Laser reflectance microscopy 2-D tissue imaging system
01 Dec 2010-pp 81-85
TL;DR: In this article, a system of confocal imaging is presented, which is capable of producing output equivalent to C.T-scan or M.R.I in one-fifth of their cost.
Abstract: The interactions of laser radiation with pathological slide reveal their diverse optical characteristic depending on their compositional variation. Their point to point compositional variation is determined by reconstruction of the reflectance images which carry valuable information. However conventional microscope only deals with giving the image as an enlarged form, and is also light dependent. The system of confocal imaging is very complex and involves large number of lenses. Surface reflected laser radiations from slide are measured by a reflectance imager. Laser radiations (680 nm) are guided by an optical fiber inclined at 45 degree angle and reflected radiations are collected by photo detectors placed at an angle of 45 degree to the source which is also at 45 degree. An array of source and detectors (i.e. 12 source and 12 detectors) are placed in a probe which is stationary. The slide is placed on a platform which moves in steps of 1mm.The platform moves and data representing two-dimensional variation are collected, after amplification, these are digitized, and post processing of the images is done. An advanced algorithm of image processing is used and color coding is done. The probe design is highly refined and first of its kind. The accuracy is high since the source is stationary. The reflected image can be inferred by the processing technique which gives useful parameters. This system is capable of producing output equivalent to C.T-scan or M.R.I in one-fifth of their cost.
References
More filters
TL;DR: In this article, a discussion of diagnostic and dosimetric optical measurements in medicine and biology is presented, including tissue optical properties, tissue boundary conditions, and invasive versus noninvasive measurements.
Abstract: A discussion is presented of diagnostic and dosimetric optical measurements in medicine and biology. Topics covered include: tissue optical properties, tissue boundary conditions, and invasive versus noninvasive measurements. Clinical applications of therapeutic dosimetry and diagnostic spectroscopy are discussed. The principles of diffuse reflectance and transmittance measurements are presented. Experimental studies illustrate reflectance spectroscopy and steady-state versus time-resolved measurements. >
497 citations
TL;DR: A full three-dimensional reconstruction of absorption images of breast from continuous-wave (cw) measurements performed on a premenopausal woman reveals a large primary tumor as well as a small secondary tumor in a separate location of the breast.
Abstract: We present for the first time a full three-dimensional (3-D) reconstruction of absorption images of breast from continuous-wave (cw) measurements performed on a premenopausal woman. Our 3-D optical images clearly reveal a large primary tumor as well as a small secondary tumor in a separate location of the breast. The multiple tumors identified by our 3-D optical imaging have been confirmed by the subsequent biopsy examination of the breast. Quantitative information of the optical images obtained is provided in terms of the location, size, and absorption coefficient of the tumors.
129 citations
TL;DR: Diffuse optical reflection tomography is used to reconstruct absorption images from continuous-wave measurements of diffuse light re-emitted from a "semi-infinite" medium.
Abstract: Diffuse optical reflection tomography is used to reconstruct absorption images from continuous-wave measurements of diffuse light re-emitted from a “semi-infinite” medium. The imaging algorithm is simple and fast and permits psuedo-3D images to be reconstructed from measurements made with a single source of light. Truly quantitative three-dimensional images will require modifications to the algorithm, such as incorporating measurements from multiple sources.
73 citations
TL;DR: These studies suggest that the optical properties of subdermal tissue can be measured from light reflectance and that the effect of the upper skin layers can be eliminated.
Abstract: Reflectance from a turbid biological tissue is discussed for a diffusive light source illuminating the surface of the medium, and is related to the optical property distribution within the medium and to photon propagation through the medium. A three-dimensional photon diffusion model with closed form is developed to describe the photon diffuse intensity in a homogeneous medium. The solution is extended by numerical methods to the medium with layered structure. The concepts of photon flux paths and of reflectance indexes are utilized, together with reflectance data, to extract information about the internal optical properties of a medium. The flux path concept was corroborated by successfully detecting in vivo and ex vivo layered differences in optical properties within the biological medium. These studies suggest that the optical properties of subdermal tissue can be measured from light reflectance and that the effect of the upper skin layers can be eliminated. >
72 citations
"Laser reflectance microscopy 2-D ti..." refers background in this paper
...As light reflection depends on the morphology and structure of the components in the tissue-slide, by reconstructing the images, the variation in composition could be determined [1]....
[...]
TL;DR: The phantoms of complex tissues, prepared by this procedure, could be used for evaluation and calibration of new optical diagnostic imaging techniques and the color composition of the phantom was so adjusted that it was matched with that of the thumb tomogram.
Abstract: Surface backscattering profiles from a human forearm and transmission profiles through a human thumb, of red and near-infrared lasers, were determined. For the preparation of tissue-equivalent phantoms, white paraffin wax mixed with various wax color pigments were used. The surface reflectance profiles of a human forearm were matched with that of the phantom by mixing color pigments in various proportions. The reconstructed surface reflectance image of the phantom prepared by this procedure was similar to that of the human forearm. The transmission tomogram of the human thumb was obtained in fan-beam configuration by a near-infrared laser tomography system. Based on the horizontal scan of this tomogram, a two-layered phantom was made. The color composition of the phantom was so adjusted that its horizontal scan was matched with that of the thumb tomogram. The phantoms of complex tissues, prepared by this procedure, could be used for evaluation and calibration of new optical diagnostic imaging techniques.
30 citations