TY  - JOUR
AB  - Interferometric fiber optic gyroscopes are widely used in spacecraft, navigation, and autopilot and missile systems due to their high accuracy and fast speed. However, the dynamic measurement range is generally limited to a small value. In this paper, an angular velocity measurement system based on a dual-comb Sagnac interferometer is proposed. The theoretical dynamic range can reach the order of 10(8) deg/s, which is remarkably superior to that of the conventional fiber optic gyroscopes. To the best of our knowledge, this is the first demonstration of a dual-comb-based passive fiber optic gyroscope system, offering an attractive tool for measuring angular velocity with large dynamic range.
AU  - Ma, R.
AU  - Yu, H.*
AU  - Ma, Q.*
AU  - Zhou, Q.*
AU  - Ni, K.*
C1  - 64292
C2  - 52057
CY  - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa
SP  - 730-733
TI  - Angular velocity measurement with wide range based on dual-comb Sagnac interferometer.
JO  - Opt. Lett.
VL  - 47
IS  - 3
PB  - Optical Soc Amer
PY  - 2022
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - The physical properties of each transducer element play a vital role in the quality of images generated in optoacoustic (photoacoustic) tomography using transducer arrays. Thorough experimental characterization of such systems is often laborious and impractical. A shortcoming of the existing impulse response correction methods, however, is the assumption that all transducers in the array are identical and therefore share one electrical impulse response (EIR). In practice, the EIRs of the transducer elements in the array vary, and the effect of this element-to-element variability on image quality has not been investigated so far, to the best of our knowledge. We hereby propose a robust EIR derivation for individual transducer elements in an array using sparse measurements of the total impulse response (TIR) and by solving the linear system for temporal convolution. Thereafter, we combine a simulated spatial impulse response with the derived individual EIRs to obtain a full characterization of the TIR, which we call individual synthetic TIR. Correcting for individual transducer responses, we demonstrate significant improvement in isotropic resolution, which further enhances the clinical potential of array-based. handheld transducers.
AU  - Basak, K.
AU  - Bader, M.
AU  - Dehner, C.
AU  - Jüstel, D.
AU  - Ntziachristos, V.
C1  - 61026
C2  - 50019
CY  - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa
SP  - 1-4
TI  - Individual transducer impulse response characterization method to improve image quality of array-based handheld optoacoustic tomography.
JO  - Opt. Lett.
VL  - 46
IS  - 1
PB  - Optical Soc Amer
PY  - 2021
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Laser ablation (LA) is a promising approach for minimally invasive cancer treatments. Its in vivo applicability is often impeded by the lack of efficient monitoring tools that can help to minimize collateral tissue damage and aid in determining the optimal treatment end-points. We have devised a new, to the best of our knowledge, hybrid LA approach combining simultaneous volumetric optoacoustic (OA) imaging to monitor the lesion progression accurately in real time and 3D. Time-lapse imaging of laser ablation of solid tumors was performed in a murine breast cancer model in vivo by irradiation of subcutaneous tumors with a 100 mJ short-pulsed (similar to 5 ns) laser operating at 1064 nm and 100 Hz pulse repetition frequency. Local changes in the OA signal intensity ascribed to structural alterations in the tumor vasculature were clearly observed, while the OA volumetric projections recorded in vivo appeared to correlate with cross sections of the excised tumors.
AU  - Periyasamy, V.
AU  - Özsoy, Ç.*
AU  - Reiss, M.*
AU  - Deán-Ben, X.L.*
AU  - Razansky, D.
C1  - 58823
C2  - 48382
CY  - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa
SP  - 2006-2009
TI  - In vivo optoacoustic monitoring of percutaneous laser ablation of tumors in a murine breast cancer model.
JO  - Opt. Lett.
VL  - 45
IS  - 7
PB  - Optical Soc Amer
PY  - 2020
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optical sensors developed for the assessment of oxygen in tissue microvasculature, such as those based on near-infrared spectroscopy, are limited in application by light scattering. Optoacoustic methods are insensitive to light scattering, and therefore, they can provide higher specificity and accuracy when quantifying local vascular oxygenation. However, currently, to the best of our knowledge, there is no low-cost, single point, optoacoustic sensor for the dedicated measurement of oxygen saturation in tissue microvasculature. This work introduces a spectroscopic optoacoustic sensor (SPOAS) for the non-invasive measurement of local vascular oxygenation in real time. SPOAS employs continuous wave laser diodes and measures at a single point, which makes it low-cost and portable. The SPOAS performance was benchmarked using blood phantoms, and it showed excellent linear correlation (R2 = 0.98) with a blood gas analyzer. Subsequent measurements of local vascular oxygenation in living mice during an oxygen stress test correlated well with simultaneous readings from a reference instrument.
AU  - Stylogiannis, A.
AU  - Riobo, L.
AU  - Prade, L.
AU  - Glasl, S.
AU  - Klein, S.*
AU  - Lucidi, G.*
AU  - Fuchs, M.*
AU  - Saur, D.*
AU  - Ntziachristos, V.
C1  - 60820
C2  - 49629
CY  - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa
SP  - 6579-6582
TI  - Low-cost single-point optoacoustic sensor for spectroscopic measurement of local vascular oxygenation.
JO  - Opt. Lett.
VL  - 45
IS  - 24
PB  - Optical Soc Amer
PY  - 2020
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Microscopic fluorescence imaging serves as a basic tool in many research areas including biology, medicine, and chemistry. With the help of optical clearing, large volume imaging of a mouse brain and even a whole body has been enabled. However, constrained by the physical principles of optical imaging, volume imaging has to balance imaging resolution and speed. Here, we develop a new, to the best of our knowledge, 3D deep learning network based on a dual generative adversarial network (dual-GAN) framework for recovering high-resolution (HR) volume images from high speed acquired low-resolution (LR) volume images. The proposed method does not require a precise image registration process and meanwhile guarantees the predicted HR volume image faithful to its corresponding LR volume image. The results demonstrated that our method can recover 20 x /1.0-NAvolume images from coarsely registered 5 x /0.16-NA volume images collected by light-sheet microscopy. This method. would provide great potential in applications which require high resolution volume imaging.
AU  - Zhou, H.*
AU  - Cai, R.
AU  - Quan, T.*
AU  - Liu, S.*
AU  - Li, S.*
AU  - Huang, Q.*
AU  - Ertürk, A.
AU  - Zeng, S.*
C1  - 58839
C2  - 48385
CY  - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa
SP  - 1695-1698
TI  - 3D high resolution generative deep-learning network for fluorescence microscopy imaging.
