Daniel Razansky

..This study is aimed at demonstrating a new method with high potential for noninvasive clinical cardiovascular diagnostics of vulnerable plaques using high-resolution deep-tissue multispectral optoacoustic tomography (MSOT) technology...

..abstract:..

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..The utility of the method is demonstrated on several whole-body models and small-animal extremities...

..Overall, the entire protocol can be completed within 15-30 min for acquisition of a whole-body multispectral data set from a living mouse...

..However, existing implementations are based on modulated-carrier-frequency amplification solutions, which are generally costly and cannot achieve ultrahigh-peak-power requirements essential for optimal thermoacoustic signal generation...

..To investigate whether multispectral optoacoustic tomography (MSOT) can reveal the heterogeneous distributions of exogenous agents of interest and vascular characteristics through tumors of several millimeters in diameter in vivo...

..In many tomographic imaging scenarios, however, only limited-view or partial projection data are available, which has been shown to generate image artifacts and overall loss of quantification accuracy...

..Superior performance versus commonly-used backprojection inversion algorithms is showcased by numerical simulations and phantom experiments...

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..Significant improvements in image fidelity and quantification are showcased both numerically and experimentally on tissue phantoms and mice...

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..We also demonstrate how MSOT offers several compelling features for brain research and allows time-dependent detection and quantification of brain parameters that are not available using other imaging methods without invasive procedures...

..Overall, such imaging performance introduces previously undocumented capabilities of fast, high resolution in vivo imaging of the fate of optical agents for drug discovery and basic biological research...

..The system performance is determined in phantom experiments involving molecular probes and validated by imaging of small animals of various scales...

..We further demonstrate its capacity with temporal unmixing on real-time MSOT data obtained in-vivo for enhancing the visualization of absorber agent flow in the mouse vascular system...

..Herein we introduce a spectral ratio approach that accounts for photon fluence variations. The performance and imaging improvement achieved with the proposed method is showcased both numerically and experimentally in phantoms and mice...

..The validity and benefits of the suggested modelling and correction approaches are experimentally validated in phantom measurements...

..The achieved sensitivity is equivalent to the theoretical limit of a 6 MHz narrow-line width laser, which is 40 times higher than what can be usually achieved by incoherent interferometry for the same optical resonator...

..It is further anticipated that the new approach will greatly facilitate development of high performance 3-D optoacoustic reconstruction methods...

..This work aimed at investigating transmission lines as a method to generate excitation pulses to improve the NRT resolution over previous implementations without compromising the energy coupled into tissue...

..The performance of the new methodology is demonstrated for the case of 2-D optoacoustic tomography for both numerically generated and experimental data...

..The correction method presented could be generally applied to other MSOT imaging applications prone to motion artifacts, for example, by respiration and heartbeat...

..We discuss the potential of this imaging ability in cardiovascular disease (CVD) research and clinical applications...

..The previously undocumented capacity of whole-body optoacoustic tomography at a video rate has been demonstrated by visualizing mouse kidney perfusion using Indocyanine Green in vivo...

..The methods are successfully confirmed experimentally by measuring the frequency response of a common piezoelectric detector having a cylindrically focused shape...

..This performance is directly related to in vivo small animal imaging applications involving imaging in the presence of bones, lungs, and other highly mismatched organs...

..This effect may lead to attenuation or distortion in the recorded signal and, consequently, in the reconstructed image...

..Experimental results in a tissue-mimicking phantom clearly demonstrate improved performance as compared to the case in which no information on the distribution of acoustic scatterers is available...

..This property reveals new possibilities for high-performance imaging using fiber-based ultrasound sensors, where knowledge of the sensor's spatial sensitivity map is generally required...

..These new-found imaging abilities directly relate to preclinical screening applications in animal models and are foreseen to significantly impact clinical decision making as well...

..The technique is expected to enable highly accurate imaging of polarization contrast in tissues, far beyond the current capabilities of pure optical polarization-imaging approaches...

..The best spatial resolution achieved for those experiments was 150 µm...

..The proposed method shows superior imaging performance over previously considered techniques...

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..This imaging approach is geared toward in vivo molecular imaging of atherosclerotic biomarkers and is engineered to allow seamless integration into the cardiac catheterization laboratory...

..System performance is showcased in phantoms and in vivo imaging of microvasculature, achieving real time operation in two dimensions and penetration of 6 mm into optically dense human tissues...

..This performance makes our design attractive for medical imaging applications, such as optoacoustic tomography, in which compact, sensitive, and wideband acoustic detectors are required...

..The theoretical predictions are further validated in phantom experiments involving Cy5.5, a common near-infrared fluorescent molecular agent...

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