1
|
Salimi M, Tabatabaei N, Villiger M. Artificial neural network for enhancing signal-to-noise ratio and contrast in photothermal optical coherence tomography. Sci Rep 2024; 14:10264. [PMID: 38704427 PMCID: PMC11069506 DOI: 10.1038/s41598-024-60682-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 04/25/2024] [Indexed: 05/06/2024] Open
Abstract
Optical coherence tomography (OCT) is a medical imaging method that generates micron-resolution 3D volumetric images of tissues in-vivo. Photothermal (PT)-OCT is a functional extension of OCT with the potential to provide depth-resolved molecular information complementary to the OCT structural images. PT-OCT typically requires long acquisition times to measure small fluctuations in the OCT phase signal. Here, we use machine learning with a neural network to infer the amplitude of the photothermal phase modulation from a short signal trace, trained in a supervised fashion with the ground truth signal obtained by conventional reconstruction of the PT-OCT signal from a longer acquisition trace. Results from phantom and tissue studies show that the developed network improves signal to noise ratio (SNR) and contrast, enabling PT-OCT imaging with short acquisition times and without any hardware modification to the PT-OCT system. The developed network removes one of the key barriers in translation of PT-OCT (i.e., long acquisition time) to the clinic.
Collapse
Affiliation(s)
- Mohammadhossein Salimi
- Department of Mechanical Engineering, Lassonde School of Engineering, York University, Toronto, ON, M3J 1P3, Canada
| | - Nima Tabatabaei
- Department of Mechanical Engineering, Lassonde School of Engineering, York University, Toronto, ON, M3J 1P3, Canada.
- Center for Vision Research, York University, Toronto, ON, M3J 1P3, Canada.
| | - Martin Villiger
- Department of Mechanical Engineering, Lassonde School of Engineering, York University, Toronto, ON, M3J 1P3, Canada.
- Harvard Medical School, Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, 02114, USA.
| |
Collapse
|
2
|
Sun J, Fang T, Wang H, Wang S. Photothermal optical coherence tomography for 3D live cell detection and mapping. OPTICS CONTINUUM 2023; 2:2468-2483. [PMID: 38665863 PMCID: PMC11044816 DOI: 10.1364/optcon.503577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/27/2023] [Indexed: 04/28/2024]
Abstract
Imaging cells in their 3D environment with molecular specificity is important to cell biology study. Widely used microscopy techniques, such as confocal microscopy, have limited imaging depth when probing cells in optically scattering media. Optical coherence tomography (OCT) can provide millimeter-level depth for imaging of highly scattering media but lacks the contrast to distinguish cells from extracellular matrix or to distinguish between different types of cells. Photothermal OCT (PT-OCT) is a promising technique to obtain molecular contrast at the imaging scale of OCT. Here, we report PT-OCT imaging of live, nanoparticle-labeled cells in 3D. In particular, we demonstrate detection and mapping of single cell in 3D without causing call death, and show the feasibility of 3D cell mapping through optical scattering media. This work presents live cell detection and mapping at an imaging scale that complements the major microscopy techniques, which is potentially useful to study cells in their 3D native or culture environment.
Collapse
Affiliation(s)
- Jingyu Sun
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Tianqi Fang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Hongjun Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| | - Shang Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030, USA
| |
Collapse
|
3
|
Salimi MH, Villiger M, Tabatabaei N. Three-dimensional opto-thermo-mechanical model for predicting photo-thermal optical coherence tomography responses in multilayer geometries. BIOMEDICAL OPTICS EXPRESS 2022; 13:3416-3433. [PMID: 35781956 PMCID: PMC9208589 DOI: 10.1364/boe.454491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/24/2022] [Accepted: 04/25/2022] [Indexed: 06/15/2023]
Abstract
Photothermal optical coherence tomography (PT-OCT) is a functional extension of OCT with the ability to generate qualitative maps of molecular absorptions co-registered with the micron-resolution structural tomograms of OCT. Obtaining refined insight into chemical information from PT-OCT images, however, requires solid understanding of the multifactorial physics behind generation of PT-OCT signals and their dependence on system and sample parameters. Such understanding is needed to decouple the various physical effects involved in the PT-OCT signal to obtain more accurate insight into sample composition. In this work, we propose an analytical model that considers the opto-thermo-mechanical properties of multi-layered samples in 3-D space, eliminating several assumptions that have been limiting previous PT-OCT models. In parametric studies, the model results are compared with experimental signals to investigate the effect of sample and system parameters on the acquired signals. The proposed model and the presented findings open the door for: 1) better understanding of the effects of system parameters and tissue opto-thermo-mechanical properties on experimental signals; 2) informed optimization of experimentation strategies based on sample and system parameters; 3) guidance of downstream signal processing for predicting tissue molecular composition.
