نتایج جستجو برای: ultrasonic imaging
تعداد نتایج: 482699 فیلتر نتایج به سال:
Most frequently applied ultrasonic inspection techniques measure the reflectivity of geometric scatterers that are caused by impurities, flaws and defects in the material. Based on the echo sounder principles, the reflector has to be insonified by directed sound pulses. This requires a large number of transducers with different incident angles and sound field patterns, which are more and more r...
In continuous wave ultrasonic Doppler tomography (DT), the ultrasonic beam moves relative to the scanned object to acquire Doppler-shifted frequency spectra which correspond to cross-range projections of the scattering and reflecting structures within the object. The relative motion can be circular or linear. These data are then backprojected to reconstruct the two-dimensional image of the obje...
The broadband narrow pulse self-focusing ultrasonic transducer was designed for the special structure of the column holes, and used to do the research for the testing of bonding layer of metal composite material with F-scan ultrasonic imaging system. The copper-steel boding layer of bimetal rotor is connected by diffusing welding. There may be delamination flaws existed here. The depth and rang...
Detection of atherosclerotic plaque vulnerability has critical clinical implications for avoiding sudden death in patients with high risk of plaque rupture. We report on multimodality imaging of ex-vivo human carotid plaque samples using a system that integrates fluorescence lifetime imaging (FLIM), ultrasonic backscatter microscopy (UBM), and photoacoustic imaging (PAI). Biochemical compositio...
The influence of the ultrasonic intensity on the cleaning efficacy of passive ultrasonic irrigation.
INTRODUCTION It is not clear whether increasing the ultrasonic intensity would enhance the cleaning efficacy of passive ultrasonic irrigation (PUI) inside a root canal. The aim of this study was to evaluate the effect of the ultrasonic intensity on PUI to remove dentin debris and whether there is any lateral effect beyond the ultrasonic tip. METHODS Each of 15 in vitro root canal models with ...
Reflection-mode photoacoustic microscopy with dark-field laser pulse illumination and high-numerical-aperture ultrasonic detection is designed and implemented in noninvasively imaged blood vessels in the skin in vivo. Dark-field optical illumination minimizes the interference caused by strong photoacoustic signals from superficial structures. A high-numerical-aperture acoustic lens provides hig...
Ultrasonic waves form a useful nondestructive evaluation (NDE) probe for determining physical, microstructural, and mechanical properties of materials and parts. Noncontacting laser ultrasonic methods are desired for remote measurements and on-line manufacture process monitoring. Researchers at the Idaho National Engineering & Environmental Laboratory (INEEL) have developed a versatile new meth...
R. Chopra, M. Bronskill, M. Haider, and L. Klotz Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada, Medical Biophysics, University of Toronto, Toronto, Ontario, Canada, Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada, Medical Imaging, University of Toronto, Toronto, Ontario, Canada, Urology, Sunnybrook Health Sciences Centre, Toronto, Ont...
A nondestructive imaging method, scanning near-field ultrasound holography (SNFUH), has been developed that provides depth information as well as spatial resolution at the 10- to 100-nanometer scale. In SNFUH, the phase and amplitude of the scattered specimen ultrasound wave, reflected in perturbation to the surface acoustic standing wave, are mapped with a scanning probe microscopy platform to...
s and Proceedings Fowlkes JB, Gardner EA, Carson PL, Ivey JA, Rubin JM: "Acoustic Interruption of Ultrasound Contrast Agents for Blood Flow Evaluation", Procs., 39th Annual Conv. of the American Institute of Ultrasound in Medicine, San Francisco, CA, March 26-29, 1995. Rubin JM, Adler RS, Fowlkes JB, Spratt S, Pallister JE, Chen J-F, Carson PL (1995) Fractional Moving Blood Volume Estimation Us...
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