JO  - Opt. Lett.
VL  - 45
IS  - 7
PB  - Optical Soc Amer
PY  - 2020
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - This publisher’s note contains corrections to Opt. Lett.  39, 6297 (2014).
AU  - Aguirre Bueno, J.
AU  - Schwarz, M.
AU  - Soliman, D.
AU  - Bühler, A.
AU  - Omar, M.
AU  - Ntziachristos, V.
C1  - 57377
C2  - 47730
CY  - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa
SP  - 5116-5116
TI  - Broadband mesoscopic optoacoustic tomography reveals skin layers (vol 39, 6297, 2014).
JO  - Opt. Lett.
VL  - 44
IS  - 21
PB  - Optical Soc Amer
PY  - 2019
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Detailed assessment of skin conditions or the efficacy of skin treatments could greatly benefit from noninvasively assessing the distribution of cutaneous and subcutaneous structures and biomolecules. We considered ultrawideband raster scan optoacoustic mesoscopy with an extended wavelength range from visible to short-wave infrared and observed previously unseen high-resolution images of lipids colocalized with water, melanin, and hemoglobin distribution in human skin. Based on this contrast, the technique resolves subcutaneous fat, the pilosebaceous unit with complete hair strand and bulb, dermal microvasculature, and epidermal structures. We further visualize melanoidins that form via the Maillard reaction in the ultrathin stratum corneum layer, analyze their absorption spectrum, and separate them from the melanin layer. The suggested method may allow novel interrogation of skin conditions, possibly impacting diagnostics and medical and cosmetic treatments.
AU  - Berezhnoi, A.
AU  - Aguirre Bueno, J.
AU  - Hindelang, B.*
AU  - Garzorz-Stark, N.*
AU  - Omar, M.
AU  - Darsow, U.*
AU  - Eyerich, K.*
AU  - Ntziachristos, V.
C1  - 56840
C2  - 47263
CY  - 2010 Massachusetts Ave Nw, Washington, Dc 20036 Usa
SP  - 4119-4122
TI  - Optical features of human skin revealed by optoacoustic mesoscopy in the visible and short-wave infrared regions.
JO  - Opt. Lett.
VL  - 44
IS  - 17
PB  - Optical Soc Amer
PY  - 2019
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Radio frequency (RF) catheter ablation is commonly used to eliminate dysfunctional cardiac tissue by heating via an alternating current. Clinical outcomes are highly dependent on careful anatomical guidance, electrophysiological mapping, and careful RF power titration during the procedure. Yet, current treatments rely mainly on the expertise of the surgeon to assess lesion formation, causing large variabilities in the success rate. We present an integrated catheter design suitable for simultaneous RF ablation and real-time optoacoustic monitoring of the forming lesion. The catheter design utilizes copper-coated multimode light guides capable of delivering both ablation current and near-infrared pulsed-laser illumination to the target tissue. The generated optoacoustic responses were used to visualize the ablation lesion formation in an ex-vivo bovine heart specimen in 3D. The presented catheter design enables the monitoring of ablation lesions with high spatiotemporal resolution while the overall therapy-monitoring approach remains compatible with commercially available catheter designs.
AU  - Rebling, J.
AU  - Oyaga Landa, F.J.
AU  - Dean-Ben, X.L.
AU  - Douplik, A.*
AU  - Razansky, D.
C1  - 53470
C2  - 44586
SP  - 1886-1889
TI  - Integrated catheter for simultaneous radio frequency ablation and optoacoustic monitoring of lesion progression.
JO  - Opt. Lett.
VL  - 43
IS  - 8
PY  - 2018
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Epifluorescence imaging is widely used in cell and molecular biology due to its excellent sensitivity, contrast, and ease of implementation. Optoacoustic imaging has been shown to deliver a highly complementary and unique set of capabilities for biological discovery, such as high spatial resolution in noninvasive deep tissue observations, fast volumetric imaging capacity, and spectrally enriched contrast. In this Letter, we report on a hybrid system combining planar fluorescence and real-time volumetric four-dimensional optoacoustic imaging by means of a fiberscope integrated within a handheld hemispherical ultrasound detection array. The in vivo imaging performance is demonstrated by noninvasive visualization of fast contrast agent perfusion through the mouse brain. The proposed synergistic combination of fluorescence and optoacoustic imaging can benefit numerous studies looking at multi-scale in vivo dynamics, such as functional neuroimaging, visualization of organ perfusion and contrast agent uptake, cell tracking, and pharmacokinetic and bio-distribution analysis.
AU  - Chen, Z.
AU  - Dean-Ben, X.L.
AU  - Gottschalk, S.
AU  - Razansky, D.
C1  - 52409
C2  - 43975
CY  - Washington
SP  - 4577-4580
TI  - Hybrid system for in vivo epifluorescence and 4D optoacoustic imaging.
JO  - Opt. Lett.
VL  - 42
IS  - 22
PB  - Optical Soc Amer
PY  - 2017
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Limited-view artifacts are commonly present in optoacoustic tomography images, mainly due to practical geometrical and physical constraints imposed by the imaging systems. Herein, a new approach called dynamic particle-enhanced optoacoustic tomography (DPOT) is proposed for improving image contrast and visibility of optoacoustic images under limited-view scenarios. The method is based on a nonlinear combination of a temporal sequence of tomographic reconstructions representing sparsely distributed moving particles. We demonstrate experimental performance by dynamically imaging the flow of suspended microspheres in three dimensions, which shows promise for DPOT applicability in angiographic imaging in living organisms.
AU  - Dean-Ben, X.L.
AU  - Ding, L
AU  - Razansky, D.
C1  - 50559
C2  - 42358
CY  - Washington
SP  - 827-830
TI  - Dynamic particle enhancement in limited-view optoacoustic tomography.
JO  - Opt. Lett.
VL  - 42
IS  - 4
PB  - Optical Soc Amer
PY  - 2017
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Genetically-encoded calcium indicators (GECIs) have revolutionized neuroimaging by enabling mapping of the activity of entire neuronal populations in vivo. Visualization of these powerful activity sensors has to date been limited to depth-restricted microscopic studies due to intense light scattering in the brain. We demonstrate, for the first time, in vivo real-time volumetric optoacoustic monitoring of calcium transients in adult transgenic zebrafish expressing the GCaMP5G calcium indicator. Fast changes in optoacoustic traces associated with GCaMP5G activity were detectable in the presence of other strongly absorbing endogenous chromophores, such as hemoglobin. The new functional optoacoustic neuroimaging method can visualize neural activity at penetration depths and spatio-temporal resolution scales not covered with the existing neuroimaging techniques.
