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Papers by Vyacheslav Nadvoretskiy

Research paper thumbnail of Image processing and analysis in a dual-modality optoacoustic/ultrasonic system for breast cancer diagnosis

Proceedings of SPIE, Feb 10, 2011

Coregistered optoacoustic (OA) and ultrasound (US) images obtained using a dual modality optoacou... more Coregistered optoacoustic (OA) and ultrasound (US) images obtained using a dual modality optoacoustic/ultrasonic breast imaging system are used together for enhanced diagnostic capabilities in comparison to each individual technology. Therefore, an operator-independent delineation of diagnostically relevant objects (in our case breast tumors) with subsequent automatic analysis of image features is required. We developed the following procedure: 1) Image filtering is implemented on a US image to minimize speckle noise and simultaneously preserve the sharpness of the boundaries of the extended objects; 2) Boundaries of the objects of interest are automatically delineated starting with an initial guess made by an operator; 3) Both US and OA images are analyzed using the detected boundaries (contrast, boundary sharpness, homogeneity of the objects and background, boundary morphology parameters are calculated). Calculated image characteristics can be used for statistically independent evaluation of structural information (US data) and vascularization (OA data) of the studied breast tissues. Operator-independent delineation of the objects of interest (e.g. tumors and blood vessels) is essential in clinical OA spectroscopy (using multiple laser wavelengths to quantify concentrations of particular tissue chromophores, such as oxy-and deoxy-hemoglobin, water, and lipids). Another potential application of the suggested image analysis algorithm could be in OA imaging system design, when system performance should be evaluated in terms of quality of the images reconstructed from the well-defined objects of interest. The discussed principles of image analysis are illustrated by using real clinical US and OA data.

Research paper thumbnail of Temperature dependence of Grüneisen parameter in optically absorbing solutions measured by 2D optoacoustic imaging

Proceedings of SPIE, Mar 3, 2014

A new experimental approach for measurements of temperature dependence of the Grüneisen parameter... more A new experimental approach for measurements of temperature dependence of the Grüneisen parameter in optically absorbing solutions is proposed. Two-dimensional optoacoustic (OA) imaging is used to improve accuracy of signal amplitude measurements and spatial localization of the studied samples. We estimated OA response of optically absorbing solutions measuring median intensity of OA images within the region of interest (ROI) as a function of temperature. We showed that when normalized to its value at a particular temperature, OA image intensity becomes an accurate metric reflecting temperature changes of Grüneisen parameter regardless of local optical fluence and absorbance, assuming those remain constant with temperature. Using the proposed method we studied temperature dependence of aqueous solutions of nickel and cupric sulfate in the range from 4 to 40°C. Obtained results were compared with temperature dependence for the Grüneisen parameter of DI-water, which we measured by using carbon ink colloid. We also found that Grüneisen-temperature relationship for nickel sulfate exhibits linear trend with respect to the concentration, and is independent of coupling medium and laser excitation wavelength.In the future, the developed methodology could be adopted for important applications of in vivo optoacoustic temperature monitoring.

Research paper thumbnail of In vivo 3D visualization of peripheral circulatory system using linear optoacoustic array

Photons Plus Ultrasound: Imaging and Sensing 2010, 2010

ABSTRACT In this work we modified light illumination of the laser optoacoustic (OA) imaging syste... more ABSTRACT In this work we modified light illumination of the laser optoacoustic (OA) imaging system to improve the D visualization of human forearm vasculature. The computer modeling demonstrated that the new illumination design that features laser beams converging on the surface of the skin in the imaging plane of the probe provides superior OA images in comparison to the images generated by the illumination with parallel laser beams. We also developed the procedure for vein/artery differentiation based on OA imaging with 690 nm and 1080 nm laser wavelengths. The procedure includes statistical analysis of the intensities of OA images of the neighboring blood vessels. Analysis of the OA images generated by computer simulation of a human forearm illuminated at 690 nm and 1080 nm resulted in successful differentiation of veins and arteries. In vivo scanning of a human forearm provided high contrast 3D OA image of a forearm skin and a superficial blood vessel. The blood vessel image contrast was further enhanced after it was automatically traced using the developed software. The software also allowed evaluation of the effective blood vessel diameter at each step of the scan. We propose that the developed 3D OA imaging system can be used during preoperative mapping of forearm vessels that is essential for hemodialysis treatment.

