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Malektaji S, Lima IT, Escobar I MR, Sherif SS. Massively parallel simulator of optical coherence tomography of inhomogeneous turbid media. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2017; 150:97-105. [PMID: 28859833 DOI: 10.1016/j.cmpb.2017.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/31/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND AND OBJECTIVE An accurate and practical simulator for Optical Coherence Tomography (OCT) could be an important tool to study the underlying physical phenomena in OCT such as multiple light scattering. Recently, many researchers have investigated simulation of OCT of turbid media, e.g., tissue, using Monte Carlo methods. The main drawback of these earlier simulators is the long computational time required to produce accurate results. We developed a massively parallel simulator of OCT of inhomogeneous turbid media that obtains both Class I diffusive reflectivity, due to ballistic and quasi-ballistic scattered photons, and Class II diffusive reflectivity due to multiply scattered photons. METHODS This Monte Carlo-based simulator is implemented on graphic processing units (GPUs), using the Compute Unified Device Architecture (CUDA) platform and programming model, to exploit the parallel nature of propagation of photons in tissue. It models an arbitrary shaped sample medium as a tetrahedron-based mesh and uses an advanced importance sampling scheme. RESULTS This new simulator speeds up simulations of OCT of inhomogeneous turbid media by about two orders of magnitude. To demonstrate this result, we have compared the computation times of our new parallel simulator and its serial counterpart using two samples of inhomogeneous turbid media. We have shown that our parallel implementation reduced simulation time of OCT of the first sample medium from 407 min to 92 min by using a single GPU card, to 12 min by using 8 GPU cards and to 7 min by using 16 GPU cards. For the second sample medium, the OCT simulation time was reduced from 209 h to 35.6 h by using a single GPU card, and to 4.65 h by using 8 GPU cards, and to only 2 h by using 16 GPU cards. Therefore our new parallel simulator is considerably more practical to use than its central processing unit (CPU)-based counterpart. CONCLUSIONS Our new parallel OCT simulator could be a practical tool to study the different physical phenomena underlying OCT, or to design OCT systems with improved performance.
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Affiliation(s)
- Siavash Malektaji
- University of Manitoba, Department of Electrical and Computer Engineering, 75A Chancellor's Circle, Winnipeg, Manitoba R3T 5V6, Canada
| | - Ivan T Lima
- North Dakota State University, Department of Electrical and Computer Engineering, 1411 Centennial Boulevard, Fargo, ND 58108-6050, USA
| | - Mauricio R Escobar I
- University of Manitoba, Department of Electrical and Computer Engineering, 75A Chancellor's Circle, Winnipeg, Manitoba R3T 5V6, Canada
| | - Sherif S Sherif
- University of Manitoba, Department of Electrical and Computer Engineering, 75A Chancellor's Circle, Winnipeg, Manitoba R3T 5V6, Canada.
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Adams DC, Pahlevaninezhad H, Szabari MV, Cho JL, Hamilos DL, Kesimer M, Boucher RC, Luster AD, Medoff BD, Suter MJ. Automated segmentation and quantification of airway mucus with endobronchial optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2017; 8:4729-4741. [PMID: 29082098 PMCID: PMC5654813 DOI: 10.1364/boe.8.004729] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 05/31/2023]
Abstract
We propose a novel suite of algorithms for automatically segmenting the airway lumen and mucus in endobronchial optical coherence tomography (OCT) data sets, as well as a novel approach for quantifying the contents of the mucus. Mucus and lumen were segmented using a robust, multi-stage algorithm that requires only minimal input regarding sheath geometry. The algorithm performance was highly accurate in a wide range of airway and noise conditions. Mucus was classified using mean backscattering intensity and grey level co-occurrence matrix (GLCM) statistics. We evaluated our techniques in vivo in asthmatic and non-asthmatic volunteers.
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Affiliation(s)
- David C. Adams
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Hamid Pahlevaninezhad
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Equal contribution
| | - Margit V. Szabari
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Equal contribution
| | - Josalyn L. Cho
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Daniel L. Hamilos
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Mehmet Kesimer
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Richard C. Boucher
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Andrew D. Luster
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Benjamin D. Medoff
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Melissa J. Suter
- Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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DeBoer EM, Spielberg DR, Brody AS. Clinical potential for imaging in patients with asthma and other lung disorders. J Allergy Clin Immunol 2016; 139:21-28. [PMID: 27871877 DOI: 10.1016/j.jaci.2016.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/10/2016] [Accepted: 11/10/2016] [Indexed: 12/12/2022]
Abstract
The ability of lung imaging to phenotype patients, determine prognosis, and predict response to treatment is expanding in clinical and translational research. The purpose of this perspective is to describe current imaging modalities that might be useful clinical tools in patients with asthma and other lung disorders and to explore some of the new developments in imaging modalities of the lung. These imaging modalities include chest radiography, computed tomography, lung magnetic resonance imaging, electrical impedance tomography, bronchoscopy, and others.
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Affiliation(s)
- Emily M DeBoer
- University of Colorado Anschutz Medical Campus, Department of Pediatrics, and Breathing Institute, Children's Hospital Colorado, Aurora, Colo.
| | - David R Spielberg
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Alan S Brody
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
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McLaughlin RA, Noble PB, Sampson DD. Optical coherence tomography in respiratory science and medicine: from airways to alveoli. Physiology (Bethesda) 2015; 29:369-80. [PMID: 25180266 DOI: 10.1152/physiol.00002.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Optical coherence tomography is a rapidly maturing optical imaging technology, enabling study of the in vivo structure of lung tissue at a scale of tens of micrometers. It has been used to assess the layered structure of airway walls, quantify both airway lumen caliber and compliance, and image individual alveoli. This article provides an overview of the technology and reviews its capability to provide new insights into respiratory disease.
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Affiliation(s)
- Robert A McLaughlin
- Optical & Biomedical Engineering Laboratory, School of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, Australia;
| | - Peter B Noble
- School of Anatomy, Physiology & Human Biology, and Centre for Neonatal Research & Education, School of Paediatrics and Child Health, The University of Western Australia, Crawley, Australia; and
| | - David D Sampson
- Optical & Biomedical Engineering Laboratory, School of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, Australia; Centre for Microscopy, Characterisation & Analysis, The University of Western Australia, Perth, Australia
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Kirillin MY, Farhat G, Sergeeva EA, Kolios MC, Vitkin A. Speckle statistics in OCT images: Monte Carlo simulations and experimental studies. OPTICS LETTERS 2014; 39:3472-5. [PMID: 24978514 DOI: 10.1364/ol.39.003472] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The speckle pattern of an optical coherence tomography (OCT) image carries potentially useful sample information that may assist in tissue characterization. Recent biomedical results in vivo indicate that the distribution of signal intensities within an OCT tissue image is well described by a log-normal-like (Gamma) function. To fully understand and exploit this finding, an OCT Monte Carlo model that accounts for speckle effects was developed. The resultant Monte Carlo speckle statistics predictions agree well with experimental OCT results from a series of control phantoms with variable scattering properties; the Gamma distribution provides a good fit to the theoretical and experimental results. The ability to quantify subresolution tissue features via OCT speckle analysis may prove useful in diagnostic photomedicine.
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