (BMI). Results: BMI was 28.66 ± 4.6 Kg/m2. SCD on CT in DD was 8.40 ± 2.06cm, in VD was 8.32 ± 1.95cm, in US was 6.74 ± 1.68cm. SCD measured by US and CT were statistically different (p < 0.001), whereas between CT in DD and VD were not. SCD of the lower calyx presented moderate correlation with BMI. Conclusion: SCD obtained by CT in ventral and dorsal decubitus may be used for calculation of the needle´s entry angle. SCD obtained by US cannot be used. A rule for the correlation between BMI and the SCD could not be determined. (author)

  10. Individually customised fetal weight charts derived from ultrasound measurements: the Generation R Study.

    Science.gov (United States)

    Gaillard, Romy; de Ridder, Maria A J; Verburg, Bero O; Witteman, Jacqueline C M; Mackenbach, Johan P; Moll, Henriëtte A; Hofman, Albert; Steegers, Eric A P; Jaddoe, Vincent W V

    2011-12-01

    Maternal and fetal characteristics are important determinants of fetal growth potential, and should ideally be taken into consideration when evaluating fetal growth variation. We developed a model for individually customised growth charts for estimated fetal weight, which takes into account physiological maternal and fetal characteristics known at the start of pregnancy. We used fetal ultrasound data of 8,162 pregnant women participating in the Generation R Study, a prospective, population-based cohort study from early pregnancy onwards. A repeated measurements regression model was constructed, using backward selection procedures for identifying relevant maternal and fetal characteristics. The final model for estimating expected fetal weight included gestational age, fetal sex, parity, ethnicity, maternal age, height and weight. Using this model, we developed individually customised growth charts, and their corresponding standard deviations, for fetal weight from 18 weeks onwards. Of the total of 495 fetuses who were classified as small size for gestational age (measurements in a large population-based study to fit a model to construct individually customised growth charts, taking into account physiological maternal and fetal characteristics. These charts might be useful for use in epidemiological studies and in clinical practice.

  11. Transabdominal ultrasound measurement of rectal diameter is dependent on time to defecation in constipated children

    DEFF Research Database (Denmark)

    Modin, Line; Dalby, Kasper; Walsted, Anne-Mette;

    2015-01-01

    AIM: To study whether diurnal variations and time in relation to defecation has to be taken into account when measurements of rectal diameter are used to determine faecal impaction in constipated children. METHODS: Repeated ultrasound measures of rectal diameter were performed in 28 children (14...... constipated/14 healthy, aged between 4 and 12 years) every third hour during 24 h. After defecation, three additional scans were performed at 1-h intervals. RESULTS: No diurnal variation in rectal diameter was found in the healthy group. In the constipated group, mean rectal diameter was significantly larger...... at 2 pm (P = 0.038) and 5 pm (P = 0.006). There were significant differences between rectal diameter in the healthy group and the constipated group at 2 pm (P = 0.016) and 5 pm (P = 0.027). When we omitted the rectal diameter of five constipated children who had their first bowel movement after 5 pm...

  12. Utilization of an ultrasound beam steering angle for measurements of tissue displacement vector and lateral displacement

    Directory of Open Access Journals (Sweden)

    Chikayoshi Sumi

    2010-09-01

    Full Text Available Chikayoshi SumiDepartment of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Tokyo, JapanAbstract: A number of ultrasonic displacement/velocity measurement methods have been extensively developed for measurements of blood flow, tissue motion, and strain. Lateral modulation (LM methods have also been reported using steered, crossed beams, and these methods permit measurements of displacement vectors. In this report, a new beam steering method for the transmission and reception of ultrasound is proposed, which can enable measurements of lateral displacements and of arbitrary displacement vectors with a very high degree of accuracy. Because this beam steering method uses only a steering angle, this method is referred to as ASTA. With ASTA, the number of available methods to obtain a displacement vector measurement is limited to previously developed block-matching methods, such as the multidimensional cross-spectrum phase gradient method, and the multidimensional autocorrelation method (MAM and the multidimensional Doppler method (MDM using a block-matching method (the methods using block matching are referred to as MAMb and MDMb, respectively. Being dependent on the measurement method, only a lateral displacement measurement can be made even if the methods are multidimensional, ie, previously developed MAM and MDM using a moving average and a mirror setting of the obtained steered beams, and one-dimensional (1D, such as an autocorrelation method. Considerations of beamforming schemes using LM and ASTA show that the simple ASTA beamforming method increases capabilities for real-time measurements and requires a small physical aperture when compared with LM. For lateral displacement measurements (eg, blood flow in a carotid artery, a lateral coordinate must correspond to the direction of the target’s lateral motion, and the steering angle used is as large as possible to increase the measurement accuracy

  13. Reliability of ultrasound imaging for the measurement of abdominal muscle thickness in typically developing children

    Directory of Open Access Journals (Sweden)

    M. Unger

    2010-02-01

    Full Text Available Introduction: A bdominal muscles are key to both posture andgait in both children with typical development (TD and with disabilities.Ultrasound (US imaging is a potential non-invasive method for investigatingactivity in these muscles. This study therefore aimed to determine the inter-tester and intra-tester reliability of B-mode US for investigating transverseabdominus (TrA , rectus abdominus (RA and external- (EO and internaloblique (IO muscle activity in children with TD. Design: A  prospective cor-relational descriptive study.  Participants:  Eighty six, 6-13year old children from one private and one public mainstream school. Outcome measures: Two sets of B-mode US images where captured per subject during rest and during head-up, resisted head-up and resisted sling activities. Intra-class Correlation Coefficients (ICC and standard error of measurement (SEM were used to analyse the data. Results: Good correlation was found for both test - retest condi-tions for all four muscles tested during rest: 0.91(TrA ; 0.90(IO; 0.91(EO; 0.94(RA for intra-tester reliability and0.74(TrA ; 0.88(IO; 0.74(EO; 0.83(RA for inter-tester reliability. Repeatability of thickness measures during activity however showed variation in recruitment patterns. A  significant correlation was found between age and BMI andresting abdominal muscle thickness (p<0.001. Conclusion: The study supports the reliability of US measurement of resting abdominal muscles and of the RA  under active conditions in children aged six to 13. However the stability o measurement of the other muscles under active conditions still needs to be established.

  14. Correlation Between Transperineal 3-Dimensional Ultrasound Measurements of Levator Hiatus and Female Sexual Function.

    Science.gov (United States)

    Aydin, Serdar; Bakar, Rabia Zehra; Arioğlu Aydin, Çağri; Ateş, Seda

    2017-03-09

    The aim of this study is to investigate the association of sexual functions with levator hiatus biometry measurements and levator ani muscle defect. In 62 heterosexual, sexually active premenopausal women without pelvic floor disorders or urinary incontinence, 3-dimensional transperineal ultrasound imaging was used. Two 3-dimensional volumes were recorded, one at rest and one on Valsalva maneuver. Levator biometry measurements and levator defect were evaluated in an axial plane. Sexual function was assessed by a validated questionnaire, Female Sexual Function Index (FSFI). The primary outcome measure was correlation of sexual functions with the levator hiatus area, transverse and anteroposterior diameters, levator ani muscle thickness, vaginal length, and changes in measurements with Valsalva and levator defect. Forty-two women (67.7%) had low total FSFI scores (<26.55). Levator defect rates were similar in female sexual dysfunction (7/42, 16.7%) and women without female sexual dysfunction (5/20, 25%). The FSFI was negatively and weakly correlated with Δhiatal anteroposterior diameter (r = -0.33, P < 0.009) in the study population. There was a weak and inverse correlation between Δhiatal anteroposterior diameter and arousal (r = -0.35, P < 0.002), desire (r = -0.38, P < 0.001), and orgasm (r = -0.33, P < 0.007). Pain and lubrication did not correlate with any measurement. Hiatal area and diameters at rest are not related to sexual functions. Changes in anteroposterior diameter of the levator hiatus during Valsalva, which may be a sign of pelvic floor laxity or levator muscle weakness, are weakly associated with sexual functions, particularly desire, arousal, and orgasm domains.

  15. Quantitative vibro-acoustography of tissue-like objects by measurement of resonant modes.

    Science.gov (United States)

    Mazumder, Dibbyan; Umesh, Sharath; Vasu, Ram Mohan; Roy, Debasish; Kanhirodan, Rajan; Asokan, Sundarrajan

    2017-01-07

    We demonstrate a simple and computationally efficient method to recover the shear modulus pertaining to the focal volume of an ultrasound transducer from the measured vibro-acoustic spectral peaks. A model that explains the transport of local deformation information with the acoustic wave acting as a carrier is put forth. It is also shown that the peaks correspond to the natural frequencies of vibration of the focal volume, which may be readily computed by solving an eigenvalue problem associated with the vibrating region. Having measured the first natural frequency with a fibre Bragg grating sensor, and armed with an expedient means of computing the same, we demonstrate a simple procedure, based on the method of bisection, to recover the average shear modulus of the object in the ultrasound focal volume. We demonstrate this recovery for four homogeneous agarose slabs of different stiffness and verify the accuracy of the recovery using independent rheometer-based measurements. Extension of the method to anisotropic samples through the measurement of a more complete set of resonant modes and the recovery of an elasticity tensor distribution, as is done in resonant ultrasound spectroscopy, is suggested.

  16. Quantitative vibro-acoustography of tissue-like objects by measurement of resonant modes

    Science.gov (United States)

    Mazumder, Dibbyan; Umesh, Sharath; Mohan Vasu, Ram; Roy, Debasish; Kanhirodan, Rajan; Asokan, Sundarrajan

    2017-01-01

    We demonstrate a simple and computationally efficient method to recover the shear modulus pertaining to the focal volume of an ultrasound transducer from the measured vibro-acoustic spectral peaks. A model that explains the transport of local deformation information with the acoustic wave acting as a carrier is put forth. It is also shown that the peaks correspond to the natural frequencies of vibration of the focal volume, which may be readily computed by solving an eigenvalue problem associated with the vibrating region. Having measured the first natural frequency with a fibre Bragg grating sensor, and armed with an expedient means of computing the same, we demonstrate a simple procedure, based on the method of bisection, to recover the average shear modulus of the object in the ultrasound focal volume. We demonstrate this recovery for four homogeneous agarose slabs of different stiffness and verify the accuracy of the recovery using independent rheometer-based measurements. Extension of the method to anisotropic samples through the measurement of a more complete set of resonant modes and the recovery of an elasticity tensor distribution, as is done in resonant ultrasound spectroscopy, is suggested.

  17. In vivo measurement of rotator cuff tendon strain with ultrasound elastography: an investigation using a porcine model.

    Science.gov (United States)

    Hatta, Taku; Yamamoto, Nobuyuki; Sano, Hirotaka; Itoi, Eiji

    2014-09-01

    To clarify the relationship between the strain ratio measured by ultrasound elastography and the mechanical properties of the tendon measured by a universal testing machine. We also attempted to determine the effect of the type and depth of soft tissue overlying the tendon on the elastographic measurement. Twelve fresh porcine shoulders were prepared. Elastographic measurement was performed on the infraspinatus tendon by manually applying repetitive compressions from an ultrasound probe with an acoustic coupler consisting of an elastomer with definite elasticity as a reference material. The strain ratio, defined as tendon/reference strain, was obtained by 4 different approaches: with the probe placed on the skin, on the subcutaneous fat after removing the skin, on the muscle after removing the subcutaneous fat, and directly on the tendon. The strain ratios measured by these approaches were compared statistically. The relationship between the depth of the tendon measured on elastography and the strain ratio was also investigated. We also attempted to clarify the relationship between the strain ratio of the tendon and its elastic property. The tendon was mounted on a testing machine, and compressive force was applied. Tendon compliance was calculated as the reciprocal of the Young modulus in the range of 5% to 10% strain, which was compared to its strain ratio. The tendon/reference strain ratio significantly correlated with the tendon compliance (r = 0.73; P tendon level (P = .8). Our results indicated that the strain ratio of the rotator cuff tendon could be measured with minimal influence by overlying soft tissues if its depth from the skin was less than 22 mm. We believe that ultrasound elastography would be a useful tool for assessment of tendon elasticity in clinical practice. © 2014 by the American Institute of Ultrasound in Medicine.

  18. Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares.

    Science.gov (United States)

    Östling, Gerd; Persson, Margaretha; Hedblad, Bo; Gonçalves, Isabel

    2013-11-01

    Grey scale median (GSM) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut-off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with Adobe Photoshop(®) and with Artery Measurement System (AMS) on duplex ultrasound images of 100 consecutive medium- to large-sized carotid plaques of the Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for Adobe Photoshop(®) and AMS, respectively. Mean difference was 20·45 (95% CI: 19·17-21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi-square test revealed a kappa value of 0·68 when studying quartiles of GSM. The intra-observer variability was 1·9% for AMS and 2·5% for Adobe Photoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries.

  19. Confiabilidade da medida de espessuras musculares pela ultrassonografia Reliability of muscle thickness measurements using ultrasound

    Directory of Open Access Journals (Sweden)

    Paulo Sergio Chagas Gomes

    2010-02-01

    Full Text Available OBJETIVO: Determinar a confiabilidade das medidas de espessuras dos músculos flexores e extensores do cotovelo e joelho pela ultrassonografia (US, quantificando o erro típico associado a essas medidas (ETM. MÉTODOS: A confiabilidade (duas medidas interdias foi determinada em 15 voluntários aparentemente saudáveis (oito mulheres, 33,9 ± 11,4 anos, 76 ± 21kg, 170 ± 10cm. As imagens da musculatura flexora (FC e extensora do cotovelo (EC e flexora (FJ e extensora do joelho (EJ foram obtidas pela US bidimensional no modo B, utilizando transdutor de 7,5MHz. As espessuras do tecido muscular compreendidas entre as interfaces com o osso e com o tecido adiposo foram medidas em sítios anatômicos identificados e registrados para ser repetidos na segunda medida. RESULTADOS: A ANOVA não identificou diferenças significativas entre as medidas repetidas. Os coeficientes de correlação intraclasse foram FC = 0,970, EC = 0,971, FJ = 0,555 e EJ = 0,929 (P PURPOSE: To determine the reliability of muscle thickness measurements of elbow and knee flexors and extensors using ultrasound, and to quantify the typical error associated to the measurements (TEM. METHODS: The test-retest reliability was determined in 15 apparently healthy volunteers (8 women, 34 ± 11 years, 76 ± 21 kg, 170 ± 10 cm. The images of elbow flexors (EF and extensors (EE and knee flexors (KF and extensors (KE were obtained using a two dimensional mode B ultrasound instrument with a 7.5 MHz transducer. Muscle thickness between the adipose tissue and bone interfaces were measured at anatomical landmarks previously identified and recorded to assure the exact site for the retest. RESULTS: ANOVA did not identify any significant differences between the repeated measurements. Intraclass correlation coefficients (ICC of each pair of measure were EF = 0.970, EE = 0.971, KF = 0.555 e KE = 0.929 (P < 0.05 for all. The coefficients of variation were 3.9 %, 6.1 %, 6.6 % e 4.6 %, and TEM 1.3 mm, 1

  20. Exploratory Analysis of Carbon Dioxide Levels, Ultrasound and Optical Coherence Tomography Measures of the Eye During ISS Missions

    Science.gov (United States)

    Schaefer, C.; Coble, C.; Mason, S.; Young, M.; Wear, M. L.; Sargsyan, A.; Garcia, K.; Patel, N.; Gibson, C.; Alexander, D.; Van Baalen, M.