Research paper thumbnail of Image reconstruction and system optimization for three-dimensional speed of sound tomography using laser-induced ultrasound

Photons Plus Ultrasound: Imaging and Sensing 2013, 2013

Research paper thumbnail of Real-time optoacoustic imaging of breast cancer using an interleaved two laser imaging system coregistered with ultrasound

Photons Plus Ultrasound: Imaging and Sensing 2010, 2010

Research paper thumbnail of Three-Dimensional Optoacoustic Imaging System and Its Applications for Functional and Molecular Imaging

Biomedical Optics and 3-D Imaging, 2010

» View Full Text: Acrobat PDF (196 KB) * * Note that full-text PDFs from conferences typically co... more » View Full Text: Acrobat PDF (196 KB) * * Note that full-text PDFs from conferences typically contain 1-3 pages of content, some or all of which might be an abstract, summary, or miscellaneous items. ... Optoacoustic system designed for three-dimensional whole body tomography of ...

Research paper thumbnail of Clinical feasibility of coregistered opto-acoustic and ultrasonic imaging for differentiation of breast tumors

Research paper thumbnail of Optoacoustic imaging system having handheld probe utilizing optically reflective material

Research paper thumbnail of Dual modality imaging system for coregistered functional and anatomical mapping

Research paper thumbnail of 3D laser optoacoustic ultrasonic imaging system for preclinical research

Photons Plus Ultrasound: Imaging and Sensing 2013, 2013

Research paper thumbnail of Using optoacoustic imaging for measuring the temperature dependence of Grüneisen parameter in optically absorbing solutions

Research paper thumbnail of Ultrasound absorption in magnetic nanofluids

A novel magnetodynamic mechanism of ultrasound absorption is proposed. It has relaxation form and... more A novel magnetodynamic mechanism of ultrasound absorption is proposed. It has relaxation form and reflects the specific properties of magnetic nanofluid due to the fact that nanoparticles of the solid phase have magnetic dipole moments. It is demonstrated that the most probable ultrasound energy dissipation channels are viscous, thermal and magnetodynamic. Comparison with existing experimental data is conducted. While the external magnetic field is applied the processes of nanoparticles aggregation are commenced. The aggregates appearing in magnetic nanofluid with external magnetic field applied are modeled by prolate spheroids of revolution. The analytical formula for ultrasound absorption coefficient in magnetic nanofluid with ellipsoidal particles is derived. The experimental results for ultrasound absorption anisotropy in dodecane-based magnetic nanofluid are received for the first time ever, and they demonstrate resonant ultrasound absorption at certain angle between ultrasound wave vector and direction of external magnetic field.

Research paper thumbnail of Generation of wide-directivity broadband ultrasound by short laser pulses

A three-dimensional mouse imaging system combining optoacoustic tomography and laser ultrasound (... more A three-dimensional mouse imaging system combining optoacoustic tomography and laser ultrasound (LOUIS-3DM) has been developed. It features broadband laser ultrasound emitters positioned opposite an array of transducers. This imaging geometry allows reconstruction of images that either depicts the speed of sound distribution from measured time of flight data, or acoustic attenuation from the measured signal amplitude. We have investigated the performance of two laser ultrasound source designs, both easily adaptable to a commercial imaging system: small diameter source (600 µm) generated off a flat surface, and larger diameter (3 mm) spherical source. Laser energy requirements are modest, well below 1 mJ per pulse for either design. Their performance at normal incidence is comparable both in amplitude and frequency response. However, off-axis generation differs dramatically and the shortcomings of the simple flat emitter design are evident. We show that, in order to achieve optimal performance through proper illumination of the detector array, spherical wave front characteristics are desired.

Research paper thumbnail of Optoacoustic angiography of peripheral vasculature

Photons Plus Ultrasound: Imaging and Sensing 2012, 2012

ABSTRACT We developed a new optoacoustic microangiography system (OmAS) intended for in-vivo vasc... more ABSTRACT We developed a new optoacoustic microangiography system (OmAS) intended for in-vivo vascular imaging of a human finger. The system employs an arc-shaped acoustic array that is rotated 360 degrees around the finger providing optoacoustic data necessary for tomographic reconstruction of the three-dimensional images of a finger. A near-infrared Q-switched laser is used to generate optoacoustic signals with increased contrast of blood vessels. The laser is coupled through two randomized fiberoptic bundles oriented in orthogonal optoacoustic mode. To demonstrate OmAS capabilities, we present a time-series of optoacoustic images of a human finger taken after the hypothermia stress test. The images show a detailed vascular anatomy of a finger down to the capillary level. A series of quick 30s scans allowed us to visualize the thermoregulatory response within the studied finger as it was manifested via vasomotor activity during the hypothermia recovery. We propose that the developed system can be used for diagnostics of various medical conditions that are manifested in change of the peripheral (finger) blood flow. Examples of the medical conditions that could be diagnosed and staged using the OmAS include the peripheral arterial disease (PAD), thrombosis, frostbite, and traumas.

