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Mukhangaliyeva L, Kocer S, Warren A, Bell K, Boktor M, Yavuz M, Abdel-Rahman E, Haji Reza P. Deformable mirror-based photoacoustic remote sensing (PARS) microscopy for depth scanning. BIOMEDICAL OPTICS EXPRESS 2022; 13:5643-5653. [PMID: 36733742 PMCID: PMC9872901 DOI: 10.1364/boe.471770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/09/2022] [Accepted: 09/19/2022] [Indexed: 05/02/2023]
Abstract
Optically shifting the focal plane to allow depth scanning of delicate biological structures and processes in their natural environment offers an appealing alternative to conventional mechanical scanning. Our technique uses a deformable mirror-based photoacoustic remote sensing microscopy (PARS) with a focus shifting of Δz ∼ 240 µm. We achieve this by integrating a deformable mirror that functions as a varifocal mirror for axial scanning. First, the system's focal shift capability was demonstrated with USAF resolution targets and carbon fiber phantoms, followed by in-vivo visualizations of blood vessels in chicken embryo chorioallantoic membrane (CAM). This work represents an initial step toward developing a non-contact, label-free, and aberration-free PARS imaging system with axial scanning capability.
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Affiliation(s)
- Lyazzat Mukhangaliyeva
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Samed Kocer
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Alkris Warren
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Kevan Bell
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Marian Boktor
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Mustafa Yavuz
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Eihab Abdel-Rahman
- Department of Systems Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
| | - Parsin Haji Reza
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada
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2
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Ma Z, Ding N, Li Z, Zhu K, Li A, Lin Z, Wang Y, Zhao Y, Yu Y, Luan J, Zhu X, Liu J. Spectral interference contrast based non-contact photoacoustic microscopy realized by SDOCT. OPTICS LETTERS 2022; 47:2895-2898. [PMID: 35648958 DOI: 10.1364/ol.458383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/15/2022] [Indexed: 06/15/2023]
Abstract
We introduce a method to extract the photoacoustic (PA) signal from a contrast reduction of the interference spectrum acquired by spectral domain optical coherence tomography (SDOCT). This all-optical detection is achieved in a noncontact manner directly on the water surface covered on the sample by using its specular reflection. During SDOCT exposure, the phase of the interference spectrum keeps shaking according to the water surface vibration induced by PA excitation. This results in an interference contrast reduction which is quantified by a fast Fourier transform (FFT) for PA imaging. A tungsten filament, asparagus fern leaf, and mouse auricle are imaged to demonstrate the method.
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3
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Hybrid confocal fluorescence and photoacoustic microscopy for the label-free investigation of melanin accumulation in fish scales. Sci Rep 2022; 12:7173. [PMID: 35504968 PMCID: PMC9065085 DOI: 10.1038/s41598-022-11262-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Lower vertebrates, including fish, can rapidly alter skin lightness through changes in melanin concentration and melanosomes’ mobility according to various factors, which include background color, light intensity, ambient temperature, social context, husbandry practices and acute or chronic stressful stimuli. Within this framework, the determination of skin chromaticity parameters in fish species is estimated either in specific areas using colorimeters or at the whole animal level using image processing and analysis software. Nevertheless, the accurate quantification of melanin content or melanophore coverage in fish skin is quite challenging as a result of the laborious chemical analysis and the typical application of simple optical imaging methods, requiring also to euthanize the fish in order to obtain large skin samples for relevant investigations. Here we present the application of a novel hybrid confocal fluorescence and photoacoustic microscopy prototype for the label-free imaging and quantification of melanin in fish scales samples with high spatial resolution, sensitivity and detection specificity. The hybrid images are automatically processed through optimized algorithms, aiming at the accurate and rapid extraction of various melanin accumulation indices in large datasets (i.e., total melanin content, melanophores’ area, density and coverage) corresponding to different fish species and groups. Furthermore, convolutional neural network-based algorithms have been trained using the recorded data towards the classification of different scales’ samples with high accuracy. In this context, we demonstrate that the proposed methodology may increase substantially the precision, as well as, simplify and expedite the relevant procedures for the quantification of melanin content in marine organisms.
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Benyamin M, Zalevsky Z. All Optical Speckle Contrast-Based Vibration Sensor for Photoacoustic Signal Detection. SENSORS (BASEL, SWITZERLAND) 2022; 22:3250. [PMID: 35590940 PMCID: PMC9102577 DOI: 10.3390/s22093250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 06/15/2023]
Abstract
Remote detection of photoacoustic signals is a well desired ability, enabling to perform advanced imaging in scenarios where contact is not possible. Various unique solutions have been suggested, including a camera-based speckle contrast photoacoustic detection. In this manuscript, a significant upgrade to the camera-based speckle contrast approach is presented and experimentally demonstrated. This solution is based on all-optical vibration sensing setup. The technique is based on spectral estimation of speckle pattern contrast and relies on several pre-developed works. First, it relies on the suggested application of speckle contrast to vibration sensing, and then on the realization of intensity pattern spectral manipulation, using a shearing interferometer. The method is evaluated and compared to traditional contrast estimation, and demonstrated in several applications in various vibration frequency band such as photoacoustic signal analysis and phonocardiographic heart sounds. The method is also applicable to measuring contrast changes due to a general speckle changing behavior, rather than surface vibration alone.