    2017-01-01

    Carbon dioxide (CO2) levels on board the International Space Station (ISS) have typically averaged 2.3 to 5.3 mmHg, with large fluctuations occurring over periods of hours and days. CO2 has effects on cerebral vascular tone, resulting in vasodilation and alteration of cerebral blood flow (CBF). Increased CBF leads to elevated intracranial pressure (ICP), a factor leading to visual disturbances, headaches, and other central nervous system symptoms. Ultrasound of the optic nerve and optical coherence tomography (OCT) provide surrogate measurements of ICP; in-flight measurements of both were implemented as enhanced screening tools for the Visual Impairment/Intracranial Pressure (VIIP) syndrome. This analysis examines the relationships between ambient CO2 levels on ISS, ultrasound and OCT measures of the eye in an effort to understand how CO2 may possibly be associated with VIIP and to inform future analysis of in-flight VIIP data.

  1. Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O

    2010-01-01

    There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

  2. Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O

    2010-01-01

    There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

  3. The reproducibility of quantitative measurements in lumbar magnetic resonance imaging of children from the general population

    DEFF Research Database (Denmark)

    Masharawi, Y; Kjær, Per; Bendix, T

    2008-01-01

    STUDY DESIGN: Quantitative lumbar magnetic resonance imaging (MRI) measurements in children were taken twice and analyzed for intra- and intertester reproducibility. OBJECTIVE: To evaluate the reproducibility of a variety of lumbar quantitative measurements taken from MRIs of children from the ge...

  4. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces ... of page What are some common uses of the procedure? A transrectal ultrasound of the prostate gland ...

  5. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... are the limitations of Pelvic Ultrasound Imaging? What is Pelvic Ultrasound Imaging? Ultrasound is safe and painless, ... through the blood vessels. top of page How is the procedure performed? Transabdominal: For most ultrasound exams, ...

  6. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate gland ... of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography , ...

  7. Ultrasound - Breast

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Ultrasound - Breast Ultrasound imaging of the breast uses sound waves ... the Breast? What is Ultrasound Imaging of the Breast? Ultrasound is safe and painless, and produces pictures ...

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Ultrasound - Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Z Ultrasound - Prostate Ultrasound of the prostate uses sound waves to produce pictures of a man’s prostate ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

  10. Prostate Ultrasound

    Medline Plus

    Full Text Available ... Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe and painless, and produces ... of page What are some common uses of the procedure? A transrectal ultrasound of the prostate gland ...

  11. Ultrasound measurement of the size of the anterior tibial muscle group: the effect of exercise and leg dominance

    LENUS (Irish Health Repository)

    McCreesh, Karen

    2011-09-13

    Abstract Background Knowledge of normal muscle characteristics is crucial in planning rehabilitation programmes for injured athletes. There is a high incidence of ankle and anterior tibial symptoms in football players, however little is known about the effect of limb dominance on the anterior tibial muscle group (ATMG). The purpose of this study was to assess the effect of limb dominance and sports-specific activity on ATMG thickness in Gaelic footballers and non-football playing controls using ultrasound measurements, and to compare results from transverse and longitudinal scans. Methods Bilateral ultrasound scans were taken to assess the ATMG size in 10 Gaelic footballers and 10 sedentary controls (age range 18-25 yrs), using a previously published protocol. Both transverse and longitudinal images were taken. Muscle thickness measurements were carried out blind to group and side of dominance, using the Image-J programme. Results Muscle thickness on the dominant leg was significantly greater than the non-dominant leg in the footballers with a mean difference of 7.3%, while there was no significant dominance effect in the controls (p < 0.05). There was no significant difference between the measurements from transverse or longitudinal scans. Conclusions A significant dominance effect exists in ATMG size in this group of Gaelic footballers, likely attributable to the kicking action involved in the sport. This should be taken into account when rehabilitating footballers with anterior tibial pathology. Ultrasound is a reliable tool to measure ATMG thickness, and measurement may be taken in transverse or longitudinal section.

  12. Measurement of cervical range of motion pattern during cyclic neck movement by an ultrasound-based motion system.

    Science.gov (United States)

    Wang, Shwu-Fen; Teng, Chin-Chih; Lin, Kwan-Hwa

    2005-02-01

    Goniometers and radiographic imaging have been used to measure active or passive cervical range of motion (ROM) in asymptomatic adults. However, the ultrasound-based coordinate measuring system (CMS) can measure continuous neck motion in three dimensions. The aims of this investigation are to evaluate the reliability and validity of ultrasound-based CMS (Zebris, CMS 70P), and to compare the cervical ROM patterns of asymptomatic young and middle-aged adults during continuous neck motions in the three cardinal planes. The ROM reciprocal ratio was defined as the ratio of the ROM from neutral position in one direction versus that in the opposite direction at the same cardinal plane. This study demonstrated the high test-retest reliability and validity of CMS during cervical motion in Chinese participants. Middle-aged adults exhibit reduced ROM ratios in the sagittal and frontal planes. The advantages and limitations of the CMS measurement tool and the potential future applications are documented. The measurement of neck motion pattern by ultrasound-based CMS may provide information on the management of neck dysfunction during functional movements.

  13. A 3D sparse motion field filtering for quantitative analysis of fascial layers mobility based on 3D ultrasound scans.

    Science.gov (United States)

    Turini, G; Condino, S; Stecco, A; Ferrari, V; Ferrari, M; Gesi, M

    2015-08-01

    In the last few years, there has been an increasing interest in the role of deep fascia mobility in musculoskeletal dynamics and chronic pain mechanisms. In a previous paper we presented an innovative semiautomatic approach to evaluate the 3D motion of the fascia using ultrasound (US) imaging, generating a sparse deformation vector field. This paper presents an improvement of our original method, focusing on the filtering of the sparse vector field and its validation. Moreover, in order to evaluate the performance of the algorithm, a method is proposed to generate synthetic deformation vector fields, including: expansion, rotation, horizontal shear, and oblique shear components. Preliminary tests on the final synthetic deformation vector fields showed promising results. Further experiments are required in order to optimize the tuning of the algorithm.

  14. Correlation of preoperative MRI and intraoperative 3D ultrasound to measure brain tissue shift

    Science.gov (United States)

    Gobbi, David G.; Lee, Belinda K. H.; Peters, Terence M.

    2001-05-01

    B-Mode ultrasound is often used during neurosurgery to provide intra-operative images of the brain though a craniotomy, but the use of 3D ultrasound during surgery is still in its infancy. We have developed a system that provides real-time freehand 3D ultrasound reconstruction at a reduced resolution. The reconstruction proceeds incrementally and the 3D image is overlayed, via a computer, on a pre-operative 3D MRI scan. This provides the operator with the necessary feedback to maintain a constant freehand sweep-rate, and also ensures that the sweep covers the desired anatomical volume. All of the ultrasound video frames are buffered, and a full-resolution, compounded reconstruction proceeds once the manual sweep is complete. We have also developed tools for manual tagging of homologous landmarks in the 3D MRI and 3D ultrasound volumes that use a piecewise cubic approximation of thin-plate spline interpolation to achieve interactive nonlinear registration and warping of the MRI volume to the ultrasound volume: Each time a homologous point-pair is identified by the use, the image of the warped MRI is updated on the computer screen after less than 0.5 s.

  15. Spectral energy measurements of simulated microemboli of various sizes using a diffraction grating ultrasound probe

    Science.gov (United States)

    Weiss, William J.; Ballakur, Sowmya G.; Tran, Hoang; Hazard, Sprague W.; Blebea, John

    2003-05-01

    This study characterizes the Doppler signal from simulated microemboli of various sizes in blood mimicking fluid using spectral energy parameters. The goal of this research is to detect microemboli as a non-invasive diagnostic tool, or intra-operatively as a surgical aid. A dual beam diffraction-grating ultrasound probe operating at 10 MHz (Model Echoflow BVM-1, EchoCath, Inc., Princeton, NJ) was used with a flow phantom. Microemboli were polystyrene microspheres in 200 to 1000 micron diameters, in concentrations of 0.1, 0.5, and 1.0 per ml. Average flow velocities were 25, 50, 75, and 100 cm/sec. The distribution of peak values of the power spectrum at 2.5 msec windows was plotted over 15 seconds. The means of the distributions corresponding to the microspheres and background fluid were averaged for the four velocity conditions. Embolic peak spectral power ranged from approximately 12 to 25 dB relative to the background. A detection method based on these measurements is currently being developed.

  16. Reliability of ultrasound texture measures of Biceps Brachialis and Gastrocnemius Lateralis muscles' images.

    Science.gov (United States)

    da Silva Pereira Júnior, Newton; da Matta, Thiago Torres; Alvarenga, André Victor; de Albuquerque Pereira, Wagner Coelho; de Oliveira, Liliam Fernandes

    2017-01-01

    Ultrasound (US) is an important tool for diagnosing of many musculoskeletal tissue conditions. Image texture analysis can be used to characterize this tissue. The complexity curve (CC) is a technique commonly used to characterize the number of grey-level transitions in an image. Variability and reliability of US texture measures in the muscle tissue are unavailable in the literature. The aim of this study was to determine the variability and reliability of five CC texture parameters from US images of healthy Biceps Brachialis and Gastrocnemius Lateralis (GL) muscles, with longitudinal and transversal orientations of the probe. Eight images per subject were obtained for 30 men in 2 days. Mean, standard deviation, coefficient of variation and intraclass correlation coefficient for the five parameters were calculated for regions of interest. Results showed that the variability was similar for both muscles and most of the parameters showed satisfactory reliability (r > 0·7) for the Biceps Brachialis with the transverse scan and for the GL with the longitudinal scan. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  17. Doppler ultrasound measurement of resistance index in the diagnosis of prostate cancer.

    Science.gov (United States)

    Huang, Wei; Cen, Son; Kang, Xin-Li; Wang, Wei Fu; Wang, Yang; Chen, Xiang

    2015-01-01

    Prostate cancer (PCa) remains the second leading cause of cancer diagnosis worldwide. Early diagnosis and treatment of PCa is critical since the long-term prognosis is excellent in patients with tumors confined to the prostate gland. The current meta-analysis investigates the diagnostic value of resistive index (RI) measurement using color Doppler ultrasound in patients with PCa. Electronic literature databases were exhaustively searched for relevant studies published prior to May 31, 2014. Nine studies met our predetermined inclusion criteria for the present meta-analysis. The methodologic quality of the selected studies was independently assessed by 2 reviewers based on Quality Assessment of Diagnostic Accuracy Studies tool. Our meta-analysis results showed that RI values were significantly higher in malignant prostate tissues compared to normal prostate tissues (standardized mean difference [SMD] 0.42, 95% confidence interval [CI] 0.12~0.73, p = 0.007) and benign prostate tissues (SMD 0.41, 95% CI 0.26~0.56, p<0.001). Subgroup analysis based on the diagnostic instruments used revealed that RI values were accurate in diagnosis of PCa when compared between malignant tissue vs normal tissue and malignant tissue vs benign tissue (all p<0.05). Taken together, our findings support the potential clinical applications of RI values in diagnosis of PCa.

  18. Frustration effects in spinel compound GeCo2O4 studied by ultrasound velocity measurements

    Science.gov (United States)

    Watanabe, Tadataka; Hara, Shigeo; Ikeda, Shin-Ichi

    2009-03-01

    Ultrasound velocity measurements of the cubic spinel GeCo2O4 in the single crystal have been performed for the investigations of shear and compression moduli. The shear moduli reveal the absence of Jahn-Teller activity despite the presence of the orbital degeneracy in the Co2+ ions. This Jahn-Teller inactivity indicates that the intersite orbital-orbital interaction is much stronger than the Jahn-Teller coupling. The compression moduli reveal that the dominant path of the exchange interactions for the antiferromagnetic transition lies in the [111] direction. This exchange-path anisotropy is consistent with the antiferromagnetic structure with the wave vector q parallel [111], suggesting the presence of bond frustration among several ferromagnetic and antiferromagientic interactions. In the JT-inactive condition, the bond frustration can be induced by geometrical orbital frustration of t2g-t2g interaction between the Co2+ ions which can be realized in the pyrochlore lattice of the high spin Co2+ with t2g -orbital degeneracy. In GeCo2O4, the tetragonal elongation below TN releases the orbital frustration by quenching the orbital degeneracy.

  19. Ultrasound Velocity Measurements in the Orbital-Degenerate Frustrated Spinel MgV2O4

    Science.gov (United States)

    Watanabe, Tadataka; Ishikawa, Takashi; Hara, Shigeo; Islam, A. T. M. Nazmul; Wheeler, Elisa M.; Lake, Bella

    2014-03-01

    Magnesium vanadate spinel MgV2O4 is a geometrically frustrated magnet with t2 g-orbital degeneracy of V3+ (3d2), which undergoes a cubic-to-tetragonal structural transition at Ts = 65 K and an antiferromagnetic (AF) transition at TN = 42 K. For MgV2O4, it is considered that the occurrence of t2 g-orbital order at Ts causes the release of frustration by the AF ordering at TN lower than Ts. We performed ultrasound velocity measurements in high-purity single crystal of MgV2O4. Temperature dependence of the tetragonal shear modulus (C11 -C12)/2 exhibits huge Curie-type softening in the cubic paramagnetic (PM) phase (T >Ts), which should be a precursor to the cubic-to-tetragonal lattice distortion at Ts. The trigonal shear modulus C44(T) exhibits softening with an upturn curvature in the cubic PM phase, indicating a coupling of the lattice to magnetic excitations. These softenings suggest the coexistence of the dynamical Jahn-Teller effect and the dynamical magnetic state in the cubic PM phase.

  20. Ultrasound Velocity Measurements in the Geometrically Frustrated Spinel MgCr2O4

    Science.gov (United States)

    Watanabe, Tadataka; Kousaka, Yusuke; Tomiyasu, Keisuke

    2012-02-01

    Magnesium chromite spinel MgCr2O4 is a geometrically frustrated magnet with the Néel temperature TN˜13 K, and the Weiss temperature θW= -390 K. Recent inelastic neutron scattering experiments provided a compelling evidence for the spin molecular ground states in not only the paramagnetic phase but also the antiferromagnetic phase. We performed ultrasound velocity measurements of MgCr2O4 in all the symmetrically independent elastic moduli of C11, (C11-C12)/2, and C44. Temperature dependence of all of these elastic moduli exhibits a remarkable softening in the paramagnetic phase. Taking into account the absence of orbital degrees of freedom in Cr^3+ (3d^3) in MgCr2O4, the spin degrees of freedom should play a significant role for the elastic softening. The most probable origin for the elastic softening in the paramagnetic phase is the strong coupling of the acoustic phonons to the molecular spin fluctuations.

  1. Comparison of Colour Duplex Ultrasound with Computed Tomography to Measure the Maximum Abdominal Aortic Aneurysmal Diameter

    Directory of Open Access Journals (Sweden)

    C. Gray

    2014-01-01

    Full Text Available Introduction. Maximum diameter of an abdominal aortic aneurysm (AAA is the main indication for surgery. This study compared colour duplex ultrasound (CDU and computed tomography (CT in assessing AAA diameter. Patients and Methods. Patients were included if they had both scans performed within 90 days. Pearson’s correlation coefficient, paired t-test, and limits of agreement (LOA were calculated for the whole group. Subgroup analysis of small (6.5 cm aneurysms was performed. A P value of <0.05 was considered statistically significant. Results. 389 patients were included, giving 130 pairs of tests for comparison. Excellent correlation was in the whole group (r = 0.95 and in the subgroups (r = 0.94; 0.69; 0.96, resp.. Small LOA between the two imaging modalities was found in all subgroups. Conclusion. Small aneurysms can be accurately measured using CDU. CDU is preferable for small AAAs, but cannot supplant CT for planning aortic intervention.

