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Farkas DL. Biomedical Applications of Translational Optical Imaging: From Molecules to Humans. Molecules 2021; 26:molecules26216651. [PMID: 34771060 PMCID: PMC8587670 DOI: 10.3390/molecules26216651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 08/24/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
Light is a powerful investigational tool in biomedicine, at all levels of structural organization. Its multitude of features (intensity, wavelength, polarization, interference, coherence, timing, non-linear absorption, and even interactions with itself) able to create contrast, and thus images that detail the makeup and functioning of the living state can and should be combined for maximum effect, especially if one seeks simultaneously high spatiotemporal resolution and discrimination ability within a living organism. The resulting high relevance should be directed towards a better understanding, detection of abnormalities, and ultimately cogent, precise, and effective intervention. The new optical methods and their combinations needed to address modern surgery in the operating room of the future, and major diseases such as cancer and neurodegeneration are reviewed here, with emphasis on our own work and highlighting selected applications focusing on quantitation, early detection, treatment assessment, and clinical relevance, and more generally matching the quality of the optical detection approach to the complexity of the disease. This should provide guidance for future advanced theranostics, emphasizing a tighter coupling-spatially and temporally-between detection, diagnosis, and treatment, in the hope that technologic sophistication such as that of a Mars rover can be translationally deployed in the clinic, for saving and improving lives.
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Affiliation(s)
- Daniel L. Farkas
- PhotoNanoscopy and Acceleritas Corporations, 13412 Ventura Boulevard, Sherman Oaks, CA 91423, USA; ; Tel.: +1-310-600-7102
- Clinical Photonics Corporation, 8591 Skyline Drive, Los Angeles, CA 90046, USA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
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2
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Nie Z, Yeh SCA, LePalud M, Badr F, Tse F, Armstrong D, Liu LWC, Deen MJ, Fang Q. Optical Biopsy of the Upper GI Tract Using Fluorescence Lifetime and Spectra. Front Physiol 2020; 11:339. [PMID: 32477151 PMCID: PMC7237753 DOI: 10.3389/fphys.2020.00339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 03/24/2020] [Indexed: 12/11/2022] Open
Abstract
Screening and surveillance for gastrointestinal (GI) cancers by endoscope guided biopsy is invasive, time consuming, and has the potential for sampling error. Tissue endogenous fluorescence spectra contain biochemical and physiological information, which may enable real-time, objective diagnosis. We first briefly reviewed optical biopsy modalities for GI cancer diagnosis with a focus on fluorescence-based techniques. In an ex vivo pilot clinical study, we measured fluorescence spectra and lifetime on fresh biopsy specimens obtained during routine upper GI screening procedures. Our results demonstrated the feasibility of rapid acquisition of time-resolved fluorescence (TRF) spectra from fresh GI mucosal specimens. We also identified spectroscopic signatures that can differentiate between normal mucosal samples obtained from the esophagus, stomach, and duodenum.
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Affiliation(s)
- Zhaojun Nie
- School of Biomedical Engineering, Faculty of Engineering, McMaster University, Hamilton, ON, Canada
| | - Shu-Chi Allison Yeh
- Advanced Microscopy Program, Center for Systems Biology and Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Michelle LePalud
- School of Biomedical Engineering, Faculty of Engineering, McMaster University, Hamilton, ON, Canada
| | - Fares Badr
- School of Biomedical Engineering, Faculty of Engineering, McMaster University, Hamilton, ON, Canada
| | - Frances Tse
- Division of Gastroenterology and Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - David Armstrong
- Division of Gastroenterology and Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Louis W. C. Liu
- Division of Gastrointestinal Diseases, Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - M. Jamal Deen
- School of Biomedical Engineering, Faculty of Engineering, McMaster University, Hamilton, ON, Canada
- Department of Electrical and Computer Engineering, Faculty of Engineering, McMaster University, Hamilton, ON, Canada
| | - Qiyin Fang
- School of Biomedical Engineering, Faculty of Engineering, McMaster University, Hamilton, ON, Canada
- Department of Engineering Physics, Faculty of Engineering, McMaster University, Hamilton, ON, Canada
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3
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Durkee MS, Cirillo JD, Maitland KC. Fluorescence modeling of in vivo optical detection of Mycobacterium tuberculosis. BIOMEDICAL OPTICS EXPRESS 2019; 10:5445-5460. [PMID: 31646057 PMCID: PMC6788618 DOI: 10.1364/boe.10.005445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/23/2019] [Accepted: 09/23/2019] [Indexed: 05/03/2023]
Abstract
Tuberculosis is one of the deadliest infectious diseases worldwide. New tools to study pathogenesis and monitor subjects in pre-clinical studies to develop treatment regimens are critical for progress. We developed an improved optical system for detecting bacteria in lungs of mice using internal illumination. We present a computational optical model of the full mouse torso to characterize the optical system. Simulated theoretical limits for the lowest detectable bacterial load support the experimental improvements with an internal illumination source, and suggest that protocol improvements could further lower the detection threshold.
