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Photoacoustics

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https://www.readbyqxmd.com/read/28603690/an-analytical-study-of-photoacoustic-and-thermoacoustic-generation-efficiency-towards-contrast-agent-and-film-design-optimization
#1
Fei Gao, Rahul Kishor, Xiaohua Feng, Siyu Liu, Ran Ding, Ruochong Zhang, Yuanjin Zheng
Photoacoustic (PA) and thermoacoustic (TA) effects have been explored in many applications, such as bio-imaging, laser-induced ultrasound generator, and sensitive electromagnetic (EM) wave film sensor. In this paper, we propose a compact analytical PA/TA generation model to incorporate EM, thermal and mechanical parameters, etc. From the derived analytical model, both intuitive predictions and quantitative simulations are performed. It shows that beyond the EM absorption improvement, there are many other physical parameters that deserve careful consideration when designing contrast agents or film composites, followed by simulation study...
September 2017: Photoacoustics
https://www.readbyqxmd.com/read/28540184/detection-of-intramyocardially-injected-dir-labeled-mesenchymal-stem-cells-by-optical-and-optoacoustic-tomography
#2
Markus T Berninger, Pouyan Mohajerani, Moritz Wildgruber, Nicolas Beziere, Melanie A Kimm, Xiaopeng Ma, Bernhard Haller, Megan J Fleming, Stephan Vogt, Martina Anton, Andreas B Imhoff, Vasilis Ntziachristos, Reinhard Meier, Tobias D Henning
The distribution of intramyocardially injected rabbit MSCs, labeled with the near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbo-cyanine-iodide (DiR) using hybrid Fluorescence Molecular Tomography-X-ray Computed Tomography (FMT-XCT) and Multispectral Optoacoustic Tomography (MSOT) imaging technologies, was investigated. Viability and induction of apoptosis of DiR labeled MSCs were assessed by XTT- and Caspase-3/-7-testing in vitro. 2 × 10(6), 2 × 10(5) and 2 × 10(4) MSCs labeled with 5 and 10 μg DiR/ml were injected into fresh frozen rabbit hearts...
June 2017: Photoacoustics
https://www.readbyqxmd.com/read/28507898/optically-and-acoustically-triggerable-sub-micron-phase-change-contrast-agents-for-enhanced-photoacoustic-and-ultrasound-imaging
#3
Shengtao Lin, Anant Shah, Javier Hernández-Gil, Antonio Stanziola, Bethany I Harriss, Terry O Matsunaga, Nicholas Long, Jeffrey Bamber, Meng-Xing Tang
We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of contrast enhancement: 1) photoacoustic imaging contrast, 2) ultrasound contrast with optical activation, and 3) ultrasound contrast with acoustic activation. This agent, which we name 'Cy-droplet', has the following novel features. It comprises a highly volatile perfluorocarbon for easy versatile activation, and a near-infrared optically absorbing dye chosen to absorb light at a wavelength with good tissue penetration...
June 2017: Photoacoustics
https://www.readbyqxmd.com/read/28417068/photoacoustic-in-vitro-flow-cytometry-for-nanomaterial-research
#4
Dmitry A Nedosekin, Tariq Fahmi, Zeid A Nima, Jacqueline Nolan, Chengzhong Cai, Mustafa Sarimollaoglu, Enkeleda Dervishi, Alexei Basnakian, Alexandru S Biris, Vladimir P Zharov
Conventional flow cytometry is a versatile tool for drug research and cell characterization. However, it is poorly suited for quantification of non-fluorescent proteins and artificial nanomaterials without the use of additional labeling. The rapid growth of biomedical applications for small non-fluorescent nanoparticles (NPs) for drug delivery and contrast and therapy enhancement, as well as research focused on natural cell pigments and chromophores, demands high-throughput quantification methods for the non-fluorescent components...