  2. Comparison of medical of volume measurement of the prostate by transrectal ultrasound: Experiment with jelly models

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jeong Yeon; Lee, Hak Jong; Kim, Sung Hyun [Samsung Seoul Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Seung Hyup [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2002-03-15

    To evaluate the accuracy of measuring the volume of the prostate using the prolate ellipsoid volume calculation method (antero-posterior (AP) diameter X length X width X {pi}6) when the antero-posterior diameter of the prostate was measured on midsagittal (sagittal volume) and axial plane (axial volume).The devil's tongue jelly was used for the creation of ultrasound model of the prostate (volume: 15-40 cc) by cutting and shaping the surface. The volume in 10 prostatic models and 30 patients was measured and calculated. First, the AP diameter and length of the prostate models in midsagittal plane, and the height and width of the models in axial plane were measured for 3 times. The volume was calculated in two ways, one using the AP diameter an midsagittal plane and the other using the AP diameter in axial plane. The true volume of the model was measured using mess cylinder. The calculated volume and true volume were compared, and the accuracy of two method of measuring the prostatic volume was evaluated by Friedman test. The intraobserver variation was evaluated by General Linear Model, Repeated Measure. The reproducibility was evaluated by Cronbach's {alpha}. In vivo study was also performed in 30 patients. The prostate volume was calculated in the same manner. These volume data were analyzed by statistical method, and the intraobeserver variation was evaluated. While there was a statistically significant difference between the sagittal and true volume of the models, there was no statistical significant difference between the axial and true volumes. There was no significant intraobserver variation between both methods. The reproducibility was high in both methods with Cronbach's {alpha} of 0.977 and 0.942. The sagittal volume was larger than the axial volume in 30 patients with a statistically significant difference. There was no significant intraobserver variation in both methods. The reproducibility was high in both methods Cronbach's {alpha

  3. Quantitative Measurement Method for Possible Rib Fractures in Chest Radiographs

    Science.gov (United States)

    Kim, Jaeil; Kim, Sungjun; Kim, Young Jae

    2013-01-01

    Objectives This paper proposes a measurement method to quantify the abnormal characteristics of the broken parts of ribs using local texture and shape features in chest radiographs. Methods Our measurement method comprises two steps: a measurement area assignment and sampling step using a spline curve and sampling lines orthogonal to the spline curve, and a fracture-ness measurement step with three measures, asymmetry and gray-level co-occurrence matrix based measures (contrast and homogeneity). They were designed to quantify the regional shape and texture features of ribs along the centerline. The discriminating ability of our method was evaluated through region of interest (ROI) analysis and rib fracture classification test using support vector machine. Results The statistically significant difference was found between the measured values from fracture and normal ROIs; asymmetry (p rib fracture classifier, trained with the measured values in ROI analysis, detected every rib fracture from chest radiographs used for ROI analysis, but it also classified some unbroken parts of ribs as abnormal parts (8 to 17 line sets; length of each line set, 2.998 ± 2.652 mm; length of centerlines, 131.067 ± 29.460 mm). Conclusions Our measurement method, which includes a flexible measurement technique for the curved shape of ribs and the proposed shape and texture measures, could discriminate the suspicious regions of ribs for possible rib fractures in chest radiographs. PMID:24175118

  4. Quantitative imaging and measurement of cell-substrate surface deformation by digital holography

    Science.gov (United States)

    Yu, Xiao; Cross, Michael; Liu, Changgeng; Clark, David C.; Haynie, Donald T.; Kim, Myung K.

    2012-10-01

    Quantitative phase microscopy by digital holography (DH-QPM) is introduced to study the cell-substrate interactions and migratory behavior of adhesive cells. A non-wrinkling elastic substrate, collagen-coated polyacrylamide (PAA) has been employed and its surface deformation due to cell adhesion and motility has been visualized as certain tangential and vertical displacement and distortion. The surface deformation on substrates of different elasticity and thickness has been quantitatively imaged and the corresponding cellular traction force of motile fibroblasts has been measured from phase profiles by DH-QPM. DH-QPM is able to yield quantitative measures directly and provide efficient and versatile means for quantitatively analyzing cellular motility.

  5. Comparison of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeters in glaucoma patients.

    Science.gov (United States)

    Salim, Sarwat; Du, Haiming; Wan, Jim

    2015-07-01

    The purpose of this study was to compare the accuracy and reproducibility of central corneal thickness measured by hand-held and desk-mounted ultrasound pachymeter in glaucoma patients under treatment. Prospective study of 65 glaucoma patients. Central corneal thickness was measured by two ultrasound pachymeters: the hand-held, portable PachPen (Accutome, Lynwood, WA), and the desk-mounted PacScan 300 (Sonomed, Lake Success, NY). The mean ± SD central corneal thickness was 526.5 ± 44.8 µm and 530.0 ± 44.7 µm for the hand-held and desk-mounted pachymeters, respectively (p = 0.15). Linear regression analysis revealed a slope of 0.97 with Pearson correlation coefficient of 0.96. Bland-Altman analysis showed a mean difference of measurements by both pachymeters of 3.22 µm with two standard deviations = 9.51. Both instruments showed high intraobserver correlation: 0.972 for the hand-held pachymeter and 0.993 for the desk-mounted pachymeter. Central corneal thickness measurements were comparable with the use of hand-held and desk-mounted ultrasound units in glaucoma patients with good intraobserver reproducibility.

  6. Evaluating quantitative measures of grammatical complexity in spontaneous speech samples.

    Science.gov (United States)

    Blake, J; Quartaro, G; Onorati, S

    1993-02-01

    The validity of MLU and a measure of syntactic complexity were tested against LARSP on spontaneous speech samples from 87 children, ranging in age from 1;6 to 4;9. Change in some LARSP clausal measures was found across MLU stages up to MLU 4.5. For the measure of syntactic complexity, no such ceiling was found for the clausal connectivity score in LARSP or for average clausal complexity in LARSP. Neither MLU nor the measure of syntactic complexity indexed LARSP phrasal complexity. It is concluded that MLU is a valid measure of clausal complexity up to 4.5 and that our measure of syntactic complexity is more valid at more advanced stages.

  7. Quantitative measurement of hypertrophic scar: interrater reliability and concurrent validity.

    Science.gov (United States)

    Nedelec, Bernadette; Correa, José A; Rachelska, Grazyna; Armour, Alexis; LaSalle, Léo

    2008-01-01

    Research into the pathophysiology and treatment of hypertrophic scar (HSc) remains limited by the heterogeneity of scar and the imprecision with which its severity is measured. The objective of this study was to test the interrater reliability and concurrent validity of the Cutometer measurement of elasticity, the Mexameter measurement of erythema and pigmentation, and total thickness measure of the DermaScan C relative to the modified Vancouver Scar Scale (mVSS) in patient-matched normal skin, normal scar, and HSc. Three independent investigators evaluated 128 sites (severe HSc, moderate or mild HSc, donor site, and normal skin) on 32 burn survivors using all of the above measurement tools. The intraclass correlation coefficient, which was used to measure interrater reliability, reflects the inherent amount of error in the measure and is considered acceptable when it is >0.75. Interrater reliability of the totals of the height, pliability, and vascularity subscales of the mVSS fell below the acceptable limit ( congruent with0.50). The individual subscales of the mVSS fell well below the acceptable level (0.89) for each study site with the exception of severe scar. Mexameter and DermaScan C reliability measurements were acceptable for all sites (>0.82). Concurrent validity correlations with the mVSS were significant except for the comparison of the mVSS pliability subscale and the Cutometer maximum deformation measure comparison in severe scar. In conclusion, the Mexameter and DermaScan C measurements of scar color and thickness of all sites, as well as the Cutometer measurement of elasticity in all but the most severe scars shows high interrater reliability. Their significant concurrent validity with the mVSS confirms that these tools are measuring the same traits as the mVSS, and in a more objective way.

  8. Effect of genotype, sex and slaughter weight on veal Longissimus muscle area measured by ultrasound and planimeter

    Directory of Open Access Journals (Sweden)

    Zoran Luković

    2010-01-01

    Full Text Available The aim of this research was to determine effect of genotype (Holstein, Simmental and their crossbreeds, sex and slaughter weight groups (SW1=150-160kg and SW2=190-200kg on veal Longissimus muscle area (LMA. Between the12th and the13th rib, two ultrasound LMA (ULMA images were taken from each animal and carcass LMA (CLMA traced on transparent foil was measured by planimeter. For both measures, Simmental calves had larger LMA than Holstein (P<0.001 and crossbreeds (P<0.05. Male and female calves did not differ significantly in ULMA and CLMA. Calves of SW2 group had larger LMA (P<0.0001 than SW1 group. High correlation coefficient between ULMA and CLMA was determined in this research. Veal LMA was significantly affected by genotype and slaughter weight. According to high correlation coefficients, ultrasound can be useful in estimating carcass traits of cattle at early age.

  9. Quantitative comparison of measurements of urgent care service quality.

    Science.gov (United States)

    Qin, Hong; Prybutok, Victor; Prybutok, Gayle

    2016-01-01

    Service quality and patient satisfaction are essential to health care organization success. Parasuraman, Zeithaml, and Berry introduced SERVQUAL, a prominent service quality measure not yet applied to urgent care. We develop an instrument to measure perceived service quality and identify the determinants of patient satisfaction/ behavioral intentions. We examine the relationships among perceived service quality, patient satisfaction and behavioral intentions, and demonstrate that urgent care service quality is not equivalent using measures of perceptions only, differences of expectations minus perceptions, ratio of perceptions to expectations, and the log of the ratio. Perceptions provide the best measure of urgent care service quality.

  10. Joseph F. Keithley Award For Advances in Measurement Science: Resonant Ultrasound Spectroscopy: An Odyssey in Measurement Science

    Science.gov (United States)

    Migliori, Albert

    Perhaps the speeds of sound, or, equivalently, the elastic moduli are some of the most fundamental attributes of a solid, connecting to fundamental physics, metallurgy, non-destructive testing, and more. Unlike most of the quantities used to characterize condensed matter, the elastic moduli are fourth-rank tensors containing a wealth of detail, directional information, and consistency constraints that provide some of the most revealing probes of solids. We describe here the current state of the art in one method, Resonant Ultrasound Spectroscopy, where the mechanical resonances of a specimen of regular shape (easy to measure) are analyzed (difficult computational problem) to obtain the full elastic tensor. With modern advances in electronics and analysis, fractions of a part per million changes in elastic moduli are detectable providing new and important insight into grand challenges in condensed matter physics. This work was supported as part of the Materials Science of Actinides, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0001089.

  11. A method for quantitative measurement of lumbar intervertebral disc structures

    DEFF Research Database (Denmark)

    Tunset, Andreas; Kjær, Per; Samir Chreiteh, Shadi

    2013-01-01

    There is a shortage of agreement studies relevant for measuring changes over time in lumbar intervertebral disc structures. The objectives of this study were: 1) to develop a method for measurement of intervertebral disc height, anterior and posterior disc material and dural sac diameter using MRI...

  12. A step towards measuring the fetal head circumference with the use of obstetric ultrasound in a low resource setting

    Science.gov (United States)

    van den Heuvel, Thomas L. A.; Petros, Hezkiel; Santini, Stefano; de Korte, Chris L.; van Ginneken, Bram

    2017-03-01

    Worldwide, 99% of all maternal deaths occur in low-resource countries. Ultrasound imaging can be used to detect maternal risk factors, but requires a well-trained sonographer to obtain the biometric parameters of the fetus. One of the most important biometric parameters is the fetal Head Circumference (HC). The HC can be used to estimate the Gestational Age (GA) and assess the growth of the fetus. In this paper we propose a method to estimate the fetal HC with the use of the Obstetric Sweep Protocol (OSP). With the OSP the abdomen of pregnant women is imaged with the use of sweeps. These sweeps can be taught to somebody without any prior knowledge of ultrasound within a day. Both the OSP and the standard two-dimensional ultrasound image for HC assessment were acquired by an experienced gynecologist from fifty pregnant women in St. Luke's Hospital in Wolisso, Ethiopia. The reference HC from the standard two-dimensional ultrasound image was compared to both the manually measured HC and the automatically measured HC from the OSP data. The median difference between the estimated GA from the manual measured HC using the OSP and the reference standard was -1.1 days (Median Absolute Deviation (MAD) 7.7 days). The median difference between the estimated GA from the automatically measured HC using the OSP and the reference standard was -6.2 days (MAD 8.6 days). Therefore, it can be concluded that it is possible to estimate the fetal GA with simple obstetric sweeps with a deviation of only one week.

  13. Predicting outcome in very low birthweight infants using an objective measure of illness severity and cranial ultrasound scanning

    OpenAIRE

    Fowlie, P; Tarnow-Mordi, W; Gould, C.; Strang, D

    1998-01-01

    AIM—To investigate the feasibility of developing an objective tool for predicting death and severe disability using routinely available data, including an objective measure of illness severity, in very low birthweight babies.
METHOD—A cohort study of 297 premature babies surviving the first three days of life was made. Predictive variables considered included birthweight, gestation, 3 day cranial ultrasound appearances and 3 day CRIB (clinical risk index for babies) score. ...

  14. Development of a method for quantitative measures of lumbar intervertebral disc structures

    DEFF Research Database (Denmark)

    Tunset, Andreas; Kjær, Per; Chreiteh, Shadi Samir

    2013-01-01

    applicable description of quantitative methods for measuring lumbar disc herniations and related structures on sagittal MRIs. The objectives of this study were: 1) to develop methods for quantitative measures of intervertebral discs, lumbar disc herniations and dural sac/spinal canal using MRIs, 2......) to evaluate the agreement of these methods, and 3) to identify factors in the measurement procedures that may compromise agreement. Methods: In this intra- and inter-rater agreement study, lumbar quantitative measurements were performed on magnetic resonance images from 32 participants from a study cohort...... representative of the Danish general population. A new method for quantitative measures of intervertebral discs and related structures was developed and systematically described. MRI-images were measured twice by one rater for intra-rater agreement and once by a second rater for inter-rater agreement. Length...

  15. Development of a method for quantitative measures of lumbar intervertebral disc structures

    DEFF Research Database (Denmark)

    Tunset, Andreas; Kjær, Per; Chreiteh, Shadi Samir;

    2013-01-01

    applicable description of quantitative methods for measuring lumbar disc herniations and related structures on sagittal MRIs. The objectives of this study were: 1) to develop methods for quantitative measures of intervertebral discs, lumbar disc herniations and dural sac/spinal canal using MRIs, 2......) to evaluate the agreement of these methods, and 3) to identify factors in the measurement procedures that may compromise agreement. Methods: In this intra- and inter-rater agreement study, lumbar quantitative measurements were performed on magnetic resonance images from 32 participants from a study cohort...... representative of the Danish general population. A new method for quantitative measures of intervertebral discs and related structures was developed and systematically described. MRI-images were measured twice by one rater for intra-rater agreement and once by a second rater for inter-rater agreement. Length...