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Affiliation(s)
- Madeleine S. Durkee
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Jeffrey D. Cirillo
- Department of Microbial Pathogenesis and Immunology, Texas A&M College of Medicine, Bryan, TX 77807, USA
| | - Kristen C. Maitland
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843, USA
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4
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Carver GE, Locknar SA, Weaver DL, Stein JL, Stein GS. Real-time detection of breast cancer at the cellular level. J Cell Physiol 2018; 234:5413-5419. [PMID: 30362286 DOI: 10.1002/jcp.27451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 08/29/2018] [Indexed: 11/05/2022]
Abstract
Novel optoelectronic instrumentation has been developed for the multispectral imaging of autofluorescence emitted by metabolic fluorophores. The images resolve individual cells while spectra are collected for each pixel in the images. These datacubes are generated at a rate of 10 per second-fast enough for surgical guidance. The data is processed in real time to provide a single color-coded image to the surgeon. To date, the system has been applied to fresh, ex vivo, human surgical specimens and has distinguished breast cancer from benign tissue. The approach is applicable to in vivo measurements of surgical margins and needle-based optical biopsies. Ongoing work demonstrates that the system has great potential for translation to a hand-held probe with high sensitivity and specificity.
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Affiliation(s)
| | | | - Donald L Weaver
- Department of Pathology and Laboratory Medicine, University of Vermont Cancer Center, Burlington, Vermont
| | - Janet L Stein
- Department of Biochemistry, University of Vermont Cancer Center, Burlington, Vermont
| | - Gary S Stein
- Department of Pathology and Laboratory Medicine, University of Vermont Cancer Center, Burlington, Vermont
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5
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Tozar T, Andrei IR, Costin R, Pirvulescu R, Pascu ML. Case series about ex vivo identification of squamous cell carcinomas by laser-induced autofluorescence and Fourier transform infrared spectroscopy. Lasers Med Sci 2018; 33:861-869. [PMID: 29380083 DOI: 10.1007/s10103-018-2445-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 01/12/2018] [Indexed: 01/10/2023]
Abstract
An ex vivo case series aimed at identification of normal laryngeal tissue from laryngeal epidermoid squamous keratinized carcinoma by measuring laser-induced autofluorescence (LIAF) and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectra is presented. The case series results were obtained for paired samples extracted from three patients (exclusion: macroscopic changes of normal vocal cord observed during surgery; surgical intervention on vocal cord, treated only with chemotherapy or radiotherapy for carcinoma; inclusion: men, aged 57-68, non-smokers). For LIAF analysis, a 375-nm picosecond pulsed laser diode with 31 MHz pulse repetition rate, 100 ps full-time width at half-maximum, and average power 0.49 μW was used. LIAF and FTIR-ATR spectra show noticeable differences between normal and malignant tissues. LIAF spectra differed in shape of emitted band, peak position, and band relative intensity of the two kinds of samples, evidencing hypsochromic shift and mean fluorescence intensity decrease of (75.42 ± 3)% in malignant tissue with respect to the normal one. The lack of 1745 cm-1 band in FTIR-ATR spectra for malignant tissues could be considered an important indicative of the presence of this kind of tissue; moreover, it resulted a greater contribution of lipids and proteins in normal tissue and of collagen in malignant tissue. Penetration depth of the evanescent wave was about 2 μm at an angle of 42°. The two spectroscopic methods are complementary, are applicable for real-time measurements, and may enhance cancer detection and diagnostics. Results presented in this study evidence the potential of the two methods for future in vivo studies.