Collapse
Affiliation(s)
- Mohammad Hossein Salimi
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
| | - Martin Villiger
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
- Harvard Medical School, Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, USA
| | - Nima Tabatabaei
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
| |
Collapse
|
4
|
Salimi MH, Villiger M, Tabatabaei N. Transient-mode photothermal optical coherence tomography. OPTICS LETTERS 2021; 46:5703-5706. [PMID: 34780441 PMCID: PMC10801791 DOI: 10.1364/ol.443987] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Photothermal optical coherence tomography (PT-OCT) is an emerging extension of OCT, which forms images based on both scattering and absorption of light. The speed of PT-OCT, however, has been limited by the necessity for lock-in detection with extensive temporal sampling of the sample's PT response. Here, we demonstrate transient-mode PT-OCT (TM-PT-OCT), which increases the effective A-line rate by orders of magnitude from 10-100 Hz to 1.5-7.5 kHz, by interrogating the sample's transient thermal response to a single diode laser pulse. Functional imaging of moving samples with TM-PT-OCT at video rate is also presented. This significant improvement in imaging speed is expected to open the door for downstream integration of PT-OCT in clinical systems for in vivo imaging.
Collapse
Affiliation(s)
- Mohammad Hossein Salimi
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
| | - Martin Villiger
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
- Harvard Medical School, Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
| | - Nima Tabatabaei
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
| |
Collapse
|
5
|
Salimi M, Villiger M, Tabatabaei N. Effects of lipid composition on photothermal optical coherence tomography signals. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200283LR. [PMID: 33369310 PMCID: PMC7757902 DOI: 10.1117/1.jbo.25.12.120501] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/01/2020] [Indexed: 05/02/2023]
Abstract
SIGNIFICANCE Photothermal optical coherence tomography (PT-OCT) has the promise to offer structural images coregistered with chemical composition information, which can offer a significant impact in early detection of diseases such as atherosclerosis. AIM We take the first step in understanding the relation between PT-OCT signals and the endogenous tissue composition by considering the interplay between the opto-thermo-physical properties of tissue as a function of its lipid composition and the ensuing effects on the PT-OCT signals. APPROACH Multiparameter theoretical estimates for PT-OCT signal as a function of composition in a two-component lipid-water model are derived and discussed. Experimental data from various concentrations of lipid in the form of droplets and injections under bovine cardiac muscle align with theoretical predictions. RESULTS Theoretical and experimental results suggest that the variations of heat capacity and mass density with tissue composition significantly contribute to the amount of optical path length difference measured by OCT phase. CONCLUSION PT-OCT has the potential to offer key insights into the chemical composition of the subsurface lipid pools in tissue; however, the interpretation of results needs to be carried out by keeping the nonlinear interplay between the tissue of opto-thermo-physical properties and PT-OCT signals in mind.
Collapse
Affiliation(s)
- Mohammadhossein Salimi
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
| | - Martin Villiger
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
- Harvard Medical School, Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Address all correspondence to Nima Tabatabaei, ; Martin Villiger,
| | - Nima Tabatabaei
- York University, Lassonde School of Engineering, Department of Mechanical Engineering, Toronto, Canada
- Address all correspondence to Nima Tabatabaei, ; Martin Villiger,
| |
Collapse
|
6
|
Leartprapun N, Lin Y, Adie SG. Microrheological quantification of viscoelastic properties with photonic force optical coherence elastography. OPTICS EXPRESS 2019; 27:22615-22630. [PMID: 31510549 PMCID: PMC6825604 DOI: 10.1364/oe.27.022615] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Photonic force optical coherence elastography (PF-OCE) is a new approach for volumetric characterization of microscopic mechanical properties of three-dimensional viscoelastic medium. It is based on measurements of the complex mechanical response of embedded micro-beads to harmonically modulated radiation-pressure force from a weakly-focused beam. Here, we utilize the Generalized Stokes-Einstein relation to reconstruct local complex shear modulus in polyacrylamide gels by combining PF-OCE measurements of bead mechanical responses and experimentally measured depth-resolved radiation-pressure force profile of our forcing beam. Data exclusion criteria for quantitative PF-OCE based on three noise-related parameters were identified from the analysis of measurement noise at key processing steps. Shear storage modulus measured by quantitative PF-OCE was found to be in good agreement with standard shear rheometry, whereas shear loss modulus was in agreement with previously published atomic force microscopy results. The analysis and results presented here may serve to inform practical, application-specific implementations of PF-OCE, and establish the technique as a viable tool for quantitative mechanical microscopy.