  16. Disordered Speech Assessment Using Automatic Methods Based on Quantitative Measures

    Directory of Open Access Journals (Sweden)

    Christine Sapienza

    2005-06-01

    Full Text Available Speech quality assessment methods are necessary for evaluating and documenting treatment outcomes of patients suffering from degraded speech due to Parkinson's disease, stroke, or other disease processes. Subjective methods of speech quality assessment are more accurate and more robust than objective methods but are time-consuming and costly. We propose a novel objective measure of speech quality assessment that builds on traditional speech processing techniques such as dynamic time warping (DTW and the Itakura-Saito (IS distortion measure. Initial results show that our objective measure correlates well with the more expensive subjective methods.

  17. Quantitative measurement of holographic image quality using Adobe Photoshop

    Science.gov (United States)

    Wesly, E.

    2013-02-01

    Measurement of the characteristics of image holograms in regards to diffraction efficiency and signal to noise ratio are demonstrated, using readily available digital cameras and image editing software. Illustrations and case studies, using currently available holographic recording materials, are presented.

  18. A Quantitative Approach for Measuring Technological Forecasting Capability

    OpenAIRE

    Ayhan, Mustafa Batuhan; Oztemel, Ercan

    2013-01-01

    Successful technological forecasting is important to invest scarce funds to emerging technologies. A generic model to measure the success of forecasting overall technological changes is introduced in this paper, called degree of Technological Forecasting Capability. It measures the success rate of forecasts in manufacturing processes based on four important aspects of a manufacturing system; Flow Time, Quantity/Day, Scrap Ratio, and New Investment Revenue. The proposed approach has been verif...

  19. Quantitating error in blood flow measurements with radioactive microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Austin, R.E. Jr.; Hauck, W.W.; Aldea, G.S.; Flynn, A.E.; Coggins, D.L.; Hoffman, J.I.

    1989-07-01

    Accurate determination of the reproducibility of measurements using the microsphere technique is important in assessing differences in blood flow to different organs or regions within organs, as well as changes in perfusion under various experimental conditions. The sources of error of the technique are briefly reviewed. In addition, we derived a method for combining quantifiable sources of error into a single estimate that was evaluated experimentally by simultaneously injecting eight or nine sets of microspheres (each with a different radionuclide label) into four anesthetized dogs. Each nuclide was used to calculate blood flow in 145-190 myocardial regions. We compared each flow determination (using a single nuclide label) with a weighted mean for the piece (based on the remaining nuclides). The difference was defined as ''measured'' error. In all, there were a total of 5,975 flow observations. We compared measured error with theoretical estimates based on the Poisson error of radioactive disintegration and microsphere entrapment, nuclide separation error, and reference flow error. We found that combined estimates based on these sources completely accounted for measured error in the relative distribution of microspheres. In addition, our estimates of the error in measuring absolute flows (which were established using microsphere reference samples) slightly, but significantly, underestimated measured error in absolute flow.

  20. Quantitative assessment of cancer vascular architecture by skeletonization of high-resolution 3-D contrast-enhanced ultrasound images: role of liposomes and microbubbles.

    Science.gov (United States)

    Molinari, F; Meiburger, K M; Giustetto, P; Rizzitelli, S; Boffa, C; Castano, M; Terreno, E

    2014-12-01

    The accurate characterization and description of the vascular network of a cancer lesion is of paramount importance in clinical practice and cancer research in order to improve diagnostic accuracy or to assess the effectiveness of a treatment. The aim of this study was to show the effectiveness of liposomes as an ultrasound contrast agent to describe the 3-D vascular architecture of a tumor. Eight C57BL/6 mice grafted with syngeneic B16-F10 murine melanoma cells were injected with a bolus of 1,2-Distearoyl-sn-glycero-3-phosphocoline (DSPC)-based non-targeted liposomes and with a bolus of microbubbles. 3-D contrast-enhanced images of the tumor lesions were acquired in three conditions: pre-contrast, after the injection of microbubbles, and after the injection of liposomes. By using a previously developed reconstruction and characterization image processing technique, we obtained the 3-D representation of the vascular architecture in these three conditions. Six descriptive parameters of these networks were also computed: the number of vascular trees (NT), the vascular density (VD), the number of branches, the 2-D curvature measure, the number of vascular flexes of the vessels, and the 3-D curvature. Results showed that all the vascular descriptors obtained by liposome-based images were statistically equal to those obtained by using microbubbles, except the VD which was found to be lower for liposome images. All the six descriptors computed in pre-contrast conditions had values that were statistically lower than those computed in presence of contrast, both for liposomes and microbubbles. Liposomes have already been used in cancer therapy for the selective ultrasound-mediated delivery of drugs. This work demonstrated their effectiveness also as vascular diagnostic contrast agents, therefore proving that liposomes can be used as efficient "theranostic" (i.e. therapeutic 1 diagnostic) ultrasound probes.

  1. Measuring of Gastric Emptying in Egyptian Pediatric Patients with Portal Hypertension by Using Real-time Ultrasound

    Science.gov (United States)

    Fahmy, Mona E.; Osman, Mahmoud A.; Mahmoud, Rehab A.; Mohamed, Lamiaa K.; Seif-elnasr, Khaled I.; Eskander, Ayman E.

    2012-01-01

    Background/Aim: Among the various methods for evaluating gastric emptying, the real-time ultrasound is safe, does not require intubation, or rely on either radiologic or radionuclide technique. The aim of our work was to measure the gastric emptying in pediatric patients with portal hypertension by using the real-time ultrasound. Patients and Methods: Forty patients with portal hypertension with mean age 7 ± 2.8 years and 20 healthy children as a control group underwent gastric emptying study by using real-time ultrasound. The cross-sectional area of the gastric antrum was measured in the fasting state and then each subject was allowed to drink tap water then calculated by using formula area (π longitudinal × anteroposterior diameter/4). The intragastric volume was assumed to be directly proportional to the cross-sectional area of the antrum. Results: The mean gastric emptying half-time volume was significantly delayed in portal hypertension patients (40 ± 6.8 min) compared with the control subjects (27.1 ± 3.6) min (P<0.05). Patients with extrahepatic portal vein obstruction had significant delayed gastric emptying in comparison to patients with portal hypertension due to other etiologies (36.14 ± 4.9 vs 44.41 ± 6.04 min; P<0.01). Conclusion: Ultrasound is a noninvasive and a reliable method for measuring gastric emptying in pediatric patients. Gastric emptying was significantly delayed in patients with portal hypertension. Etiology of portal hypertension may influence gastric emptying time in patients with chronic liver disease. PMID:22249091

  2. Quantitative assessment of impedance tomography for temperature measurements in hyperthermia.

    Science.gov (United States)

    Blad, B; Persson, B; Lindström, K

    1992-01-01

    The objective of this study is a non-invasive assessment of the thermal dose in hyperthermia. Electrical impedance tomography (EIT) has previously been given a first trial as a temperature monitoring method together with microwave-induced hyperthermia treatment, but it has not been thoroughly investigated. In the present work we have examined this method in order to investigate the correlation in vitro between the true spatial temperature distribution and the corresponding measured relative resistivity changes. Different hyperthermia techniques, such as interstitial water tubings, microwave-induced, laser-induced and ferromagnetic seeds have been used. The results show that it is possible to find a correlation between the measured temperature values and the tomographically measured relative resistivity changes in tissue-equivalent phantoms. But the uncertainty of the temperature coefficients, which has been observed, shows that the method has to be improved before it can be applied to clinical in vivo applications.

  3. Quantitative measurement of metal chelation by fourier transform infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Monika E. Miller

    2015-12-01

    Full Text Available Nutritionally important minerals are more readily absorbed by living systems when complexed with organic acids, resulting in higher consumer demand and premium prices for these products. These chelated metals are produced by reaction of metal oxides and acids in aqueous solution. However, unreacted dry blends are sometimes misrepresented as metal chelates, when in reality they are only simple mixtures of the reactants typically used to synthesize them. This practice has increased interest in developing analytical methods that are capable of measuring the extent of metal chelation for quality control and regulatory compliance. We describe a novel method to rapidly measure the percent chelation of citric and malic acids with calcium, magnesium, and zinc. Utilization of attenuated total reflectance (FTIR-ATR provides for the direct, rapid measurement of solid samples. The inclusion of an internal standard allows independent determination of either free or chelated acids from integrated areas in a single spectrum.

  4. Challenge in Enhancing the Teaching and Learning of Variable Measurements in Quantitative Research

    Science.gov (United States)

    Kee, Chang Peng; Osman, Kamisah; Ahmad, Fauziah

    2013-01-01

    Statistical analysis is one component that cannot be avoided in a quantitative research. Initial observations noted that students in higher education institution faced difficulty analysing quantitative data which were attributed to the confusions of various variable measurements. This paper aims to compare the outcomes of two approaches applied in…

  5. Initial Description of a Quantitative, Cross-Species (Chimpanzee-Human) Social Responsiveness Measure

    Science.gov (United States)

    Marrus, Natasha; Faughn, Carley; Shuman, Jeremy; Petersen, Steve E.; Constantino, John N.; Povinelli, Daniel J.; Pruett, John R., Jr.

    2011-01-01

    Objective: Comparative studies of social responsiveness, an ability that is impaired in autism spectrum disorders, can inform our understanding of both autism and the cognitive architecture of social behavior. Because there is no existing quantitative measure of social responsiveness in chimpanzees, we generated a quantitative, cross-species…

  6. Comparison of the POP-Q examination, transvaginal ultrasound, and direct anatomic measurement of cervical length.

    Science.gov (United States)

    Dancz, Christina E; Werth, Lisa; Sun, Vanessa; Lee, Sandy; Walker, Daphne; Özel, Begüm

    2014-04-01

    Our objective was to determine the relationship between the Pelvic Organ Prolapse Quantification (POP-Q) examination for determining cervical length (CL) and CL at hysterectomy. Secondary objectives were to define cervical elongation using both measures in a urogynecologic population, determine the relationship between POP-Q estimate and CL on ultrasound (US) and examine the interobserver reliability of each mode of measurement. This was a prospective cohort study of women scheduled for hysterectomy at the Los Angeles County + University of Southern California (LAC + USC) medical center. CLs were measured by POP-Q and at the time of hysterectomy. Transvaginal US CLs were determined when available. Exam CL (eCL) was compared with anatomic (aCL) and US (uCL) CL. Repeat measures of eCL, uCL, and aCL were all compared for interobserver reliability. The study enrolled 151 women. Median eCL was 3.0 cm (0.5-9.0) (n = 149); average uCL was 2.3 cm ± 0.7 (n = 108), average aCL 2.8 cm ± 1.1 (n = 87); eCL correlated fairly with aCL (r = 0.3, p = 0.005, n = 88) but poorly with uCL (r = -0.13, p = 0.18, n = 105); uCL correlated poorly with aCL (r = 0.19, p = 0.14, n = 64). Interobserver reliability for eCL and aCL were good to excellent (eCL α=0.881; aCL α=0.889) but for uCL adequate (α=0.699). The 97.5 percentile cutoff for aCL was 5.0 cm and for eCL 8.0 cm. The POP-Q examination estimate of CL correlates fairly with aCL at the time of hysterectomy; uCL does not appear to correlate with aCL or eCL. Cervical elongation may be defined as an anatomic length of 5.0 cm or a POP-Q estimate of 8.0 cm.

  7. A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force.

    Science.gov (United States)

    Yoon, Sangpil; Aglyamov, Salavat; Karpiouk, Andrei; Emelianov, Stanislav

    2012-08-07

    A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young's moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young's moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed.

  8. Measurements in quantitative research: how to select and report on research instruments.

    Science.gov (United States)

    Hagan, Teresa L

    2014-07-01

    Measures exist to numerically represent degrees of attributes. Quantitative research is based on measurement and is conducted in a systematic, controlled manner. These measures enable researchers to perform statistical tests, analyze differences between groups, and determine the effectiveness of treatments. If something is not measurable, it cannot be tested.

  9. The investigation of ultrasound technology to measure breast muscle depth as a correlated trait to breast meat yield in turkey (Meleagris gallopavo).

    Science.gov (United States)

    Case, L A; Wood, B J; Miller, S P

    2012-10-01

    Ultrasound measurements of muscle depth were analyzed to determine if these traits could be used to increase the rate of genetic gain in breast meat yield (BMY). Two measurements of breast depth, one taken horizontally across both breast lobes and one parallel to the keel, were captured using ultrasound. Heritabilities of muscle depth traits ranged from 0.35 to 0.70. These values were greater than heritabilities of conformation scores, which ranged from 0.25 to 0.47 within sex and line. The ultrasound traits also showed strong genetic correlations to BMY, ranging from 0.43 to 0.75, indicating that selection, using ultrasound depth as a correlated information source, could result in improved BMY. Including each ultrasound trait in a linear regression model predicting BMY increased the proportion of variation explained by the models by 0.08 to 0.17, relative to using conformation score as the only in vivo estimate. Based on results from a simulated turkey breeding program with selection pressure only on BMY, the ultrasound measures could increase the accuracy of a selection index for BMY by 0.02 to 0.16. As a result, ultrasound technology has the potential to improve the rate of genetic gain in BMY in a breeding program.

  10. The thickness of the retrobulbar portion of the optic nerve in Graves ophthalmopathy measured by ultrasound

    Directory of Open Access Journals (Sweden)

    Stefanović Ivan

    2009-01-01

    Full Text Available Introduction. The clinical diagnostic of Graves ophthalmopathy is based on the association of ocular signs and the disease of the thyroid gland. The evolution of the disease involves the development of eye globe protrusion, extraocular muscle thickening pressuring the optic nerve, which can result in its thickness. Objective. The aim of the paper is to find whether the retrobulbar optic nerve thickened and if there was a correlation between its possible thickening and the thickness of the muscles in Graves ophthalmopathy. We also wished to test the theory of compressive aetiology of such thickening using a 30-degree test. Methods. We examined 28 patients with Graves ophthalmopathy. The thickness of the retrobulbar optic nerve was measured by ultrasound on a B-scan using the Schraeder's method and by the largest thickness of the internal muscle. Results. The thickness of the retrobulbar portion of the optic nerve in the 52 analyzed eyes with signs of the disease ranged between 3.24 mm to 6.30 mm, with median of 5.13 mm, indicating that the majority of the patients had optic nerve thickening rating at this value. Forty-eight eyes had a marked retrobulbar optic nerve thickening, with the thickening over 4 mm, while in 4 eyes with signs of Graves ophthalmopathy the thickness of the optic nerve was within normal limits. We detected that 92.3% of the patients with muscular thickening also had a directly proportional thickening of the retrobulbar optic nerve. By using the 30-degree test we confirmed the diagnosis of compressive neuropathy. Conclusion. Patients with Graves ophthalmopathy and thickened muscles, also have a thickening of the retrobulbar optic nerve; the rate of the thickness directly depends on the degree of the muscular thickness. The word is of compressive neuropathy, i.e. the thickness of the optic nerve is the result of subarachnoid fluid stasis caused by the compression on the optic nerve.

