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Multimode imaging applied toward diagnosis of skin
cancer (SkinSpect)
Fartash Vasefi a, Nicholas MacKinnon a, and Daniel L. Farkas a, b
a Spectral Molecular Imaging Inc., 250 N. Robertson Blvd, Beverly Hillsb Biomedical Engineering, University of Southern California, Los Angeles
Spectral Molecular Imaging Inc.
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Safe Harbor
“Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995. A number of the matters and subject areas discussed in this presentation that are not historical or current facts deal with potential future circumstances and developments. The discussion of such matters and subject areas is qualified by the inherent risks and uncertainties surrounding future expectations generally and also may materially differ from Spectral Molecular Imaging’s (SMI’s) future experience involving any of or more of such matters and subject areas. Such risks and uncertainties include: the early stage of products in development, the uncertainty of market acceptance of products, the uncertainty of development or effectiveness of distribution channels, the intense competition in the medical device industry, the uncertainty of capital to develop products, the uncertainty of regulatory approval of products, dependence on licensed intellectual property, as well as those that are more fully described from time to time under the heading “Risk Factors” in SMI’s filed with the SEC, including SMI’s Report on Form 10-K for the fiscal year ended December 31, 2010 and subsequent quarterly reports.
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"Financial support from NIH and the USDHHS Qualifying Therapeutic Discovery Program is gratefully acknowledged".
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Outline
• Motivation
• Dermoscopes using Biological Models Vs. Statistical classifiers
• To address misestimations in current melanin and hemoglobin quantifications in pigmented skin lesions
• Objective
• To evaluate the performance of a quantitative imaging approach that combines two depth-sensitive imaging techniques, polarization and hyperspectral imaging, to produce a new multimode dermoscopy method that accurately maps melanin and hemoglobin oxygenation distribution in human skin.
• Methods
• Multimode imaging dermoscope and tissue measurements
• Rapid quantification model for preliminary data validation
• Results
• Measurements of human in vivo skin with melanocytic nevus and venous occlusion
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Recent NewsNature: Scientific Reports - May 12, 2014
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
• Spectral Molecular Imaging (SMI), Inc., a subsidiary of Cascade Technologies Corp., is developing high-resolution, hyperspectral imaging for early and accurate diagnosis of cancer and other major diseases
• SkinSpectTM is a hyperspectral imaging system designed to meet the need for accurate diagnosisof skin cancer.
Spectral Molecular Imaging - SkinSpectTM
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Melanoma IncidenceMelanoma MortalityW.H.O. - 2004
USA/Canada94,000/yr13,000/yr
Europe65,000/yr28,000/yr
Melanoma Prevalence and Mortality
(per 100,000)
0
5
10
15
20
25
30
1975 1980 1985 1990 1995 2000 2005 2010
Year
Melanoma Prevalence
Modeled Rate
Melanoma Mortality
Modeled Rate
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Biological Models vs. Statistical Classifiers (Black Boxes)
Black Box
• Need big trials to have sufficient data for BlackBox algorithm validation
• Exceptional data qualification/validation through standards and well developed data quality algorithms
Biological Model (Method we have adopted)
• Directly linked to tissue properties with well developed scientific basis
• Biological plausibility that is easily understood by clinicians (and makes sense to regulatory authorities)
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Melanin vs. hemoglobin misestimations
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Hb estimation Mel estimation
• Instances of results that are contrary to
physiological expectations:
– Local variation in oxygen saturation under
perfectly normal pigmented nevi1
– Data showing that people of different races have
different regional oxygen saturation2,3
– Collagen fluorescence is different under
pigmented and non-pigmented regions4
– A poor correlation between the SIAscans and
histopathological findings in pigmented skin
lesions5
1. Kapsokalyvas, D., et al. Spectral morphological analysis of skin lesions with a polarization
multispectral dermoscope. , Opt Express, 21, 4826-4840 (2013)
2. Vyas, S., Banerjee, A., & Burlina, P. Estimating physiological skin parameters from hyperspectral
signatures. , J Biomed Opt, 18, 057008 (2013)
3. Yudovsky, D. & Pilon, L. Retrieving skin properties from in vivo spectral reflectance
measurements. ,J Biophotonics, 4, 305–314 (2011)
4. Na, R., Stender, I. M., Henriksen, M., & Wulf, H. C. Autofluorescence of human skin is age-
related after correction for skin pigmentation and redness. , J. Invest Derm, 116, 536-540 (2001)5. Terstappen, K., Suurküla, M., Hallberg, H., Ericson M. B., & Wennberg, A. M., Poor correlation between
spectrophotometric intracutaneous analysis and histopathology in melanoma and nonmelanoma lesions. , J Biomed Opt, 18, 061223 (2013)
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Hemoglobin misestimation using ratiometric analysis
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Diebele, I., A. Bekina, A. Derjabo, J. Kapostinsh, I. Kuzmina, and J. Spigulis. "Analysis of skin basalioma and melanoma by multispectral imaging." In Proc.
