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Eshein A, Radosevich AJ, Gould B, Wu W, Konda V, Yang LW, Koons A, Feder S, Valuckaite V, Roy HK, Backman V, Nguyen TQ. Fully automated fiber-based optical spectroscopy system for use in a clinical setting. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-10. [PMID: 29981224 PMCID: PMC8357326 DOI: 10.1117/1.jbo.23.7.075003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/05/2018] [Indexed: 05/04/2023]
Abstract
While there are a plethora of in vivo fiber-optic spectroscopic techniques that have demonstrated the ability to detect a number of diseases in research trials with highly trained personnel familiar with the operation of experimental optical technologies, very few techniques show the same level of success in large multicenter trials. To meet the stringent requirements for a viable optical spectroscopy system to be used in a clinical setting, we developed components including an automated calibration tool, optical contact sensor for signal acquisition, and a methodology for real-time in vivo probe calibration correction. The end result is a state-of-the-art medical device that can be realistically used by a physician with spectroscopic fiber-optic probes. We show how the features of this system allow it to have excellent stability measuring two scattering phantoms in a clinical setting by clinical staff with ∼0.5 % standard deviation over 25 unique measurements on different days. In addition, we show the systems' ability to overcome many technical obstacles that spectroscopy applications often face such as speckle noise and user variability. While this system has been designed and optimized for our specific application, the system and design concepts are applicable to most in vivo fiber-optic-based spectroscopic techniques.
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Affiliation(s)
- Adam Eshein
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Andrew J. Radosevich
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Bradley Gould
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Wenli Wu
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Vani Konda
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Leslie W. Yang
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Ann Koons
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Seth Feder
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Vesta Valuckaite
- University of Chicago Medicine, Center for Endoscopic Research and Therapeutics, Chicago, Illinois, United States
| | - Hemant K. Roy
- Boston Medical Center, Department of Gastroenterology, Boston, Massachusetts, United States
| | - Vadim Backman
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - The-Quyen Nguyen
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Address all correspondence to: The-Quyen Nguyen, E-mail:
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Radosevich AJ, Eshein A, Nguyen TQ, Backman V. Subdiffusion reflectance spectroscopy to measure tissue ultrastructure and microvasculature: model and inverse algorithm. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:097002. [PMID: 26414387 PMCID: PMC4963470 DOI: 10.1117/1.jbo.20.9.097002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/31/2015] [Indexed: 05/19/2023]
Abstract
Reflectance measurements acquired from within the subdiffusion regime (i.e., lengthscales smaller than a transport mean free path) retain much of the original information about the shape of the scattering phase function. Given this sensitivity, many models of subdiffusion regime light propagation have focused on parametrizing the optical signal through various optical and empirical parameters. We argue, however, that a more useful and universal way to characterize such measurements is to focus instead on the fundamental physical properties, which give rise to the optical signal. This work presents the methodologies that used to model and extract tissue ultrastructural and microvascular properties from spatially resolved subdiffusion reflectance spectroscopy measurements. We demonstrate this approach using ex-vivo rat tissue samples measured by enhanced backscattering spectroscopy.
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Affiliation(s)
- Andrew J. Radosevich
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Address all correspondence to: Andrew J. Radosevich, E-mail:
| | - Adam Eshein
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - The-Quyen Nguyen
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Vadim Backman
- Northwestern University, Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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Radosevich AJ, Mutyal NN, Yi J, Stypula-Cyrus Y, Rogers JD, Goldberg MJ, Bianchi LK, Bajaj S, Roy HK, Backman V. Ultrastructural alterations in field carcinogenesis measured by enhanced backscattering spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:097002. [PMID: 24008865 PMCID: PMC3764252 DOI: 10.1117/1.jbo.18.9.097002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/16/2013] [Accepted: 08/07/2013] [Indexed: 05/10/2023]
Abstract
Optical characterization of biological tissue in field carcinogenesis offers a method with which to study the mechanisms behind early cancer development and the potential to perform clinical diagnosis. Previously, low-coherence enhanced backscattering spectroscopy (LEBS) has demonstrated the ability to discriminate between normal and diseased organs based on measurements of histologically normal-appearing tissue in the field of colorectal (CRC) and pancreatic (PC) cancers. Here, we implement the more comprehensive enhanced backscattering (EBS) spectroscopy to better understand the structural and optical changes which lead to the previous findings. EBS provides high-resolution measurement of the spatial reflectance profile P(rs) between 30 microns and 2.7 mm, where information about nanoscale mass density fluctuations in the mucosa can be quantified. A demonstration of the length-scales at which P(rs) is optimally altered in CRC and PC field carcinogenesis is given and subsequently these changes are related to the tissue's structural composition. Three main conclusions are made. First, the most significant changes in P(rs) occur at short length-scales corresponding to the superficial mucosal layer. Second, these changes are predominantly attributable to a reduction in the presence of subdiffractional structures. Third, similar trends are seen for both cancer types, suggesting a common progression of structural alterations in each.