  11. Cultural Values Predicting Acculturation Orientations: Operationalizing a Quantitative Measure

    Science.gov (United States)

    Ehala, Martin

    2012-01-01

    This article proposes that acculturation orientations are related to two sets of cultural values: utilitarianism (Ut) and traditionalism (Tr). While utilitarian values enhance assimilation, traditional values support language and identity maintenance. It is proposed that the propensity to either end of this value opposition can be measured by an…

  12. Cultural Values Predicting Acculturation Orientations: Operationalizing a Quantitative Measure

    Science.gov (United States)

    Ehala, Martin

    2012-01-01

    This article proposes that acculturation orientations are related to two sets of cultural values: utilitarianism (Ut) and traditionalism (Tr). While utilitarian values enhance assimilation, traditional values support language and identity maintenance. It is proposed that the propensity to either end of this value opposition can be measured by an…

  13. Quantitative Spectral Radiance Measurements in the HYMETS Arc Jet

    Science.gov (United States)

    Danehy, Paul M.; Hires, Drew V.; Johansen, Craig T.; Bathel, Brett F.; Jones, Stephen B.; Gragg, Jeffrey G.; Splinter, Scott C.

    2012-01-01

    Calibrated spectral radiance measurements of gaseous emission spectra have been obtained from the HYMETS (Hypersonic Materials Environmental Test System) 400 kW arc-heated wind tunnel at NASA Langley Research Center. A fiber-optic coupled spectrometer collected natural luminosity from the flow. Spectral radiance measurements are reported between 340 and 1000 nm. Both Silicon Carbide (SiC) and Phenolic Impregnated Carbon Ablator (PICA) samples were placed in the flow. Test gases studied included a mostly-N2 atmosphere (95% nitrogen, 5% argon), a simulated Earth Air atmosphere (75% nitrogen, 20% oxygen, 5% argon) and a simulated Martian atmosphere (71% carbon dioxide, 24% nitrogen, 5% argon). The bulk enthalpy of the flow was varied as was the location of the measurement. For the intermediate flow enthalpy tested (20 MJ/kg), emission from the Mars simulant gas was about 10 times higher than the Air flow and 15 times higher than the mostly-N2 atmosphere. Shock standoff distances were estimated from the spectral radiance measurements. Within-run, run-to-run and day-to-day repeatability of the emission were studied, with significant variations (15-100%) noted.

  14. Quantitative measurement of the orbital angular momentum density of light

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2012-03-01

    Full Text Available In this work we derive expressions for the orbital angular momentum (OAM) density of light, for both symmetric and nonsymmetric optical fields, that allow a direct comparison between theory and experiment. We present a simple method for measuring...

  15. Quantitative approach to measuring the cerebrospinal fluid space with CT

    Energy Technology Data Exchange (ETDEWEB)

    Zeumer, H.; Hacke, W.; Hartwich, P.

    1982-01-01

    A method for measuring the subarachnoid space by using an independent CT evaluation unit is described. The normal values have been calculated for patients, according to age, and three examples are presented demonstrating reversible decrease of brain volume in patients suffering anorexia nervosa and chronic alcoholism.

  16. Conducting Art Therapy Research Using Quantitative EEG Measures

    Science.gov (United States)

    Belkofer, Christopher M.; Konopka, Lukasz M.

    2008-01-01

    This study presents a modified, single subject design that measured the patterns of electrical activity of a participant's brain following an hour spent painting and drawing. Paired t tests were used to compare pre and post art-making electroencephalograph (EEG) data. The results indicated that neurobiological activity after drawing and painting…

  17. Phase transition traced by conductivity measurements: quantitative analysis

    DEFF Research Database (Denmark)

    Keding, Ralf; Ruessel, Christian; Tauch, Diana

    2008-01-01

    to the electrodes, all in a cylindrical geometry. The electrical resistivity of a sample in the system BaAl2B2O7 was measured during cooling between liquidus temperature (T-l) and transformation temperature (T-g) using a fixed frequency of 3.7 Hz. The melt crystallised in this temperature range during cooling...

  18. High frequency measurements of the contact between machine elements using ultrasound

    Science.gov (United States)

    Quinn, A. M.; Drinkwater, B. W.; Dwyer-Joyce, R. S.

    2002-05-01

    This paper describes a study of the experimental interaction of ultrasound with real rough surfaces, and the modeled interaction of ultrasound with an infinite array of holes, using Finite Element Analysis, in an attempt to discover the limit of applicability of the quasi-static spring model. The relationship between reflected amplitude of the scattered wave, and the size of the hole acting as reflector, was found and used to create a finite element independent scatter model. This was compared to the quasi-static model and it was found that the two models diverge at a ka value of approximately 0.6.

  19. Quantitative Doppler measures in coiled vessels: investigation on excised umbilical veins.

    Science.gov (United States)

    Guiot, C; Roatta, S; Piccoli, E; Saccomandi, F; Todros, T

    1999-11-01

    Quantitative assessment of umbilical venous blood velocity with Doppler ultrasound (US) must cope with the coiled structure of the vein inside the cord. Both an experimental and a theoretical approach showed remarkable variations in the insonation angle when the probe was moved along the vein, provided the inclination between the Doppler probe and the cord was kept constant. Inaccurate signal processing, stochastic variability and flow disturbances could, however, mask the influence of the geometry. The above hypotheses were assessed by investigating five cords in vitro a few hours after delivery from normal pregnancies at term. The Doppler signal was sampled at different sites along each cord and the mean Doppler shift estimated by FFT spectral analysis, both directly and through the noise rejection D'Alessio's algorithm, which proved effective in improving the Doppler shift estimate in condition of low signal-to-noise ratio (SNR).

  20. Measurement of the external parameters in quantitative active thermography

    Science.gov (United States)

    Olmi, R.; Inglese, G.

    2017-10-01

    Infrared thermography is widely used in non-destructive testing and in the non-destructive evaluation of subsurface defects in several materials. The detection and reconstruction (location and shape) of a defect inside a material from thermal data requires the solution of an inverse heat conduction problem. Here the problem is tackled by the thin-plate approximation of the investigated domain. A number of physical quantities must be known for the reconstruction procedure to be successful: some relating to the material (thermal conductivity, heat capacity, density), usually known, and others relating to the heating process. This paper proposes procedures for accurately measuring the latter, whose importance is often not given due consideration. Those procedures allow us to accurately measure the heat flux distribution produced by the sources on the heated surface, and the heat exchange coefficient at the remaining surfaces, and are easily applicable in ‘on field’ situations.

  1. OPPORTUNISTIC ASPERGILLUS PATHOGENS MEASURED IN HOME AND HOSPITAL TAP WATER BY MOLD SPECIFIC QUANTITATIVE PCR (MSQPCR)

    Science.gov (United States)

    Opportunistic fungal pathogens are a concern because of the increasing number of immunocompromised patients. The goal of this research was to test a simple extraction method and rapid quantitative PCR (QPCR) measurement of the occurrence of potential pathogens, Aspergillus fumiga...

  2. Reproducibility of 3-Dimensional Ultrasound Measurements of Placental Volume at Gestational Ages 11 - 14 Weeks

    DEFF Research Database (Denmark)

    Larsen, M L; Naver, K V; Kjaer, M M;

    2015-01-01

    OBJECTIVE: To evaluate the reproducibility of placental volume using three-dimensional ultrasound. METHODS: The VOCAL (Virtual Organ Computer-aided AnaLysis) technique involves rotating an image of an object along an established axis using predefined angles. This provides a number of sections to ...

  3. Reproducibility of 3-Dimensional Ultrasound Measurements of Placental Volume at Gestational Ages 11 - 14 Weeks

    DEFF Research Database (Denmark)

    Larsen, M L; Naver, K V; Kjaer, M M

    2015-01-01

    OBJECTIVE: To evaluate the reproducibility of placental volume using three-dimensional ultrasound. METHODS: The VOCAL (Virtual Organ Computer-aided AnaLysis) technique involves rotating an image of an object along an established axis using predefined angles. This provides a number of sections to ...

  4. Visualizing and Measuring the Temperature Field Produced by Medical Diagnostic Ultrasound Using Thermography

    Science.gov (United States)

    Vachutka, J.; Grec, P.; Mornstein, V.; Caruana, C. J.

    2008-01-01

    The heating of tissues by diagnostic ultrasound can pose a significant hazard particularly in the imaging of the unborn child. The demonstration of the temperature field in tissue is therefore an important objective in the teaching of biomedical physics to healthcare professionals. The temperature field in a soft tissue model was made visible and…

  5. First measurements on a novel type of optical micro-machined ultrasound transducer (OMUT)

    NARCIS (Netherlands)

    Leinders, S.M.; Dongen, K.W.A. van; Jong, N. de; Verweij, M.D.; Westerveld, W.J.; Urbach, H.P.; Neer, P.L.M.J. van; Pozo Torres, J.M.

    2014-01-01

    Several types of ultrasound sensors have been developed and are used in the field of medical imaging. Conventional transducers are made of piezo-electric material and show good practical performance. However, when the piezo-electric elements need to be small (below 100 μm × 100 μm), these transducer

  6. First measurements on a novel type of optical micro-machined ultrasound transducer (OMUT)

    NARCIS (Netherlands)

    Leinders, S.M.; Dongen, K.W.A. van; Jong, N. de; Verweij, M.D.; Westerveld, W.J.; Urbach, H.P.; Neer, P.L.M.J. van; Pozo Torres, J.M.

    2014-01-01

    Several types of ultrasound sensors have been developed and are used in the field of medical imaging. Conventional transducers are made of piezo-electric material and show good practical performance. However, when the piezo-electric elements need to be small (below 100 μm × 100 μm), these transducer

  7. The quantitative measurement of consciousness during epileptic seizures.

    Science.gov (United States)

    Nani, Andrea; Cavanna, Andrea E

    2014-01-01

    The assessment of consciousness is a fundamental element in the classification of epileptic seizures. It is, therefore, of great importance for clinical practice to develop instruments that enable an accurate and reliable measurement of the alteration of consciousness during seizures. Over the last few years, three psychometric scales have been specifically proposed to measure ictal consciousness: the Ictal Consciousness Inventory (ICI), the Consciousness Seizure Scale (CSS), and the Responsiveness in Epilepsy Scale--versions I and II (RES-I and RES-II). The ICI is a self-report psychometric instrument which retrospectively assesses ictal consciousness along the dimensions of the level/arousal and contents/awareness. The CSS has been used by clinicians to quantify the impairment of consciousness in order to establish correlations with the brain mechanisms underlying alterations of consciousness during temporal lobe seizures. The most recently developed observer-rated instrument is the RES-I, which has been used to assess responsiveness during epileptic seizures in patients undergoing video-EEG. The implementation of standardized psychometric tools for the assessment of ictal consciousness can complement clinical observations and contribute to improve accuracy in seizure classification.

  8. Laboratory technique for quantitative thermal emissivity measurements of geological samples

    Indian Academy of Sciences (India)

    George Mathew; Archana Nair; T K Gundu Rao; Kanchan Pande

    2009-08-01

    Thermal infrared spectroscopy is a powerful technique for the compositional analysis of geological materials. The spectral feature in the mid-IR region is diagnostic of the mineralogy and spectral signatures of mixtures of minerals that add linearly, and therefore, can be used as an important tool to determine the mineralogy of rocks in the laboratory and remotely for planetary exploration. The greatest challenge in the emission measurement lies in the measurement of the weak thermal photons emitted from geological materials in a laboratory setup, and accurately records the temperature of the rock sample. The present work pertains to the details of a new Thermal Emission Spectrometer (TES) laboratory that has been developed under the ISRO Planetary Science and Exploration (PLANEX) programme, for emission related mineralogical investigations of planetary surfaces. The focus of the paper is on the acquisition and calibration technique for obtaining emissivity, and the deconvolution procedure to obtain the modal abundances of the thermal emission spectra in the range of 6–25 m using Fourier Transform Infrared (FTIR) spectroscopy. The basic technique is adopted from the work of Ruff et al (1997). This laboratory at the Department of Earth Sciences, IIT-Bombay is currently developing pure end mineral library of mineral particulates (> 65 m), and adding new end members to the existing ASU spectral library. The paper argues the need for considering Lunar Orbiter Thermal Emission Spectrometer (LOTES) for future Indian Moon mission programme (Chandrayan-II) to determine evidences of varied lithologies on the lunar surface.

  9. Quantitative Measurements of CME-driven Shocks from LASCO Observations

    CERN Document Server

    Ontiveros, Veronica

    2008-01-01

    In this paper, we demonstrate that CME-driven shocks can be detected in white light coronagraph images and in which properties such as the density compression ratio and shock direction can be measured. Also, their propagation direction can be deduced via simple modeling. We focused on CMEs during the ascending phase of solar cycle 23 when the large-scale morphology of the corona was simple. We selected events which were good candidates to drive a shock due to their high speeds (V>1500 km/s). The final list includes 15 CMEs. For each event, we calibrated the LASCO data, constructed excess mass images and searched for indications of faint and relatively sharp fronts ahead of the bright CME front. We found such signatures in 86% (13/15) of the events and measured the upstream/downstream densities to estimate the shock strength. Our values are in agreement with theoretical expectations and show good correlations with the CME kinetic energy and momentum. Finally, we used a simple forward modeling technique to esti...

  10. Doppler Ultrasound: What Is It Used for?

    Science.gov (United States)

    ... in your neck (carotid artery stenosis) A Doppler ultrasound can estimate how fast blood flows by measuring the rate of change in its pitch (frequency). During a Doppler ultrasound, a technician trained in ultrasound imaging (sonographer) presses ...

  11. Quantitative CT measures of emphysema and airway wall thickness are related to D(L)CO

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Thorsen, Einar; Dirksen, Asger

    2011-01-01

    There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness.......There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness....

  12. Quantitative CT measures of emphysema and airway wall thickness are related to D(L)CO

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Thorsen, Einar; Dirksen, Asger;

    2011-01-01

    There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness.......There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness....

  13. Influence of coupling substances in the measurement of ultrasound velocity in stone materials

    Science.gov (United States)

    Giuzio, Beatrice; Alvarez de Buergo, Monica; Fort, Rafael; Masini, Nicola

    2015-04-01

    Ultrasonic (US) testing is widely applied in many fields (i.e. aviation, petrochemical, power engineering, construction and metallurgical industries). In the field of built cultural heritage and science conservation, US testing can provide the quality of the historic building materials (physic-mechanical properties), their heterogeneity/homogeinity and anisotropy, in terms of materials characterization, but also how deterioration processes can affect their quality (either after natural decay or simulation ageing tests in the laboratory). Moreover, US testing is a useful technique in evaluating the effectiveness of conservation and restoration techniques such as assessing the compatibility among original and restoration materials, identification of original quarries, and the success or not in the increase of a material cohesion when applying consolidating products. In order to obtain precise, real and reliable measurements, coupling substances between the material surface and the ultrasonic sensors are frequently used, to provide a proper contact between the transducer and the material, to assure the perfect transmission of the ultrasonic wave. Various coupling agents can be applied for this purpose. According to Wesolowski (2012), the choice of the coupling agent significantly affects the measurement of propagation velocity in material samples and, as a consequence, the US test results. In this paper, the effect of six coupling agents (medical gel used for ultrasonography, gel + parafilm, plasticine, honey, glicerine and a plastic material provided for ultrasound measurement by Panametrics) on ultrasonic measurements conducted on specific building materials is investigated on two different types of building stones (granite and dolostone from the area of Madrid, traditionally used in the construction of the built heritage, 4 stone specimens for each rock variety, 20 x 6 x 8 cm). Direct and indirect modes measuring were performed, the first one with the transducers

  14. Bovine serum albumin detection and quantitation based on capacitance measurements of liquid crystals

    Science.gov (United States)

    Lin, Chi-Hao; Lee, Mon-Juan; Lee, Wei

    2016-08-01

    Liquid crystal (LC)-based biosensing is generally limited by the lack of accurate quantitative strategies. This study exploits the unique electric capacitance properties of LCs to establish quantitative assay methods for bovine serum albumin (BSA) biomolecules. By measuring the voltage-dependent electric capacitance of LCs under an alternating-current field with increasing amplitude, positive correlations were derived between the BSA concentration and the electric capacitance parameters of LCs. This study demonstrates that quantitative analysis can be achieved in LC-based biosensing through electric capacitance measurements extensively employed in LCD research and development.