AU  - Dean-Ben, X.L.
AU  - Gottschalk, S.
AU  - Sela, G.
AU  - Shoham, S.*
AU  - Razansky, D.
C1  - 50711
C2  - 42463
SP  - 959-962
TI  - Functional optoacoustic neuro-tomography of calcium fluxes in adult zebrafish brain in vivo.
JO  - Opt. Lett.
VL  - 42
IS  - 5
PY  - 2017
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optoacoustic tomography based on insufficient spatial sampling of ultrasound waves leads to loss of contrast and artifacts on the reconstructed images. Compared to reconstructions based on L2-norm regularization, sparsity-based reconstructions may improve contrast and reduce image artifacts but at a high computational cost, which has so far limited their use to 2D optoacoustic tomography. Here we propose a fast, sparsity-based reconstruction algorithm for 3D optoacoustic tomography, based on gradient descent with Barzilai-Borwein line search (L1-GDBB). Using simulations and experiments, we show that the L1-GDBB offers fourfold faster reconstruction than the previously reported L1-norm regularized reconstruction based on gradient descent with backtracking line search. Moreover, the new algorithm provides higher-quality images with fewer artifacts than the L2-norm regularized reconstruction and the back-projection reconstruction.
AU  - Han, Y.
AU  - Ding, L.
AU  - Dean-Ben, X.L.
AU  - Razansky, D.
AU  - Prakash, J.
AU  - Ntziachristos, V.
C1  - 50710
C2  - 42462
SP  - 979-982
TI  - Three-dimensional optoacoustic reconstruction using fast sparse representation.
JO  - Opt. Lett.
VL  - 42
IS  - 5
PY  - 2017
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Multispectral tissue imaging based on optical cameras and continuous-wave tissue illumination is commonly used in medicine and biology. Surprisingly, there is a characteristic absence of a critical look at the quantities that can be uniquely characterized from optically diffuse matter by multispectral imaging. Here, we investigate the fundamental question of uniqueness in epi-illumination measurements from turbid media obtained at multiple wavelengths. By utilizing an analytical model, tissue-mimicking phantoms, and an in vivo imaging experiment we show that independent of the bands employed, spectral measurements cannot uniquely retrieve absorption and scattering coefficients. We also establish that it is, nevertheless, possible to uniquely quantify oxygen saturation and the Mie scattering power-a previously undocumented uniqueness condition.
AU  - Garcia-Allende, P.
AU  - Radrich, K.
AU  - Symvoulidis, P.
AU  - Glatz, J.
AU  - Koch, M.
AU  - Jentoft, K.*
AU  - Ripoll, J.*
AU  - Ntziachristos, V.
C1  - 49025
C2  - 41555
SP  - 3098-3101
TI  - Uniqueness in multispectral constant-wave epi-illumination imaging.
JO  - Opt. Lett.
VL  - 41
IS  - 13
PY  - 2016
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We propose the implementation of hybrid optical and acoustic resolution optoacoustic endoscopy. Laser light is transmitted to tissue by two types of illumination for achieving optical and acoustic resolution imaging. A 20 MHz ultrasound detector is used for recording optoacoustic signals. The endoscopy probe attains a 3.6 mm diameter and is fully encapsulated into a catheter system. We validate the imaging performance of the hybrid endoscope on phantoms and ex vivo, and discuss the necessity for the extended resolution and depth range of endoscopy achieved.
AU  - He, H.
AU  - Wissmeyer, G.
AU  - Ovsepian, S.V.
AU  - Bühler, A.
AU  - Ntziachristos, V.
C1  - 48886
C2  - 41444
CY  - Washington
SP  - 2708-2710
TI  - Hybrid optical and acoustic resolution optoacoustic endoscopy.
JO  - Opt. Lett.
VL  - 41
IS  - 12
PB  - Optical Soc Amer
PY  - 2016
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Lack of haptic feedback during laser surgery makes it difficult to control the incision depth, leading to high risk of undesired tissue damage. Here, we present a new feedback sensing method that accomplishes noncontact real-time monitoring of laser ablation procedures by detecting shock waves emanating from the ablation spot with air-coupled transducers. Experiments in soft and hard tissue samples attained high reproducibility in real-time depth estimation of the laser-induced cuts. The advantages derived from the noncontact nature of the suggested monitoring approach are expected to advance the general applicability of laser-based surgeries.
AU  - Oyaga Landa, F.J.
AU  - Dean-Ben, X.L.
AU  - de Espinosa, F.M.*
AU  - Razansky, D.
C1  - 48762
C2  - 41400
CY  - Washington
SP  - 2704-2707
TI  - Noncontact monitoring of incision depth in laser surgery with air-coupled ultrasound transducers.
JO  - Opt. Lett.
VL  - 41
IS  - 12
PB  - Optical Soc Amer
PY  - 2016
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optical and optoacoustic (photoacoustic) microscopy have been recently joined in hybrid implementations that resolve extended tissue contrast compared to each modality alone. Nevertheless, the application of the hybrid technique is limited by the requirement to combine an optical objective with ultrasound detection collecting signal from the same micro-volume. We present an all-optical optoacoustic microscope based on a pi-phase-shifted fiber Bragg grating (π-FBG) with coherence-restored pulsed interferometry (CRPI) used as the interrogation method. The sensor offers an ultra-small footprint and achieved higher sensitivity over piezoelectric transducers of similar size. We characterize the spectral bandwidth of the ultrasound detector and interrogate the imaging performance on phantoms and tissues. We show the first optoacoustic images of biological specimen recorded with π-FBG sensors. We discuss the potential uses of π-FBG sensors based on CRPI.
AU  - Wissmeyer, G.
AU  - Soliman, D.
AU  - Shnaiderman, R.
AU  - Rosenthal, A.
AU  - Ntziachristos, V.
C1  - 48440
C2  - 41093
CY  - Washington
SP  - 1953-1956
TI  - All-optical optoacoustic microscope based on wideband pulse interferometry.
JO  - Opt. Lett.
VL  - 41
IS  - 9
PB  - Optical Soc Amer
PY  - 2016
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Focusing light through turbid media represents a highly fascinating challenge in modern biophotonics. The unique capability of opto-acoustics for high-resolution imaging of light absorption contrast in deep tissues can provide a natural and efficient feedback to control light delivery in a scattering medium. While the basic feasibility of using opto-acoustic readings as a feedback mechanism for wavefront shaping has been recently reported, the suggested approaches may require long acquisition times, making them challenging to be translated into realistic tissue environments. In an attempt to significantly accelerate dynamic wavefront shaping capabilities, we present here a feedback-based approach using real-time three-dimensional opto-acoustic imaging assisted with genetic-algorithm-based optimization. The new technique offers robust performance in the presence of noisy measurements and can simultaneously control the scattered wave field in an entire volumetric region.