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Affiliation(s)
- Andrew J. Radosevich
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Nikhil N. Mutyal
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Ji Yi
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Yolanda Stypula-Cyrus
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Jeremy D. Rogers
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
| | - Michael J. Goldberg
- NorthShore University Healthsystems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Laura K. Bianchi
- NorthShore University Healthsystems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Shailesh Bajaj
- NorthShore University Healthsystems, Department of Internal Medicine, Evanston, Illinois 60201
| | - Hemant K. Roy
- Boston Medical Center, Department of Medicine, Boston, Massachusetts 02118
| | - Vadim Backman
- Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208
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Backman V, Roy HK. Advances in biophotonics detection of field carcinogenesis for colon cancer risk stratification. J Cancer 2013; 4:251-61. [PMID: 23459690 PMCID: PMC3584838 DOI: 10.7150/jca.5838] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 02/11/2013] [Indexed: 02/06/2023] Open
Abstract
The process of neoplastic transformation of the colon involves a progression through hyperproliferative epithelium through the aberrant crypt foci→small adenoma→large adenoma→invasive cancer→metastatic disease. These are orchestrated by sequential genetic and epigenetic events which provide the underpinnings of cellular alterations such as early induction in proliferation/suppression of apoptosis, along with the late stage increase in invasiveness. Colorectal cancer (CRC) averages 49-111 mutations per tumor encompassing 10-15 critical signaling pathways[1]. Accumulating such a high number of mutations requires a fertile mutational field, which is the hallmark of colon carcinogenesis. While genetic susceptibility to colorectal cancer is well-known, at least half of the risk is believed to be due to exogeneous factors (e.g., obesity, diet, exercise). Understanding these risk factors represents a promising mode of tailoring screening modality and intensity. However, previous attempts using these factors (i.e., NCI risk calculator) have only been modestly successful with an area under receiver operating characteristics (ROC) curve (AUC) of just 0.61. One of the most important concepts is that risk is the interaction between these genetic and environmental components and is driven by the variety of polymorphisms. Thus, predicting risk is difficult given the complexity. On the other hand, the colonic mucosa represents the end product of the complex interplay between these multiple factors. The power of field carcinogenesis is that it reflects this interplay between genetics and environment.
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Affiliation(s)
- Vadim Backman
- 1. Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
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Radosevich AJ, Rogers JD, Turzhitsky V, Mutyal NN, Yi J, Roy HK, Backman V. Polarized Enhanced Backscattering Spectroscopy for Characterization of Biological Tissues at Subdiffusion Length-scales. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2012; 18:1313-1325. [PMID: 24163574 PMCID: PMC3806115 DOI: 10.1109/jstqe.2011.2173659] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Since the early 1980's, the enhanced backscattering (EBS) phenomenon has been well-studied in a large variety of non-biological materials. Yet, until recently the use of conventional EBS for the characterization of biological tissue has been fairly limited. In this work we detail the unique ability of EBS to provide spectroscopic, polarimetric, and depth-resolved characterization of biological tissue using a simple backscattering instrument. We first explain the experimental and numerical procedures used to accurately measure and model the full azimuthal EBS peak shape in biological tissue. Next we explore the peak shape and height dependencies for different polarization channels and spatial coherence of illumination. We then illustrate the extraordinary sensitivity of EBS to the shape of the scattering phase function using suspensions of latex microspheres. Finally, we apply EBS to biological tissue samples in order to measure optical properties and observe the spatial length-scales at which backscattering is altered in early colon carcinogenesis.
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Affiliation(s)
- Andrew J Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208 USA
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Turzhitsky V, Mutyal NN, Radosevich AJ, Backman V. Multiple scattering model for the penetration depth of low-coherence enhanced backscattering. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:097006. [PMID: 21950941 PMCID: PMC3188644 DOI: 10.1117/1.3625402] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 07/20/2011] [Accepted: 07/21/2011] [Indexed: 05/24/2023]
Abstract
Low-coherence enhanced backscattering (LEBS) is a depth-selective self-interference phenomenon that originates from light traveling time-reversed paths in a scattering medium. The depth selectivity of LEBS and its sensitivity to optical properties of the scattering medium has made it a promising technique for probing the structure of biological tissue with applications to disease diagnosis and, in particular, precancerous conditions. The ability to accurately predict the penetration depth of the LEBS signal is important in targeting an optimal tissue depth for detecting precancerous cells. This prediction is further complicated by the variation in optical properties of different tissue types. In this paper, the effects of the reduced scattering coefficient (μ(s)'), the phase function and the instrument spatial coherence length (L(sc)) on the LEBS penetration depth are quantified. It is determined that the LEBS penetration depth is primarily dependent on L(sc), μ(s)', and the anisotropy factor (g), but has minimal dependence on higher moments of the phase function. An empirical expression, having a similar form as the double scattering approximation for LEBS, is found to accurately predict the average penetration depth in the multiple scattering regime. The expression is shown to be accurate for a broad range of experimentally relevant optical properties and spatial coherence lengths.
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Affiliation(s)
- Vladimir Turzhitsky
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60208, USA.
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Turzhitsky V, Radosevich AJ, Rogers JD, Mutyal NN, Backman V. Measurement of optical scattering properties with low-coherence enhanced backscattering spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:067007. [PMID: 21721828 PMCID: PMC3138801 DOI: 10.1117/1.3589349] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Low-coherence enhanced backscattering (LEBS) is a depth selective technique that allows noninvasive characterization of turbid media such as biological tissue. LEBS provides a spectral measurement of the tissue reflectance distribution as a function of distance between incident and reflected ray pairs through the use of partial spatial coherence broadband illumination. We present LEBS as a new depth-selective technique to measure optical properties of tissue in situ. Because LEBS enables measurements of reflectance due to initial scattering events, LEBS is sensitive to the shape of the phase function in addition to the reduced scattering coefficient (μ(s) (*)). We introduce a simulation of LEBS that implements a two parameter phase function based on the Whittle-Matérn refractive index correlation function model. We show that the LEBS enhancement factor (E) primarily depends on μ(s) (*), the normalized spectral dependence of E (S(n)) depends on one of the two parameters of the phase function that also defines the functional type of the refractive index correlation function (m), and the LEBS peak width depends on both the anisotropy factor (g) and m. Three inverse models for calculating these optical properties are described and the calculations are validated with an experimental measurement from a tissue phantom.
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Affiliation(s)
- Vladimir Turzhitsky
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60208, USA.
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