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Affiliation(s)
- Matan Benyamin
- Faculty of Engineering and the Nanotechnology Center, Bar Ilan University, Ramat Gan 5290002, Israel;
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5
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Photoacoustic Imaging in Biomedicine and Life Sciences. Life (Basel) 2022; 12:life12040588. [PMID: 35455079 PMCID: PMC9028050 DOI: 10.3390/life12040588] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 02/19/2022] [Indexed: 12/25/2022] Open
Abstract
Photo-acoustic imaging, also known as opto-acoustic imaging, has become a widely popular modality for biomedical applications. This hybrid technique possesses the advantages of high optical contrast and high ultrasonic resolution. Due to the distinct optical absorption properties of tissue compartments and main chromophores, photo-acoustics is able to non-invasively observe structural and functional variations within biological tissues including oxygenation and deoxygenation, blood vessels and spatial melanin distribution. The detection of acoustic waves produced by a pulsed laser source yields a high scaling range, from organ level photo-acoustic tomography to sub-cellular or even molecular imaging. This review discusses significant novel technical solutions utilising photo-acoustics and their applications in the fields of biomedicine and life sciences.
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6
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Hosseinaee Z, Le M, Bell K, Reza PH. Towards non-contact photoacoustic imaging [review]. PHOTOACOUSTICS 2020; 20:100207. [PMID: 33024694 PMCID: PMC7530308 DOI: 10.1016/j.pacs.2020.100207] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/29/2020] [Accepted: 07/10/2020] [Indexed: 05/06/2023]
Abstract
Photoacoustic imaging (PAI) takes advantage of both optical and ultrasound imaging properties to visualize optical absorption with high resolution and contrast. Photoacoustic microscopy (PAM) is usually categorized with all-optical microscopy techniques such as optical coherence tomography or confocal microscopes. Despite offering high sensitivity, novel imaging contrast, and high resolution, PAM is not generally an all-optical imaging method unlike the other microscopy techniques. One of the significant limitations of photoacoustic microscopes arises from their need to be in physical contact with the sample through a coupling media. This physical contact, coupling, or immersion of the sample is undesirable or impractical for many clinical and pre-clinical applications. This also limits the flexibility of photoacoustic techniques to be integrated with other all-optical imaging microscopes for providing complementary imaging contrast. To overcome these limitations, several non-contact photoacoustic signal detection approaches have been proposed. This paper presents a brief overview of current non-contact photoacoustic detection techniques with an emphasis on all-optical detection methods and their associated physical mechanisms.
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Affiliation(s)
- Zohreh Hosseinaee
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
| | - Martin Le
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
| | - Kevan Bell
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
- IllumiSonics Inc., Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | - Parsin Haji Reza
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
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7
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Hosseinaee Z, Khalili L, Simmons JAT, Bell K, Haji Reza P. Label-free, non-contact, in vivo ophthalmic imaging using photoacoustic remote sensing microscopy. OPTICS LETTERS 2020; 45:6254-6257. [PMID: 33186963 DOI: 10.1364/ol.410171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/24/2020] [Indexed: 06/11/2023]
Abstract
We present, to the best of our knowledge, the first label-free, non-contact, in vivo imaging of the ocular vasculature using photoacoustic remote sensing (PARS) microscopy. Both anterior and posterior segments of a mouse eye were imaged. Vasculature of the iris, sclera, and retina tissues were clearly resolved. To the best of our knowledge, this is the first study showing non-contact photoacoustic imaging conducted on in vivo ocular tissue. We believe that PARS microscopy has the potential to advance the diagnosis and treatment of ocular diseases.
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Disposable ultrasound-sensing chronic cranial window by soft nanoimprinting lithography. Nat Commun 2019; 10:4277. [PMID: 31537800 PMCID: PMC6753120 DOI: 10.1038/s41467-019-12178-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 08/27/2019] [Indexed: 01/31/2023] Open
Abstract
Chronic cranial window (CCW) is an essential tool in enabling longitudinal imaging and manipulation of various brain activities in live animals. However, an active CCW capable of sensing the concealed in vivo environment while simultaneously providing longitudinal optical access to the brain is not currently available. Here we report a disposable ultrasound-sensing CCW (usCCW) featuring an integrated transparent nanophotonic ultrasonic detector fabricated using soft nanoimprint lithography process. We optimize the sensor design and the associated fabrication process to significantly improve detection sensitivity and reliability, which are critical for the intend longitudinal in vivo investigations. Surgically implanting the usCCW on the skull creates a self-contained environment, maintaining optical access while eliminating the need for external ultrasound coupling medium for photoacoustic imaging. Using this usCCW, we demonstrate photoacoustic microscopy of cortical vascular network in live mice over 28 days. This work establishes the foundation for integrating photoacoustic imaging with modern brain research. Chronic cranial windows (CCW) enable long-term imaging of brain activity, but usually they only provide passive optical access to the tissue. Here the authors develop an active CCW integrated with an ultrasound detector which enables long-term photoacoustic imaging of the cortical vasculature in live mice with higher image quality.