AU  - Dean-Ben, X.L.
AU  - Estrada, H.
AU  - Razansky, D.
C1  - 43271
C2  - 36278
CY  - Washington
SP  - 443-446
TI  - Shaping volumetric light distribution through turbid media using real-time three-dimensional opto-acoustic feedback.
JO  - Opt. Lett.
VL  - 40
IS  - 4
PB  - Optical Soc Amer
PY  - 2015
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Discerning the accurate distribution of chromophores and biomarkers by means of optoacoustic imaging is commonly challenged by the highly heterogeneous excitation light patterns resulting from strong spatial variations of tissue scattering and absorption. Here we used the light-fluence dependent switching kinetics of reversibly switchable fluorescent proteins (RSFPs), in combination with real-time acquisition of volumetric multi-spectral optoacoustic data to correct for the light fluence distribution deep in scattering media. The new approach allows for dynamic fluence correction in time-resolved imaging, e.g., of moving organs, and can be extended to work with a large palette of available synthetic and genetically encoded photochromic substances for multiplexed wavelength-specific fluence normalization.
AU  - Dean-Ben, X.L.
AU  - Stiel, A.C.*
AU  - Jiang, Y.
AU  - Ntziachristos, V.
AU  - Westmeyer, G.G.
AU  - Razansky, D.
C1  - 47179
C2  - 39138
SP  - 4691-4694
TI  - Light fluence normalization in turbid tissues via temporally unmixed multispectral optoacoustic tomography.
JO  - Opt. Lett.
VL  - 40
IS  - 20
PY  - 2015
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - The recently demonstrated control over light distribution through turbid media based on real-time three-dimensional optoacoustic feedback has offered promising prospects to interferometrically focus light within scattering objects. Nevertheless, the focusing capacity of the feedback-based approach is strongly conditioned by the number of optical modes (speckle grains) enclosed in the volume that can be resolved with the optoacoustic imaging system. In this Letter, we experimentally tested the light intensity enhancement achieved with optoacoustic feedback measurements from different sizes of absorbing microparticles. The importance of the obtained results is discussed in the context of potential signal enhancement at deep locations within a scattering medium where the effective speckle grain sizes approach the minimum values dictated by optical diffraction.
AU  - Dean-Ben, X.L.
AU  - Estrada, H.
AU  - Ozbek, A.
AU  - Razansky, D.
C1  - 47448
C2  - 39315
SP  - 5395-5398
TI  - Influence of the absorber dimensions on wavefront shaping based on volumetric optoacoustic feedback.
JO  - Opt. Lett.
VL  - 40
IS  - 22
PY  - 2015
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Unlike near-infrared spectroscopy, multispectral opto-acoustic tomography (MSOT) has the potential to offer high-resolution imaging assessment of hemodynamics and blood saturation levels in muscle. However motion artifacts impede the real-time applications of the technique. We developed fast-MSOT with motion tracking that reduces motion artifacts. We used this algorithm to follow blood oxygenation level changes associated with muscle exercise in the muscle and the skin of healthy volunteers.
AU  - Diot, G.
AU  - Dima, A.
AU  - Ntziachristos, V.
C1  - 44333
C2  - 36769
SP  - 1496-1499
TI  - Multispectral opto-acoustic tomography of exercised muscle oxygenation.
JO  - Opt. Lett.
VL  - 40
IS  - 7
PY  - 2015
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - The optoacoustic (photoacoustic) technique has been shown to resolve anatomical, functional, and molecular features at depths that go beyond the reach of epi-illumination optical microscopy, offering new opportunities for endoscopic imaging. In this Letter, we investigate the merits of optoacoustic endoscopy implemented by translating a sound detector in linear or curved geometries. The linear and curved detection geometries are achieved by employing an intravascular ultrasound transducer within a plastic guide shaped to a line or a curve. This concept could be used together with optical endoscopes to yield hybrid optical and optoacoustic imaging.
AU  - He, H.
AU  - Bühler, A.
AU  - Ntziachristos, V.
C1  - 47177
C2  - 39136
SP  - 4667-4670
TI  - Optoacoustic endoscopy with curved scanning.
JO  - Opt. Lett.
VL  - 40
IS  - 20
PY  - 2015
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We present a hybrid preclinical imaging scanner that optimally supports image acquisition in both reflection-mode ultrasonography and optoacoustic (OA) tomography modes. The system comprises a quasi-full-ring tomographic geometry capable of the simultaneous dual-mode imaging through entire cross sections of mice with in-plane spatial resolution in the range of 150 and 350 mu m in the respective OA and ultrasound (US) imaging modes with an imaging speed of up to 10 two-dimensional frames per second. Three-dimensional whole-body data is subsequently rendered by rapid scanning of the imaged plane. The system further incorporates rapid laser wavelength tuning for real-time acquisition of multispectral OA data, which enables studies of longitudinal dynamics as well as fast kinetics and biodistribution of contrast agents. In vivo imaging performance is demonstrated by label-free hybrid anatomical scans through living mice, as well as real-time visualization of optical contrast agent perfusion. By setting new standards for wholebody tomographic imaging performance in both the OA and pulse-echo US modes, the developed hybrid imaging approach is expected to benefit numerous applications where the availability of high-quality structural information provided by the tomographic reflection-mode US can ease interpretation of the functional and molecular imaging results attained by the OA modality.
AU  - Mercep, E.
AU  - Burton, N.C.
AU  - Claussen, J.*
AU  - Razansky, D.
C1  - 47479
C2  - 40602
SP  - 4643-4646
TI  - Whole-body live mouse imaging by hybrid reflection-mode ultrasound and optoacoustic tomography.
JO  - Opt. Lett.
VL  - 40
IS  - 20
PY  - 2015
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Photocontrol of reversibly switchable fluorescent proteins (RSFPs) was used to program optoacoustic signal time courses that were temporally unmixed to increase the proteins' contrast-to-noise-ratios (CNRs) in optoacoustic imaging. In this way, two variants of the RSFP Dronpa with very similar optoacoustic spectra could be readily discriminated in the presence of highly absorbing blood. Addition of temporal unmixing to multispectral optoacoustic tomography (tuMSOT) in conjunction with synthetic or genetically encoded photochromic contrast agents and customized photoswitching schedules can increase the performance of multiplexed and high-contrast molecular optoacoustic imaging.
