The invention relates in general to a microscopy system, and more particularly to a microscopy system having a revolvable stage.
Confocal laser scanning microscopy (CLSM or LSCM) is a valuable tool for obtaining high resolution images and 3-D reconstructions by using a spatial pinhole to eliminate out-of-focus light or flare. This technology permits one to obtain images of various Z-axis planes (Z-stacks) of the sample. The detected light originating from an illuminated volume element within the specimen represents one pixel in the resulting image. As the laser scans over the plane of interest, a whole image is obtained pixel by pixel and line by line. The beam is scanned across the sample in the horizontal plane using one or more (servo-controlled) oscillating mirrors. Information can be collected from different focal planes by raising or lowering the microscope stage. The computer can calculate and then generate a three-dimensional picture of the specimen by assembling a stack of these two-dimensional images from successive focal planes.
However, the Z-axis direction in the stacked 3D image has a much poor resolution (e.g., about 1.2 μm/slice) than in the X-axis and Y-axis directions (about 0.15 μm/pixel) under the limitation of the dimension of the pinhole and other mechanical or physical properties. A poor resolved Z-axis direction hampers the spatial reliability of the high resolution neural network images reconstructed, especially when comparison of two different samples is necessary. The same problem happens to the transmitted light microscope. One of the inventors, Ann-Shyn Chiang, has disclosed an aqueous tissue clearing solution in U.S. Pat. No. 6,472,216 B1. In the '216 patent, the depth of observation may reach the level of hundreds micrometers. In the currently developing method, fluorescent molecules are attached to or combined with the biological tissue. Thus, making the tissue become transparent is a key point for the break-through of the depth of observation, and the way of solving the bottleneck of the Z-axis resolution is greatly needed.
It is therefore an object of the invention to provide a microscopy system with a revolvable stage for rotating a sample and holding the sample in a suitable situation so that enabling an image focusing module to acquire sliced images of the sample from different observation angles.
Another object of the invention is to provide a microscopy system with an image fusion unit for fusing a plurality of sliced images of the sample acquired from different observation angles into a final image with higher resolution.
Another object of the invention is to increasing the resolution of 3D image by means of fusing a plurality of sliced images of the sample acquired from different observation angles, especially increasing z-axis resolution of the 3D image of the sample.
It is a still further object of the invention to provide a microscopy system for increasing the depth resolution of the image by fusing two sliced images perpendicular to each other into one final image stack.
It is a further object of the invention to provide a microscopy system for fusing three-dimensional images to greater accuracy by means of image intensity remapping, resampling, three-dimensional table establishing, and tri-linear interpolation or non-linear interpolation.
The invention achieves the above-identified object by providing a microscopy system comprising an image focusing module and a stage for holding a sample. The image focusing module comprising at least one objective lens configured to collimate light radiated from the sample. The stage for supporting and/or holding a sample wherein the stage is revolvable around an axis which is substantially perpendicular to an extending direction from the sample to the image focusing module so that enabling the image focusing module to acquire sliced images of the sample from different observation angles. The microscopy system further comprises an image collecting unit for collecting the sliced images of the sample acquired by the image focusing module, and an image fusion unit for fusing the sliced images of the sample acquired from different observation angles, wherein the image fusion unit is coupled to the image collecting unit. The image fusion unit is used for fusing/remapping the sliced images acquired from different observation angles into a reference coordinate system, converting anisotropic voxels resolution of the sliced images to isotropic resolution, establishing a three-dimensional table with coordinate system indices, recording known image intensity of the sliced images into corresponding index location, calculating unknown image intensity on the corresponding coordinate system index location, and fusing the sliced images at different observation angles into the final image stack. The microscopy system further comprises a light input aperture, with or without a beam splitter, and a light output aperture. The beam splitter is substantially aligned with the light source, the light input aperture, the image focusing module and the stage, wherein the light source emits the light to the sample sequentially through the light input aperture, the beam splitter and the image focusing module. The light output aperture is for collecting the sliced images of the sample acquired by the image focusing module and substantially aligned with the beam splitter if necessary. When the light source illuminates the sample, the sample generates reflected/refracted or fluorescent light and the reflected/refracted or fluorescent light passes through the image focusing module and is reflected/refracted, by the beam splitter if necessary, to the image collecting unit for collecting the sliced images of the sample acquired by the image focusing module through the light output aperture.
In embodiments, the image collecting unit for collecting the sliced images of the sample acquired by the image focusing module is a photosensor for the purpose of collecting the sliced images of the sample acquired from different observation angles by the image focusing module. A storage medium coupled to the image collecting unit is configured to temporally store the sliced images. The image fusion unit uses one of the sliced images collected by said image collecting unit as a reference image, and defines the coordinate system of the reference image as a reference coordinate system. Then, the image fusion unit fuses/remaps another sliced images acquired from a different observation angle into the reference coordinate system.