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Benyamin M, Genish H, Califa R, Schwartz A, Zalevsky Z, Ozana N. Non-contact photoacoustic imaging using laser speckle contrast analysis. OPTICS LETTERS 2019; 44:3110-3113. [PMID: 31199393 DOI: 10.1364/ol.44.003110] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 05/18/2019] [Indexed: 06/09/2023]
Abstract
A novel method for non-contact and continuous detection of photoacoustic signals is presented and experimentally demonstrated. The approach is based on analysis of the contrast of time-varying speckle patterns, and suggests a more robust alternative in respect to interferometric and refractometric available solutions.
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Nguyen VP, Li Y, Aaberg M, Zhang W, Wang X, Paulus YM. In Vivo 3D Imaging of Retinal Neovascularization Using Multimodal Photoacoustic Microscopy and Optical Coherence Tomography Imaging. J Imaging 2018; 4:150. [PMID: 31681820 PMCID: PMC6824200 DOI: 10.3390/jimaging4120150] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The pathological process of neovascularization of the retina plays a critical role in causing vision loss in several diseases, including diabetes, retinal vein occlusion, and sickle cell disease. Retinal neovascularization can lead to vitreous hemorrhage and retinal detachment, yet the pathological process of neovascularization is a complex phenomenon under active investigation. Understanding and monitoring retinal neovascularization is critically important in clinical ophthalmology. This study describes a novel multimodal ocular imaging system which combines photoacoustic microscopy (PAM) and a spectral domain optical coherence tomography (SD-OCT) to improve the visualization of retinal neovascularization (RNV), their depth, and the surrounding anatomy in living rabbits. RNV was induced in New Zealand rabbits by intravitreal injection of vascular endothelial growth factor (VEGF). The retinal vasculature before and after injection at various times was monitored and evaluated using multimodal imaging including color fundus photography, fluorescein angiography (FA), OCT, and PAM. In vivo experiments demonstrate that PAM imaging distinctly characterized the location as well as the morphology of individual RNV with high contrast at a safe laser energy of 80 nJ. SD-OCT was used to identify a cross-sectional structure of RNV. In addition, dynamic changes in the retinal morphology and retinal neovascularization were observed at day 4, 5, 6, 7, 9, 11, 14, 28, and day 35 after VEGF injection. PAM demonstrated high-resolution optical absorption of hemoglobin and vascular imaging of the retina and choroid with increased depth of penetration. With the current multimodal imaging system, RNV can be easily visualized in both 2D and 3D angiography. This multimodal ocular imaging system provides improved characterization of the microvasculature in a safe manner in larger rabbit eyes.
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Affiliation(s)
- Van Phuc Nguyen
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yanxiu Li
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Michael Aaberg
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Wei Zhang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
| | - Xueding Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Radiology, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yannis M. Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
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Abstract
Photoacoustic ophthalmoscopy (PAOM) is a novel, hybrid, non-ionizing, and non-invasive imaging technology that has been used to assess the retina. PAOM can provide both anatomic and functional retinal characterizations with high resolution, high sensitivity, high contrast, and a high depth of penetration. Thus, ocular diseases can be precisely detected and visualized at earlier stages, resulting in an improved understanding of pathophysiology, improved management, and the improved monitoring of retinal treatment to prevent vision loss. To better visualize ocular components such as retinal vessels, choroidal vessels, choroidal neovascularization, retinal neovascularization, and the retinal pigment epithelium, an advanced multimodal ocular imaging platform has been developed by a combination of PAOM with other optical imaging techniques such as optical coherence tomography (OCT), scanning laser ophthalmoscopy (SLO), and fluorescence microscopy. The multimodal images can be acquired from a single imaging system and co-registered on the same image plane, enabling an improved evaluation of disease. In this review, the potential application of photoacoustic ophthalmoscopy in both research and clinical diagnosis are discussed as a medical screening technique for the visualization of various ocular diseases. The basic principle and requirements of photoacoustic ocular imaging are introduced. Then, various photoacoustic microscopy imaging systems of the retina in animals are presented. Finally, the future development of PAOM and multimodal imaging is discussed.