AU  - Stiel, A.C.*
AU  - Dean-Ben, X.L.
AU  - Jiang, Y.
AU  - Ntziachristos, V.
AU  - Razansky, D.
AU  - Westmeyer, G.G.
C1  - 43345
C2  - 36341
CY  - Washington
SP  - 367-370
TI  - High-contrast imaging of reversibly switchable fluorescent proteins via temporally unmixed multispectral optoacoustic tomography.
JO  - Opt. Lett.
VL  - 40
IS  - 3
PB  - Optical Soc Amer
PY  - 2015
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We have imaged for the first time human skin in vivo with a raster-scan optoacoustic mesoscopy system based on a spherically focused transducer with a central frequency of 102.8 MHz and large bandwidth (relative bandwidth 105 %). Using tissue phantoms we have studied the ability of the system to image vessels of sizes within the anatomically significant range from the key anatomical vasculature sites. The reconstructed images from experiments in vivo show several structures from the capillary loops at the dermal papillae, the horizontal plexus and the difference between the dermis and the epidermis layers.
AU  - Aguirre Bueno, J.
AU  - Schwarz, M.
AU  - Soliman, D.
AU  - Bühler, A.
AU  - Omar, M.
AU  - Ntziachristos, V.
C1  - 32597
C2  - 35152
SP  - 6297-6300
TI  - Broadband mesoscopic optoacoustic tomography 2 reveals skin layers.
JO  - Opt. Lett.
VL  - 39
IS  - 21
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We interrogated whether optoacoustic tomography could be employed to study blood flow kinetics and bio-distribution of injected fluorescent agents in humans. Using a 128-channel scanner at a frame rate of 10 images per second, we obtained cross-sectional images of the human finger, before and after the administration of Indocyanine Green (ICG). We demonstrate that multi-spectral optoacoustic tomography (MSOT) can sense fast flow kinetics and resolve spatio-temporal characteristics of a common fluorochrome in human vasculature at clinically relevant concentrations. We further register ICG images with oxygen saturation maps and anatomical views of the proximal interphalangeal joint of a healthy volunteer.
AU  - Lutzweiler, C.
AU  - Meier, R.*
AU  - Rummeny, E.*
AU  - Ntziachristos, V.
AU  - Razansky, D.
C1  - 31639
C2  - 34594
CY  - Washington
SP  - 4061-4064
TI  - Real-time optoacoustic tomography of indocyanine green perfusion in human vasculature.
JO  - Opt. Lett.
VL  - 39
IS  - 14
PB  - Optical Soc Amer
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AU  - Mohajerani, P.
AU  - Kellnberger, S.
AU  - Ntziachristos, V.
C1  - 32563
C2  - 35151
SP  - 5455-5458
TI  - Fast Fourier backprojection for frequency-domain optoacoustic tomography.
JO  - Opt. Lett.
VL  - 39
IS  - 18
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We developed a reflection-mode optoacoustic mesoscopy system, based on raster-scanning of a custom designed spherically focused ultrasound detector, enabling seamless epi-illumination of the volume imaged. We study the performance of acoustic-resolution mesoscopy operating at an ultrawideband bandwidth of 20–180 MHz. i.e., a frequency band spreading over virtually an order of magnitude. Using tomographic reconstruction we showcase previously unreported, to our knowledge, axial resolutions of 4 μm and transverse resolutions of 18 μm reaching depths of up to 5 mm. We further investigate the frequency-dependence of features seen on the images to understand the implications of ultrawideband measurements. We show the overall imaging performance and the frequency ranges that contribute to observable resolution improvements from phantoms and animals.
AU  - Omar, M.
AU  - Soliman, D.
AU  - Gateau, J.*
AU  - Ntziachristos, V.
C1  - 31709
C2  - 34676
CY  - Washington
SP  - 3911-3914
TI  - Ultrawideband reflection-mode optoacoustic mesoscopy.
JO  - Opt. Lett.
VL  - 39
IS  - 13
PB  - Optical Soc Amer
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - The increasing preclinical and clinical utilization of digital cameras for photographic measurements of tissue conditions motivates the study of reflectance measurements obtained with planar illumination. We examine herein a formula that models the total diffuse reflectance measured from a semi-infinite medium using an exponentially decaying source, assuming continuous plane wave epi-illumination. The model is validated with experimental reflectance measurements from tissue mimicking phantoms. The need for adjusting the blood absorption spectrum due to pigment packaging is discussed along with the potential applications of the proposed formulation
AU  - Symvoulidis, P.
AU  - Jentoft, K.
AU  - Garcia-Allende, P.
AU  - Glatz, J.
AU  - Ripoll, J.*
AU  - Ntziachristos, V.
C1  - 31711
C2  - 34678
CY  - Washington
SP  - 3919-3922
TI  - Steady-state total diffuse reflectance with an exponential decaying source.
JO  - Opt. Lett.
VL  - 39
IS  - 13
PB  - Optical Soc Amer
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We present a hybrid microscope combining multiphoton microscopy incorporating second-harmonic generation contrast and optical-resolution optoacoustic (photoacoustic) microscopy. We study the relative performance of the two systems and investigate the complementarity of contrast by demonstrating the label-free imaging capabilities of the hybrid microscope on zebrafish larvae ex vivo, concurrently visualizing the fish musculature and melanocytes. This implementation can prove useful in multiparametric microscopy studies, enabling broader information to be collected from biological specimens.
AU  - Tserevelakis, G.J.
AU  - Soliman, D.
AU  - Omar, M.
AU  - Ntziachristos, V.
C1  - 30994
C2  - 34063
CY  - Washington
SP  - 1819-1822
TI  - Hybrid multiphoton and optoacoustic microscope.
JO  - Opt. Lett.
VL  - 39
IS  - 7
PB  - Optical Soc Amer
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Synthetic aperture focusing technique (SAFT) is effective in restoring lateral resolution of ultrasonic images for scans with focusing-related distortions. Although successfully applied in pulse-echo ultrasonics, the physical nature of an optoacoustic modality requires a modified algorithm to return accurate results. The SIR-SAFT method reported here uses the spatial impulse response (SIR) of the transducer to weight the contributions to the SAFT and is tailored to provide significant resolution and signal gains for out-of-focus sources in scanning optoacoustic microscopy systems. Furthermore, the SIR-SAFT is implemented in full three dimensions, applicable to signals both far of and at the focus of the ultrasonic detector. The method has been further shown to outperform conventional SAFT algorithms for both simulated and experimental optoacoustic data.