June 2017: Photoacoustics
https://www.readbyqxmd.com/read/28417067/quantitative-photoacoustic-integrating-sphere-qpais-platform-for-absorption-coefficient-and-gr%C3%A3-neisen-parameter-measurements-demonstration-with-human-blood
#5
Yolanda Villanueva-Palero, Erwin Hondebrink, Wilma Petersen, Wiendelt Steenbergen
Quantitative photoacoustic imaging in biomedicine relies on accurate measurements of relevant material properties of target absorbers. Here, we present a method for simultaneous measurements of the absorption coefficient and Grüneisen parameter of small volume of liquid scattering and absorbing media using a coupled-integrating sphere system which we refer to as quantitative photoacoustic integrating sphere (QPAIS) platform. The derived equations do not require absolute magnitudes of optical energy and pressure values, only calibration of the setup using aqueous ink dilutions is necessary...
June 2017: Photoacoustics
https://www.readbyqxmd.com/read/28393018/sonophore-labeled-rgd-a-targeted-contrast-agent-for-optoacoustic-imaging
#6
Katja Haedicke, Christian Brand, Murad Omar, Vasilis Ntziachristos, Thomas Reiner, Jan Grimm
Optoacoustic imaging is a rapidly expanding field for the diagnosis, characterization, and treatment evaluation of cancer. However, the availability of tumor specific exogenous contrast agents is still limited. Here, we report on a small targeted contrast agent for optoacoustic imaging using a black hole quencher(®) (BHQ) dye. The sonophore BHQ-1 exhibited strong, concentration-dependent, optoacoustic signals in phantoms, demonstrating its ideal suitability for optoacoustic imaging. After labeling BHQ-1 with cyclic RGD-peptide, BHQ-1-cRGD specifically bound to αvβ3-integrin expressing glioblastoma cell spheroids in vitro...
June 2017: Photoacoustics
https://www.readbyqxmd.com/read/28393017/photoacoustic-signal-characterization-of-cancer-treatment-response-correlation-with-changes-in-tumor-oxygenation
#7
Eno Hysi, Lauren A Wirtzfeld, Jonathan P May, Elijus Undzys, Shyh-Dar Li, Michael C Kolios
Frequency analysis of the photoacoustic radiofrequency signals and oxygen saturation estimates were used to monitor the in-vivo response of a novel, thermosensitive liposome treatment. The liposome encapsulated doxorubicin (HaT-DOX) releasing it rapidly (<20 s) when the tumor was exposed to mild hyperthermia (43 °C). Photoacoustic imaging (VevoLAZR, 750/850 nm, 40 MHz) of EMT-6 breast cancer tumors was performed 30 min pre- and post-treatment and up to 7 days post-treatment (at 2/5/24 h timepoints)...
March 2017: Photoacoustics
https://www.readbyqxmd.com/read/28239554/the-development-and-characterization-of-a-novel-yet-simple-3d-printed-tool-to-facilitate-phantom-imaging-of-photoacoustic-contrast-agents
#8
Santiago J Arconada-Alvarez, Jeanne E Lemaster, Junxin Wang, Jesse V Jokerst
We report a new approach to preparing phantoms using 3D printing. This device supports plastic tubing containing the contrast agent and is immersed in a solution with absorption or scattering properties that mimic tissue. Up to 12 tubing samples could be placed in the device with sample-to-sample spacing as low as 0.3 mm and at a constant distance from the transducer (±0.16 mm), which is critical in validating photoacoustic contrast agents. We also studied different types of tubing and found that tubing with a larger outside diameter has more inherent signal...
March 2017: Photoacoustics
https://www.readbyqxmd.com/read/28239553/on-the-use-of-an-optoacoustic-and-laser-ultrasonic-imaging-system-for-assessing-peripheral-intravenous-access
#9
A S Bychkov, V P Zarubin, A A Karabutov, V A Simonova, E B Cherepetskaya
We describe a universal system for research in combined real-time optoacoustic (OA) and laser-ultrasonic (LU) imaging. The results of its testing on the task of needle insertion into the blood vessel model diagnostics are presented. In OA mode, where laser light is absorbed directly in the sample, the contents of blood vessel model is clearly visible. In LU mode, where the short ultrasonic probe pulse scattered on the sample is detected, the needle is clearly visible. The developed solution combining OA and LU imaging modalities due to the common detection system allowed real-time diagnostics of the position of medical needles (0...
