A high-frequency linear probe with H-topology for PWV measurements on superficial arteries

2021 ◽  
Author(s):  
Maxime Benchemoul ◽  
Agnes Lejeune ◽  
Nicolas Porcher ◽  
Emmanuel Montauban ◽  
Guillaume Ferin ◽  
...  
Keyword(s):  
High Frequency ◽  
Linear Probe

Abstract 12678: Clinical Utility of Echocardiographic Epicardial Adipose Tissue Thickness Measured Using a High-frequency Linear Probe in Patients With Coronary Artery Disease

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yukia Hirata ◽  
Hirotsugu Yamada ◽  
Kenya Kusunose ◽  
Susumu Nishio ◽  
Mika Bando ◽  
...  
Keyword(s):  
Risk Factors ◽  
Coronary Artery Disease ◽  
Adipose Tissue ◽  
Coronary Artery ◽  
Coronary Angiography ◽  
High Frequency ◽  
Epicardial Adipose Tissue ◽  
Linear Probe ◽  
Significant Difference ◽  
Artery Disease

Introduction: Epicardial adipose tissue(EAT), which is thought to be an ectopic adipose tissue, has been paid attention in association with coronary artery disease (CAD). Hypothesis: We hypothesized that EAT in anterior interventricular groove (AIG) obtained by echocardiography can be an additional marker over classical risk factors for prediction of CAD. Methods: We enrolled 311 patients (mean age 67±11 yrs, 208 men) who underwent coronary angiography between December 2011 and December 2013 at our hospital. We measured EAT thickness on the AIG and right ventricular free wall (EAT-RV) using high-frequency linear probe. Subjects were divided into 2 groups with and without significant coronary stenosis (≧75%) from coronary angiography. The performance of clinical risk factors (including age, male gender, body mass index (BMI), diabetes mellitus, hypertension, dyslipidemia, and smoking) plus various combinations of EAT thickness measurements for predicting CAD was assessed using the area under the curve (AUC) in ROC analysis. Results: The EAT-AIG thickness was significantly greater in the CAD group than that in the non-CAD group (8.3±3.0 vs. 6.3±2.5 mm, p<0.001), and there as also significant difference in the EAT-RV between the two groups (5.0±2.1 vs. 4.4±2.3 mm, p=0.009). Adding the EAT-AIG thickness over classical risk factors improved prediction of presence CAD (AUC 0.692 vs. 0.788, p<0.001), while the EAT-RV did not (AUC 0.692 vs. 0.704, p=0.343). Conclusions: Echocardiographic EAT-AIG thickness was greater in the CAD group than the non-CAD group. This non-invasive index may have clinical potential as a maker for predicting coronary atherosclerosis.

scholarly journals Role of high-frequency linear probe in ultrasound diagnosis of biliary atresia

2014 ◽  
Vol 7 (5) ◽  
pp. 665
Author(s):  
Sanjay Khaladkar ◽  
Amarjit Singh ◽  
PallaviJ Agrawal ◽  
VilasM Kulkarni
Keyword(s):  
Biliary Atresia ◽  
High Frequency ◽  
Ultrasound Diagnosis ◽  
Linear Probe

scholarly journals Prevalence and diagnostic value of the ultrasonographic honeycomb appearance of the spleen in cats

2019 ◽  
Vol 22 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Mathieu Harel ◽  
Chloe Touzet ◽  
Anthony Barthélemy ◽  
Emilie M Ségard-Weisse
Keyword(s):  
High Frequency ◽  
Complete Blood Count ◽  
Diagnostic Value ◽  
Needle Aspiration ◽  
Cytological Diagnosis ◽  
Extramedullary Haematopoiesis ◽  
Clinical Criteria ◽  
Linear Probe ◽  
Honeycomb Appearance ◽  
Honeycomb Pattern

Objectives The aim of this study was to report the prevalence of a honeycomb appearance of the spleen in a population of referral cats presented for ultrasound examination, and to determine the diagnostic value of this finding vs the definitive diagnosis, the splenic cytological and haematological results. Methods Data were obtained from the medical records (2016–2018) of cats that had an ultrasonographic honeycomb appearance of the spleen, a splenic cytological diagnosis and a complete blood count. Results Twenty-five cats were included. Prevalence of the honeycomb pattern was 6.8%. None of the spleen was considered normal on cytology and four types of lesions were found: lymphoid hyperplasia (64%), neoplasia (16%), extramedullary haematopoiesis (12%) and splenitis (8%). A honeycomb pattern was successfully identified with a linear high-frequency probe in all cats, but only in 36% of cases with the micro-convex probe. Follow-up information was available for four cats, in which the honeycomb appearance persisted up to 105 days after the first examination; there was persistence of the honeycomb pattern in all cases. Cats with a splenic cytological diagnosis of extramedullary haematopoiesis had the lowest haemoglobin plasma concentration ( P = 0.011). Conclusions and relevance Honeycomb appearance of the spleen is uncommon in cats and, in our study, was systematically associated with cytological alterations; most of the time it was benign (84%). The use of a high-frequency linear probe improves its detection rate. No epidemiological, ultrasonographic or clinical criteria allow differentiation between the different types of infiltration and fine-needle aspiration is therefore recommended.

scholarly journals Evaluation of the visibility of peri-implant bone defects using ultrasonography with two types of probes

2021 ◽  
Vol 21 (86) ◽  
pp. e206-e212
Author(s):  
Kaan Orhan ◽  
◽  
Gozde Serindere ◽  
Ceren Aktuna Belgin ◽  
Mehmet Hakan Kurt ◽  
...  
Keyword(s):  
Gold Standard ◽  
High Frequency ◽  
Interobserver Reliability ◽  
Bone Defects ◽  
Good Effect ◽  
High Agreement ◽  
Hockey Stick ◽  
Alternative Method ◽  
Linear Probe ◽  
Different Types

Background: The aim of the present study was to evaluate the efficacy of intraoral and extraoral ultrasonography evaluations performed with two different types of probes (linear and “hockey stick”) for the visibility of peri-implant bone defects. Material and methods: Fourteen implants were inserted into sheep heads. Peri-implant bone defects were created without knowing the depth, which served as the gold standard for the defects. The defects were scanned with two different probe types (linear and hockey stick probes) extraorally and intraorally, using two different ultrasonography systems. For intra- and interobserver agreements for each probe types, Kappa coefficients were calculated. Results: The lowest ICC values were found in both intra- (ICC = 0.696) and interobserver reliability (ICC = 0.762) obtained with the extraorally used linear probe. There was a high agreement with the gold standard when using hockey sticky probes intraorally. For both linear probes, there were no significant differences in agreement among the two observers and the gold standard (p >0.05). Conclusions: High agreement was found when using high-frequency hockey stick probes intraorally, which means that they can be used with good effect for the evaluation of the visibility of peri-implant bone defects. To the best of our knowledge, this study is the first one on this subject. Thus, it can be stated that US can be an alternative method of examining defects. However, further studies are needed to evaluate the effectiveness of US in visualizing peri-implant bone defects.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

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