AU  - Turner, J.E.
AU  - Estrada, H.
AU  - Kneipp, M.
AU  - Razansky, D.
C1  - 31710
C2  - 34677
CY  - Washington
SP  - 3390-3393
TI  - Improved optoacoustic microscopy through three-dimensional spatial impulse response synthetic aperture focusing technique.
JO  - Opt. Lett.
VL  - 39
IS  - 12
PB  - Optical Soc Amer
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Multispectral optoacoustic tomography (MSOT) offers the potential to image in high-resolution cells tagged with optical labels. In contrast to single wavelength imaging, multispectral excitation and spectral unmixing can differentiate labeled moieties over tissue absorption in the absence of background measurements. This feature can enable longitudinal cellular biology studies well beyond the depths reached by optical microscopy. However, the relation between spectrally resolved fluorescently labeled cells and optoacoustic detection has not been systematically investigated. Herein, we measured titrations of fluorescently labeled cells and establish the optoacoustic signal generated by these cells as a function of cell number and across different cell types. We then assess the MSOT sensitivity to resolve cells implanted in animals.
AU  - Tzoumas, S.
AU  - Zaremba, A.
AU  - Klemm, U.
AU  - Nunes, A.
AU  - Schaefer, K.
AU  - Ntziachristos, V.
C1  - 31640
C2  - 34595
SP  - 3523-3526
TI  - Immune cell imaging using multi-spectral optoacoustic tomography.
JO  - Opt. Lett.
VL  - 39
IS  - 12
PY  - 2014
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Multispectral optoacoustic tomography (MSOT) of functional and molecular contrast has the potential to find broad deployment in clinical practice. We have developed the first handheld MSOT imaging device with fast wavelength tuning achieving a frame rate of 50 Hz. In this Letter, we demonstrate its clinical potential by dynamically resolving multiple disease-relevant tissue chromophores, including oxy-/deoxyhemoglobin, and melanin, in human volunteers.
AU  - Bühler, A.
AU  - Kacprowicz, M.*
AU  - Taruttis, A.
AU  - Ntziachristos, V.
C1  - 24362
C2  - 31507
SP  - 1404-1406
TI  - Real-time handheld multispectral optoacoustic imaging.
JO  - Opt. Lett.
VL  - 38
IS  - 9
PB  - Optical Soc. Amer.
PY  - 2013
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Broadband optoacoustic waves generated by biological tissues excited with nanosecond laser pulses carry information corresponding to a wide range of geometrical scales. Typically, the frequency content present in the signals generated during optoacoustic imaging is much larger compared to the frequency band captured by common ultrasonic detectors, the latter typically acting as bandpass filters. To image optical absorption within structures ranging from entire organs to microvasculature in three dimensions, we implemented optoacoustic tomography with two ultrasound linear arrays featuring a center frequency of 6 and 24 MHz, respectively. In the present work, we show that complementary information on anatomical features could be retrieved and provide a better understanding on the localization of structures in the general anatomy by analyzing multi-bandwidth datasets acquired on a freshly excised kidney.
AU  - Gateau, J.
AU  - Chekkoury, A.
AU  - Ntziachristos, V.
C1  - 28633
C2  - 33505
SP  - 4671-4674
TI  - Ultra-wideband three-dimensional optoacoustic tomography.
JO  - Opt. Lett.
VL  - 38
IS  - 22
PB  - Optical Soc. Amer.
PY  - 2013
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - The 360° rotation geometry of the hybrid fluorescence molecular tomography/x-ray computed tomography modality allows for acquisition of very large datasets, which pose numerical limitations on the reconstruction. We propose a compression method that takes advantage of the correlation of the Born-normalized signal among sources in spatially formed clusters to reduce the size of system model. The proposed method has been validated using an ex vivo study and an in vivo study of a nude mouse with a subcutaneous 4T1 tumor, with and without inclusion of a priori anatomical information. Compression rates of up to two orders of magnitude with minimum distortion of reconstruction have been demonstrated, resulting in large reduction in weight matrix size and reconstruction time.
AU  - Mohajerani, P.
AU  - Ntziachristos, V.
C1  - 26007
C2  - 32019
SP  - 2324-2326
TI  - Compression of Born ratio for fluorescence molecular tomography/X-ray computed tomography hybrid imaging: Methodology and in vivo validation.
JO  - Opt. Lett.
VL  - 38
IS  - 13
PB  - Optical Soc. Amer.
PY  - 2013
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We developed a raster-scan acoustic resolution broadband optoacoustic mesoscopy system and investigated the imaging performance using ultrasonic frequencies up to 125 MHz. The developed system achieves 7 μm axial resolution and transverse resolution of 30 μm reaching depths of at least 5 mm. This unprecedented performance is achieved by operating at out-of-focus ultrasonic detection and tomographic reconstruction. We demonstrate the limits reached due to the width of the laser pulse employed and showcase the technique on drosophila fly and drosophila pupae ex vivo.
AU  - Omar, M.
AU  - Gateau, J.
AU  - Ntziachristos, V.
C1  - 26005
C2  - 32018
SP  - 2472-2474
TI  - Raster-scan optoacoustic mesoscopy in the 25-125 MHz range.
JO  - Opt. Lett.
VL  - 38
IS  - 14
PB  - Optical Soc. Amer.
PY  - 2013
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optoacoustic (photoacoustic) mesoscopic and microscopic imaging is often implemented by linearly scanning a spherically focused ultrasound transducer. In this case, the resolution and sensitivity along the scan direction are limited by diffraction and therefore degrade rapidly for imaging depths away from the focal point. Partial restoration of the lost resolution can be achieved by using data-processing techniques, such as the virtual detector delay-and-sum method. However, these techniques are based on an approximate description of the detector properties, which limits the improvement in image quality they achieve. Herein we propose a reconstruction method based on an exact model of the optoacoustic generation and propagation that incorporates the spatial response of the sensor. The proposed method shows superior imaging performance over previously considered techniques.
AU  - Caballero, M.A.A.
AU  - Rosenthal, A.
AU  - Gateau, J.
AU  - Razansky, D.
AU  - Ntziachristos, V.
C1  - 10821
C2  - 30410
SP  - 4080-4082
TI  - Model-based optoacoustic imaging using focused detector scanning.
JO  - Opt. Lett.
VL  - 37
IS  - 19
PB  - Optical Soc. Amer.