Collapse
|
7
|
Lapierre-Landry M, Huckenpahler AL, Link BA, Collery RF, Carroll J, Skala MC. Imaging Melanin Distribution in the Zebrafish Retina Using Photothermal Optical Coherence Tomography. Transl Vis Sci Technol 2018; 7:4. [PMID: 30197836 PMCID: PMC6126953 DOI: 10.1167/tvst.7.5.4] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 07/31/2018] [Indexed: 11/29/2022] Open
Abstract
Purpose To demonstrate and validate that photothermal optical coherence tomography (PT-OCT) can image melanin in the retinal pigment epithelium (RPE) and can observe light-driven melanosome translocation in the zebrafish retina. Methods A commercial spectral domain OCT system was modified to perform both OCT and PT-OCT. Four adult tyrosinase-mosaic zebrafish with varying levels of melanin expression across their retinas were imaged, and the PT-OCT signal for pigmented and nonpigmented regions were compared. Wild-type dark-adapted (n = 11 fish) and light-adapted (n = 10 fish) zebrafish were also imaged with OCT and PT-OCT. Longitudinal reflectivity and absorption profiles were generated from B-scans to compare the melanin distribution between the two groups. Results A significant increase in PT-OCT signal (P < 0.0001, Student's t-test) was observed in pigmented regions of interest (ROI) compared to nonpigmented ROIs in the tyrosinase-mosaic zebrafish, which confirms the PT-OCT signal is specific to melanin in the eye. A significant increase in PT-OCT signal intensity (P < 0.0001, Student's t-test) was also detected in the light-adapted wild-type zebrafish group compared to the dark-adapted group. Additionally, light-adapted zebrafish display more distinct melanin banding patterns than do dark-adapted zebrafish in PT-OCT B-scans. Conclusions PT-OCT can detect different levels of melanin absorption and characterize pigment distribution in the zebrafish retina, including intracellular changes due to light-driven melanosome translocation within the RPE. Translational Relevance PT-OCT could quantify changes in pigmentation that occur in retinal diseases. The functional information provided by PT-OCT may also enable a better understanding of the anatomical features within conventional OCT images.
Collapse
Affiliation(s)
- Maryse Lapierre-Landry
- Biomedical Engineering, Vanderbilt University, Nashville, TN, USA.,Morgridge Institute for Research, Madison, WI, USA
| | - Alison L Huckenpahler
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Brian A Link
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ross F Collery
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Carroll
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.,Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Melissa C Skala
- Morgridge Institute for Research, Madison, WI, USA.,Biomedical Engineering, University of Wisconsin Madison, Madison, WI, USA
| |
Collapse
|
8
|
Lapierre-Landry M, Connor TB, Carroll J, Tao YK, Skala MC. Photothermal optical coherence tomography of indocyanine green in ex vivo eyes. OPTICS LETTERS 2018; 43:2470-2473. [PMID: 29856406 PMCID: PMC8148624 DOI: 10.1364/ol.43.002470] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/25/2018] [Indexed: 05/03/2023]
Abstract
Indocyanine green (ICG) is routinely used during surgery to stain the inner limiting membrane (ILM) and provide contrast on white light surgical microscopy. While translation of optical coherence tomography (OCT) for intraoperative imaging during ophthalmic surgery has enhanced visualization, the ILM remains difficult to distinguish from underlying retinal structures and ICG does not provide additional OCT contrast. We present photothermal OCT (PT-OCT) for high-specificity detection of ICG on retinal OCT images. We demonstrate our technique by performing an ILM peel in ex vivo eyes using low ICG concentrations and laser powers. These results establish the feasibility of PT-OCT for intraoperative guidance during retinal surgery.
Collapse
Affiliation(s)
- Maryse Lapierre-Landry
- Department of Biomedical Engineering, Vanderbilt University, 2201 West End Ave., Nashville, Tennessee 37235, USA
- Morgridge Institute for Research, 330 N Orchard St., Madison, Wisconsin 53715, USA
| | - Thomas B. Connor
- Department of Ophthalmology & Visual Sciences, The Medical College of Wisconsin, 8701 W Watertown Plank Rd., Milwaukee, Wisconsin 53226, USA
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, The Medical College of Wisconsin, 8701 W Watertown Plank Rd., Milwaukee, Wisconsin 53226, USA
| | - Yuankai K. Tao
- Department of Biomedical Engineering, Vanderbilt University, 2201 West End Ave., Nashville, Tennessee 37235, USA
| | - Melissa C. Skala
- Morgridge Institute for Research, 330 N Orchard St., Madison, Wisconsin 53715, USA
- Department of Biomedical Engineering, University of Wisconsin, 1550 Engineering Drive, Madison, Wisconsin 53706, USA
| |
Collapse
|
9
|
Photonic force optical coherence elastography for three-dimensional mechanical microscopy. Nat Commun 2018; 9:2079. [PMID: 29802258 PMCID: PMC5970204 DOI: 10.1038/s41467-018-04357-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/10/2018] [Indexed: 11/08/2022] Open
Abstract
Optical tweezers are an invaluable tool for non-contact trapping and micro-manipulation, but their ability to facilitate high-throughput volumetric microrheology of biological samples for mechanobiology research is limited by the precise alignment associated with the excitation and detection of individual bead oscillations. In contrast, radiation pressure from a low-numerical aperture optical beam can apply transversely localized force over an extended depth range. Here we present photonic force optical coherence elastography (PF-OCE), leveraging phase-sensitive interferometric detection to track sub-nanometer oscillations of beads, embedded in viscoelastic hydrogels, induced by modulated radiation pressure. Since the displacements caused by ultra-low radiation-pressure force are typically obscured by absorption-mediated thermal effects, mechanical responses of the beads were isolated after independent measurement and decoupling of the photothermal response of the hydrogels. Volumetric imaging of bead mechanical responses in hydrogels with different agarose concentrations by PF-OCE was consistent with bulk mechanical characterization of the hydrogels by shear rheometry.
