Dual-Axis Confocal Microscopy for Point-of-Care Pathology

Dual-axis confocal (DAC) microscopy is a high-resolution optical imaging modality that utilizes simple low-numerical-aperture (NA) beams to achieve effective optical sectioning and superior image contrast in biological tissues. In addition to providing enhanced imaging performance, the DAC architecture provides certain advantages for miniaturization, facilitating the development of endoscopic, and handheld systems for in vivo imaging. This article reviews the principles of DAC microscopy, highlighting the differences between DAC microscopy and conventional confocal microscopy. Several technical variations of DAC microscopy will be surveyed, as well as clinical DAC microscopy prototypes that have been developed as noninvasive real-time alternatives to conventional biopsy and histopathology.

[1]  T Wilson,et al.  Depth of field in the scanning microscope. , 1978, Optics letters.

[2]  W. Piyawattanametha,et al.  MEMS-Based Dual-Axes Confocal Microendoscopy , 2010, IEEE Journal of Selected Topics in Quantum Electronics.

[3]  David D Sampson,et al.  Energy-efficient low-Fresnel-number Bessel beams and their application in optical coherence tomography. , 2014, Optics letters.

[4]  Milind Rajadhyaksha,et al.  Confocal theta line-scanning microscope for imaging human tissues. , 2007, Applied optics.

[5]  Matthew D. Chidley,et al.  In vivo fiber-optic confocal reflectance microscope with an injection-molded plastic miniature objective lens. , 2005, Applied optics.

[6]  Milind Rajadhyaksha,et al.  Compact divided-pupil line-scanning confocal microscope for investigation of human tissues , 2013, Photonics West - Biomedical Optics.

[7]  Y. Wang,et al.  Comparison of line-scanned and point-scanned dual-axis confocal microscope performance. , 2013, Optics letters.

[8]  A. Polglase,et al.  A fluorescence confocal endomicroscope for in vivo microscopy of the upper- and the lower-GI tract. , 2005, Gastrointestinal endoscopy.

[9]  D. Meza,et al.  Sheet-scanned dual-axis confocal microscopy using Richardson-Lucy deconvolution. , 2014, Optics letters.

[10]  Xingde Li,et al.  Compensation-free, all-fiber-optic, two-photon endomicroscopy at 1.55 μm. , 2011, Optics letters.

[11]  W. Piyawattanametha,et al.  Miniaturized probe for femtosecond laser microsurgery and two-photon imaging. , 2008, Optics express.

[12]  Chengbo Yin,et al.  Optical-sectioning microscopy of protoporphyrin IX fluorescence in human gliomas: standardization and quantitative comparison with histology , 2017, Journal of biomedical optics.

[13]  Nathan O. Loewke,et al.  Micromirror-scanned dual-axis confocal microscope utilizing a gradient-index relay lens for image guidance during brain surgery. , 2010, Journal of biomedical optics.

[14]  Pierre Nassoy,et al.  Light-sheet microscopy in thick media using scanned Bessel beams and two-photon fluorescence excitation. , 2013, Optics express.

[15]  Ye Chen,et al.  Optimizing the performance of dual-axis confocal microscopes via Monte-Carlo scattering simulations and diffraction theory , 2013, Journal of biomedical optics.

[16]  Richard M. Levenson,et al.  Point-of-Care Pathology with Miniature Microscopes , 2011, Analytical cellular pathology.

[17]  Dean Wilding,et al.  High-speed 2D and 3D fluorescence microscopy of cardiac myocytes. , 2011, Optics express.

[18]  Milind Rajadhyaksha,et al.  Line-scanning reflectance confocal microscopy of human skin: comparison of full-pupil and divided-pupil configurations. , 2009, Optics letters.

[19]  Steffen Lindek,et al.  Fundamental reduction of the observation volume in far-field light microscopy by detection orthogonal to the illumination axis: confocal theta microscopy , 1994 .

[20]  R Richards-Kortum,et al.  Near real time in vivo fibre optic confocal microscopy: sub‐cellular structure resolved , 2002, Journal of microscopy.

[21]  Milind Rajadhyaksha,et al.  Optimization of pupil design for point-scanning and line-scanning confocal microscopy , 2011, Biomedical optics express.

[22]  R. Richards-Kortum,et al.  Fiber-optic confocal microscope using a MEMS scanner and miniature objective lens. , 2007, Optics express.

[23]  Thomas D. Wang,et al.  Dual-axis confocal microscope for high-resolution in vivo imaging. , 2003, Optics letters.