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Affiliation(s)
- Van Phuc Nguyen
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yannis M. Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105, USA
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Mohammadi-Nejad AR, Mahmoudzadeh M, Hassanpour MS, Wallois F, Muzik O, Papadelis C, Hansen A, Soltanian-Zadeh H, Gelovani J, Nasiriavanaki M. Neonatal brain resting-state functional connectivity imaging modalities. PHOTOACOUSTICS 2018; 10:1-19. [PMID: 29511627 PMCID: PMC5832677 DOI: 10.1016/j.pacs.2018.01.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 01/12/2018] [Accepted: 01/27/2018] [Indexed: 05/12/2023]
Abstract
Infancy is the most critical period in human brain development. Studies demonstrate that subtle brain abnormalities during this state of life may greatly affect the developmental processes of the newborn infants. One of the rapidly developing methods for early characterization of abnormal brain development is functional connectivity of the brain at rest. While the majority of resting-state studies have been conducted using magnetic resonance imaging (MRI), there is clear evidence that resting-state functional connectivity (rs-FC) can also be evaluated using other imaging modalities. The aim of this review is to compare the advantages and limitations of different modalities used for the mapping of infants' brain functional connectivity at rest. In addition, we introduce photoacoustic tomography, a novel functional neuroimaging modality, as a complementary modality for functional mapping of infants' brain.
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Affiliation(s)
- Ali-Reza Mohammadi-Nejad
- CIPCE, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran
- Departments of Radiology and Research Administration, Henry Ford Health System, Detroit, MI, USA
| | - Mahdi Mahmoudzadeh
- INSERM, U1105, Université de Picardie, CURS, F80036, Amiens, France
- INSERM U1105, Exploration Fonctionnelles du Système Nerveux Pédiatrique, South University Hospital, F80054, Amiens Cedex, France
| | | | - Fabrice Wallois
- INSERM, U1105, Université de Picardie, CURS, F80036, Amiens, France
- INSERM U1105, Exploration Fonctionnelles du Système Nerveux Pédiatrique, South University Hospital, F80054, Amiens Cedex, France
| | - Otto Muzik
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Radiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Christos Papadelis
- Boston Children’s Hospital, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Anne Hansen
- Boston Children’s Hospital, Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Hamid Soltanian-Zadeh
- CIPCE, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran
- Departments of Radiology and Research Administration, Henry Ford Health System, Detroit, MI, USA
- Department of Radiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Juri Gelovani
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, USA
- Molecular Imaging Program, Barbara Ann Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Mohammadreza Nasiriavanaki
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, USA
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, USA
- Molecular Imaging Program, Barbara Ann Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
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13
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Choi SY, Lee Y, Kim M, Park YH. Scleral Buckling under a Slit-lamp Illumination System with a Contact Wide-angle Viewing Lens Compared with an Indirect Ophthalmoscope. KOREAN JOURNAL OF OPHTHALMOLOGY 2018; 32:126-133. [PMID: 29611372 PMCID: PMC5906397 DOI: 10.3341/kjo.2017.0092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 09/04/2017] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To investigate the outcomes of scleral buckling surgery performed under a slit-lamp illumination system (Visulux) with a contact wide-angle viewing lens (Mini Quad) in patients with rhegmatogenous retinal detachment (RRD) and to compare these outcomes with those of surgery performed under an indirect ophthalmoscope. METHODS By retrospective review of electronic medical records, patients with RRD who had undergone scleral buckling surgery were identified. Scleral buckling surgeries were performed with two illumination instruments, a slit-lamp (SL group) and an indirect ophthalmoscope (IO group). Subretinal fluid drainage, cryopexy, and intravitreal gas injection were performed optionally. At 6 months after surgery, anatomical and functional outcomes were evaluated and compared between the two groups. Operation time was also compared between the two groups. RESULTS Of the 45 total patients (45 eyes), 28 were included in the SL group, and 17 were included in the IO group. In the SL and IO groups, the primary anatomical success rate was 89.3% and 88.2%, respectively (p = 0.92). The logarithm of the minimal angle of resolution change, which reflects improvement in best-corrected visual acuity after surgery, was -0.19 ± 0.38 in the SL group and -0.21 ± 0.63 in the IO group; this difference was not statistically significant (p = 0.91). The mean operation time was significantly shorter in the SL group (78.9 ± 11.8 minutes) than in the IO group (100.0 ± 13.9 minutes, p < 0.001), especially for patients who underwent additional procedures such as subretinal fluid drainage and cryopexy (81.4 ± 12.9 and 103.5 ± 12.3 minutes, respectively, p < 0.001). CONCLUSIONS Scleral buckling surgery performed under a slit-lamp illumination system yielded a similar anatomical success rate and similar functional improvement in RRD compared with surgery performed under an indirect ophthalmoscope. The slit-lamp system could save time, especially in bullous RRD, which requires additional subretinal fluid drainage.
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Affiliation(s)
- Seung Yong Choi
- Department of Ophthalmology and Visual Science, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Youlim Lee
- Department of Ophthalmology and Visual Science, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Mirinae Kim
- Department of Ophthalmology and Visual Science, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Young Hoon Park
- Department of Ophthalmology and Visual Science, The Catholic University of Korea College of Medicine, Seoul, Korea.,Catholic Institute for Visual Science, The Catholic University of Korea College of Medicine, Seoul, Korea.