Collapse
|
10
|
Tang P, Liu S, Chen J, Yuan Z, Xie B, Zhou J, Tang Z. Cross-correlation photothermal optical coherence tomography with high effective resolution. OPTICS LETTERS 2017; 42:4974-4977. [PMID: 29216159 DOI: 10.1364/ol.42.004974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/02/2017] [Indexed: 06/07/2023]
Abstract
We developed a cross-correlation photothermal optical coherence tomography (CC-PTOCT) system for photothermal imaging with high lateral and axial resolution. The CC-PTOCT system consists of a phase-sensitive OCT system, a modulated pumping laser, and a digital cross-correlator. The pumping laser was used to induce the photothermal effect in the sample, causing a slight phase modulation of the OCT signals. A spatial phase differentiation method was employed to reduce phase accumulation. The noise brought by the phase differentiation method and the strong background noise were suppressed efficiently by the cross-correlator, which was utilized to extract the photothermal signals from the modulated signals. Combining the cross-correlation technique with spatial phase differentiation can improve both lateral and axial resolution of the PTOCT imaging system. Clear photothermal images of blood capillaries of a mouse ear in vivo were successfully obtained with high lateral and axial resolution. The experimental results demonstrated that this system can enhance the effective transverse resolution, effective depth resolution, and contrast of the PTOCT image effectively, aiding the ongoing development of the accurate 3D functional imaging.
Collapse
|
11
|
In vivo photothermal optical coherence tomography of endogenous and exogenous contrast agents in the eye. Sci Rep 2017; 7:9228. [PMID: 28835698 PMCID: PMC5569082 DOI: 10.1038/s41598-017-10050-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/02/2017] [Indexed: 11/08/2022] Open
Abstract
Optical coherence tomography (OCT) has become a standard-of-care in retinal imaging. OCT allows non-invasive imaging of the tissue structure but lacks specificity to contrast agents that could be used for in vivo molecular imaging. Photothermal OCT (PT-OCT) is a functional OCT-based technique that has been developed to detect absorbers in a sample. We demonstrate in vivo PT-OCT in the eye for the first time on both endogenous (melanin) and exogenous (gold nanorods) absorbers. Pigmented mice and albino mice (n = 6 eyes) were used to isolate the photothermal signal from the melanin in the retina. Pigmented mice with laser-induced choroidal neovascularization lesions (n = 7 eyes) were also imaged after a systemic injection of gold nanorods to observe their passive accumulation in the retina. This experiment demonstrates the feasibility of PT-OCT to image the distribution of both endogenous and exogenous absorbers in the mouse retina.
Collapse
|
12
|
Robles FE, Zhou KC, Fischer MC, Warren WS. Stimulated Raman scattering spectroscopic optical coherence tomography. OPTICA 2017; 4:243-246. [PMID: 29302608 PMCID: PMC5749255 DOI: 10.1364/optica.4.000243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We integrate spectroscopic optical coherence tomography (SOCT) with stimulated Raman scattering (SRS) to enable simultaneously multiplexed spatial and spectral imaging with sensitivity to many endogenous biochemical species that play an important role in biology and medicine. The combined approach, termed SRS-SOCT, overcomes the limitations of each individual method. Ultimately, SRS-SOCT has the potential to achieve fast, volumetric, and highly sensitive label-free molecular imaging. We demonstrate the approach by imaging excised human adipose tissue and detecting the lipids' Raman signatures in the high-wavenumber region.
Collapse
Affiliation(s)
- Francisco E. Robles
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
- Currently at Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory School of Medicine, tlanta, Georgia 30332, USA
| | - Kevin C. Zhou
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Martin C. Fischer
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Warren S. Warren
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| |
Collapse
|