Research paper thumbnail of Imaging technique for real-time temperature monitoring during cryotherapy of lesions

Journal of Biomedical Optics, 2016

Research paper thumbnail of Abstract 2339: A Novel Semi-automated Algorithm for Analysis of Right Ventricular Volume and Function by Real-time 3-Dimensional Echocardiography in Children

Circulation, Oct 31, 2007

Research paper thumbnail of Abstract 3414: Assessment of Right Ventricular Volumes and Ejection Fraction by Real-Time 3-Dimensional Echocardiography in Children: A Validation Study Compared with Magnetic Resonance Imaging

Circulation, Oct 31, 2006

Research paper thumbnail of Effect of rotating partial illumination on image reconstruction for optoacoustic breast tomography

Photons Plus Ultrasound: Imaging and Sensing 2015, 2015

Research paper thumbnail of Measurement of Volumetric Flow by Real-time 3-Dimensional Doppler Echocardiography in Children

Journal of the American Society of Echocardiography, 2007

Research paper thumbnail of How accurately, reproducibly, and efficiently can we measure left ventricular indices using M-mode, 2-dimensional, and 3-dimensional echocardiography in children?

American Heart Journal, 2008

Background Measurements of left ventricular (LV) size, mass, and function are the most common and... more Background Measurements of left ventricular (LV) size, mass, and function are the most common and important tasks for echocardiography in clinical practice and research in children with congenital and acquired heart diseases. There are little data to compare the utility of M-mode (MM), 2-dimensional (2D), and 3-dimensional (3D) echocardiographic techniques for quantification of LV indices. The objective of the study was to assess the accuracy, reproducibility, and efficiency of these echocardiographic methods for measurement of LV indices in children.

Research paper thumbnail of Image processing and analysis in a dual-modality optoacoustic/ultrasonic system for breast cancer diagnosis

Proceedings of SPIE, Feb 10, 2011

Coregistered optoacoustic (OA) and ultrasound (US) images obtained using a dual modality optoacou... more Coregistered optoacoustic (OA) and ultrasound (US) images obtained using a dual modality optoacoustic/ultrasonic breast imaging system are used together for enhanced diagnostic capabilities in comparison to each individual technology. Therefore, an operator-independent delineation of diagnostically relevant objects (in our case breast tumors) with subsequent automatic analysis of image features is required. We developed the following procedure: 1) Image filtering is implemented on a US image to minimize speckle noise and simultaneously preserve the sharpness of the boundaries of the extended objects; 2) Boundaries of the objects of interest are automatically delineated starting with an initial guess made by an operator; 3) Both US and OA images are analyzed using the detected boundaries (contrast, boundary sharpness, homogeneity of the objects and background, boundary morphology parameters are calculated). Calculated image characteristics can be used for statistically independent evaluation of structural information (US data) and vascularization (OA data) of the studied breast tissues. Operator-independent delineation of the objects of interest (e.g. tumors and blood vessels) is essential in clinical OA spectroscopy (using multiple laser wavelengths to quantify concentrations of particular tissue chromophores, such as oxy-and deoxy-hemoglobin, water, and lipids). Another potential application of the suggested image analysis algorithm could be in OA imaging system design, when system performance should be evaluated in terms of quality of the images reconstructed from the well-defined objects of interest. The discussed principles of image analysis are illustrated by using real clinical US and OA data.