March 2017: Photoacoustics
https://www.readbyqxmd.com/read/28239552/fiber-optic-annular-detector-array-for-large-depth-of-field-photoacoustic-macroscopy
#10
Johannes Bauer-Marschallinger, Astrid Höllinger, Bernhard Jakoby, Peter Burgholzer, Thomas Berer
We report on a novel imaging system for large depth of field photoacoustic scanning macroscopy. Instead of commonly used piezoelectric transducers, fiber-optic based ultrasound detection is applied. The optical fibers are shaped into rings and mainly receive ultrasonic signals stemming from the ring symmetry axes. Four concentric fiber-optic rings with varying diameters are used in order to increase the image quality. Imaging artifacts, originating from the off-axis sensitivity of the rings, are reduced by coherence weighting...
March 2017: Photoacoustics
https://www.readbyqxmd.com/read/28066714/on-the-link-between-the-speckle-free-nature-of-optoacoustics-and-visibility-of-structures-in-limited-view-tomography
#11
Xosé Luís Deán-Ben, Daniel Razansky
Similar to pulse-echo ultrasound, optoacoustic imaging encodes the location of optical absorbers by the time-of-flight of ultrasound waves. Yet, signal generation mechanisms are fundamentally different for the two modalities, leading to significant distinction between the optimum image formation strategies. While interference of back-scattered ultrasound waves with random phases causes speckle noise in ultrasound images, speckle formation is hindered by the strong correlation between the optoacoustic responses corresponding to individual sources...
December 2016: Photoacoustics
https://www.readbyqxmd.com/read/27833857/detection-numerical-simulation-and-approximate-inversion-of-optoacoustic-signals-generated-in-multi-layered-pva-hydrogel-based-tissue-phantoms
#12
E Blumenröther, O Melchert, M Wollweber, B Roth
Optoacoustic (OA) measurements can not only be used for imaging purposes but as a more general tool to "sense" physical characteristics of biological tissue, such as geometric features and intrinsic optical properties. In order to pave the way for a systematic model-guided analysis of complex objects we devised numerical simulations in accordance with the experimental measurements. We validate our computational approach with experimental results observed for layered polyvinyl alcohol hydrogel samples, using melanin as the absorbing agent...
December 2016: Photoacoustics
https://www.readbyqxmd.com/read/27761410/photoacoustic-imaging-of-the-eye-a-mini-review
#13
Wenzhong Liu, Hao F Zhang
The eye relies on the synergistic cooperation of many different ocular components, including the cornea, crystalline lens, photoreceptors, and retinal neurons, to precisely sense visual information. Complications with a single ocular component can degrade vision and sometimes cause blindness. Immediate treatment and long-term monitoring are paramount to alleviate symptoms, restore vision, and cure ocular diseases. However, successful treatment requires understanding ocular pathological mechanisms, precisely detecting and monitoring the diseases...
September 2016: Photoacoustics
https://www.readbyqxmd.com/read/27761409/multimodal-optoacoustic-and-multiphoton-microscopy-of-human-carotid-atheroma
#14
Markus Seeger, Angelos Karlas, Dominik Soliman, Jaroslav Pelisek, Vasilis Ntziachristos
Carotid artery atherosclerosis is a main cause of stroke. Understanding atherosclerosis biology is critical in the development of targeted prevention and treatment strategies. Consequently, there is demand for advanced tools investigating atheroma pathology. We consider hybrid optoacoustic and multiphoton microscopy for the integrated and complementary interrogation of plaque tissue constituents and their mutual interactions. Herein, we visualize human carotid plaque using a hybrid multimodal imaging system that combines optical resolution optoacoustic (photoacoustic) microscopy, second and third harmonic generation microscopy, and two-photon excitation fluorescence microscopy...