PY  - 2012
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Image reconstruction in fluorescence diffuse optical tomography (FDOT) is a highly ill-posed inverse problem due to a large number of unknowns and limited measurements. In FDOT, the fluorophore distribution is often sparse in the imaging domain, since most fluorophores are designed to accumulate in relatively small regions. Compressive sensing theory has shown that sparse signals can be recovered exactly from only a small number of measurements when the forward sensing matrix is sufficiently incoherent. In this Letter, we present a method of preconditioning the FDOT forward matrix to reduce its coherence. The reconstruction results using real data obtained from a phantom experiment show visual and quantitative improvements due to preconditioning in conjunction with convex relaxation and greedy-type sparse signal recovery algorithms.
AU  - Jin, A.*
AU  - Yazici, B.*
AU  - Ale, A.B.F
AU  - Ntziachristos, V.
C1  - 11379
C2  - 30643
SP  - 4326-4328
TI  - Preconditioning of the fluorescence diffuse optical tomography sensing matrix based on compressive sensing.
JO  - Opt. Lett.
VL  - 37
IS  - 20
PB  - Optical Society of America
PY  - 2012
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optoacoustic imaging has been primarily implemented in the time domain, i.e., using ultrashort nanosecond laser pulses for illumination. Alternatively, frequency domain optoacoustic imaging can be performed when employing amplitude modulated light sources. We present herein a tomographic implementation of optoacoustic imaging using a linear frequency modulated laser source. The method developed demonstrated the ability to produce tomographic images of optical absorbing phantoms and in vivo images, by enabling visualization of the mouse tail following ICG injection.
AU  - Kellnberger, S.
AU  - Deliolanis, N.C.
AU  - Queirós, D.
AU  - Sergiadis, G.*
AU  - Ntziachristos, V.
C1  - 10412
C2  - 30244
SP  - 3423-3425
TI  - In vivo frequency domain optoacoustic tomography.
JO  - Opt. Lett.
VL  - 37
IS  - 16
PB  - Optical Soc. Amer.
PY  - 2012
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optical fibers have long been recognized as a promising technology for remote sensing of ultrasound. Nonetheless, very little is known about the characteristics of their spatial response, which is significantly affected by the strong acoustic mismatches between the fiber and surrounding medium. In this Letter, a new method is demonstrated for wideband spatial acoustic characterization of optical fibers. The method is based on the excitation of a point-like acoustic source via the opto-acoustic effect, while a miniature fiber sensor is implemented by a p-phase-shifted fiber Bragg grating. Despite the relative complexity of acoustic wave propagation in the fiber, its spatial sensitivity in the high frequency band (6-30 MHz) exhibited an orderly pattern, which can be described by a simple model. 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.
AU  - Rosenthal, A.
AU  - Caballero, M.A.A.
AU  - Kellnberger, S.
AU  - Razansky, D.
AU  - Ntziachristos, V.
C1  - 10413
C2  - 30253
SP  - 3174-3176
TI  - Spatial characterization of the response of a silica optical fiber to wideband ultrasound.
JO  - Opt. Lett.
VL  - 37
IS  - 15
PB  - Optical Soc. Amer.
PY  - 2012
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Quantification of biomarkers using multispectral optoacoustic tomography can be challenging due to photon fluence variations with depth and spatially heterogeneous tissue optical properties. 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.
AU  - Jetzfellner, T.
AU  - Rosenthal, A.
AU  - Bühler, A.
AU  - Englmeier, K.-H.
AU  - Razansky, D.
AU  - Ntziachristos, V.
C1  - 6609
C2  - 28964
CY  - New York, NJ
SP  - 4176-4178
TI  - Multispectral optoacoustic tomography by means of normalized spectral ratio.
JO  - Opt. Lett.
VL  - 36
IS  - 21
PB  - Optical Society of America
PY  - 2011
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - The normalized Born approximation has been suggested as a ratiometric method in fluorescence molecular tomography (FMT) applications, to account for heterogeneity variations. The method enabled practical inversions, as it offered fluorescence reconstruction accuracy over a wide range of absorption heterogeneity, while also accounting for unknown experimental factors, such as the various system gains and losses. Yet it was noted that scattering variations affect the robustness and accuracy. Herein we decompose the effects of absorption and scattering and capitalize on the recent development of hybrid FMT/x-ray computed tomography imaging methods to proposed amendments to the method, which improve the overall accuracy of the approach.
AU  - Pyka, T.
AU  - Schulz, R.B.
AU  - Ale, A.B.F.
AU  - Ntziachristos, V.
C1  - 6362
C2  - 29215
SP  - 4329-4331
TI  - Revisiting the normalized Born approximation: Effects of scattering.
JO  - Opt. Lett.
VL  - 36
IS  - 22
PB  - Optical Society of America
PY  - 2011
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - A highly sensitive compact hydrophone, based on a pi-phase-shifted fiber Bragg grating, has been developed for the measurement of wideband ultrasonic fields. The grating exhibits a sharp resonance, whose centroid wavelength is pressure sensitive. The resonance is monitored by a continuous-wave (CW) laser to measure ultrasound-induced pressure variations within the grating. In contrast to standard fiber sensors, the high finesse of the resonance-which is the reason for the sensor's high sensitivity-is not associated with a long propagation length. Light localization around the phase shift reduces the effective size of the sensor below that of the grating and is scaled inversely with the resonance spectral width. In our system, an effective sensor length of 270 μm, pressure sensitivity of 440 Pa, and effective bandwidth of 10 MHz were achieved. This performance makes our design attractive for medical imaging applications, such as optoacoustic tomography, in which compact, sensitive, and wideband acoustic detectors are required.
AU  - Rosenthal, A.
AU  - Razansky, D.
AU  - Ntziachristos, V.
C1  - 5962
C2  - 28586
SP  - 1833-1835
TI  - High-sensitivity compact ultrasonic detector based on a pi-phase-shifted fiber Bragg grating.
JO  - Opt. Lett.
VL  - 36
IS  - 10
PB  - Optical Society of America
PY  - 2011
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optoacoustic tomography can visualize optical contrast in tissues while capitalizing on the advantages of ultrasound, such as high spatial resolution and fast imaging capabilities. We report a novel multispectral optoacoustic tomography system for deep tissue small animal imaging. 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.
AU  - Bühler, A.
AU  - Herzog, E.
AU  - Razansky, D.
AU  - Ntziachristos, V.
C1  - 3235
C2  - 27299
SP  - 2475-2477
TI  - Video rate optoacoustic tomography of mouse kidney perfusion.
JO  - Opt. Lett.