  15. Laser-induced incandescence: Towards quantitative soot volume fraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tzannis, A.P.; Wienbeucker, F.; Beaud, P.; Frey, H.-M.; Gerber, T.; Mischler, B.; Radi, P.P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Laser-Induced Incandescence has recently emerged as a versatile tool for measuring soot volume fraction in a wide range of combustion systems. In this work we investigate the essential features of the method. LII is based on the acquisition of the incandescence of soot when heated through a high power laser pulse. Initial experiments have been performed on a model laboratory flame. The behaviour of the LII signal is studied experimentally. By applying numerical calculations we investigate the possibility to obtain two-dimensional soot volume fraction distributions. For this purpose a combination of LII with other techniques is required. This part is discussed in some extent and the future work is outlined. (author) 4 figs., 3 refs.

  16. A quantitative measurement of spatial order in ventricular fibrillation

    CERN Document Server

    Bayly, P V; Wolf, P D; Greenside, H S; Smith, W M; Ideker, R E

    1993-01-01

    As an objective measurement of spatial order in ventricular fibrillation (VF), spatial correlation functions and their characteristic lengths were estimated from epicardial electrograms of pigs in VF. The correlation length of the VF in pigs was found to be approximately 4-10 mm, varying as fibrillation progressed. The degree of correlation decreased in the first 4 seconds after fibrillation then increased over the next minute. The correlation length is much smaller than the scale of the heart, suggesting that many independent regions of activity exist on the epicardium at any one time. On the other hand, the correlation length is 4 to 10 times the interelectrode spacing, indicating that some coherence is present. These results imply that the heart behaves during VF as a high-dimensional, but not random, system involving many spatial degrees of freedom, which may explain the lack of convergence of fractal dimension estimates reported in the literature. Changes in the correlation length also suggest that VF re...

  17. Teaching to the Test: A Controversial Issue in Quantitative Measurement

    Directory of Open Access Journals (Sweden)

    Jennifer L. Styron

    2012-10-01

    Full Text Available discussion of the pros and cons of focusing curricular and pedagogical decisions primarily on mastery of those skills and concepts measured by standardized tests. This paper presents scholarly discourse based on testing systems and school accountability, along with a presentation of the advantages and disadvantages of what is commonly referred to as 'teaching to the test.' The authors of this document found research studies to be inconclusive with no clear indication of whether or not there is an advantage or disadvantage to the practice of teaching to the test. But most notably, the actual issue connected to this debate may be the lack of understanding of item-teaching and curricular teaching. In the mind of many educators, item teaching, curriculum teaching and teaching to the test are synonymous.

  18. Measurement of Cervical Length Changes During Normal Pregnancy by Endovaginal Ultrasound Device

    Directory of Open Access Journals (Sweden)

    Morteza Tahmasebi

    2009-01-01

    Full Text Available "nIntroduction: Cervical disability for preservation of pregnancy is called cervical insufficiency. On time diagnosis of cervical insufficiency is important for preventing actions. Endovaginal sonography is one of the most important methods. The importance of cervical length measurement is to diagnose cervical insufficiency and to decide on cerclage. In this study, we evaluated endovaginal sonography assessment of the cervical length changes during a normal pregnancy. "nMaterials and Methods: In a prospective cross-sectional study, endovaginal sonography was performed to measure the cervical length and the mean of the cervical lengths on 150 pregnant women (50 in every trimester. They were  compared together by the one way Anova test. The patients were followed until labor. Twin pregnancies and cases with a history of uterus curettage, cervical anomaly, preterm labor and cerclage were eliminated from the study. "nResults: The mean of the cervical length in the first, second and third trimesters of pregnancy were 39 mm, 40.7mm and 39.3mm, respectively. Also, the minimum and the maximum length of the cervix in the same trimesters were: 28 and 56 mm, 26 and 52 mm, 27 and 52mm, respectively. It was noted to history of normal vaginal delivery (NVD, past cesarean and the first pregnancy. The minimum cervical length was seen in the first pregnancy and the maximum cervical length was seen in past NVD. Between the means of cervical length in three trimesters of pregnancy there was no significant statistical difference, but there was a significant statistical difference between the mean cervical length and the maternal parity. On the other hand between maternal age and cervical length there was no significant statistical difference. "nConclusion: By comparing the mean cervical length in three trimesters, 39 mm was accepted for mean cervical length in different trimesters. There was a significant statistical correlation between the mean cervical lengths

  19. Quantitative measurements of active Ionian volcanoes in Galileo NIMS data

    Science.gov (United States)

    Saballett, Sebastian; Rathbun, Julie A.; Lopes, Rosaly M. C.; Spencer, John R.

    2016-10-01

    Io is the most volcanically active body in our solar system. The spatial distribution of volcanoes a planetary body's surface gives clues into its basic inner workings (i.e., plate tectonics on earth). Tidal heating is the major contributor to active surface geology in the outer solar system, and yet its mechanism is not completely understood. Io's volcanoes are the clearest signature of tidal heating and measurements of the total heat output and how it varies in space and time are useful constraints on tidal heating. Hamilton et al. (2013) showed through a nearest neighbor analysis that Io's hotspots are globally random, but regionally uniform near the equator. Lopes-Gautier et al. (1999) compared the locations of hotspots detected by NIMS to the spatial variation of heat flow predicted by two end-member tidal heating models. They found that the distribution of hotspots is more consistent with tidal heating occurring in asthenosphere rather than the mantle. Hamilton et al. (2013) demonstrate that clustering of hotspots also supports a dominant role for asthenosphere heating. These studies were unable to account for the relative brightness of the hotspots. Furthermore, studies of the temporal variability of Ionian volcanoes have yielded substantial insight into their nature. The Galileo Near Infrared Mapping Spectrometer (NIMS) gave us a large dataset from which to observe active volcanic activity. NIMS made well over 100 observations of Io over an approximately 10-year time frame. With wavelengths spanning from 0.7 to 5.2 microns, it is ideally suited to measure blackbody radiation from surfaces with temperatures over 300 K. Here, we report on our effort to determine the activity level of each hotspot observed in the NIMS data. We decide to use 3.5 micron brightness as a proxy for activity level because it will be easy to compare to, and incorporate, ground-based observations. We fit a 1-temperature blackbody to spectra in each grating position and averaged the

  20. Quantitative and qualitative measures of decomposition: Is there a link?

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, Robert, J.; Sanchez, Felipe, G.

    2009-03-01

    Decomposition rates of loblolly pine coarse woody debris (CWD) were determined by mass loss and wood density changes for trees that differed in source of mortality (natural, girdle-poison, and felling). Specifically, three treatments were examined: (1) control (CON): natural mortality; (2) CD: 5-fold increase in CWD compared with the CON; and (3) CS: 12-fold increase in snags compared with the CON. The additional CWD in the CD treatment plots and the additional snags in the CS plots were achieved by felling (for the CD plots) or girdling followed by herbicide injection (for the CS plots) select trees in these plots. Consequently,mortality on the CD plots is due to natural causes and felling. Likewise, mortality on the CS plots is due to natural causes and girdle-poison. In each treatment plot, mortality due to natural causes was inventoried since 1997, whereas mortality due to girdle-poison and felling were inventoried since 2001. No significant difference was detected between the rates of decomposition for the CWD on these treatment plots, indicating that source of the tree mortality did not influence rates of decomposition once the tree fell. These experimental measures of decomposition were compared with two decay classification systems (three- and five-unit classifications) to determine linkages. Changes in wood density did not correlate to any decay classification, whereas mass loss had a weak correlation with decay class. However, the large degree of variation limits the utility of decay classification systems in estimating mass loss.

  1. Qualitative and quantitative measurement of the singing voice.

    Science.gov (United States)

    Cesari, U; Iengo, M; Apisa, P

    2012-01-01

    The aim of the study was to clarify the mechanisms underlying the singing voice. Forty-eight professional opera singers underwent flexible and rigid endoscopy, spectrographic analysis and perceptual evaluation. The data provided by voice analysis were not as clear and relevant to the aim of our study as those commonly obtained for speech evaluation. Laryngoscopy with rigid and flexible fiber optics and the singing power ratio (SPR) measurement provided more applicable data. Indeed, the former allowed us to assess laryngeal position, the glottic pattern and vocal tract modifications during the actual singing performance. The latter, already recommended by other authors as a reliable vocal emission index, also yielded more relevant information in comparison with the assessment of voice quality. Specifically, SPR provided data directly correlated to both the years of singing activity and the vocal category of each singer (the higher the singing pitch, the wider the vocal extension). More importantly, the data fully reflected the subjective assessment of each phoniatrician. We suggest that the SPR indices can be used as the electroacoustic equivalent of the subjective judgment of vocal focus. Copyright © 2013 S. Karger AG, Basel.

  2. Site-specific ultrasound reflection properties and superficial collagen content of bovine knee articular cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Laasanen, Mikko S [Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Kuopio, POB 1777, FIN-70211 Kuopio (Finland); Department of Surgery, Division of Orthopaedics and Traumatology, Jyvaeskylae Central Hospital, Keskussairaalantie 19, FIN-40620 Jyvaeskylae (Finland); Saarakkala, Simo [Department of Nuclear Medicine, Etelae-Savo Hospital District, Mikkeli Central Hospital, Porrassalmenkatu 35-37, 50100 Mikkeli (Finland); Toeyraes, Juha [Department of Clinical Neurophysiology, Kuopio University Hospital and University of Kuopio, POB 1777, FIN-70211 Kuopio (Finland); Rieppo, Jarno [Department of Anatomy, University of Kuopio, POB 1627, FIN-70211 Kuopio (Finland); Jurvelin, Jukka S [Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital and University of Kuopio, POB 1777, FIN-70211 Kuopio (Finland); Department of Applied Physics, University of Kuopio, POB 1627, FIN-70211 Kuopio (Finland)

    2005-07-21

    Previous quantitative 2D-ultrasound imaging studies have demonstrated that the ultrasound reflection measurement of articular cartilage surface sensitively detects degradation of the collagen network, whereas digestion of cartilage proteoglycans has no significant effect on the ultrasound reflection. In this study, the first aim was to characterize the ability of quantitative 2D-ultrasound imaging to detect site-specific differences in ultrasound reflection and backscattering properties of cartilage surface and cartilage-bone interface at visually healthy bovine knee (n = 30). As a second aim, we studied factors controlling ultrasound reflection properties of an intact cartilage surface. The ultrasound reflection coefficient was determined in time (R) and frequency domains (IRC) at medial femoral condyle, lateral patello-femoral groove, medial tibial plateau and patella using a 20 MHz ultrasound imaging instrument. Furthermore, cartilage surface roughness was quantified by calculating the ultrasound roughness index (URI). The superficial collagen content of the cartilage was determined using a FT-IRIS-technique. A significant site-dependent variation was shown in cartilage thickness, ultrasound reflection parameters, URI and superficial collagen content. As compared to R and IRC, URI was a more sensitive parameter in detecting differences between the measurement sites. Ultrasound reflection parameters were not significantly related to superficial collagen content, whereas the correlation between R and URI was high. Ultrasound reflection at the cartilage-bone interface showed insignificant site-dependent variation. The current results suggest that ultrasound reflection from the intact cartilage surface is mainly dependent on the cartilage surface roughness and the collagen content has a less significant role.

  3. Analytical and Biological Variables Influencing Quantitative Hepatitis C Virus (HCV) Measurement in HIV-HCV Coinfection

    OpenAIRE

    Curtis Cooper; Paul MacPherson; William Cameron

    2006-01-01

    The present review considers issues pertaining to the precision and variability of quantitative hepatitis C virus (HCV) measurement in general, outlines the characteristics of HCV RNA in HIV-HCV coinfection and evaluates those factors which may affect this measure. The clinical relevance of accurate HCV measurement in HIV-HCV coinfection is discussed.

  4. Quantitative Measurement of Communication Ability in Children with Angelman Syndrome.

    Science.gov (United States)

    Grieco, Joseph C; Bahr, Ruth H; Schoenberg, Mike R; Conover, Laura; Mackie, Lauren N; Weeber, Edwin J

    2016-12-19

    Angelman syndrome is a rare disorder in which most individuals do not develop speech. Testing of communication ability using traditional neuropsychological measures reveals a performance level at or near the floor of the instrument resulting in an inability to detect change when experimental therapeutics are applied. Nine individuals, with molecularly confirmed AS, ranging in age from 34 to 126 months, and a single healthy control child (age 16 months) were audio and video-recorded while interacting with a licensed speech-language pathologist in an attempt to elicit vocalization and non-verbal communication. Thirty-minute audio recordings were transcribed and categorized per the Stark Assessment of Early Vocal Development-Revised and a phonetic inventory was created. Using video recordings, gestures were classified by function, either behavioral regulation or social interaction and further categorized as deictic or representational (i.e., behavioral regulation) and joint attention or shared engagement (i.e., social interaction). The range of vocalizations produced by the children with AS was characteristic of children between 0-6 months and none of the children with AS used advanced forms of vocalizations. The mean frequency of reflexive vocalizations, control of phonation and expansion far exceeded the number of uses of canonical syllables, consistant with the characteristics of children around 12 months of age. Most vocalizations were either laughter or isolated vowels, only three children with AS produced consonant-vowel combinations. Children with AS tended to use central and low vowels with few producing high vowels, suggesting the presence of childhood apraxia of speech. Our results show the utilization of video-recorded behavioral observations provides a feasible and reliable alternative for quantification of communication ability in this patient population and may be employed during future clinical studies of potential therapeutics. © 2016 The Authors

  5. Precision of Corneal Thickness Measurements Obtained Using the Scheimpflug-Placido Imaging and Agreement with Ultrasound Pachymetry

    Directory of Open Access Journals (Sweden)

    Jinhai Huang

    2015-01-01

    Full Text Available Purpose. To assess the reliability and comparability of measuring central corneal thickness (CCT and thinnest corneal thickness (TCT using a new Scheimpflug-Placido analyzer (TMS-5, Japan and ultrasound (US pachymetry. Methods. Seventy-six healthy subjects were prospectively measured 3 times by 1 operator using the TMS-5, 3 additional consecutive scans were performed by a second operator, and ultrasound (US pachymetry measurements were taken. The test-retest repeatability (TRT, coefficient of variation (CoV, and intraclass correlation coefficient (ICC were calculated to evaluate intraoperator repeatability and interoperator reproducibility. Agreement among the devices was assessed using Bland-Altman plots and 95% limits of agreement (LoA. Results. The intraoperators TRT and CoV were 0.90. The mean CCT and TCT measurements using the TMS-5 were 15.97 μm (95% LoA from −26.42 to −5.52 μm and 20.32 μm (95% LoA from −30.67 to −9.97 μm smaller, respectively, than those using US pachymetry. Conclusions. The TMS-5 shows good repeatability and reproducibility for measuring CCT and TCT in normal subjects but only moderate agreement with US pachymetry results. Caution is warranted before using these techniques interchangeably.