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Affiliation(s)
- Tatiana Tozar
- National Institute for Laser, Plasma and Radiation Physics, Magurele, Ilfov, Romania
| | - Ionut Relu Andrei
- National Institute for Laser, Plasma and Radiation Physics, Magurele, Ilfov, Romania
| | - Romeo Costin
- Carol Davila Central University Emergency Military Hospital, Bucharest, Romania
| | - Ruxandra Pirvulescu
- Ophthalmology Clinic, University of Medicine and Pharmacy "Carol Davila", Emergency University Hospital, Bucharest, Romania
| | - Mihail Lucian Pascu
- National Institute for Laser, Plasma and Radiation Physics, Magurele, Ilfov, Romania. .,Faculty of Physics, University of Bucharest, Magurele, Ilfov, Romania.
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6
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Kilin V, Mas C, Constant S, Wolf JP, Bonacina L. Health state dependent multiphoton induced autofluorescence in human 3D in vitro lung cancer model. Sci Rep 2017; 7:16233. [PMID: 29176571 PMCID: PMC5701152 DOI: 10.1038/s41598-017-16628-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 11/15/2017] [Indexed: 12/18/2022] Open
Abstract
Lung diseases pose the highest risk of death and lung cancer is a top killer among cancers with a mortality rate up to 70% within 1 year after diagnosis. Such a fast escalation of this cancer development makes early diagnosis and treatment a highly challenging task, and currently there are no effective tools to diagnose the disease at an early stage. The ability to discriminate between healthy and tumorous tissue has made autofluorescence bronchoscopy a promising tool for detection of lung cancer; however, specificity of this method remains insufficiently low. Here, we perform autofluorescence imaging of human lung cancer invading a human functional airway using an in vitro model of Non Small Cell Lung Cancer which combines a reconstituted human airway epithelium, human lung fibroblasts and lung adenocarcinoma cell lines, OncoCilAir™. By using two-photon laser induced autofluorescence microscopy combined with spectrally resolved imaging, we found that OncoCilAir™ provides tissue's health dependent autofluorescence similar as observed in lung tissue in patients. Moreover, we found spectral and intensity heterogeneity of autofluorescence at the edges of tumors. This metabolic related heterogeneity demonstrates ability of tumor to influence its microenvironment. Together, our result shows that OncoCilAir™ is a promising model for lung cancer research.
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Affiliation(s)
- Vasyl Kilin
- GAP, University of Geneva, 22 chemin de Pinchat, CH-1211, Geneva 4, Switzerland.
| | - Christophe Mas
- OncoTheis Sàrl, 18 chemin des aulx, CH-1228, Plan-les-Ouates, Geneva, Switzerland
| | - Samuel Constant
- OncoTheis Sàrl, 18 chemin des aulx, CH-1228, Plan-les-Ouates, Geneva, Switzerland
- Epithelix SAS, 219 Rue Laszlo Biro, 74160, Archamps, France
| | - Jean-Pierre Wolf
- GAP, University of Geneva, 22 chemin de Pinchat, CH-1211, Geneva 4, Switzerland
| | - Luigi Bonacina
- GAP, University of Geneva, 22 chemin de Pinchat, CH-1211, Geneva 4, Switzerland
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7
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Lin CW, Weisman RB. In vivo detection of single-walled carbon nanotubes: progress and challenges. Nanomedicine (Lond) 2016; 11:2885-2888. [DOI: 10.2217/nnm-2016-0338] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Ching-Wei Lin
- Department of Chemistry & Smalley–Curl Institute, Rice University, Houston, TX 77005, USA
| | - R Bruce Weisman
- Department of Chemistry & Smalley–Curl Institute, Rice University, Houston, TX 77005, USA
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8
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Carver GE, Locknar SA, Morrison WA, Krishnan Ramanujan V, Farkas DL. High-speed multispectral confocal biomedical imaging. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:36016. [PMID: 24658777 PMCID: PMC3962271 DOI: 10.1117/1.jbo.19.3.036016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/20/2014] [Accepted: 02/12/2014] [Indexed: 06/03/2023]
Abstract
A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues.
