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Yoon C, Kang J, Song TK, Chang JH. Elevational Synthetic Aperture Focusing for Three-Dimensional Photoacoustic Imaging Using a Clinical One-Dimensional Array Transducer. IEEE Trans Biomed Eng 2022; 69:2817-2825. [PMID: 35226597 PMCID: PMC9520468 DOI: 10.1109/tbme.2022.3154754] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Two-dimensional (2D) photoacoustic (PA) imaging based on array transducers provide high spatial resolution in the lateral direction by adopting receive dynamic focusing. However, the quality of PA image is often deteriorated by poor elevational resolution which is achieved by an acoustic lens. To overcome this limitation, we present a three-dimensional (3D) image reconstruction method using a commercial one-dimensional (1D) array transducer. METHODS In the method, the elevational resolution is improved by applying synthetic aperture focusing (SAF) technique along the elevational direction. For this, a commercially available 1D array transducer with an acoustic lens is modeled and appropriate synthetic focusing delay that can minimize the effect of the acoustic lens is derived by mathematical analysis. RESULTS From the simulation and experiment results, it was demonstrated that the proposed method can enhance the image quality of PA imaging, i.e., elevational resolution and signal-to-noise ratio (SNR). CONCLUSION 3D PA images with improved elevational resolution were achieved using a clinical 1D array transducer. SIGNIFICANCE The presented method may be useful for clinical application such as detecting microcalcification, imaging of tumor vasculature and guidance of biopsy in real time.
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Xie HW, Guo H, Zhou GQ, Nguyen NQ, Prager RW. Improved ultrasound image quality with pixel-based beamforming using a Wiener-filter and a SNR-dependent coherence factor. ULTRASONICS 2022; 119:106594. [PMID: 34628298 DOI: 10.1016/j.ultras.2021.106594] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 09/18/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Pixel-based beamforming generates focused data by assuming that the waveforms received on a linear transducer array are composed of spherical pulses. It does not take into account the spatiotemporal spread in the data from the length of the excitation pulse or from the transfer functions of the transducer elements. As a result, these beamformers primarily have impacts on lateral, rather than axial, resolution. This paper proposes an efficient method to improve the axial resolution for pixel-based beamforming. We extend our field pattern analysis and show that the received waveforms should be passed through a Wiener filter before being used in the coherent pixel-based beamformer. This filter is designed based on signals echoed from a single scatterer at the transmit focus. The beamformer output is then combined with a coherence factor, that is adaptive to the signal-to-noise ratio, to improve the image contrast and suppress artifacts that have arisen during the filtering process. We validate the proposed method and compare it with other beamforming strategies using a series of experiments, including simulation, phantom and in vivo studies. It is shown to offer significant improvements in axial resolution and contrast over coherent pixel-based beamforming, as well as other spatial filters derived from synthetic aperture imaging. The method also demonstrates robustness to modeling errors in the experimental data. Overall, the imaging results show that the proposed approach has the potential to be of value in clinical applications.
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Affiliation(s)
- Hui-Wen Xie
- The School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Hao Guo
- The School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Guang-Quan Zhou
- The School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
| | - Nghia Q Nguyen
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK; Cambridge University - Nanjing Centre of Technology and Innovation, Nanjing, China
| | - Richard W Prager
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK; Cambridge University - Nanjing Centre of Technology and Innovation, Nanjing, China
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Duan Y, Cheng Z, Qiu T, Wen L, Xiong K. Spherical-matching hyperbolic-array photoacoustic computed tomography. JOURNAL OF BIOPHOTONICS 2021; 14:e202100023. [PMID: 33729687 DOI: 10.1002/jbio.202100023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/13/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Linear-array photoacoustic computed tomography (LA-PACT), for its flexibility and simplicity, has great potential in providing anatomical and functional information of tissues. However, the limited coverage view impedes the LA-PACT obtaining high-quality images. In this study, a photoacoustic tomographic system with a hyperbolic-array transducer was developed for stereoscopic PA imaging of carotid artery. The hyperbolic-array PACT increases the receiving sensitivity for PA signal detection due to its transducer's geometric structure matching with the spherical wave. The control phantom experiment shows that the proposed system can expand the angular coverage of ∼1/3 more than that of the LA-PACT system, and the volumetric PA images of rat's carotid artery demonstrates the potential of the system for carotid artery imaging. Furthermore, volumetric imaging of the human forearm verifies that the system has significant capability in human imaging, which indicates that it has bright prospect for assisting diagnosis in the vascular disease.