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Zou C, Wu B, Dong Y, Song Z, Zhao Y, Ni X, Yang Y, Liu Z. Biomedical photoacoustics: fundamentals, instrumentation and perspectives on nanomedicine. Int J Nanomedicine 2016; 12:179-195. [PMID: 28053532 PMCID: PMC5191855 DOI: 10.2147/ijn.s124218] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Photoacoustic imaging (PAI) is an integrated biomedical imaging modality which combines the advantages of acoustic deep penetration and optical high sensitivity. It can provide functional and structural images with satisfactory resolution and contrast which could provide abundant pathological information for disease-oriented diagnosis. Therefore, it has found vast applications so far and become a powerful tool of precision nanomedicine. However, the investigation of PAI-based imaging nanomaterials is still in its infancy. This perspective article aims to summarize the developments in photoacoustic technologies and instrumentations in the past years, and more importantly, present a bright outlook for advanced PAI-based imaging nanomaterials as well as their emerging biomedical applications in nanomedicine. Current challenges and bottleneck issues have also been discussed and elucidated in this article to bring them to the attention of the readership.
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Affiliation(s)
- Chunpeng Zou
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
| | - Beibei Wu
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
| | - Yanyan Dong
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
| | - Zhangwei Song
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
| | - Yaping Zhao
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
| | - Xianwei Ni
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
| | - Yan Yang
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
| | - Zhe Liu
- Department of Ultrasonic Diagnosis, The Second Affiliated Hospital and Yuying Children’s Hospital, Wenzhou Medical University
- Wenzhou Institute of Biomaterials and Engineering, Chinese Academy of Sciences
- Wenzhou Institute of Biomaterials and Engineering, Wenzhou Medical University, Wenzhou, People’s Republic of China
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15
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DeBuc DC. The Role of Retinal Imaging and Portable Screening Devices in Tele-ophthalmology Applications for Diabetic Retinopathy Management. Curr Diab Rep 2016; 16:132. [PMID: 27841014 DOI: 10.1007/s11892-016-0827-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In the years since its introduction, retinal imaging has transformed our capability to visualize the posterior pole of the eye. Increasing practical advances in mobile technology, regular monitoring, and population screening for diabetic retinopathy management offer the opportunity for further development of cost-effective applications through remote assessment of the diabetic eye using portable retinal cameras, smart-phone-based devices and telemedicine networks. Numerous retinal imaging methods and mobile technologies in tele-ophthalmology applications have been reported for diabetic retinopathy screening and management. They provide several advantages of automation, sensitivity, specificity, portability, and miniaturization for the development of point-of-care diagnostics for eye complications in diabetes. The aim of this paper is to review the role of retinal imaging and mobile technologies in tele-ophthalmology applications for diabetic retinopathy screening and management. At large, although improvements in current technology and telemedicine services are still needed, telemedicine has demonstrated to be a worthy tool to support health caregivers in the effective management and prevention of diabetes and its complications.
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Affiliation(s)
- Delia Cabrera DeBuc
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 900 NW 17th Street, Miami, FL, 33136, USA.
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16
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Liu W, Zhang HF. Photoacoustic imaging of the eye: A mini review. PHOTOACOUSTICS 2016; 4:112-123. [PMID: 27761410 PMCID: PMC5063360 DOI: 10.1016/j.pacs.2016.05.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 04/15/2016] [Accepted: 05/17/2016] [Indexed: 05/04/2023]
Abstract
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. The investigation and diagnosis of ocular diseases require advanced medical tools. In this mini review, we discuss non-invasive photoacoustic (PA) imaging as a potential research tool and medical screening device. In the research setting, PA imaging can provide valuable information on the disease progression. In the clinical setting, PA imaging can potentially aid in disease detection and treatment monitoring.
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Affiliation(s)
- Wenzhong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208,USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208,USA
- Department of Ophthalmology, Northwestern University, Chicago, IL 60611, USA
- Corresponding author at: Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.