VL  - 35
IS  - 14
PB  - Optical Soc. Amer.
PY  - 2010
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - The highly diffuse nature of light propagation in biological tissue is a major challenge for obtaining high-fidelity fluorescence tomographic images. In this work we investigated the use of time-gated detection of early-arriving photons for reducing the effects of light scatter in mice relative to quasi-cw photons. When analyzing sinographic representations of the measured data, it was determined that early photons allowed a reduction in the measured FWHM of fluorescent targets by a factor of approximately 2-3, yielding a significant improvement in the tomographic image reconstruction quality.
AU  - Niedre, M.*
AU  - Ntziachristos, V.
C1  - 1648
C2  - 27287
SP  - 369-371
TI  - Comparison of fluorescence tomographic imaging in mice with early-arriving and quasi-continuous-wave photons.
JO  - Opt. Lett.
VL  - 35
IS  - 3
PB  - Optical Soc. Amer.
PY  - 2010
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Optical projection tomography is a new ex vivo imaging technique that allows imaging of whole organs in three dimensions at high spatial resolutions. In this Letter we demonstrate its capability to tomographically visualize molecular activity in whole organs of mice. In particular, eosinophil activity in asthmatic lungs is resolved using a Born-normalized fluorescence optical projection tomography and employing a near-IR molecular probe. The possibility to achieve molecularly sensitive imaging contrast in optical projection tomography by means of targeted and activatable imaging reporter agents adds a new range of capabilities for investigating molecular signatures of pathophysiological processes and a wide variety of diseases and their development.
AU  - Vinegoni, C.*
AU  - Feruglio, P.F.*
AU  - Cortez-Retamozo, V.*
AU  - Razansky, D.
AU  - Medoff, B.D.*
AU  - Ntziachristos, V.
AU  - Sbarbati, A.*
AU  - Pittet, M.*
AU  - Weissleder, R.*
C1  - 903
C2  - 27151
SP  - 1088-1090
TI  - Imaging of molecular probe activity with Born-normalized fluorescence optical projection tomography.
JO  - Opt. Lett.
VL  - 35
IS  - 7
PB  - Optical Soc. Amer.
PY  - 2010
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Fluorescence diffuse optical tomography (FDOT) is a computationally demanding imaging problem. The discretizations of FDOT forward and inverse problems pose a trade-off between the accuracy and the computational efficiency of the image reconstruction. To address this trade-off, we analyzed the effect of discretization on the accuracy of FDOT imaging and proposed novel adaptive meshing algorithms for FDOT in a series of studies. In this Letter, we apply these new adaptive meshing algorithms to FDOT imaging using real data from a phantom experiment to demonstrate the practical advantages of our algorithms in FDOT image reconstruction.
AU  - Zhou, L.*
AU  - Yazici, B.*
AU  - Ale, A.B.F.
AU  - Ntziachristos, V.
C1  - 3839
C2  - 27857
CY  - Massachusetts
SP  - 3727-3729
TI  - Performance evaluation of adaptive meshing algorithms for fluorescence diffuse optical tomography using experimental data.
JO  - Opt. Lett.
VL  - 35
IS  - 22
PB  - Optical Soc. Amer.
PY  - 2010
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We present a normalized Born approach for fluorescence optical projection tomography that takes into account tissue absorption properties. This approach can be particularly useful to study fluorochrome distribution within tissue. We use the algorithm to three-dimensionally reconstruct and characterize a fluorescein isothiocyanate containing absorptive phantom and an infarcted mouse heart previously injected with a fluorescent molecular probe.
AU  - Vinegoni, C.*
AU  - Razansky, D.
AU  - Figueiredo, J.L.*
AU  - Nahrendorf, M.*
AU  - Ntziachristos, V.
AU  - Weissleder, R.*
C1  - 1330
C2  - 26055
SP  - 319-321
TI  - Normalized Born ratio for fluorescence optical projection tomography.
JO  - Opt. Lett.
VL  - 34
IS  - 3
PB  - Optical Soc Amer
PY  - 2009
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We report on a systematic study of upconverting fluorescence signal generation within turbid
      phantoms and real tissues. An accurate three-point Green's function, describing the forward model
      of photon propagation, is established and experimentally validated. We further demonstrate, for the
      first time to our knowledge, autofluorescence-free transillumination imaging of mice that have
      received biocompatible upconverting nanoparticles. The method holds great promise for artifact-free
      whole-body visualization of optical molecular probes.
AU  - Vinegoni, C.*
AU  - Razansky, D.
AU  - Hilderbrand, S.A.*
AU  - Shao, F.W.*
AU  - Ntziachristos, V.
AU  - Weissleder, R.*
C1  - 5731
C2  - 28363
SP  - 2566-2568
TI  - Transillumination fluorescence imaging in mice using biocompatible upconverting nanoparticles.
JO  - Opt. Lett.
VL  - 34
IS  - 17
PB  - Optical Society America
PY  - 2009
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - Polarization is indicative of material anisotropy, a property that reveals structural orientation information of molecules inside the material. Herein we investigate whether polarization can be detected optoacoustically in scattering and absorbing tissues. Using a laboratory prototype of polarization-sensitive optoacoustic tomography, we demonstrate high-resolution reconstructions of dichroism contrast deep in optically diffusive tissue-mimicking phantoms. 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.
AU  - Razansky, D.
AU  - Vinegoni, C.*
AU  - Ntziachristos, V.
C1  - 3322
C2  - 25807
SP  - 2308-2310
TI  - Polarization-sensitive optoacoustic tomography of optically diffuse tissues.
JO  - Opt. Lett.
VL  - 33
IS  - 20
PB  - Optical Society of America
PY  - 2008
SN  - 0146-9592
ER  - 

TY  - JOUR
AB  - We present a method for multispectral imaging. This method uses color CCD cameras with a multiple-bandpass filter, which modifies the spectral response of the cameras used and enables concurrent acquisition of multiple images at defined spectral bands. We experimentally demonstrate methodological feasibility using two color CCD cameras and a polychroic mirror to simultaneously capture eight spectral bands. We discuss how the method developed is well suited for multispectral applications of transient phenomena or for real-time measurements.
AU  - Themelis, G.
AU  - Yoo, J.S.
AU  - Ntziachristos, V.
C1  - 3018
C2  - 25468
SP  - 1023-1025
TI  - Multispectral imaging using multiple-bandpass filters.
JO  - Opt. Lett.
VL  - 33
IS  - 9
PB  - Optical Soc. Amer.
PY  - 2008
SN  - 0146-9592
ER  -