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Affiliation(s)
- Yihao Duan
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
| | - Zhongwen Cheng
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
| | - Tengsen Qiu
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
| | - Liewei Wen
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Jinan University, Zhuhai, Guangdong, China
| | - Kedi Xiong
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
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Kang S, Lee J, Chang JH. Effectiveness of synthetic aperture focusing and coherence factor weighting for intravascular ultrasound imaging. ULTRASONICS 2021; 113:106364. [PMID: 33517139 DOI: 10.1016/j.ultras.2021.106364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/21/2020] [Accepted: 01/15/2021] [Indexed: 06/12/2023]
Abstract
Synthetic aperture focusing (SAF) and coherence factor weighting (CFW) have been used to improve the lateral resolution of ultrasound images. Although the two methods are effective for array-based ultrasound imaging, many researchers have also employed the methods for single-element-based imaging including intravascular ultrasound (IVUS) imaging. For single-element-based imaging, CFW is generally calculated from the scanlines obtained by SAF and applied to the scanline obtained after coherent summation of the SAF delayed scanlines, which is called a SAF-CFW method. In the paper, a theoretical model was derived to explore the effectiveness of SAF and CFW for single-element-based imaging, and the model was used to explain that SAF is not effective for IVUS imaging in terms of enhancing the spatial resolution, although it has the advantage of improving a contrast-to-noise ratio (CNR). This means that the SAF-CFW method is not optimal for improving the spatial resolution of IVUS imaging. In contrast, it was found in simulations and experiments that applying CFW to the target scanline itself is beneficial for the spatial resolution rather than a coherent summed scanline for IVUS SAF imaging, but CNR was not as good as SAF and SAF-CFW. As a result of both simulation and experimentation, it could be concluded that focused IVUS transducers without the application of those methods may be more advantageous to improve the spatial and contrast resolution simultaneously, considering the system complexity in the implementation of such imaging methods.
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Affiliation(s)
- Sungwoo Kang
- Department of Electronic Engineering, Sogang University, Seoul, South Korea
| | - Junsu Lee
- Department of Electronic Engineering, Sogang University, Seoul, South Korea
| | - Jin Ho Chang
- Department of Information and Communication Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea.
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Zhang Y, Wang L. Video-Rate Ring-Array Ultrasound and Photoacoustic Tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:4369-4375. [PMID: 32813650 DOI: 10.1109/tmi.2020.3017815] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Ultrasonography and photoacoustic tomography provide complementary contrasts in preclinical studies, disease diagnoses, and imaging-guided interventional procedures. Here, we present a video-rate (20 Hz) dual-modality ultrasound and photoacoustic tomographic platform that has a high resolution, rich contrasts, deep penetration, and wide field of view. A three-quarter ring-array ultrasonic transducer is used for both ultrasound and photoacoustic imaging. Plane-wave transmission/receiving approach is used for ultrasound imaging, which improves the imaging speed by nearly two folds and reduces the RF data size compared with the sequential single-channel scanning approach. GPU-based image reconstruction is developed to advance computational speed. We demonstrate fast dual-modality imaging in phantom, mouse, and human finger joint experiments. The results show respiration motion, heart beating, and detailed features in the mouse internal organs. To our knowledge, this is the first report on fast plane-wave ultrasound imaging and single-shot photoacoustic computed tomography in a ring-array system.
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Choi WY, Kwon SW, Kim YH, Kang KC, Park KK. Single-Shot Near-Field Volumetric Imaging System for Optical Ultrasound and Photoacoustics Using Capacitive Micromachined Ultrasonic Transducer Without Transmission Mode. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2020; 67:1151-1158. [PMID: 31976884 DOI: 10.1109/tuffc.2020.2965600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this article, we present a single-shot dual-mode imaging system that uses optical ultrasound (US) as an ultrasonic pulser without a transmission circuit. The ultrasonic pulse-echo system comprises an optical US pulser generated by carbon nanotubes (CNTs), which generate a high-power photoacoustic (PA) signal and a capacitive micromachined ultrasonic transducer (CMUT) receiver. By fabricating a thin CNT-polydimethylsiloxane (PDMS) composite capable of semiabsorption of the laser, a single-shot imaging system was developed. By transmitting a semipenetration light to the object, US and PA imaging were performed in a single shot. A CNT thickness of [Formula: see text] produced a maximum pressure of 154 kPa, and US was received by CMUT with a 2-MHz center frequency in PDMS. Additionally, a low-profile and near-depth imaging system was constructed with an intermediate layer of the 6-mm PDMS for the dry contact method. We performed a single-shot dual-mode imaging experiment on point and line phantoms, as well as the particle spread in the soft tissue. Thus, we examined the feasibility of the near-depth and single-shot dual-mode (US and PA) imaging system capable of a dry contact.