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Blair NP, Wanek J, Teng PY, Shahidi M. The effect of intravitreal vascular endothelial growth factor on inner retinal oxygen delivery and metabolism in rats. Exp Eye Res 2015; 143:141-7. [PMID: 26518179 DOI: 10.1016/j.exer.2015.09.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/15/2015] [Accepted: 09/29/2015] [Indexed: 02/08/2023]
Abstract
Vascular endothelial growth factor (VEGF) is stimulated by hypoxia and plays an important role in pathologic vascular leakage and neovascularization. Increased VEGF may affect inner retinal oxygen delivery (DO2) and oxygen metabolism (MO2), however, quantitative information is lacking. We tested the hypotheses that VEGF increases DO2, but does not alter MO2. In 10 rats, VEGF was injected intravitreally into one eye, whereas balanced salt solution (BSS) was injected into the fellow eye, 24 h prior to imaging. Vessel diameters and blood velocities were determined by red-free and fluorescent microsphere imaging, respectively. Vascular PO2 values were derived by phosphorescence lifetime imaging of an intravascular oxyphor. Retinal blood flow, vascular oxygen content, DO2 and MO2 were calculated. Retinal arterial and venous diameters were larger in VEGF-injected eyes compared to control eyes (P < 0.03), however no significant difference was observed in blood velocity (P = 0.21). Thus, retinal blood flow was greater in VEGF-injected eyes (P = 0.007). Retinal vascular PO2 and oxygen content were similar between control and VEGF-injected eyes (P > 0.11), while the arteriovenous oxygen content difference was marginally lower in VEGF-injected eyes (P = 0.05). DO2 was 950 ± 340 and 1380 ± 650 nL O2/min in control and VEGF-injected eyes, respectively (P = 0.005). MO2 was 440 ± 150 and 490 ± 190 nL O2/min in control and VEGF-injected eyes, respectively (P = 0.31). Intravitreally administered VEGF did not alter MO2 but increased DO2, suggesting VEGF may play an offsetting role in conditions characterized by retinal hypoxia.
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Affiliation(s)
- Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL 60612, USA.
| | - Justin Wanek
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL 60612, USA.
| | - Pang-yu Teng
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL 60612, USA; UCLA Radiological Sciences, Suite 650, 924 Westwood Boulevard, Los Angeles, CA 90024, USA.
| | - Mahnaz Shahidi
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 West Taylor Street, Chicago, IL 60612, USA.
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Shu X, Liu W, Zhang HF. Monte Carlo investigation on quantifying the retinal pigment epithelium melanin concentration by photoacoustic ophthalmoscopy. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:106005. [PMID: 26469564 PMCID: PMC4881288 DOI: 10.1117/1.jbo.20.10.106005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/04/2015] [Indexed: 05/20/2023]
Abstract
The retinal pigment epithelium (RPE) melanin plays an important role in maintaining normal visual functions. A decrease in the RPE melanin concentration with aging is believed to be associated with several blinding diseases, including age-related macular degeneration. Quantifying the RPE melanin noninvasively is therefore important in evaluating the retinal health and aging conditions. Photoacoustic ophthalmoscopy (PAOM), as an optical absorption-based imaging technology, can potentially be applied to measure variations in the RPE melanin if the relationship between the detected photoacoustic (PA) signal amplitudes and the RPE melanin concentrations can be established. In this work, we tested the feasibility of using PA signals from retinal blood vessels as references to measure RPE melanin variation using Monte Carlo (MC) simulation. The influences from PAOM axial resolution, the depth and diameter of the retinal blood vessel, and the RPE thickness were examined. We proposed a calibration scheme by relating detected PA signals to the RPE melanin concentrations, and we found that the scheme is robust to these tested parameters. This study suggests that PAOM has the capability of quantitatively measuring the RPE melanin in vivo.
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Affiliation(s)
- Xiao Shu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60208
| | - Wenzhong Liu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60208
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60208
- Northwestern University, Department of Ophthalmology, Chicago, Illinois 60611
- Address all correspondence to: Hao F. Zhang, E-mail:
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España-Contreras M, Fernández-Baca-Casares I, Santos-Bueso E. Evolution, recent progress and future development of optical coherence tomography. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2015; 90:353-355. [PMID: 25869314 DOI: 10.1016/j.oftal.2015.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 03/07/2015] [Indexed: 06/04/2023]
Affiliation(s)
- M España-Contreras
- Unidad de Neurooftalmología, angiografía y tomografía de coherencia óptica, Hospital Regional Universitario Carlos Haya, Málaga, España.
| | | | - E Santos-Bueso
- Unidad de Neurooftalmología, Hospital Clínico Universitario San Carlos, Madrid, España
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Kim J, Lee D, Jung U, Kim C. Photoacoustic imaging platforms for multimodal imaging. Ultrasonography 2015; 34:88-97. [PMID: 25754364 PMCID: PMC4372714 DOI: 10.14366/usg.14062] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/09/2015] [Accepted: 02/16/2015] [Indexed: 11/22/2022] Open
Abstract
Photoacoustic (PA) imaging is a hybrid biomedical imaging method that exploits both acoustical Epub ahead of print and optical properties and can provide both functional and structural information. Therefore, PA imaging can complement other imaging methods, such as ultrasound imaging, fluorescence imaging, optical coherence tomography, and multi-photon microscopy. This article reviews techniques that integrate PA with the above imaging methods and describes their applications.