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Affiliation(s)
- Gary E. Carver
- Omega Optical Inc., 21 Omega Drive, Brattleboro, Vermont 05301
| | | | | | | | - Daniel L. Farkas
- University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90089
- Spectral Molecular Imaging, 250 N. Robertson Boulevard, Beverly Hills, California 90211
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9
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Yang C, Hou VW, Girard EJ, Nelson LY, Seibel EJ. Target-to-background enhancement in multispectral endoscopy with background autofluorescence mitigation for quantitative molecular imaging. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:76014. [PMID: 25027002 PMCID: PMC4098034 DOI: 10.1117/1.jbo.19.7.076014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 06/25/2014] [Indexed: 05/05/2023]
Abstract
Fluorescence molecular imaging with exogenous probes improves specificity for the detection of diseased tissues by targeting unambiguous molecular signatures. Additionally, increased diagnostic sensitivity is expected with the application of multiple molecular probes. We developed a real-time multispectral fluorescence-reflectance scanning fiber endoscope (SFE) for wide-field molecular imaging of fluorescent dye-labeled molecular probes at nanomolar detection levels. Concurrent multichannel imaging with the wide-field SFE also allows for real-time mitigation of the background autofluorescence (AF) signal, especially when fluorescein, a U.S. Food and Drug Administration approved dye, is used as the target fluorophore. Quantitative tissue AF was measured for the ex vivo porcine esophagus and murine brain tissues across the visible and nearinfrared spectra. AF signals were then transferred to the unit of targeted fluorophore concentration to evaluate the SFE detection sensitivity for sodium fluorescein and cyanine. Next, we demonstrated a real-time AF mitigation algorithm on a tissue phantom, which featured molecular probe targeted cells of high-grade dysplasia on a substrate containing AF species. The target-to-background ratio was enhanced by more than one order of magnitude when applying the real-time AF mitigation algorithm. Furthermore, a quantitative estimate of the fluorescein photodegradation (photobleaching) rate was evaluated and shown to be insignificant under the illumination conditions of SFE. In summary, the multichannel laser-based flexible SFE has demonstrated the capability to provide sufficient detection sensitivity, image contrast, and quantitative target intensity information for detecting small precancerous lesions in vivo.
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Affiliation(s)
- Chenying Yang
- University of Washington, Department of Bioengineering, Seattle, Washington 98195, United States
| | - Vivian W. Hou
- University of Washington, Department of Biology, Seattle, Washington 98195, United States
| | - Emily J. Girard
- Fred Hutchinson Cancer Research Center, Clinical Research Division, Seattle, Washington 98109, United States
| | - Leonard Y. Nelson
- University of Washington, Department of Mechanical Engineering, Seattle, Washington 98195, United States
| | - Eric J. Seibel
- University of Washington, Department of Mechanical Engineering, Seattle, Washington 98195, United States
- Address all correspondence to: Eric J. Seibel,
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10
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Marcu L. Fluorescence lifetime techniques in medical applications. Ann Biomed Eng 2012; 40:304-31. [PMID: 22273730 PMCID: PMC3368954 DOI: 10.1007/s10439-011-0495-y] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Accepted: 12/17/2011] [Indexed: 12/20/2022]
Abstract
This article presents an overview of time-resolved (lifetime) fluorescence techniques used in biomedical diagnostics. In particular, we review the development of time-resolved fluorescence spectroscopy (TRFS) and fluorescence lifetime imaging (FLIM) instrumentation and associated methodologies which allow in vivo characterization and diagnosis of biological tissues. Emphasis is placed on the translational research potential of these techniques and on evaluating whether intrinsic fluorescence signals provide useful contrast for the diagnosis of human diseases including cancer (gastrointestinal tract, lung, head and neck, and brain), skin and eye diseases, and atherosclerotic cardiovascular disease.
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Affiliation(s)
- Laura Marcu
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA.
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11
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Celli JP, Spring BQ, Rizvi I, Evans CL, Samkoe KS, Verma S, Pogue BW, Hasan T. Imaging and photodynamic therapy: mechanisms, monitoring, and optimization. Chem Rev 2010; 110:2795-838. [PMID: 20353192 PMCID: PMC2896821 DOI: 10.1021/cr900300p] [Citation(s) in RCA: 1619] [Impact Index Per Article: 115.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jonathan P Celli
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
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12
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Drzazga ZK, Kluczewska-Gałka A, Michnik A, Kaszuba M, Trzeciak H. Fluorescence spectroscopy as tool for bone development monitoring in newborn rats. J Fluoresc 2010; 21:851-7. [PMID: 20069348 DOI: 10.1007/s10895-009-0584-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 12/14/2009] [Indexed: 11/25/2022]
Abstract
Autofluorescence of the mandible and femur bones taken from newborn rats (7-, 14- and 28-day old) was studied. Endogenous fluorophores were excited with 231 nm, 291 nm, 340 nm and 360 nm wavelengths. Modifications in content and microenvironment of both noncolagenous and collagenous constituents of bone tissue as well as metabolic coenzymes during the bone formation with age were reflected in fluorescence emission spectra. The increase of emission from peptide bonds and tryptophan residues was noted with rat age while for collagen and metabolic coenzymes at the first 2 weeks only. After maternal administration of indinavir the changes in fluorescence intensity and shifts in position of peak maximum were found. The distinct drop of emission from peptide bonds and tryptophan residues in studied bones was detected. In the case of collagen and metabolic coenzymes the red shift of peak maximum was revealed. Fluorescence spectroscopy could be used to follow bone development in newborn rats and effect of maternal indinavir administration on offspring.