[24]  M. Rajadhyaksha,et al.  Miniature in vivo MEMS-based line-scanned dual-axis confocal microscope for point-of-care pathology. , 2016, Biomedical optics express.

[25]  Kazunori Hoshino,et al.  Handheld subcellular-resolution single-fiber confocal microscope using high-reflectivity two-axis vertical combdrive silicon microscanner , 2008, Biomedical microdevices.

[26]  Javier A. Jo,et al.  Handheld tunable focus confocal microscope utilizing a double-clad fiber coupler for in vivo imaging of oral epithelium , 2017, Journal of biomedical optics.

[27]  C J Koester,et al.  Scanning mirror microscope with optical sectioning characteristics: applications in ophthalmology. , 1980, Applied optics.

[28]  Timothy D. Soper,et al.  Scanning fiber endoscopy with highly flexible, 1 mm catheterscopes for wide‐field, full‐color imaging , 2010, Journal of biophotonics.

[29]  Haijun Li,et al.  Integrated monolithic 3D MEMS scanner for switchable real time vertical/horizontal cross-sectional imaging. , 2016, Optics express.

[30]  Thomas D. Wang,et al.  In vivo near-infrared dual-axis confocal microendoscopy in the human lower gastrointestinal tract. , 2012, Journal of biomedical optics.

[31]  Xingde Li,et al.  Fiber-optic scanning two-photon fluorescence endoscope. , 2006, Optics letters.

[32]  M. Kimmey,et al.  Scanning single fiber endoscopy: a new platform technology for integrated laser imaging, diagnosis, and future therapies. , 2008, Gastrointestinal endoscopy clinics of North America.

[33]  J. Pawley,et al.  Handbook of Biological Confocal Microscopy , 1990, Springer US.

[34]  R. Webb.  Confocal optical microscopy , 1996 .

[35]  Jonathan T. C. Liu,et al.  Modulated alignment dual-axis (MAD) confocal microscopy for deep optical sectioning in tissues , 2014, translational-biophotonics.

[36]  Thomas D. Wang,et al.  Miniature near-infrared dual-axes confocal microscope utilizing a two-dimensional microelectromechanical systems scanner. , 2007, Optics letters.

[37]  R. Webb,et al.  Confocal microscope with large field and working distance. , 1999, Applied optics.

[38]  Jonathan T. C. Liu,et al.  Assessing the tissue-imaging performance of confocal microscope architectures via Monte Carlo simulations. , 2012, Optics letters.

[39]  Tim N. Ford,et al.  Fluorescence endomicroscopy with structured illumination. , 2008, Optics express.

[40]  Ye Chen,et al.  Modulated-Alignment Dual-Axis (MAD) Confocal Microscopy Optimized for Speed and Contrast , 2016, IEEE Trans. Biomed. Eng..

[41]  A. Polglase,et al.  Confocal laser endoscopy for diagnosing intraepithelial neoplasias and colorectal cancer in vivo. , 2004, Gastroenterology.

[42]  E. Wolf,et al.  Principles of Optics (7th Ed) , 1999 .

[43]  Steffen Lindek,et al.  Confocal theta microscopy and 4Pi-confocal theta microscopy , 1994, Electronic Imaging.

[44]  Kenn Oldham,et al.  Targeted vertical cross-sectional imaging with handheld near-infrared dual axes confocal fluorescence endomicroscope , 2013, Biomedical optics express.

[45]  T. Collier,et al.  Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved , 2002 .

[46]  Ming Zhao,et al.  Cellular imaging of deep organ using two-photon Bessel light-sheet nonlinear structured illumination microscopy. , 2014, Biomedical optics express.

[47]  R. Mann,et al.  Swept confocally-aligned planar excitation (SCAPE) microscopy for high speed volumetric imaging of behaving organisms , 2014, Nature Photonics.

[48]  Milind Rajadhyaksha,et al.  Confocal reflectance theta line scanning microscope for imaging human skin in vivo. , 2006, Optics letters.

[49]  J. Liu,et al.  Assessing the imaging performance of light sheet microscopies in highly scattering tissues. , 2016, Biomedical optics express.

[50]  Jonathan T. C. Liu,et al.  Characterizing the beam steering and distortion of Gaussian and Bessel beams focused in tissues with microscopic heterogeneities. , 2015, Biomedical optics express.