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Affiliation(s)
- Jeesu Kim
- Departments of Electrical Engineering, Pohang University of Science and Technology, Pohang, Korea
| | - Donghyun Lee
- Departments of Creative IT Engineering, Pohang University of Science and Technology, Pohang, Korea
| | - Unsang Jung
- Departments of Future IT Innovation Laboratory, Pohang University of Science and Technology, Pohang, Korea
| | - Chulhong Kim
- Departments of Electrical Engineering, Pohang University of Science and Technology, Pohang, Korea ; Departments of Creative IT Engineering, Pohang University of Science and Technology, Pohang, Korea
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Dong B, Li H, Zhang Z, Zhang K, Chen S, Sun C, Zhang HF. Isometric multimodal photoacoustic microscopy based on optically transparent micro-ring ultrasonic detection. OPTICA 2015; 2:169-176. [PMID: 29805988 PMCID: PMC5969522 DOI: 10.1364/optica.2.000169] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Photoacoustic microscopy (PAM) is an attractive imaging tool complementary to established optical microscopic modalities by providing additional molecular specificities through imaging optical absorption contrast. While the development of optical resolution photoacoustic microscopy (ORPAM) offers high lateral resolution, the acoustically-determined axial resolution is limited due to the constraint in ultrasonic detection bandwidth. ORPAM with isometric spatial resolution along both axial and lateral direction is yet to be developed. Although recently developed sophisticated optical illumination and reconstruction methods offer improved axial resolution in ORPAM, the image acquisition procedures are rather complicated, limiting their capabilities for high-speed imaging and being easily integrated with established optical microscopic modalities. Here we report an isometric ORPAM based on an optically transparent micro-ring resonator ultrasonic detector and a commercial inverted microscope platform. Owing to the superior spatial resolution and the ease of integrating our ORPAM with established microscopic modalities, single cell imaging with extrinsic fluorescence staining, intrinsic autofluorescence, and optical absorption can be achieved simultaneously. This technique holds promise to greatly improve the accessibility of PAM to the broader biomedical researchers.
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Affiliation(s)
- Biqin Dong
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208
- Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
| | - Hao Li
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208
| | - Zhen Zhang
- Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
| | - Kevin Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208
| | - Siyu Chen
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208
| | - Cheng Sun
- Department of Mechanical Engineering, Northwestern University, Evanston IL 60208
- Corresponding author: &
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston IL 60208
- Department of Ophthalmology, Northwestern University, Chicago IL 60611
- Corresponding author: &
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Keane PA, Sadda SR. Retinal imaging in the twenty-first century: state of the art and future directions. Ophthalmology 2014; 121:2489-500. [PMID: 25282252 DOI: 10.1016/j.ophtha.2014.07.054] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/31/2014] [Accepted: 07/29/2014] [Indexed: 02/06/2023] Open
Abstract
Assessment of chorioretinal disease is dependent on the ability to visualize pathologic changes occurring in the posterior segment of the eye using optical instruments, termed ophthalmoscopy. Ophthalmoscopy, in turn, has been enhanced greatly by the development of techniques that allow recording of these changes, termed retinal imaging. As well as documenting pathologic features, retinal and fundal imaging facilitates the identification of morphologic features not visible to the clinician on biomicroscopy. As such, advances in retinal imaging have proven fundamental to many paradigm shifts in our understanding and treatment of ocular disease. In the 1950s, with the advent of electronic flashes and 35-mm cameras, the field of modern fundus photography was born. Similarly, in the 1960s and 1970s, the introduction of fluorescein and indocyanine green angiography revolutionized our ability to assess the integrity of the chorioretinal vasculature. More recently, in the 1990s, the introduction of a wholly new form of noninvasive cross-sectional imaging, optical coherence tomography, has greatly facilitated use of emerging pharmacotherapies in diagnosing and monitoring chorioretinal disease. In this translational science review, we provide an overview of current, state-of-the-art retinal imaging technologies, as well as highlight many emerging imaging technologies that we believe are likely to transform the provision of eye care in the 21st century.
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Affiliation(s)
- Pearse A Keane
- NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
| | - Srinivas R Sadda
- Doheny Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California.
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Ma T, Zhang X, Chiu CT, Chen R, Kirk Shung K, Zhou Q, Jiao S. Systematic study of high-frequency ultrasonic transducer design for laser-scanning photoacoustic ophthalmoscopy. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:16015. [PMID: 24441942 PMCID: PMC3895818 DOI: 10.1117/1.jbo.19.1.016015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 12/02/2013] [Indexed: 05/04/2023]
Abstract
Photoacoustic ophthalmoscopy (PAOM) is a high-resolution in vivo imaging modality that is capable of providing specific optical absorption information for the retina. A high-frequency ultrasonic transducer is one of the key components in PAOM, which is in contact with the eyelid through coupling gel during imaging. The ultrasonic transducer plays a crucial role in determining the image quality affected by parameters such as spatial resolution, signal-to-noise ratio, and field of view. In this paper, we present the results of a systematic study on a high-frequency ultrasonic transducer design for PAOM. The design includes piezoelectric material selection, frequency selection, and the fabrication process. Transducers of various designs were successfully applied for capturing images of biological samples in vivo. The performances of these designs are compared and evaluated.
