Ultrasound-modulated optical parallel speckle measurement with stroboscopic illumination in a coaxial reflection system

Abstract

Ultrasound-modulated optical parallel speckle measurement with stroboscopic illumination in a coaxial reflection system has been developed in order to investigate the biological speckle pattern behavior modulated by a pulsed-ultrasound wave propagating through strong scattering media. An optically absorptive object located at a distance of 5.0millimeters from the surface of a 10.0millimeter thick acoustically impedance-matched scattering media has been measured with submillimeter spatial resolution by detecting backscattered light with a charge-coupled device camera. In addition, a series of absorptive dependence measurements were also acquired.

Light Scattering Characteristics of Biological Tissues in Coaxial Ultrasound-Modulated Optical Tomography

“…In particular, ultrasound-modulated optical measurement techniques have the potential for observing optical tissue structures at depths of several centimeters, with spatial resolutions of a few submillimeters. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Visualization of internal structures from acoustically impedance-matched tissues is also possible, a capability unattainable in ultrasonography. Thus, a very important medical application of this technique is that cancerous lesions could be revealed at an earlier stage.…”

“…Several groups have examined this measurement with a single photodetector [1][2][3][4][11][12][13] as well as the parallel speckle measurement with a charge-coupled device (CCD) camera [5][6][7][8][9]13) for detecting the ensuing modulated optical signals. The modulation signals have been examined by coaxial systems [12][13][14] as well as with orthogonal systems, [1][2][3][4][5][6][7][8][9][10][11] where the optical axis is perpendicular to the propagation of the ultrasound wave. In addition, pulsed-ultrasound propagation technology [12][13][14] and ultrasound frequency sweep technology 4) have also been explored as ways of obtaining depth resolution in the sample.…”

“…The modulation signals have been examined by coaxial systems [12][13][14] as well as with orthogonal systems, [1][2][3][4][5][6][7][8][9][10][11] where the optical axis is perpendicular to the propagation of the ultrasound wave. In addition, pulsed-ultrasound propagation technology [12][13][14] and ultrasound frequency sweep technology 4) have also been explored as ways of obtaining depth resolution in the sample. For the aim of practical medical applications, our group developed a coaxial ultrasoundmodulated optical tomography system with parallel speckle detection that has the advantages of coaxial illumination generated from ultrasound waves and light photons, along with a reflection configuration, axial discrimination, and high signal to noise ratio detection.…”

Coaxial ultrasound-modulated optical spectroscopy in scattering medium

“…© 2008 American Institute of Physics. ͓DOI: 10.1063/1.2917459͔ Ultrasound-modulated optical tomography [1][2][3][4][5][6][7][8][9][10][11] has the possibility of detecting optical tissue structures at depths of several centimeters below the skin surface at spatial resolutions of better than a millimeter, and to reveal internal structures in acoustically impedance-matched tissues, which ultrasonography cannot visualize. Ultrasound-modulated optical spectroscopy, which combines ultrasound-modulated optical tomography with spectroscopic techniques, achieves active spectroscopy forced by external ultrasonic pressure waves enabling the measurement of physiological soft tissue.…”

Ultrasound-modulated optical tomography in reflection mode with ring-shaped light illumination

“…The line focus of the light is aligned with the ultrasonic focal zone in the water, forming a quasi-confocal configuration of optical illumination and ultrasound. Compared with a coaxial bright-field light illumination design,16 this configuration has the following advantages: First, the large area of donut-shaped illumination reduces the optical fluence on the sample surface to 8 mW/cm 2 , within the current safety limit 17. Second, thanks to the evenly distributed light illumination, the light shadow effect can be alleviated.…”