[51]  Xiao Wang,et al.  Needle-based fluorescence endomicroscopy via structured illumination with a plastic, achromatic objective , 2013, Journal of biomedical optics.

[52]  Lawrence D. True,et al.  Light-sheet microscopy for slide-free non-destructive pathology of large clinical specimens , 2017, Nature Biomedical Engineering.

[53]  Christopher H Contag,et al.  Dual-axes confocal microscopy with post-objective scanning and low-coherence heterodyne detection. , 2003, Optics letters.

[54]  A. Rouse,et al.  Clinical confocal microlaparoscope for real-time in vivo optical biopsies. , 2009, Journal of biomedical optics.

[55]  M. Davidson,et al.  Rapid three-dimensional isotropic imaging of living cells using Bessel beam plane illumination , 2011, Nature Methods.

[56]  S Lindek,et al.  Resolution improvement by nonconfocal theta microscopy. , 1999, Optics letters.

[57]  Yu Wang,et al.  Video-rate in vivo fluorescence imaging with a line-scanned dual-axis confocal microscope , 2015, Journal of biomedical optics.

[58]  R. Webb,et al.  Video-rate confocal scanning laser microscope for imaging human tissues in vivo. , 1999, Applied optics.

[59]  Jonathan T. C. Liu,et al.  Comparing high‐resolution microscopy techniques for potential intraoperative use in guiding low‐grade glioma resections , 2015, Lasers in surgery and medicine.

[60]  Xiaoyang Zhang,et al.  MEMS-BASED 3D CONFOCAL SCANNING MICROENDOSCOPE USING MEMS SCANNERS FOR BOTH LATERAL AND AXIAL SCAN. , 2014, Sensors and actuators. A, Physical.

[61]  Juan Zhou,et al.  Visualizing Epithelial Expression in Vertical and Horizontal Planes With Dual Axes Confocal Endomicroscope Using Compact Distal Scanner , 2017, IEEE Transactions on Medical Imaging.

[62]  W. Piyawattanametha,et al.  Two-Dimensional MEMS Scanner for Dual-Axes Confocal Microscopy , 2007, Journal of Microelectromechanical Systems.

[63]  F. Del Bene,et al.  Optical Sectioning Deep Inside Live Embryos by Selective Plane Illumination Microscopy , 2004, Science.

[64]  G S Kino,et al.  Depth response of confocal optical microscopes. , 1986, Optics letters.

[65]  J. Fujimoto,et al.  Imaging needle for optical coherence tomography. , 2000, Optics letters.

[66]  Thomas D. Wang,et al.  In vivo near-infrared imaging of ErbB2 expressing breast tumors with dual-axes confocal endomicroscopy using a targeted peptide , 2017, Scientific Reports.

[67]  Katsumi Midorikawa,et al.  Background-free deep imaging by spatial overlap modulation nonlinear optical microscopy , 2012, Biomedical optics express.

[68]  Xingde Li,et al.  Rapid-scanning forward-imaging miniature endoscope for real-time optical coherence tomography. , 2004, Optics letters.

[69]  Thomas D. Wang,et al.  Efficient rejection of scattered light enables deep optical sectioning in turbid media with low-numerical-aperture optics in a dual-axis confocal architecture. , 2008, Journal of biomedical optics.

[70]  Nanguang Chen,et al.  Focal modulation microscopy. , 2008, Optics express.

[71]  Thomas D. Wang,et al.  Improved rejection of multiply scattered photons in confocal microscopy using dual-axes architecture. , 2007, Optics letters.

[72]  D. Madoff,et al.  Handheld histology-equivalent sectioning laser-scanning confocal optical microscope for interventional imaging , 2010, Biomedical microdevices.

[73]  R. D. Ferguson,et al.  Combined reflectance confocal microscopy/optical coherence tomography imaging for skin burn assessment , 2013, Biomedical optics express.

[74]  Christopher H Contag,et al.  Dual-axes confocal reflectance microscope for distinguishing colonic neoplasia. , 2006, Journal of biomedical optics.

[75]  Christopher H Contag,et al.  Functional imaging of colonic mucosa with a fibered confocal microscope for real-time in vivo pathology. , 2007, Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association.

[76]  Bessel‐beam illumination in dual‐axis confocal microscopy mitigates resolution degradation caused by refractive heterogeneities , 2017, Journal of biophotonics.

[77]  Jerome Mertz,et al.  Fast optically sectioned fluorescence HiLo endomicroscopy. , 2012, Journal of biomedical optics.