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Affiliation(s)
- Zofia Krystyna Drzazga
- A. Chełkowski' Institute of Physics, Department of Medical Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland.
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Drzazga Z, Michalik K, Maciejewska K, Kaszuba M, NowiÅska B, Trzeciak H. Optical and X-ray Fluorescence Spectroscopy Studies of Bone and Teeth in Newborn Rats After Maternal Treatment with Indinavir. Photochem Photobiol 2010; 86:87-95. [DOI: 10.1111/j.1751-1097.2009.00632.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Improvement of the specificity of cancer detection by autofluorescence imaging in the tracheo-bronchial tree using backscattered violet light. Photodiagnosis Photodyn Ther 2008; 5:2-9. [PMID: 19356630 DOI: 10.1016/j.pdpdt.2008.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 01/17/2008] [Accepted: 01/18/2008] [Indexed: 11/21/2022]
Abstract
BACKGROUND Autofluorescence bronchoscopy (AFB) is a highly sensitive tool for the detection of early bronchial cancers. However, its specificity remains limited due to primarily false positive results induced by hyperplasia, metaplasia and inflammation. We have investigated the potential of blue-violet backscattered light to eliminate false positive results during AFB in a clinical pilot study. METHODS The diagnostic autofluorescence endoscopy (DAFE) system was equipped with a variable band pass filter in the imaging detection path. The backscattering properties of normal and abnormal bronchial mucosae were assessed by computing the contrast between the two tissue types for blue-violet wavelengths ranging between 410 and 490 nm in 12 patients undergoing routine DAFE examination. In a second study including 6 patients we used a variable long pass (LP) filter to determine the spectral design of the emission filter dedicated to the detection of this blue-violet light with the DAFE system. RESULTS (Pre-)neoplastic mucosa showed a clear wavelength dependence of the backscattering properties of blue-violet light while the reflectivity of normal, metaplastic and hyperplastic autofluorescence positive mucosa was wavelength independent. CONCLUSIONS Our results showed that the detection of blue-violet light has the potential to reduce the number of false positive results in AFB. In addition we determined the spectral design of the emission filter dedicated to the detection of this blue-violet light with the DAFE system.
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15
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Autofluorescence bronchoscopy: quantification of inter-patient variations of fluorescence intensity. Lasers Med Sci 2007; 24:45-51. [PMID: 18060444 DOI: 10.1007/s10103-007-0518-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 10/18/2007] [Indexed: 10/22/2022]
Abstract
Autofluorescence (AF) from bronchial tissue is increasingly used for the endoscopic detection of early bronchial neoplasia. Several imaging systems are commercially available, all detecting the absolute or relative AF intensity and/or spectral contrasts between normal tissue and early neoplastic lesions. These devices have a high sensitivity for flat neoplasia, but the specificity remains limited. Variations in the AF intensity between individuals (inter-patient variations) is considered one of the most limiting factors. In the clinical study presented here, we quantified those variations using a non-invasive optical reference positioned in situ during AF bronchoscopy. The inter-patient variations in intensity on the main carina were in the order of 25- 30%. The results of this study are quite useful for improving and defining the design of the optical features (dynamic range, physical sensitivity) of AF detection systems.
