950 research outputs found

    Optimization of Axial Resolution

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    Abstract: To improve the axial resolution of ultrasonic elastography, by taking the advantage of code excitation and frequency compounding, multi-frequency with coded excitation for elastography (FCCE) was proposed. FCCE adopts the Chirp signal excitation scheme and strikes a balance in the selection of sub-signal bandwidth, the bandwidth overlap and the number of sub-strain image based on theoretical derivation, so as to further improve the axial resolution of elastic image. On MATLAB, multi-frequency with coded excitation for elastography was implemented and compared with short pulse. Experiments have proved that, compared with the short pulse, the elastographic signal-to-noise ratio (SNRe) and contrast-to-noise ratio (CNRe) were improved significantly. Moreover, probing depth, axial resolution and target detection were improved too. Therefore, the FCCE technology can effectively improve the elastography quality and can be applied to ultrasonic clinical trials. Copyright © 2014 IFSA Publishing, S. L

    Does Intravenous Infusion Influence Diagnostic Ultrasound‐Induced Pulmonary Capillary Hemorrhage?

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145537/1/jum14555.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145537/2/jum14555_am.pd

    Myocardial involvement during the early course of type 2 diabetes mellitus: usefulness of Myocardial Performance Index

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    To evaluate whether myocardial performance index detects a subclinical impairment of left ventricular systolic and diastolic function in patients with early stage of type 2 diabetes, without coronary artery disease, with or without hypertension. Furthermore, to evaluate whether some echocardiographic parameters relate to the metabolic control. Fourty-five consecutive male patients (mean age 52.5 years) with type 2 diabetes mellitus of recent onset (23 hypertensives and 22 normotensives) and 22 age matched healthy controls males were analysed. All participants had normal exercise ECG. All subjects underwent standard and Doppler echocardiography for the assessment of the isovolumic Doppler time interval and Doppler-derived myocardial performance index. In all diabetic patients a glycated haemoglobin test was also performed

    Diffusion and applications of musculoskeletal ultrasound in Italian Rheumatology Units

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    The Musculoskeletal Ultrasound Study Group of the Italian Society of Rheumatology (SIR) was founded during the 68th SIR Congress, on November 2011. The request of activation of this group was based on the increasing interest and the widespread diffusion of ultrasound in the scientific rheumatology community and on the solid experience of some Italian rheumatologists in the field. The aims of the Study Group are to stimulate the applications and use of ultrasound in the clinical practice at the level of the Italian rheumatology units and, in addition, to develop research projects at a national level..

    Improvement of convective drying of carrot by applying power ultrasound. Influence of mass load density

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    [EN] Power ultrasound is considered to be a novel and promising technology with which to improve heat and mass transfer phenomena in drying processes. The aim of this work was to contribute to the knowledge of ultrasound application to air drying by addressing the influence of mass load density on the ultrasonically assisted air drying of carrot. Drying kinetics of carrot cubes were carried out (in triplicate) with or without power ultrasound application (75 W, 21.7 kHz) at 40 C, 1 m/s, and several mass load densities: 12, 24, 36, 42, 48, 60, 72, 84, 96, 108, and 120 kg/m3 . The experimental results showed a significant (p < 0.05) influence of both factors, mass load density and power ultrasound application, on drying kinetics. As expected, the increase of mass load density did not affect the effective moisture diffusivity (De, m2 /s) but produced a reduction of the mass transfer coefficient (k, kg water/m2 /s). This was explained by considering perturbations in the air flow through the drying chamber thus creating preferential pathways and, as a consequence, increasing external mass transfer resistance. On the other hand, it was found that the power ultrasound application increased the mass transfer coefficient and the effective moisture diffusivity regardless of the mass load density used. However, the influence of power ultrasound was not significant at the highest mass load densities tested (108 and 120 kg/m3 ), which may be explained from the high ratio (acoustic energy/sample mass) found under those experimental conditions. Therefore, the application of ultrasound was considered as a useful technology with which to improve the convective drying, although its effects may be reduced at high mass load densities.The authors acknowledge the financial support of the Spanish Ministry of Science and Technology (DPI2009-14549-C04-04) and the Universidad Politecnica de Valencia (PAID-06-08-3180).Cárcel Carrión, JA.; García Pérez, JV.; Riera, E.; Mulet Pons, A. (2011). Improvement of convective drying of carrot by applying power ultrasound. Influence of mass load density. Drying Technology. 29(2):174-182. https://doi.org/10.1080/07373937.2010.483032S17418229

