The xAM method derives from counterpropagating wave interaction theory, which predicts that, in media exhibiting quadratic elastic nonlinearity like biological tissue, the nonlinear interaction of counterpropagating acoustic waves is inefficient. To address this issue, we present an imaging paradigm, cross-amplitude modulation (xAM), which relies on cross-propagating plane-wave transmissions of finite aperture X waves to achieve quasi-artifact-free in vivo imaging of GVs. Unfortunately, the in vivo specificity of AM ultrasound imaging is systematically compromised by the nonlinearity added by the GVs to propagating waves, resulting in strong image artifacts from linear scatterers downstream of GV inclusions. We previously engineered GVs exhibiting a nonlinear scattering behavior in response to acoustic pressures above 300 kPa and showed that amplitude-modulated (AM) ultrasound pulse sequences that excite both the linear and nonlinear GV scattering regimes were highly effective at distinguishing GVs from linear scatterers like soft biological tissues. Acoustical methods for the in vivo detection of GVs are now required to maximize the impact of this technology in biology and medicine. The expression of these unique air-filled proteins, known as gas vesicles (GVs), in cells allows ultrasound to image cellular functions such as gene expression in vivo, providing ultrasound with its analog of optical fluorescent proteins. Recently, this capability was enhanced with the development of acoustic biomolecules-proteins with physical properties enabling them to scatter sound. 13, 1719-1727, 1996.The basic physics of sound waves enables ultrasound to visualize biological tissues with high spatial and temporal resolution. Besieris, "On the diffraction length of localized waves generated by dynamic apertures," J. Sprangle, "Diffraction effects in directed radiation beams," J. Wolf, Principles of Optics, Pergamon Press, Oxford, 1989.Ģ3. Sedky, "Generation of approximate focus wave mode pulses from wide-band dynamic Gaussian aperture," J. Besieris, "On the evanescent fields and the causality of the focus wave modes," J. Salomaa, "Space-frequency analysis of nondiffracting pulses," Opt. Salomaa, "Angular-spectrum representation of nondiffracting X waves," Phys. Besieris, "Reflection and transmission of electromagnetic X-waves in the presence of planarly layered media: The pulsed plane wave representation," submitted to J. El-Diwany, "Acoustic X-wave reflection and transmission at a planar interface: spectral analysis," J. Power, "The behavior of electromagnetic localized waves at a planar interface," IEEE Trans. Hillion, P., "How do focus wave modes propagate across a discontinuity in a medium?," Optik, Vol. Greenleaf, "Pulsed-echo imaging with X wave," Acoust. MacIsaac, "Spherical scattering of superpositions of localized waves," Phys. Reivelt, "Evidence of X-shaped propagationinvariant localized light waves," Phys.
.jpg "xwave echo 6w")
XWAVE ECHO 6W VERIFICATION
Greenleaf, "Experimental verification of nondiffracting X waves," IEEE Trans. Cook, "Experimental verification of the localized wave transmission effect," Phys. M., "Comparison of two localized wavefields generated from dynamic apertures," J. Chatzipetros, "Two fundamental representations of localized pulse solutions of the scalar wave equation," Progress in Electromagnetics Research (PIER), Vol. Recami, E., "On the localized ‘X-shaped’ superluminal solutions to Maxwell’s equations," Physica A, Vol.
Shaarawi, "Aperture realizations of the exact solutions to homogeneous-wave equations," J.
XWAVE ECHO 6W FREE
Greenleaf, "Nondiffracting X waves - exact solutions to free space scalar wave equation and their finite aperture realization," IEEE Trans. Ziolkowski, "A bidirectional traveling plane wave representation of exact solutions of the scalar wave equation," J. W., "Exact solutions of the wave equation with complex source locations," J. N., "Focus wave modes in homogeneous Maxwell equations: Transverse electric mode," J.
0 kommentar(er)
