TY - JOUR AB - Deep learning (DL) shows promise for quantitating anatomical features and functional parameters of tissues in quantitative optoacoustic tomography (QOAT), but its application to deep tissue is hindered by a lack of ground truth data. We propose DL-based "QOAT-Net,"which functions without labeled experimental data: A dual-path convolutional network estimates absorption coefficients after training with data-label pairs generated via unsupervised "simulation-to-experiment"data translation. In simulations, phantoms, and ex vivo and in vivo tissues, QOAT-Net affords quantitative absorption images with high spatial resolution. This approach makes DL-based QOAT and other imaging applications feasible in the absence of ground truth data. AU - Li, J.* AU - Wang, C.* AU - Chen, T.* AU - Lu, T.* AU - Li, S.* AU - Sun, B.* AU - Gao, F.* AU - Ntziachristos, V. C1 - 64114 C2 - 51810 CY - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa SP - 32-41 TI - Deep learning-based quantitative optoacoustic tomography of deep tissues in the absence of labeled experimental data. JO - Optica VL - 9 IS - 1 PB - Optical Soc Amer PY - 2022 SN - 2334-2536 ER - TY - JOUR AB - State-of-the-art optoacoustic tomographic imaging systems have been shown to attain three-dimensional (3D) frame rates of the order of 100 Hz. While such a high volumetric imaging speed is beyond reach for other bio-imaging modalities, it may still be insufficient to accurately monitor some faster events occurring on a millisecond scale. Increasing the 3D imaging rate is usually hampered by the limited throughput capacity of the data acquisition electronics and memory used to capture vast amounts of the generated optoacoustic (OA) data in real time. Herein, we developed a sparse signal acquisition scheme and a total-variation-based reconstruction approach in a combined space-time domain in order to achieve 3D OA imaging at kilohertz rates. By continuous monitoring of freely swimming zebrafish larvae in a 3D region, we demonstrate that the new approach enables significantly increasing the volumetric imaging rate by using a fraction of the tomographic projections without compromising the reconstructed image quality. The suggested method may benefit studies looking at ultrafast biological phenomena in 3D, such as large-scale neuronal activity, cardiac motion, or freely behaving organisms. AU - Özbek, A. AU - Dean-Ben, X.L. AU - Razansky, D. C1 - 53918 C2 - 45046 SP - 857-863 TI - Optoacoustic imaging at kilohertz volumetric frame rates. JO - Optica VL - 5 IS - 7 PY - 2018 SN - 2334-2536 ER - TY - JOUR AB - The addition of optoacoustic sensing to optical microscopy may supplement fluorescence contrast with label-free measurements of optical absorption, enhancing biological observation. However, the physical dimensions of many optoacoustic systems have restricted the implementation of hybrid optical and optoacoustic (O2A) microscopy to imaging thin samples in transmission mode or to ex-vivo investigations. Here we describe a miniaturized optoacoustic sensor, based on a AU - Shnaiderman, R. AU - Wissmeyer, G. AU - Seeger, M. AU - Soilman, D. AU - Estrada, H. AU - Razansky, D. AU - Rosenthal, A. AU - Ntziachristos, V. C1 - 52035 C2 - 43658 CY - Washington SP - 1180-1187 TI - Fiber interferometer for hybrid optical and optoacoustic intravital microscopy. JO - Optica VL - 4 IS - 10 PB - Optical Soc Amer PY - 2017 SN - 2334-2536 ER - TY - JOUR AB - Optoacoustic microscopy (OAM) is a hybrid imaging method that can achieve high spatial resolution at superficial depths through use of focused illumination; it can be adapted for imaging with ultrasonic resolution at much greater depths where the excitation light is diffuse. These two distinct modes of operation can be further combined to create a highly scalable technique that can image at multiple penetration scales by gradually exchanging microscopic optical resolution in superficial tissue layers with ultrasonic resolution at diffuse (macroscopic) depths. However, OAM commonly employs scanning acquisition geometries that impede the effective use of synthetic aperture focusing techniques due to varying illumination patterns and non-uniformity of the excitation light field. Here we present a universal framework for scanning optoacoustic microscopy that uses a weighted synthetic aperture focusing technique (W-SAFT) to create a uniform imaging sensitivity across microscopic, mesoscopic, and macroscopic penetration regimes. Robust performance of the new multi-scale reconstruction methodology is showcased with simulations and synthetic phantoms, and validated with experimental data acquired from a highly scattering juvenile zebrafish specimen. It is shown that consideration of the light fluence is vital for maintaining the optically dictated lateral resolution at ballistic depths while optimizing the resolution of out-of-focus ultrasonic data; additionally, the dynamic-range compression facilitates the visualization across the entire imaged volume. The newly introduced W-SAFT reconstruction framework is universally applicable to a wide palette of scanning-based optoacoustic imaging techniques employing non-uniform and/or varying illumination, such as acoustic resolution and hybrid focus microscopy, raster-scan optoacoustic mesoscopy, as well as tomographic approaches using scanning of focused array transducers. AU - Turner, J.E. AU - Estrada, H. AU - Kneipp, M. AU - Razansky, D. C1 - 51569 C2 - 43213 CY - Washington SP - 770-778 TI - Universal weighted synthetic aperture focusing technique (W-SAFT) for scanning optoacoustic microscopy. JO - Optica VL - 4 IS - 7 PB - Optical Soc Amer PY - 2017 SN - 2334-2536 ER - TY - JOUR AB - Accurate visualization of biological events occurring on a sub-second scale requires high frame rate acquisition of image data from living tissues. Yet,fast imaging performance commonly comes at the cost of limited field-of-view and reduced image quality. Here,we report on a small-animal optoacoustic tomographic imaging concept based on scanning of a spherical detection array. The suggested approach delivers whole-body images of unparalleled quality while retaining real-time volumetric imaging capability within selected regions at the whole organ scale. Imaging performance was tested in tissue-mimicking phantoms and living animals,attaining nearly isotropic three-dimensional spatial resolution in the range of 250-500 µm across fields of view covering the entire mouse body. The system maintained high volumetric imaging rates of 100 frames per second within volumes of up to 1.5 cm3,which further allowed visualizing the fast motion of a beating mouse heart without gating the acquisition. The newly introduced approach is ideally suited for acquisition of both real-time and whole-body volumetric image data,thus offering powerful capacities for simultaneous anatomical,functional,and molecular imaging with optoacoustics. AU - Fehm, T. AU - Dean-Ben, X.L. AU - Ford, S.J. AU - Razansky, D. C1 - 50048 C2 - 41998 CY - Washington SP - 1153-1159 TI - In vivo whole-body optoacoustic scanner with real-time volumetric imaging capacity. JO - Optica VL - 3 IS - 11 PB - Optical Soc Amer PY - 2016 SN - 2334-2536 ER -