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Abstract
Abstract
Purpose
Photoacoustic (PA) microscopy has emerged as a useful tool in biomedical imaging applications such as visualization of microvasculature and hemoglobin oxygen saturation, single-cell, and label-free imaging of organs including cancer. Since the ultrasound transducers used for PA signal detection are not optically transparent, the integration of optical and acoustic modules for coaxial alignment of laser and acoustic beam fields in PA microscopy is complex and costly.
Methods
Here, we report a recently developed optically transparent focused transducer for combined PA and ultrasound (US) microscopy. All the acoustic layers including the acoustic lens are optically transparent, enabling simple integration of optical and acoustic modules for both imaging modalities.
Results
The mean light transmittance of the transducer’s backing layer and acoustic lens and of the transducer itself were measured at 92%, 83%, and 66%, respectively. Results from in vitro and in vivo experiments demonstrated the transducer to be suitable for both US and PA imaging.
Conclusions
The results of this study represent a step toward efficient construction of probes for combined PA and US microscopy.
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Kim H, Jo G, Chang JH. Ultrasound-assisted photothermal therapy and real-time treatment monitoring. BIOMEDICAL OPTICS EXPRESS 2018; 9:4472-4480. [PMID: 30615724 PMCID: PMC6157783 DOI: 10.1364/boe.9.004472] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/25/2018] [Accepted: 08/20/2018] [Indexed: 06/09/2023]
Abstract
Photothermal therapy (PTT) has the capability for selective treatment, in which light delivered to the target is converted into heat and subsequently causes coagulative necrosis. However, optical scattering in biological media limits light penetration, thus reducing therapeutic efficacy. Here, we demonstrate that the temperatures generated by light and ultrasound energies can be added constructively in resected melanoma cancers, which causes an increase in treatment depth. This method is called dual thermal therapy (DTT). It is also shown that combined ultrasound and photoacoustic images acquired using the pulse sequence proposed in this paper can be used for real-time monitoring of DTT.
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Affiliation(s)
- Haemin Kim
- Department of Biomedical Engineering, Sogang University, Seoul, 04107, South Korea
| | - Gyuwon Jo
- Department of Electronic Engineering, Sogang University, Seoul, 04107, South Korea
| | - Jin Ho Chang
- Department of Biomedical Engineering, Sogang University, Seoul, 04107, South Korea
- Department of Electronic Engineering, Sogang University, Seoul, 04107, South Korea
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Kim H, Chang JH. Multimodal photoacoustic imaging as a tool for sentinel lymph node identification and biopsy guidance. Biomed Eng Lett 2018; 8:183-191. [PMID: 30603202 PMCID: PMC6208518 DOI: 10.1007/s13534-018-0068-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Revised: 04/14/2018] [Accepted: 04/15/2018] [Indexed: 02/06/2023] Open
Abstract
As a minimally invasive method, sentinel lymph node biopsy (SLNB) in conjunction with guidance methods is the standard method to determine cancer metastasis in breast. The desired guidance methods for SLNB should be capable of precise SLN localization for accurate diagnosis of micro-metastases at an early stage of cancer progression and thus facilitate reducing the number of SLN biopsies for minimal surgical complications. For this, high sensitivity to the administered dyes, high spatial and contrast resolutions, deep imaging depth, and real-time imaging capability are pivotal requirements. Currently, various methods have been used for SLNB guidance, each with their own advantages and disadvantages, but no methods meet the requirements. In this review, we discuss the conventional SLNB guidance methods in this perspective. In addition, we focus on the role of the PA imaging modality on real-time SLN identification and biopsy guidance. In particular, PA-based hybrid imaging methods for precise SLN identification and efficient biopsy guidance are introduced, and their unique features, advantages, and disadvantages are discussed.