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Gabrecht T, Glanzmann T, Freitag L, Weber BC, van den Bergh H, Wagnières G. Optimized autofluorescence bronchoscopy using additional backscattered red light. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:064016. [PMID: 18163832 DOI: 10.1117/1.2811952] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Autofluorescence bronchoscopy (AFB) has been shown to be a highly sensitive tool for the detection of early endobronchial cancers. When excited with blue-violet light, early neoplasia in the bronchi tend to show a decrease of autofluorescence in the green region of the spectrum and a relatively smaller decrease in the red region of the spectrum. Superposing the green foreground image and the red background image creates the resultant autofluorescence image. Our aim was to investigate whether the addition of backscattered red light to the tissue autofluorescence signal could improve the contrast between healthy and diseased tissue. We have performed a clinical study involving 41 lung cancers using modified autofluorescence bronchoscopy systems. The lesions were examined sequentially with conventional violet autofluorescence excitation (430 nm+/-30 nm) and violet autofluorescence excitation plus backscattered red light (430 nm+/-40 nm plus 665 nm+/-15 nm). The contrast between (pre-)neoplastic and healthy tissue was quantified with off-line image analysis. We observed a 2.7 times higher contrast when backscattered red light was added to the violet excitation. In addition, the image quality was improved in terms of the signal-to-noise ratio (SNR) with this spectral design.
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Affiliation(s)
- Tanja Gabrecht
- Swiss Federal Institute of Technology (EPFL), Laboratory for Air and Soil Pollution, 1015 Lausanne, Switzerland
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17
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Lovisa B, Gabrecht T, Andrejevic S, Grosjean P, Radu A, Monnier P, van den Bergh H, Wagnières G. Improvement of the contrast in cancer detection by autofluorescence bronchoscopy using a narrowband spectral violet excitation: A preliminary study. Biomed Signal Process Control 2007. [DOI: 10.1016/j.bspc.2007.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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18
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Gabrecht T, Lovisa B, Borle F, Wagnières G. Design of an endoscopic optical reference to be used for autofluorescence bronchoscopy with a commercially available diagnostic autofluorescence endoscopy (DAFE) system. Phys Med Biol 2007; 52:N163-71. [PMID: 17404451 DOI: 10.1088/0031-9155/52/8/n02] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We present the design of a sterilizable optical reference to characterize and quantify the inter-patient variations in tissue autofluorescence during autofluorescence bronchoscopy with Richard Wolf's diagnostic autofluorescence endoscopy (DAFE) system. The reference was designed to have optical and spectral properties similar to those of the human bronchial wall in spectral conditions corresponding to autofluorescence bronchoscopy conducted with the DAFE system (fluorescence excitation at 390-470 nm and red backscattering light at 590-680 nm). The reference's effective attenuation coefficient and reflectance were measured at 675 nm. In addition, its fluorescence emission spectrum was determined under 430 nm wavelength excitation. The reference is photostable, reproducible, biocompatible and small enough to be easily inserted through the working channel of a conventional bronchofibrescope. This cylindrical (length: 2 mm; diameter: 2 mm) optical reference was validated in a clinical environment.
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Affiliation(s)
- T Gabrecht
- Swiss Federal Institute of Technology (EPFL), Photomedicine Laboratory, Station 6, 1015 Lausanne, Switzerland
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Gabrecht T, Andrejevic-Blant S, Wagnières G. Blue-Violet Excited Autofluorescence Spectroscopy and Imaging of Normal and Cancerous Human Bronchial Tissue after Formalin Fixation. Photochem Photobiol 2007; 83:450-8. [PMID: 17094717 DOI: 10.1562/2006-03-20-ra-852] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Autofluorescence (AF) imaging is a powerful tool for the detection of (pre-)neoplastic lesions in the bronchi. Several endoscopic imaging systems exploit the spectral and intensity contrast of AF between healthy and (pre-)neoplastic bronchial tissues, yet, the mechanisms underlying these contrasts are poorly understood. In this report, the effect of formalin fixation on the human bronchi AF, hence on the contrast, was studied by spectrofluorometric point measurements and DAFE (Diagnostic AutoFluorescence Endoscopy) broad field imaging. Generally, formalin-fixed samples have higher AF intensity than in vivo, whereas the emission spectral shape is similar. Additionally, the spectrofluorometric data showed a moderate decrease of the AF intensity on (pre-)neoplastic lesions relative to the healthy bronchial samples. However, this decrease was lower than that reported from in vivo measurements. Neither spectral measurements nor imaging revealed spectral contrast between healthy bronchial tissue and (pre-)neoplastic lesions in formalin. These results indicate that epithelial thickening and blood supply in the adjacent lamina propria are likely to play a key role in the generation of the AF contrast in bronchial tissues. Our results show that the AF contrast in bronchial tissues was significantly affected by standard, 10% buffered, formalin fixation. Therefore, these samples are not suited to AF contrast studies.