Research paper thumbnail of Temperature dependence of Grüneisen parameter in optically absorbing solutions measured by 2D optoacoustic imaging

Proceedings of SPIE, Mar 3, 2014

A new experimental approach for measurements of temperature dependence of the Grüneisen parameter... more A new experimental approach for measurements of temperature dependence of the Grüneisen parameter in optically absorbing solutions is proposed. Two-dimensional optoacoustic (OA) imaging is used to improve accuracy of signal amplitude measurements and spatial localization of the studied samples. We estimated OA response of optically absorbing solutions measuring median intensity of OA images within the region of interest (ROI) as a function of temperature. We showed that when normalized to its value at a particular temperature, OA image intensity becomes an accurate metric reflecting temperature changes of Grüneisen parameter regardless of local optical fluence and absorbance, assuming those remain constant with temperature. Using the proposed method we studied temperature dependence of aqueous solutions of nickel and cupric sulfate in the range from 4 to 40°C. Obtained results were compared with temperature dependence for the Grüneisen parameter of DI-water, which we measured by using carbon ink colloid. We also found that Grüneisen-temperature relationship for nickel sulfate exhibits linear trend with respect to the concentration, and is independent of coupling medium and laser excitation wavelength.In the future, the developed methodology could be adopted for important applications of in vivo optoacoustic temperature monitoring.

Research paper thumbnail of In vivo 3D visualization of peripheral circulatory system using linear optoacoustic array

Photons Plus Ultrasound: Imaging and Sensing 2010, 2010

ABSTRACT In this work we modified light illumination of the laser optoacoustic (OA) imaging syste... more ABSTRACT In this work we modified light illumination of the laser optoacoustic (OA) imaging system to improve the D visualization of human forearm vasculature. The computer modeling demonstrated that the new illumination design that features laser beams converging on the surface of the skin in the imaging plane of the probe provides superior OA images in comparison to the images generated by the illumination with parallel laser beams. We also developed the procedure for vein/artery differentiation based on OA imaging with 690 nm and 1080 nm laser wavelengths. The procedure includes statistical analysis of the intensities of OA images of the neighboring blood vessels. Analysis of the OA images generated by computer simulation of a human forearm illuminated at 690 nm and 1080 nm resulted in successful differentiation of veins and arteries. In vivo scanning of a human forearm provided high contrast 3D OA image of a forearm skin and a superficial blood vessel. The blood vessel image contrast was further enhanced after it was automatically traced using the developed software. The software also allowed evaluation of the effective blood vessel diameter at each step of the scan. We propose that the developed 3D OA imaging system can be used during preoperative mapping of forearm vessels that is essential for hemodialysis treatment.

Research paper thumbnail of Image reconstruction and system optimization for three-dimensional speed of sound tomography using laser-induced ultrasound

Photons Plus Ultrasound: Imaging and Sensing 2013, 2013

Research paper thumbnail of Real-time optoacoustic imaging of breast cancer using an interleaved two laser imaging system coregistered with ultrasound

Photons Plus Ultrasound: Imaging and Sensing 2010, 2010

Research paper thumbnail of Three-Dimensional Optoacoustic Imaging System and Its Applications for Functional and Molecular Imaging

Biomedical Optics and 3-D Imaging, 2010

» View Full Text: Acrobat PDF (196 KB) * * Note that full-text PDFs from conferences typically co... more » View Full Text: Acrobat PDF (196 KB) * * Note that full-text PDFs from conferences typically contain 1-3 pages of content, some or all of which might be an abstract, summary, or miscellaneous items. ... Optoacoustic system designed for three-dimensional whole body tomography of ...

Research paper thumbnail of Clinical feasibility of coregistered opto-acoustic and ultrasonic imaging for differentiation of breast tumors

Research paper thumbnail of Optoacoustic imaging system having handheld probe utilizing optically reflective material

Research paper thumbnail of Dual modality imaging system for coregistered functional and anatomical mapping

Research paper thumbnail of 3D laser optoacoustic ultrasonic imaging system for preclinical research

Photons Plus Ultrasound: Imaging and Sensing 2013, 2013

Research paper thumbnail of Using optoacoustic imaging for measuring the temperature dependence of Grüneisen parameter in optically absorbing solutions

Research paper thumbnail of Ultrasound absorption in magnetic nanofluids

A novel magnetodynamic mechanism of ultrasound absorption is proposed. It has relaxation form and... more A novel magnetodynamic mechanism of ultrasound absorption is proposed. It has relaxation form and reflects the specific properties of magnetic nanofluid due to the fact that nanoparticles of the solid phase have magnetic dipole moments. It is demonstrated that the most probable ultrasound energy dissipation channels are viscous, thermal and magnetodynamic. Comparison with existing experimental data is conducted. While the external magnetic field is applied the processes of nanoparticles aggregation are commenced. The aggregates appearing in magnetic nanofluid with external magnetic field applied are modeled by prolate spheroids of revolution. The analytical formula for ultrasound absorption coefficient in magnetic nanofluid with ellipsoidal particles is derived. The experimental results for ultrasound absorption anisotropy in dodecane-based magnetic nanofluid are received for the first time ever, and they demonstrate resonant ultrasound absorption at certain angle between ultrasound wave vector and direction of external magnetic field.