SPIE, vol. 8427, p. 842732. 2012.
M = 100 (OD650 – OD700), E = 100 (OD560 – OD650),
Melanin masking Hb estimation
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Spectral
Molecular
Imaging
Hemoglobin misestimation using ratiometric analysis (cont.)
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Kapsokalyvas, D., et al. Spectral morphological analysis of skin lesions with a polarization multispectral dermoscope. , Opt Express, 21, 4826-4840 (2013)
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
SkinSpect – clinical vs research prototype
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2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Spectral
Molecular
Imaging
SkinSpect™ overview
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RGB: P-polarized
RGB: X-polarized
Fluorescence:
P and X-polarized
Reflectance datacube : P-polarized
Reflectance datacube : X-polarized
Wavebands ( ~ 33)
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
SkinSpect Data output (Overview)
•
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Visible Light Hand Imaging Characteristics
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Spectral
Molecular
Imaging
SkinSpect Key SpecificationsSpatial
• Total FOV Dia ~ 11 mm
• Each pixel in the FOV = 27 µm
• Each pixel in the camera: 6.45 µm
• Detection lens system:
×0.5 Magnification
• The minimum spatially resolvable line-
width detected by the P and X cameras
was approximately 110 µm, measured
by imaging a USAF 1951 resolution
test target.
Spectral
• RGB: 50nm FWHM
– OneLight®
• Spectral scanning
– 468nm – 857nm (33 wavelengths)
– FWHM: 22 nm
– Average Wavelength interval: 12.2 nm
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
SkinSpect Data analysis
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• Calibrating datacubes:
• Apol spectral function:
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
SkinSpect Data analysis (Cont.)
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• Estimation of relative deep melanin concentration map:
• Estimation of relative oxy- and deoxy-hemoglobin concentration maps using melanin corrected Apol (500 nm -600 nm):
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Apol spectra in highly pigmented skin
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RGB ┴
OD ┴Apol
Deep melanin estimation using ApolMelanin estimation using OD ┴
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Hemoglobin concentration misestimation
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oHb
tHb
tHb
OSP
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Melanin corrected Hemoglobin relative concentrationmaps
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Melanin corrected Hemoglobin relative concentrationmaps
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Mel
A A’
Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
SkinSpect functional mapping- proof of concept
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Summary
Melanoma detection: “Blackbox” versus “biological model”
– Lack of specificity
– We want to address it by multimode imaging concept
SkinSpect Research prototype system and measurements
– Spatial and spectral specification
Two-layer skin optical model proposed for preliminary data validation
– Effect of crosstalk between melanin and deoxy-hemoglobin
– Our approach: Two-step least square solver in different wavelength range
This dermoscope and its quantitative skin analysis algorithm allows us to characterize highly pigmented lesions more accurately, and is to improve detection of potentially cancerous lesions.
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Spectral
Molecular
Imaging
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
2014 CMBEC37 ConferenceVancouver, BC
May 21 – 23, 2014
Nature: Scientific Reports - May 12, 2014
Questions?
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