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Affiliation(s)
- Tanja Gabrecht
- Swiss Federal Institute of Technology (EPFL), Laboratory for Air and Soil Pollution, 1015 Lausanne, Switzerland
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Crowell E, Wang G, Cox J, Platz CP, Geng L. Correlation coefficient mapping in fluorescence spectroscopy: tissue classification for cancer detection. Anal Chem 2007; 77:1368-75. [PMID: 15732920 DOI: 10.1021/ac049074+] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Correlation coefficient mapping has been applied to intrinsic fluorescence spectra of colonic tissue for the purpose of cancer diagnosis. Fluorescence emission spectra were collected of 57 colonic tissue sites in a range of 4 physiological conditions: normal (29), hyperplastic (2), adenomatous (5), and cancerous tissues (21). The sample-sample correlation was used to examine the ability of correlation coefficient mapping to determine tissue disease state. The correlation coefficient map indicates two main categories of samples. These categories were found to relate to disease states of the tissue. Sensitivity, selectivity, predictive value positive, and predictive value negative for differentiation between normal tissue and all other categories were all above 92%. This was found to be similar to, or higher than, tissue classification using existing methods of data reduction. Wavelength-wavelength correlation among the samples highlights areas of importance for tissue classification. The two-dimensional correlation map reveals absorption by NADH and hemoglobin in the samples as negative correlation, an effect not obvious from the one-dimensional fluorescence spectra alone. The integrity of tissue was examined in a time series of spectra of a single tissue sample taken after tissue resection. The wavelength-wavelength correlation coefficient map shows the areas of significance for each fluorophore and their relation to each other. NADH displays negative correlation to collagen and FAD, from the absorption of emission or fluorescence resonance energy transfer. The wavelength-wavelength correlation map for the decay set also clearly shows that there are only three fluorophores of importance in the samples, by the well-defined pattern of the map. The sample-sample correlation coefficient map reveals the changes over time and their impact on tissue classification. Correlation coefficient mapping proves to be an effective method for sample classification and cancer detection.
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Affiliation(s)
- Ed Crowell
- Department of Chemistry, the Optical Science and Technology Center, and the Center for Biocatalysis and Bioprocessing, University of Iowa, Iowa City, Iowa 52242, USA
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De Rosa FS, Lopez RFV, Thomazine JA, Tedesco AC, Lange N, Bentley MVLB. In Vitro Metabolism of 5-ALA Esters Derivatives in Hairless Mice Skin Homogenate and in Vivo PpIX Accumulation Studies. Pharm Res 2004; 21:2247-52. [PMID: 15648256 DOI: 10.1007/s11095-004-7677-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE In topical photodynamic therapy, 5-ALA and its esters are enzymatically converted in the endogenous photosensitizing compounds such as, for example, protoporphyrin IX (PpIX). In order to elucidate in more detail their enzymatic fate, we have determined in vitro the enzymatic degradation of methyl, butyl, hexyl, and octyl-5-ALA ester derivatives in skin homogenate. Furthermore, in vivo porphyrin accumulation was measured in healthy hairless mice skins. METHODS Hairless mouse skins were homogenized in isotonic phosphate buffer pH 7.4. 5-ALA esters were added, and aliquots were colleted for HPLC-fluorimetric determinations of remaining content of 5-ALA esters. Furthermore, oil-in-water emulsions containing esters were topically applied to mice skin for 6 h, and the amount of accumulated PpIX in the treated areas was determined by quantitative extraction and confocal fluorescence microscopy. RESULTS The enzymatic degradation of esters follows pseudo first-order kinetics. The octyl ester had the largest rate constant for enzymatic degradation, followed by hexyl-, butyl-, and methyl-ALA. The long-chained 5-ALA esters, butyl-, hexyl-, and octyl ester, induced significantly more porphyrins than 5-ALA and 5-ALA methyl ester as shown by confocal microscopy and quantitative extraction studies. CONCLUSIONS 5-ALA derivatives differ widely with respect to their enzymatic degradation. The presence of alkyl chains in 5-ALA esters significantly influences the in vitro enzymatic metabolism and the in vivo PpIX formation in healthy hairless mice skins.