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Affiliation(s)
- Haemin Kim
- Department of Biomedical Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul, 04107 South Korea
| | - Jin Ho Chang
- Department of Biomedical Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul, 04107 South Korea
- Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul, 04107 South Korea
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Mozaffarzadeh M, Mahloojifar A, Orooji M, Kratkiewicz K, Adabi S, Nasiriavanaki M. Linear-array photoacoustic imaging using minimum variance-based delay multiply and sum adaptive beamforming algorithm. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-15. [PMID: 29405047 DOI: 10.1117/1.jbo.23.2.026002] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/08/2018] [Indexed: 05/20/2023]
Abstract
In photoacoustic imaging, delay-and-sum (DAS) beamformer is a common beamforming algorithm having a simple implementation. However, it results in a poor resolution and high sidelobes. To address these challenges, a new algorithm namely delay-multiply-and-sum (DMAS) was introduced having lower sidelobes compared to DAS. To improve the resolution of DMAS, a beamformer is introduced using minimum variance (MV) adaptive beamforming combined with DMAS, so-called minimum variance-based DMAS (MVB-DMAS). It is shown that expanding the DMAS equation results in multiple terms representing a DAS algebra. It is proposed to use the MV adaptive beamformer instead of the existing DAS. MVB-DMAS is evaluated numerically and experimentally. In particular, at the depth of 45 mm MVB-DMAS results in about 31, 18, and 8 dB sidelobes reduction compared to DAS, MV, and DMAS, respectively. The quantitative results of the simulations show that MVB-DMAS leads to improvement in full-width-half-maximum about 96%, 94%, and 45% and signal-to-noise ratio about 89%, 15%, and 35% compared to DAS, DMAS, MV, respectively. In particular, at the depth of 33 mm of the experimental images, MVB-DMAS results in about 20 dB sidelobes reduction in comparison with other beamformers.
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Affiliation(s)
- Moein Mozaffarzadeh
- Tarbiat Modares University, Department of Biomedical Engineering, Tehran, Iran
| | - Ali Mahloojifar
- Tarbiat Modares University, Department of Biomedical Engineering, Tehran, Iran
| | - Mahdi Orooji
- Tarbiat Modares University, Department of Biomedical Engineering, Tehran, Iran
| | - Karl Kratkiewicz
- Wayne State University, Department of Biomedical, Detroit, Michigan, United States
| | - Saba Adabi
- Wayne State University, Department of Biomedical, Detroit, Michigan, United States
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Gu J, Jing Y. Modeling of wave propagation for medical ultrasound: a review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2015; 62:1979-1993. [PMID: 26559627 DOI: 10.1109/tuffc.2015.007034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Numerical modeling of medical ultrasound has advanced tremendously in the past two decades. This opens up a great number of opportunities for medical ultrasound and associated technologies. Numerous new governing equations and algorithms have emerged and been applied to studying various medical ultrasound applications, including ultrasound imaging, photo-acoustic imaging, and therapeutic ultrasound. In addition, thanks to the rapid development of computers, modeling acoustic wave propagation in three-dimensional, large-scale domains has become a reality. This article will provide an indepth literature and technical review of recent progress on numerical modeling of medical ultrasound. Future challenges will also be discussed.
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Dovlo E, Lashkari B, Mandelis A, Shi W, Liu FF. Photoacoustic radar phase-filtered spatial resolution and co-registered ultrasound image enhancement for tumor detection. BIOMEDICAL OPTICS EXPRESS 2015; 6:1003-1009. [PMID: 25798321 PMCID: PMC4361416 DOI: 10.1364/boe.6.001003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 02/09/2015] [Accepted: 02/23/2015] [Indexed: 06/04/2023]
Abstract
Co-registered ultrasound (US) and frequency-domain photoacoustic radar (FD-PAR) imaging is reported for the first time in this paper. The merits of ultrasound and cross-correlation (radar) frequency-domain photoacoustic imaging are leveraged for accurate tumor detection. Commercial US imagers possess sophisticated, optimized software for rapid image acquisition that could dramatically speed-up PA imaging. The PAR image generated from the amplitude of the cross-correlation between detected and input signals was filtered by the standard deviation (SD) of the phase of the correlation signal, resulting in strong improvement of image spatial resolution, signal-to-noise ratio (SNR) and contrast. Application of phase-mediated image improvement is illustrated by imaging a cancer cell-injected mouse. A 14-15 dB SNR gain was recorded for the phase-filtered image compared to the amplitude and phase independently, while ~340 μm spatial resolution was seen for the phase PAR image compared to ~840 μm for the amplitude image.
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Affiliation(s)
- Edem Dovlo
- Center for Advanced Diffusion-Wave Technologies (CADIFT), Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8,
Canada
| | - Bahman Lashkari
- Center for Advanced Diffusion-Wave Technologies (CADIFT), Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8,
Canada
| | - Andreas Mandelis
- Center for Advanced Diffusion-Wave Technologies (CADIFT), Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8,
Canada
| | - Wei Shi
- Ontario Cancer Institute, Princess Margaret Hospital, 610 University Ave., Toronto, ON M5G 2M9,
Canada
| | - Fei-Fei Liu
- Ontario Cancer Institute, Princess Margaret Hospital, 610 University Ave., Toronto, ON M5G 2M9,
Canada
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