September 2016: Photoacoustics
https://www.readbyqxmd.com/read/27761408/all-optical-optoacoustic-microscopy-based-on-probe-beam-deflection-technique
#15
Saher M Maswadi, Bennett L Ibey, Caleb C Roth, Dmitri A Tsyboulski, Hope T Beier, Randolph D Glickman, Alexander A Oraevsky
Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii) high sensitivity and (iv) ultrawide bandwidth...
September 2016: Photoacoustics
https://www.readbyqxmd.com/read/27761407/near-infrared-multispectral-photoacoustic-microscopy-using-a-graded-index-fiber-amplifier
#16
Takashi Buma, Jessica L Farland, Margaret R Ferrari
We demonstrate optical resolution photoacoustic microscopy (OR-PAM) of lipid-rich tissue using a multi-wavelength pulsed laser based on nonlinear fiber optics. 1047 nm laser pulses are converted to 1098, 1153, 1215, and 1270 nm pulses via stimulated Raman scattering in a graded-index multimode fiber. Multispectral PAM of a lipid phantom is demonstrated with our low-cost and simple technique.
September 2016: Photoacoustics
https://www.readbyqxmd.com/read/27761406/special-issue-introduction-photoacoustic-microscopy
#17
Hao F Zhang, Daniel Razansky
No abstract text is available yet for this article.
September 2016: Photoacoustics
https://www.readbyqxmd.com/read/27766211/multiple-irradiation-sensing-of-the-optical-effective-attenuation-coefficient-for-spectral-correction-in-handheld-oa-imaging
#18
K Gerrit Held, Michael Jaeger, Jaro Rička, Martin Frenz, H Günhan Akarçay
Spectral optoacoustic (OA) imaging enables spatially-resolved measurement of blood oxygenation levels, based on the distinct optical absorption spectra of oxygenated and de-oxygenated blood. Wavelength-dependent optical attenuation in the bulk tissue, however, distorts the acquired OA spectrum and thus makes quantitative oxygenation measurements challenging. We demonstrate a correction for this spectral distortion without requiring a priori knowledge of the tissue optical properties, using the concept of multiple irradiation sensing: recording the OA signal amplitude of an absorbing structure (e...
June 2016: Photoacoustics
https://www.readbyqxmd.com/read/27766210/in-vivo-handheld-optoacoustic-tomography-of-the-human-thyroid
#19
Alexander Dima, Vasilis Ntziachristos
We interrogated the application and imaging features obtained by non-invasive and handheld optoacoustic imaging of the thyroid in-vivo. Optoacoustics can offer complementary contrast to ultrasound, by resolving optical absorption-based and offering speckle-free imaging. In particular we inquired whether vascular structures could be better resolved using optoacoustics. For this reason we developed a compact handheld version of real-time multispectral optoacoustic tomography (MSOT) using a detector adapted to the dimensions and overall geometry of the human neck...
June 2016: Photoacoustics
https://www.readbyqxmd.com/read/27766209/high-resolution-imaging-of-impacted-cfrp-composites-with-a-fiber-optic-laser-ultrasound-scanner
#20
Ivan Pelivanov, Łukasz Ambroziński, Anton Khomenko, Ermias G Koricho, Gary L Cloud, Mahmoodul Haq, Matthew O'Donnell
Damage induced in polymer composites by various impacts must be evaluated to predict a component's post-impact strength and residual lifetime, especially when impacts occur in structures related to human safety (in aircraft, for example). X-ray tomography is the conventional standard to study an internal structure with high resolution. However, it is of little use when the impacted area cannot be extracted from a structure. In addition, X-ray tomography is expensive and time-consuming. Recently, we have demonstrated that a kHz-rate laser-ultrasound (LU) scanner is very efficient both for locating large defects and evaluating the material structure...
June 2016: Photoacoustics
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