    Ultrasonography of Quadriceps Femoris Muscle and Subcutaneous Fat Tissue and Body Composition by BIVA in Chronic Dialysis Patients

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    Protein Energy Wasting (PEW) in hemodialysis (HD) patients is a multifactorial condition due to specific pathology-related pathogenetic mechanisms, leading to loss of skeletal muscle mass in HD patients. Computed Tomography and Magnetic Resonance Imaging still represent the gold standard techniques for body composition assessment. However, their widespread application in clinical practice is difficult and body composition evaluation in HD patients is mainly based on conventional anthropometric nutritional indexes and bioelectrical impedance vector analysis (BIVA). Little data is currently available on ultrasound (US)-based measurements of muscle mass and fat tissue in this clinical setting. The purpose of our study is to ascertain: (1) if there are differences between quadriceps rectus femoris muscle (QRFM) thickness and abdominal/thigh subcutaneous fat tissue (SFT) measured by US between HD patients and healthy subjects; (2) if there is any correlation between QRFM and abdominal/thigh SFT thickness by US, and BIVA/conventional nutritional indexes in HD patients. We enrolled 65 consecutive HD patients and 33 healthy subjects. Demographic and laboratory were collected. The malnutrition inflammation score (MIS) was calculated. Using B-mode US system, the QRFM and SFT thicknesses were measured at the level of three landmarks in both thighs (superior anterior iliac spine, upper pole of the patella, the midpoint of the tract included between the previous points). SFT was also measured at the level of the periumbilical point. The mono frequency (50 KHz) BIVA was conducted using bioelectrical measurements (Rz, resistance; Xc, reactance; adjusted for height, Rz/H and Xc/H; PA, phase angle). 58.5% were men and the mean age was 69 (SD 13.7) years. QRFM and thigh SFT thicknesses were reduced in HD patients as compared to healthy subjects (p &lt; 0.01). Similarly, also BIVA parameters, expression of lean body mass, were lower (p &lt; 0.001), except for Rz and Rz/H in HD patients. The average QRFM thickness of both thighs at top, mid, lower landmarks were positively correlated with PA and body cell mass (BCM) by BIVA, while negatively correlated with Rz/H (p &lt; 0.05). Abdominal SFT was positively correlated with PA, BCM and basal metabolic rate (BMR) (p &lt; 0.05). Our study shows that ultrasound QRFM and thigh SFT thicknesses were reduced in HD patients and that muscle ultrasound measurements were significantly correlated with BIVA parameters

    Current and prospective use of musculoskeletal diagnostic ultrasound imaging at chiropractic teaching institutions: A worldwide survey of diagnostic imaging staff

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    Objective The purpose of this study was to survey the use of musculoskeletal diagnostic ultrasound imaging (MSK-DUSI) at chiropractic educational programs worldwide and to elicit opinions of academic diagnostic imaging staff of its prospective use at their teaching institutions. Methods An electronic questionnaire was delivered in 2014 using SurveyMonkey and notifications were disseminated by e-mail to 127 diagnostic imaging staff at chiropractic programs worldwide. The questionnaire consisted of 27 items using multiple-choice, Likert-type, and open-ended questions. Descriptive statistics were used for basic demographic data and the results of the numerical scales used in each item. Results Fifty-nine respondents (46.5%) from 24 (24/41) chiropractic programs returned questionnaires. The reported use of MSK-DUSI at chiropractic programs is low (n = 5/24); however, respondents from 9 institutions stated that it is planned to be implemented. Few respondents stated they had formal MSK-DUSI qualifications (4/59); however, 7 respondents stated they were in the process of becoming certified. Most respondents expressed an interest in the prospect of incorporating MSK-DUSI at their chiropractic program. Sixty-five percent stated that chiropractic programs should provide MSK-DUSI training to chiropractic students, and 75% of respondents stated that chiropractic programs should be providing accredited postgraduate MSK-DUSI courses. Conclusions The current use of MSK-DUSI among chiropractic programs that responded to this survey is low. The opinions of diagnostic imaging staff who responded suggest a positive attitude to its use and possible growth in its use if foundational work, including gaining funding, accreditation, and acceptance of within the scope of chiropractic practice, is undertaken
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