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Affiliation(s)
- Teng Ma
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90033
| | - Xiangyang Zhang
- University of Southern California, Keck School of Medicine, Department of Ophthalmology, Los Angeles, California 90033
| | - Chi Tat Chiu
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90033
| | - Ruimin Chen
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90033
| | - K. Kirk Shung
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90033
| | - Qifa Zhou
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90033
- Address all correspondence to: Qifa Zhou and Shuliang Jiao, E-mail: and
| | - Shuliang Jiao
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90033
- University of Southern California, Keck School of Medicine, Department of Ophthalmology, Los Angeles, California 90033
- Address all correspondence to: Qifa Zhou and Shuliang Jiao, E-mail: and
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Nie L, Chen X. Structural and functional photoacoustic molecular tomography aided by emerging contrast agents. Chem Soc Rev 2014; 43:7132-70. [PMID: 24967718 PMCID: PMC4569000 DOI: 10.1039/c4cs00086b] [Citation(s) in RCA: 269] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Photoacoustic tomography (PAT) can offer structural, functional and molecular contrasts at scalable observation level. By ultrasonically overcoming the strong optical scattering, this imaging technology can reach centimeters penetration depth while retaining high spatial resolution in biological tissue. Recent extensive research has been focused on developing new contrast agents to improve the imaging sensitivity, specificity and efficiency. These emerging materials have substantially accelerated PAT applications in signal sensing, functional imaging, biomarker labeling and therapy monitoring etc. Here, the potentials of different optical probes as PAT contrast agents were elucidated. We first describe the instrumental embodiments and the measured functional parameters, then focus on emerging contrast agent-based PAT applications, and finally discuss the challenges and prospects.
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Affiliation(s)
- Liming Nie
- Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Bethesda, Maryland 20892, USA.
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Liu T, Li H, Song W, Jiao S, Zhang HF. Fundus camera guided photoacoustic ophthalmoscopy. Curr Eye Res 2013; 38:1229-34. [PMID: 24131226 DOI: 10.3109/02713683.2013.815219] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE To demonstrate the feasibility of fundus camera guided photoacoustic ophthalmoscopy (PAOM) system and its multimodal imaging capabilities. METHODS We integrated PAOM and a fundus camera consisting of a white-light illuminator and a high-sensitivity, high-speed CCD. The fundus camera captures both retinal anatomy and PAOM illumination at the same time to provide a real-time feedback when we position the PAOM illuminating light. We applied the integrated system to image rat eyes in vivo and used full-spectrum, visible (VIS), and near infrared (NIR) illuminations in fundus photography. RESULTS Both albino and pigmented rat eyes were imaged in vivo. During alignment, different trajectories of PAOM laser scanning were successfully visualized by the fundus camera, which reduced the PAOM alignment time from several minutes to 30 s. In albino eyes, in addition to retinal vessels, main choroidal vessels were observed using VIS-illumination, which is similar to PAOM images. In pigmented eyes, the radial striations of retinal nerve fiber layer were visualized by fundus photography using full-spectrum illumination; meanwhile, PAOM imaged both retinal vessels and the retinal pigmented epithelium melanin distribution. CONCLUSIONS The results demonstrated that PAOM can be well-integrated with fundus camera without affecting its functionality. The fundus camera guidance is faster and easier comparing with our previous work. The integrated system also set the stage for the next-step verification between oximetry methods based on PAOM and fundus photography.
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Affiliation(s)
- Tan Liu
- Department of Biomedical Engineering, Northwestern University , Evanston, IL , USA
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Rousseau G, Gauthier B, Blouin A, Monchalin JP. Non-contact biomedical photoacoustic and ultrasound imaging. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:061217. [PMID: 22734747 DOI: 10.1117/1.jbo.17.6.061217] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The detection of ultrasound in photoacoustic tomography (PAT) usually relies on ultrasonic transducers in contact with the biological tissue through a coupling medium. This is a major drawback for important potential applications such as surgery. Here we report the use of a remote optical method, derived from industrial laser-ultrasonics, to detect ultrasound in tissues. This approach enables non-contact PAT (NCPAT) without exceeding laser exposure safety limits. The sensitivity of the method is based on the use of suitably shaped detection laser pulses and a confocal Fabry-Perot interferometer in differential configuration. Reliable image reconstruction is obtained by measuring remotely the surface profile of the tissue with an optical coherence tomography system. The proposed method also allows non-contact ultrasound imaging (US) by applying a second reconstruction algorithm to the data acquired for NCPAT. Endogenous and exogenous inclusions exhibiting optical and acoustic contrasts were detected ex vivo in chicken breast and calf brain specimens. Inclusions down to 0.3 mm in size were detected at depths exceeding 1 cm. The method could expand the scope of photoacoustic and US to in-vivo biomedical applications where contact is impractical.
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Affiliation(s)
- Guy Rousseau
- Industrial Materials Institute, National Research Council of Canada, 75 De Mortagne Boulevard, Boucherville, Québec J4B 6Y4, Canada.
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