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Affiliation(s)
- Fernanda Scarmato De Rosa
- Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo, Ribeirão Preto, Brazil
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de Veld DCG, Sterenborg HJCM, Roodenburg JLN, Witjes MJH. Effects of individual characteristics on healthy oral mucosa autofluorescence spectra. Oral Oncol 2004; 40:815-23. [PMID: 15288837 DOI: 10.1016/j.oraloncology.2004.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Accepted: 02/19/2004] [Indexed: 10/26/2022]
Abstract
Autofluorescence spectroscopy is a tool for detecting tissue alterations in vivo. In a previous study, we found spectral differences between clinically normal mucosa of different patient groups. These are possibly caused by associated patient characteristics. In the present study, we explore the influences of volunteer characteristics on healthy oral mucosa autofluorescence. Autofluorescence spectra were recorded in 96 volunteers with no clinically observable oral lesions. We applied principal components analysis to extract the relevant information. We used multivariate linear regression techniques to estimate the effect of volunteer characteristics on principal component scores. Statistically significant differences were found for all factors but age. Skin color strongly affected autofluorescence intensity. Gender differences were found in blood absorption. Alcohol consumption was associated with porphyrin-like peaks. However, all differences but those associated with skin color were of the same order of magnitude as standard deviations within categories. The effects of volunteer characteristics on autofluorescence spectra of the oral mucosa are measurable. Only the effects of skin color were large. Therefore, in lesion classification, skin color should be taken into account.
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Affiliation(s)
- Diana C G de Veld
- Photodynamic Therapy and Optical Spectroscopy Research Programme, Department of Radiation Oncology, Erasmus Medical Center, P.O. Box 2400, 3000 CA Rotterdam, The Netherlands
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Fang Q, Papaioannou T, Jo JA, Vaitha R, Shastry K, Marcu L. Time-domain laser-induced fluorescence spectroscopy apparatus for clinical diagnostics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2004; 75:151-162. [PMID: 35291695 PMCID: PMC8920500 DOI: 10.1063/1.1634354] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report the design and development of a compact optical fiber-based apparatus for in situ time-resolved laser-induced fluorescence spectroscopy (tr-LIFS) of biological systems. The apparatus is modular, optically robust, and compatible with the clinical environment. It incorporates a dual output imaging spectrograph, a gated multichannel plate photomultiplier (MCP-PMT), an intensified charge-coupled-device (ICCD) camera, and a fast digitizer. It can accommodate various types of light sources and optical fiber probes for selective excitation and remote light delivery/collection as required by different applications. The apparatus allows direct recording of the entire fluorescence decay with high sensitivity (nM range fluorescein dye concentration with signal-to-noise ratio of 46) and with four decades dynamic range. It is capable of resolving a broad range of fluorescence lifetimes from hundreds of picoseconds (as low as 300 ps) using the MCP-PMT coupled to the digitizer to milliseconds using the ICCD. The data acquisition and analysis process is fully automated, enabling fast recording of fluorescence intensity decay across the entire emission spectrum (0.8 s per wavelength or ~40 s for a 200 nm wavelength range at 5 nm increments). The spectral and temporal responses of the apparatus were calibrated and its performance was validated using fluorescence lifetime standard dyes (Rhodamin B, 9-cyanoanthracene, and rose Bengal) and tissue endogenous fluorophores (elastin, collagen, nicotinamide adenine dinucleotide, and flavin adenine dinucleotide). Fluorescence decay lifetimes and emission spectra of all tested compounds measured with the current tr-LIFS apparatus were found in good agreement with the values reported in the literature. The design and performance of tr-LIFS apparatus have enabled in vivo studies of atherosclerotic plaques and brain tumors.
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Affiliation(s)
- Qiyin Fang
- Biophotonics Research and Technology Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | - Thanassis Papaioannou
- Biophotonics Research and Technology Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | - Javier A Jo
- Biophotonics Research and Technology Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | - Russel Vaitha
- Biophotonics Research and Technology Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | - Kumar Shastry
- Biophotonics Research and Technology Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048
| | - Laura Marcu
- Biophotonics Research and Technology Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California 90048 and Department of Biomedical Engineering and Department of Electrical Engineering-Electrophysics, University of Southern California, Los Angeles, California 90089
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van den Bergh H. Early Detection of Lung Cancer and the Role of Endoscopic Fluorescence Imaging. ACTA ACUST UNITED AC 2003. [DOI: 10.1078/1615-1615-00083] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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The Biomedical Use of Rescaling Procedures in Optical Biopsy and Optical Molecular Imaging. ACTA ACUST UNITED AC 2002. [DOI: 10.1007/978-3-642-56067-5_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
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