  6. Precision of Corneal Thickness Measurements Obtained Using the Scheimpflug-Placido Imaging and Agreement with Ultrasound Pachymetry

    Science.gov (United States)

    Huang, Jinhai; Wang, Chengfang; Lu, Weicong; Gao, Rongrong; Li, Yuanguang; Wang, Qinmei; Zhao, Yune

    2015-01-01

    Purpose. To assess the reliability and comparability of measuring central corneal thickness (CCT) and thinnest corneal thickness (TCT) using a new Scheimpflug-Placido analyzer (TMS-5, Japan) and ultrasound (US) pachymetry. Methods. Seventy-six healthy subjects were prospectively measured 3 times by 1 operator using the TMS-5, 3 additional consecutive scans were performed by a second operator, and ultrasound (US) pachymetry measurements were taken. The test-retest repeatability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability and interoperator reproducibility. Agreement among the devices was assessed using Bland-Altman plots and 95% limits of agreement (LoA). Results. The intraoperators TRT and CoV were 0.90. The mean CCT and TCT measurements using the TMS-5 were 15.97 μm (95% LoA from −26.42 to −5.52 μm) and 20.32 μm (95% LoA from −30.67 to −9.97 μm) smaller, respectively, than those using US pachymetry. Conclusions. The TMS-5 shows good repeatability and reproducibility for measuring CCT and TCT in normal subjects but only moderate agreement with US pachymetry results. Caution is warranted before using these techniques interchangeably. PMID:25810919

  7. Prostate Ultrasound

    Medline Plus

    Full Text Available ... are the limitations of Prostate Ultrasound Imaging? What is Ultrasound Imaging of the Prostate? Ultrasound is safe ... transducer into the body. top of page How is the procedure performed? In men, the prostate gland ...

  8. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... Pelvis Ultrasound imaging of the pelvis uses sound waves to produce pictures of the structures and organs ... of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or sonography , ...

  9. Prostate Ultrasound

    Medline Plus

    Full Text Available ... gel. top of page How does the procedure work? Ultrasound imaging is based on the same principles ... to-use and less expensive than other imaging methods. Ultrasound imaging uses no ionizing radiation. Ultrasound scanning ...

  10. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... a pelvic ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is a special ultrasound technique that ... and processes the sounds and creates graphs or color pictures that represent the flow of blood through ...

  11. Intravascular ultrasound

    Science.gov (United States)

    IVUS; Ultrasound - coronary artery; Endovascular ultrasound; Intravascular echocardiography ... A tiny ultrasound wand is attached to the top of a thin tube. This tube is called a catheter. The catheter ...

  12. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... three types of pelvic ultrasound: abdominal, vaginal (for women), and rectal (for men). These exams are frequently ... pelvic ultrasound: abdominal ( transabdominal ) vaginal ( transvaginal / endovaginal ) for women rectal ( transrectal ) for men A Doppler ultrasound exam ...

  13. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... ultrasound images are captured in real-time, they can show the structure and movement of the body's ... Obstetrical Ultrasound page for more information . Ultrasound examinations can help diagnose symptoms experienced by women such as: ...

  14. Quantitative measurement of high flow velocities by a spin echo MR technique

    Energy Technology Data Exchange (ETDEWEB)

    Lin Yigun (First Military Medical Coll., Quangzhou, FJ (China)); Kojima, Akihiro; Shinzato, Jintetsu; Sakamoto, Yuji; Ueno, Sukeyoshi; Takahashi, Mutsumasa; Higashida, Yoshiharu

    A new method of flow measurement using a spin echo (SE) technique has been developed on the basis of the flow effect that at high velocities signal intensity decreases linearly with increasing flow velocity. Flow velocity is calculated from the signal intensity ratio of the flowing material in two images with the same imaging parameters but different echo times. The linear relationship between the signal intensity and flow velocity was examined with a steady flow phantom. When assessed with steady flows in the phantom, flow velocities calculated by this method were in good agreement with velocities measured by a flow meter. This method was used with ECG gating to measure the blood flow of the right common carotid artery of a healthy volunteer. The measured peak flow velocity and the pattern of flow velocities during systole correlated well with the results obtained by Doppler ultrasound. (author).

  15. Ultrasound -- Pelvis

    Medline Plus

    Full Text Available ... through blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. There are three types of pelvic ultrasound: ...

  16. Multicenter assessment of the reproducibility of volumetric radiofrequency-based intravascular ultrasound measurements in coronary lesions that were consecutively stented

    DEFF Research Database (Denmark)

    Huisman, Jennifer; Egede, Rasmus; Rdzanek, Adam

    2012-01-01

    To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibili...... on average the highest measurement reproducibility. A central analysis for VH-IVUS multicenter studies of lesions prior to PCI should be pursued. Moreover, it may be problematical to pool VH-IVUS data of individual trials analyzed by independent centers.......To assess in a multicenter design the between-center reproducibility of volumetric virtual histology intravascular ultrasound (VH-IVUS) measurements with a semi-automated, computer-assisted contour detection system in coronary lesions that were consecutively stented. To evaluate the reproducibility...... of volumetric VH-IVUS measurements, experienced analysts of 4 European IVUS centers performed independent analyses (in total 8,052 cross-sectional analyses) to obtain volumetric data of 40 coronary segments (length 20.0 ± 0.3 mm) from target lesions prior to percutaneous intervention that were performed...

  17. Non-contact, ultrasound-based indentation method for measuring elastic properties of biological tissues using harmonic motion imaging (HMI).

    Science.gov (United States)

    Vappou, Jonathan; Hou, Gary Y; Marquet, Fabrice; Shahmirzadi, Danial; Grondin, Julien; Konofagou, Elisa E

    2015-04-07

    Noninvasive measurement of mechanical properties of biological tissues in vivo could play a significant role in improving the current understanding of tissue biomechanics. In this study, we propose a method for measuring elastic properties non-invasively by using internal indentation as generated by harmonic motion imaging (HMI). In HMI, an oscillating acoustic radiation force is produced by a focused ultrasound transducer at the focal region, and the resulting displacements are estimated by tracking radiofrequency signals acquired by an imaging transducer. In this study, the focal spot region was modeled as a rigid cylindrical piston that exerts an oscillatory, uniform internal force to the underlying tissue. The HMI elastic modulus EHMI was defined as the ratio of the applied force to the axial strain measured by 1D ultrasound imaging. The accuracy and the precision of the EHMI estimate were assessed both numerically and experimentally in polyacrylamide tissue-mimicking phantoms. Initial feasibility of this method in soft tissues was also shown in canine liver specimens in vitro. Very good correlation and agreement was found between the measured Young's modulus and the HMI modulus in the numerical study (r(2) > 0.99, relative error tissues at a submillimeter scale using an internal indentation-like approach. Ongoing studies include in vitro experiments in a larger number of samples and feasibility testing in in vivo models as well as pathological human specimens.

  18. Evaluation of airway protection: Quantitative timing measures versus penetration/aspiration score.

    Science.gov (United States)

    Kendall, Katherine A

    2017-10-01

    Quantitative measures of swallowing function may improve the reliability and accuracy of modified barium swallow (MBS) study interpretation. Quantitative study analysis has not been widely instituted, however, secondary to concerns about the time required to make measures and a lack of research demonstrating impact on MBS interpretation. This study compares the accuracy of the penetration/aspiration (PEN/ASP) scale (an observational visual-perceptual assessment tool) to quantitative measures of airway closure timing relative to the arrival of the bolus at the upper esophageal sphincter in identifying a failure of airway protection during deglutition. Retrospective review of clinical swallowing data from a university-based outpatient clinic. Swallowing data from 426 patients were reviewed. Patients with normal PEN/ASP scores were identified, and the results of quantitative airway closure timing measures for three liquid bolus sizes were evaluated. The incidence of significant airway closure delay with and without a normal PEN/ASP score was determined. Inter-rater reliability for the quantitative measures was calculated. In patients with a normal PEN/ASP score, 33% demonstrated a delay in airway closure on at least one swallow during the MBS study. There was no correlation between PEN/ASP score and airway closure delay. Inter-rater reliability for the quantitative measure of airway closure timing was nearly perfect (intraclass correlation coefficient = 0.973). The use of quantitative measures of swallowing function, in conjunction with traditional visual perceptual methods of MBS study interpretation, improves the identification of airway closure delay, and hence, potential aspiration risk, even when no penetration or aspiration is apparent on the MBS study. 4. Laryngoscope, 127:2314-2318, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  19. Measurement of compartment elasticity using pressure related ultrasound: a method to identify patients with potential compartment syndrome.

    Science.gov (United States)

    Sellei, R M; Hingmann, S J; Kobbe, P; Weber, C; Grice, J E; Zimmerman, F; Jeromin, S; Gansslen, A; Hildebrand, F; Pape, H C

    2015-01-01

    PURPOSE OF THE STUDY Decision-making in treatment of an acute compartment syndrome is based on clinical assessment, supported by invasive monitoring. Thus, evolving compartment syndrome may require repeated pressure measurements. In suspected cases of potential compartment syndromes clinical assessment alone seems to be unreliable. The objective of this study was to investigate the feasibility of a non-invasive application estimating whole compartmental elasticity by ultrasound, which may improve accuracy of diagnostics. MATERIAL AND METHODS In an in-vitro model, using an artificial container simulating dimensions of the human anterior tibial compartment, intracompartmental pressures (p) were raised subsequently up to 80 mm Hg by infusion of saline solution. The compartmental depth (mm) in the cross-section view was measured before and after manual probe compression (100 mm Hg) upon the surface resulting in a linear compartmental displacement (Δd). This was repeated at rising compartmental pressures. The resulting displacements were related to the corresponding intra-compartmental pressures simulated in our model. A hypothesized relationship between pressures related compartmental displacement and the elasticity at elevated compartment pressures was investigated. RESULTS With rising compartmental pressures, a non-linear, reciprocal proportional relation between the displacement (mm) and the intra-compartmental pressure (mm Hg) occurred. The Pearson's coefficient showed a high correlation (r2 = -0.960). The intraobserver reliability value kappa resulted in a statistically high reliability (κ = 0.840). The inter-observer value indicated a fair reliability (κ = 0.640). CONCLUSIONS Our model reveals that a strong correlation between compartmental strain displacements assessed by ultrasound and the intra-compartmental pressure changes occurs. Further studies are required to prove whether this assessment is transferable to human muscle tissue. Determining the complete

  20. The effect of the sample size and location on contrast ultrasound measurement of perfusion parameters.

    Science.gov (United States)

    Leinonen, Merja R; Raekallio, Marja R; Vainio, Outi M; Ruohoniemi, Mirja O; O'Brien, Robert T

    2011-01-01

    Contrast-enhanced ultrasound can be used to quantify tissue perfusion based on region of interest (ROI) analysis. The effect of the location and size of the ROI on the obtained perfusion parameters has been described in phantom, ex vivo and in vivo studies. We assessed the effects of location and size of the ROI on perfusion parameters in the renal cortex of 10 healthy, anesthetized cats using Definity contrast-enhanced ultrasound to estimate the importance of the ROI on quantification of tissue perfusion with contrast-enhanced ultrasound. Three separate sets of ROIs were placed in the renal cortex, varying in location, size or depth. There was a significant inverse association between increased depth or increased size of the ROI and peak intensity (P < 0.05). There was no statistically significant difference in the peak intensity between the ROIs placed in a row in the near field cortex. There was no significant difference in the ROIs with regard to arrival time, time to peak intensity and wash-in rate. When comparing two different ROIs in a patient with focal lesions, such as suspected neoplasia or infarction, the ROIs should always be placed at same depth and be as similar in size as possible.

  1. A tissue phantom for visualization and measurement of ultrasound-induced cavitation damage.

    Science.gov (United States)

    Maxwell, Adam D; Wang, Tzu-Yin; Yuan, Lingqian; Duryea, Alexander P; Xu, Zhen; Cain, Charles A

    2010-12-01

    Many ultrasound studies involve the use of tissue-mimicking materials to research phenomena in vitro and predict in vivo bioeffects. We have developed a tissue phantom to study cavitation-induced damage to tissue. The phantom consists of red blood cells suspended in an agarose hydrogel. The acoustic and mechanical properties of the gel phantom were found to be similar to soft tissue properties. The phantom's response to cavitation was evaluated using histotripsy. Histotripsy causes breakdown of tissue structures by the generation of controlled cavitation using short, focused, high-intensity ultrasound pulses. Histotripsy lesions were generated in the phantom and kidney tissue using a spherically focused 1-MHz transducer generating 15 cycle pulses, at a pulse repetition frequency of 100 Hz with a peak negative pressure of 14 MPa. Damage appeared clearly as increased optical transparency of the phantom due to rupture of individual red blood cells. The morphology of lesions generated in the phantom was very similar to that generated in kidney tissue at both macroscopic and cellular levels. Additionally, lesions in the phantom could be visualized as hypoechoic regions on a B-mode ultrasound image, similar to histotripsy lesions in tissue. High-speed imaging of the optically transparent phantom was used to show that damage coincides with the presence of cavitation. These results indicate that the phantom can accurately mimic the response of soft tissue to cavitation and provide a useful tool for studying damage induced by acoustic cavitation.

  2. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... may also be saved. Doppler ultrasound, a special application of ultrasound, measures the direction and speed of ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  3. WE-EF-210-06: Ultrasound 2D Strain Measurement of Radiation-Induced Toxicity: Phantom and Ex Vivo Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T; Torres, M; Rossi, P; Jani, A; Curran, W; Yang, X [Emory Univ, Atlanta, GA (United States)

    2015-06-15

    Purpose: Radiation-induced fibrosis is a common long-term complication affecting many patients following cancer radiotherapy. Standard clinical assessment of subcutaneous fibrosis is subjective and often limited to visual inspection and palpation. Ultrasound strain imaging describes the compressibility (elasticity) of biological tissues. This study’s purpose is to develop a quantitative ultrasound strain imaging that can consistently and accurately characterize radiation-induce fibrosis. Methods: In this study, we propose a 2D strain imaging method based on deformable image registration. A combined affine and B-spline transformation model is used to calculate the displacement of tissue between pre-stress and post-stress B-mode image sequences. The 2D displacement is estimated through a hybrid image similarity measure metric, which is a combination of the normalized mutual information (NMI) and normalized sum-of-squared-differences (NSSD). And 2D strain is obtained from the gradient of the local displacement. We conducted phantom experiments under various compressions and compared the performance of our proposed method with the standard cross-correlation (CC)- based method using the signal-to-noise (SNR) and contrast-to-noise (CNS) ratios. In addition, we conducted ex-vivo beef muscle experiment to further validate the proposed method. Results: For phantom study, the SNR and CNS values of the proposed method were significantly higher than those calculated from the CC-based method under different strains. The SNR and CNR increased by a factor of 1.9 and 2.7 comparing to the CC-based method. For the ex-vivo experiment, the CC-based method failed to work due to large deformation (6.7%), while our proposed method could accurately detect the stiffness change. Conclusion: We have developed a 2D strain imaging technique based on the deformable image registration, validated its accuracy and feasibility with phantom and ex-vivo data. This 2D ultrasound strain imaging

  4. Comparison of Dual Energy X-Ray Absorptiometry and Quantitative Ultrasonography Measurements in Osteoporotic Patients - Original Investigation

    Directory of Open Access Journals (Sweden)

    Şule Tütün

    2008-08-01

    Full Text Available Aim: Osteoporosis (OP is a skelatal disease of bone fragility resulting from micro-architectural deteriotarion and decreased bone mass. There are many studies in literature that show high sensibility and specifity of quantitative ultrasonography (QUS. Recently many comparatives studies of QUS and dual energy X-ray absorbtiometry (DEXA have been made. In this study we aimed to investigate correlation of QUS and DEXA measurments in 53 women with postmenopausal osteoporosis were enrolled in this study. Material and Method: Fifty three postmenopausal women with osteoporosis were studied: Ultrasound parameters were measured by the DTU-one imaging ultrasonometer in the calcaneus. BMD was assessed by dual-energy X-ray absorptiometry (DEXA at the lumbar spine, femoral neck, and trochanter. QUS measurements of the postmenopausal women was compared with DEXA measurements. Results: There was a significant correlation between QUS T scores and DEXA L2-L4 T scores (r =0.463 p=0.000 p<0.005, there was a significant correlation between QUS Z scores and DEXA L2-L4 Z scores (r =0.589 p=0.000 p<0.005 , there was a significant correlation between QUS T scores and DEXA femur neck T scores (r =0.463 p=0.000 p<0.005 , there was a significant correlation between QUS Z scores and DEXA femur Z scores (r =0.418 p=0.000 p<0.005. Conclusion: Consequently QUS results were correlated with DEXA results in postmenopausal osteoporotic patients. (From the World of Osteoporosis 2008;14:26-8

  5. ALA-PpIX variability quantitatively imaged in A431 epidermoid tumors using in vivo ultrasound fluorescence tomography and ex vivo assay

    Science.gov (United States)

    DSouza, Alisha V.; Flynn, Brendan P.; Gunn, Jason R.; Samkoe, Kimberley S.; Anand, Sanjay; Maytin, Edward V.; Hasan, Tayyaba; Pogue, Brian W.