Research paper thumbnail of Generation of wide-directivity broadband ultrasound by short laser pulses

A three-dimensional mouse imaging system combining optoacoustic tomography and laser ultrasound (... more A three-dimensional mouse imaging system combining optoacoustic tomography and laser ultrasound (LOUIS-3DM) has been developed. It features broadband laser ultrasound emitters positioned opposite an array of transducers. This imaging geometry allows reconstruction of images that either depicts the speed of sound distribution from measured time of flight data, or acoustic attenuation from the measured signal amplitude. We have investigated the performance of two laser ultrasound source designs, both easily adaptable to a commercial imaging system: small diameter source (600 µm) generated off a flat surface, and larger diameter (3 mm) spherical source. Laser energy requirements are modest, well below 1 mJ per pulse for either design. Their performance at normal incidence is comparable both in amplitude and frequency response. However, off-axis generation differs dramatically and the shortcomings of the simple flat emitter design are evident. We show that, in order to achieve optimal performance through proper illumination of the detector array, spherical wave front characteristics are desired.

Research paper thumbnail of Optoacoustic angiography of peripheral vasculature

Photons Plus Ultrasound: Imaging and Sensing 2012, 2012

ABSTRACT We developed a new optoacoustic microangiography system (OmAS) intended for in-vivo vasc... more ABSTRACT We developed a new optoacoustic microangiography system (OmAS) intended for in-vivo vascular imaging of a human finger. The system employs an arc-shaped acoustic array that is rotated 360 degrees around the finger providing optoacoustic data necessary for tomographic reconstruction of the three-dimensional images of a finger. A near-infrared Q-switched laser is used to generate optoacoustic signals with increased contrast of blood vessels. The laser is coupled through two randomized fiberoptic bundles oriented in orthogonal optoacoustic mode. To demonstrate OmAS capabilities, we present a time-series of optoacoustic images of a human finger taken after the hypothermia stress test. The images show a detailed vascular anatomy of a finger down to the capillary level. A series of quick 30s scans allowed us to visualize the thermoregulatory response within the studied finger as it was manifested via vasomotor activity during the hypothermia recovery. We propose that the developed system can be used for diagnostics of various medical conditions that are manifested in change of the peripheral (finger) blood flow. Examples of the medical conditions that could be diagnosed and staged using the OmAS include the peripheral arterial disease (PAD), thrombosis, frostbite, and traumas.

Research paper thumbnail of Imaging technique for real-time temperature monitoring during cryotherapy of lesions

Journal of Biomedical Optics, 2016

Research paper thumbnail of Abstract 2339: A Novel Semi-automated Algorithm for Analysis of Right Ventricular Volume and Function by Real-time 3-Dimensional Echocardiography in Children

Circulation, Oct 31, 2007

Research paper thumbnail of Abstract 3414: Assessment of Right Ventricular Volumes and Ejection Fraction by Real-Time 3-Dimensional Echocardiography in Children: A Validation Study Compared with Magnetic Resonance Imaging

Circulation, Oct 31, 2006

Research paper thumbnail of Effect of rotating partial illumination on image reconstruction for optoacoustic breast tomography

Photons Plus Ultrasound: Imaging and Sensing 2015, 2015

Research paper thumbnail of Measurement of Volumetric Flow by Real-time 3-Dimensional Doppler Echocardiography in Children

Journal of the American Society of Echocardiography, 2007

Research paper thumbnail of How accurately, reproducibly, and efficiently can we measure left ventricular indices using M-mode, 2-dimensional, and 3-dimensional echocardiography in children?

American Heart Journal, 2008

Background Measurements of left ventricular (LV) size, mass, and function are the most common and... more Background Measurements of left ventricular (LV) size, mass, and function are the most common and important tasks for echocardiography in clinical practice and research in children with congenital and acquired heart diseases. There are little data to compare the utility of M-mode (MM), 2-dimensional (2D), and 3-dimensional (3D) echocardiographic techniques for quantification of LV indices. The objective of the study was to assess the accuracy, reproducibility, and efficiency of these echocardiographic methods for measurement of LV indices in children.