    2014-03-01

    Treatment monitoring of Aminolevunilic-acid (ALA) - Photodynamic Therapy (PDT) of basal-cell carcinoma (BCC) calls for superficial and subsurface imaging techniques. While superficial imagers exist for this purpose, their ability to assess PpIX levels in thick lesions is poor; additionally few treatment centers have the capability to measure ALA-induced PpIX production. An area of active research is to improve treatments to deeper and nodular BCCs, because treatment is least effective in these. The goal of this work was to understand the logistics and technical capabilities to quantify PpIX at depths over 1mm, using a novel hybrid ultrasound-guided, fiber-based fluorescence molecular spectroscopictomography system. This system utilizes a 633nm excitation laser and detection using filtered spectrometers. Source and detection fibers are collinear so that their imaging plane matches that of ultrasound transducer. Validation with phantoms and tumor-simulating fluorescent inclusions in mice showed sensitivity to fluorophore concentrations as low as 0.025μg/ml at 4mm depth from surface, as presented in previous years. Image-guided quantification of ALA-induced PpIX production was completed in subcutaneous xenograft epidermoid cancer tumor model A431 in nude mice. A total of 32 animals were imaged in-vivo, using several time points, including pre-ALA, 4-hours post-ALA, and 24-hours post-ALA administration. On average, PpIX production in tumors increased by over 10-fold, 4-hours post-ALA. Statistical analysis of PpIX fluorescence showed significant difference among all groups; p<0.05. Results were validated by exvivo imaging of resected tumors. Details of imaging, analysis and results will be presented to illustrate variability and the potential for imaging these values at depth.

  6. The Kety-Schmidt Technique for Quantitative Perfusion and Oxygen Metabolism Measurements in the MR Environment

    Science.gov (United States)

    Lee, John J.; Powers, William J.; Faulkner, Chad B.; Boyle, Patrick J.; Derdeyn, Colin P.

    2013-01-01

    The Kety-Schmidt technique provides quantitative measurement of whole brain cerebral blood flow (CBF). CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous samples. In this report we present a method for performing these measurements in an MR environment. This technique could be useful for validation of MR methods of hemodynamic and metabolic measurements in humans. PMID:22997166

  7. Longitudinal change in quantitative meniscus measurements in knee osteoarthritis--data from the Osteoarthritis Initiative.

    Science.gov (United States)

    Bloecker, Katja; Wirth, W; Guermazi, A; Hitzl, W; Hunter, D J; Eckstein, F

    2015-10-01

    We aimed to apply 3D MRI-based measurement technology to studying 2-year change in quantitative measurements of meniscus size and position. Forty-seven knees from the Osteoarthritis Initiative with medial radiographic joint space narrowing had baseline and 2-year follow-up MRIs. Quantitative measures were obtained from manual segmentation of the menisci and tibia using coronal DESSwe images. The standardized response mean (SRM = mean/SD change) was used as measure of sensitivity to longitudinal change. Medial tibial plateau coverage decreased from 34.8% to 29.9% (SRM -0.82; p quantitative 3D meniscus measurements in knee osteoarthritis. It provides evidence of improved sensitivity to change of 3D measurements compared with single slice analysis. • First longitudinal MRI-based measurements of change of meniscus position and size. • Quantitative longitudinal evaluation of meniscus change in knee osteoarthritis. • Improved sensitivity to change of 3D measurements compared with single slice analysis.

  8. Preliminary Evidence of the Reliability and Validity of a Quantitative Measure of Self-Authorship

    Science.gov (United States)

    Creamer, Elizabeth G.; Magolda, Marcia Baxter; Yue, Jessica

    2010-01-01

    This article presents preliminary evidence of the reliability and validity of a measure of self-authorship derived from 18 items in the Career Decision Making Survey. The research conceptualizes a quantitative measure of self-authorship as a three-part score that reflects level of agreement with statements at each of the first three phases of…

  9. High temperature and high pressure gas cell for quantitative spectroscopic measurements

    DEFF Research Database (Denmark)

    Christiansen, Caspar; Stolberg-Rohr, Thomine; Fateev, Alexander

    2016-01-01

    A high temperature and high pressure gas cell (HTPGC) has been manufactured for quantitative spectroscopic measurements in the pressure range 1-200 bar and temperature range 300-1300 K. In the present work the cell was employed at up to 100 bar and 1000 K, and measured absorption coefficients...

  10. Quantitative laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine

    NARCIS (Netherlands)

    Verbiezen, K.; Klein-Douwel, R. J. H.; van Viet, A. P.; Donkerbroek, A. J.; Meerts, W. L.; Dam, N. J.; ter Meulen, J. J.

    2007-01-01

    We present quantitative, in-cylinder, UV-laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine. Processing of the raw fluorescence signals includes a detailed correction, based on additional measurements, for the effect of laser beam and fluorescence attenuation, and

  11. Ultrasound imaging in lower limb prosthetics.

    Science.gov (United States)

    Douglas, Tania; Solomonidis, Stephan; Sandham, William; Spence, William

    2002-03-01

    The biomechanical interaction between the residual limb and the prosthetic socket determines the quality of fit of the socket in lower limb prosthetics. An understanding of this interaction and the development of quantitative measures to predict the quality of fit of the socket are important for optimal socket design. Finite-element modeling is used widely for biomechanical modeling of the limb/socket interaction and requires information on the internal and external geometry of the residual limb. Volumetric imaging methods such as X-ray computed tomography, magnetic resonance imaging, and ultrasound have been used to obtain residual limb shape information. Of these modalities, ultrasound has been introduced most recently and its development for visualization in prosthetics is the least mature. This paper reviews ultrasound image acquisition and processing methods as they have been applied in lower limb prosthetics.

  12. Quantitative assessment of erythropoiesis and functional classification of anemia based on measurements of serum transferrin receptor and erythropoietin

    National Research Council Canada - National Science Library

    Beguin, Y; Clemons, G K; Pootrakul, P; Fillet, G

    1993-01-01

    .... The RBC mass was quantitated by direct isotopic measurement (RCM), Epo production by serum Epo levels, and erythropoiesis by the ferrokinetic measurement of the erythron transferrin uptake (ETU...

  13. Quantitative ultrasound for the detection and management of osteoporosis Ultrasonido cuantitativo para la detección y manejo de osteoporosis

    Directory of Open Access Journals (Sweden)

    Didier Hans

    2009-01-01

    Full Text Available Quantitative ultrasound (QUS appears to be developing into an acceptable, low-cost and readily-accessible alternative to dual X-ray absorptiometry (DXA measurements of bone mineral density (BMD in the detection and management of osteoporosis. Perhaps the major difficulty with their widespread use is that many different QUS devices exist that differ substantially from each other, in terms of the parameters they measure and the strength of empirical evidence supporting their use. But another problem is that virtually no data exist outside of Caucasian or Asian populations. In general, heel QUS appears to be most tested and most effective. Some, but not all heel QUS devices are effective assessing fracture risk in some, but not all populations, the evidence being strongest for Caucasian females > 55 years old, though some evidence exists for Asian females > 55 and for Caucasian and Asian males > 70. Certain devices may allow to estimate the likelihood of osteoporosis, but very limited evidence exists supporting QUS use during the initiation or monitoring of osteoporosis treatment. Likely, QUS is most effective when combined with an assessment of clinical risk factors (CRF; with DXA reserved for individuals who are not identified as either high or low risk using QUS and CRF. However, monitoring and maintenance of test and instrument accuracy, precision and reproducibility are essential if QUS devices are to be used in clinical practice; and further scientific research in non-Caucasian, non-Asian populations clearly is compulsory to validate this tool for more widespread use.El ultrasonido cuantitativo (QUS es una alternativa para la detección y manejo de la osteoporosis de bajo costo y uso práctico, si se compara con las densitometrías de rayos X de doble haz de baja energía (DXA que determinan densidad mineral ósea (BMD. La mayor dificultad para el uso generalizado del QUS por un lado es que existen muchos instrumentos que son

  14. Clinical Conformity Between Heel Ultrasound and Densitometry in Postmenopausal Women: A Systematic Review.

    Science.gov (United States)

    Tabor, Elżbieta; Pluskiewicz, Wojciech; Tabor, Kamil

    2017-08-04

    To assess the conformity between heel ultrasound and densitometry, and the clinical application of densitometry T-score "gold standard" in quantitative ultrasound as a method of osteoporosis diagnosis in postmenopausal women. The study is a systematic review of studies published in the last 17 years in PubMed, NLM Gateway, Medline, Embase, and Cochrane Library. Calcaneal quantitative ultrasound sensitivity and specificity were analyzed with regard to densitometry measurements in postmenopausal women. In addition, we summarized the values of ultrasound T-scores, for which their accuracy in osteoporosis diagnosis is the highest. The inclusion criteria met 15 research studies conducted on postmenopausal women. In 11 of them, the authors concluded that clinical conformity between heel ultrasound and densitometry is good. The recommended quantitative ultrasound T-score for osteoporosis diagnosis ranged between -1 and -3.65. Heel ultrasound should be considered to be as accurate as densitometry in diagnosing osteoporosis. Nevertheless, it needs to have separate T-score ranges determined, because those used in densitometry are not adequate. © 2017 by the American Institute of Ultrasound in Medicine.

  15. The World Health Organization Fetal Growth Charts: A Multinational Longitudinal Study of Ultrasound Biometric Measurements and Estimated Fetal Weight

    Science.gov (United States)

    Carroli, Guillermo; Widmer, Mariana; Neerup Jensen, Lisa; Giordano, Daniel; Abdel Aleem, Hany; Talegawkar, Sameera A.; Benachi, Alexandra; Diemert, Anke; Tshefu Kitoto, Antoinette; Thinkhamrop, Jadsada; Lumbiganon, Pisake; Tabor, Ann; Kriplani, Alka; Gonzalez Perez, Rogelio; Hecher, Kurt; Hanson, Mark A.; Gülmezoglu, A. Metin; Platt, Lawrence D.

    2017-01-01

    Background Perinatal mortality and morbidity continue to be major global health challenges strongly associated with prematurity and reduced fetal growth, an issue of further interest given the mounting evidence that fetal growth in general is linked to degrees of risk of common noncommunicable diseases in adulthood. Against this background, WHO made it a high priority to provide the present fetal growth charts for estimated fetal weight (EFW) and common ultrasound biometric measurements intended for worldwide use. Methods and Findings We conducted a multinational prospective observational longitudinal study of fetal growth in low-risk singleton pregnancies of women of high or middle socioeconomic status and without known environmental constraints on fetal growth. Centers in ten countries (Argentina, Brazil, Democratic Republic of the Congo, Denmark, Egypt, France, Germany, India, Norway, and Thailand) recruited participants who had reliable information on last menstrual period and gestational age confirmed by crown–rump length measured at 8–13 wk of gestation. Participants had anthropometric and nutritional assessments and seven scheduled ultrasound examinations during pregnancy. Fifty-two participants withdrew consent, and 1,387 participated in the study. At study entry, median maternal age was 28 y (interquartile range [IQR] 25–31), median height was 162 cm (IQR 157–168), median weight was 61 kg (IQR 55–68), 58% of the women were nulliparous, and median daily caloric intake was 1,840 cal (IQR 1,487–2,222). The median pregnancy duration was 39 wk (IQR 38–40) although there were significant differences between countries, the largest difference being 12 d (95% CI 8–16). The median birthweight was 3,300 g (IQR 2,980–3,615). There were differences in birthweight between countries, e.g., India had significantly smaller neonates than the other countries, even after adjusting for gestational age. Thirty-one women had a miscarriage, and three fetuses had

  16. The World Health Organization Fetal Growth Charts: A Multinational Longitudinal Study of Ultrasound Biometric Measurements and Estimated Fetal Weight.

    Directory of Open Access Journals (Sweden)

    Torvid Kiserud

    2017-01-01

    Full Text Available Perinatal mortality and morbidity continue to be major global health challenges strongly associated with prematurity and reduced fetal growth, an issue of further interest given the mounting evidence that fetal growth in general is linked to degrees of risk of common noncommunicable diseases in adulthood. Against this background, WHO made it a high priority to provide the present fetal growth charts for estimated fetal weight (EFW and common ultrasound biometric measurements intended for worldwide use.We conducted a multinational prospective observational longitudinal study of fetal growth in low-risk singleton pregnancies of women of high or middle socioeconomic status and without known environmental constraints on fetal growth. Centers in ten countries (Argentina, Brazil, Democratic Republic of the Congo, Denmark, Egypt, France, Germany, India, Norway, and Thailand recruited participants who had reliable information on last menstrual period and gestational age confirmed by crown-rump length measured at 8-13 wk of gestation. Participants had anthropometric and nutritional assessments and seven scheduled ultrasound examinations during pregnancy. Fifty-two participants withdrew consent, and 1,387 participated in the study. At study entry, median maternal age was 28 y (interquartile range [IQR] 25-31, median height was 162 cm (IQR 157-168, median weight was 61 kg (IQR 55-68, 58% of the women were nulliparous, and median daily caloric intake was 1,840 cal (IQR 1,487-2,222. The median pregnancy duration was 39 wk (IQR 38-40 although there were significant differences between countries, the largest difference being 12 d (95% CI 8-16. The median birthweight was 3,300 g (IQR 2,980-3,615. There were differences in birthweight between countries, e.g., India had significantly smaller neonates than the other countries, even after adjusting for gestational age. Thirty-one women had a miscarriage, and three fetuses had intrauterine death. The 8,203 sets of

  17. The World Health Organization Fetal Growth Charts: A Multinational Longitudinal Study of