After the sliced images have been remapped, the image fusion unit converts anisotropic voxels resolution of the remapped images to isotropic resolution. And then, the image fusion unit establishes a three-dimensional table with coordinate system indices corresponding to the converted isotropic images. The image intensity of the sliced images are recorded into the corresponding coordinate system index of the three-dimensional table, wherein the unknown image intensity on the corresponding coordinate system index is calculated by tri-linear interpolation based on the known image intensity of the neighboring sliced images as a reference. By means of tri-linear interpolation or non-linear interpolation, the sliced images are fused into a finally reconstructed image in high resolution.
The microscopy system disclosed in the present invention can be used in laser confocal microscopy or laser scanning confocal microscopy.
The remapping of the sliced images is implemented by means of Intensity-based registration.
The anisotropic voxel resolutions of the sliced images are converted to isotropic resolution by means of resampling techniques.
The recording known image intensity on the corresponding coordinate system index is implemented by joining, selecting and recording reliable grey level intensity value.
The unknown image intensity on the corresponding coordinate system index is calculated by tri-linear interpolation.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention.
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
The present inventors have found that the sample may be rotated by a specific angle about an X-axis or a Y-axis so as to acquire segment images of the sample from different observation angles. Then, the image fusion may be performed by way of image processing in order to solve the problem of the too-low resolution in the Z-axis direction. In order to achieve this effect, a stage for supporting and holding the sample has to be configured to be revolvable. It is to be noted that the term “revolvable” means the revolvable angle ranges from 0 to 360 degrees, and this rotation may be out of the plane of the microscope platen. That is, the axis of rotation is not perpendicular to the plane of the microscope platen. The detailed structure of the microscopy system of the invention will be described in the following.
The present invention discloses a microscopy system.
With reference to
As shown in
In yet another preferred embodiment, as shown in
The stage 14 is used for supporting the sample 12 and is configured to be revolvable about a rotational axis 18, which is substantially perpendicular to an extending direction 16 from the sample 12 to the image focusing module 10, as shown in
When being applied to the CLSM, the microscopy system may further include a light source 1, a light input aperture 2, a beam splitter 3, a light output aperture 4 and the photosensor 5. For example, the light source 1, such as a laser light source, outputs the incident light L1 to the sample 12 sequentially through the light input aperture 2, the beam splitter 3 and the image focusing module 10 so that reflected/refracted or fluorescent light L 2 is generated. The reflected/refracted or fluorescent light L 2 passes through the image focusing module 10 and is reflected, by the beam splitter 3, to the photosensor 5 through the light output aperture 4. In this embodiment, the light source 1 is aligned with the light input aperture 2, the beam splitter 3, the image focusing module 10 and the stage 14. The photosensor 5 is aligned with the light output aperture 4 and the beam splitter 3.
In one example, the stage 14 may also be configured to be movable along the extending direction 16. Therefore, the photosensor 5 may sense the sample 12 disposed on a focal plane FP so that the stage 14 can be moved along the extending direction 16, the sample 12 can be moved along the extending direction 16, and various images at various depths of the sample 12 may be located on the focal plane FP.
In one embodiment, as
Then, the stage 14 is rotated around the rotational axis 18 with 90 degree in a counter-clockwise direction so that a second sliced image stack 71 (D2) of the sample 12 is acquired by the image focusing module 10 and collected by the photosensor 5. As
In the embodiment, as
After the sliced images have been remapped, as
Referring to
In the embodiment, while comparing the first sliced image stack 61(D1), the image fusion unit 6 is used to respectively record the exact image intensity of the In-plane into a corresponding index location based on the three-dimensional table 81, and the index locations corresponding to unknown image intensity remain vacant temporarily. Afterwards, the image fusion unit 6 is used to compare the second sliced image stack 71(D2) and record the exact image intensity of the In-plane into a corresponding index location. As regards the vacant index locations, the unknown image intensity are calculated by tri-linear interpolation or non-linear interpolation based on the known image intensity of the most neighboring voxel as a reference. In other words, the image fusion unit 6 is used to record the known image intensity of the images 601 of the first sliced image stack 61 (D1) and the images 701 of the second sliced image stack 71 (D2) into corresponding index locations, and the unknown image intensity on the corresponding coordinate system index is tri-linear interpolated or non-linear interpolated based on the known image intensity of the neighboring sliced images as a reference for the purpose of fusing/reassembling higher-resolution three-dimensional image, as shown in
In the preferred embodiment, the image fusion unit 6 includes an image processing member. The image processing member comprises a processing unit, an image mapping unit for remapping the sliced images acquired from different observation angles into a reference coordinate system and an image mapping unit for reassembling the sliced images into a final image with high resolution. The present invention further comprises a storage medium coupled to the image collecting unit to store the sliced images.
The microscopy system with the revolvable stage according to the invention makes the sample be revolvable so that the image focusing module acquires the sliced images of the sample from different observation angles. In addition, different sliced image stacks are collected at different observation angles, such as 0 and 90 degrees, can be integrated. So, it is possible to fuse/reconstruct a three-dimensional image having the high resolution at three primary axes, and thus to implement other diversified image sensing functions. The image fusion unit 6 of the present invention is configured to record the known image intensity of the first sliced image stack and the second sliced image stack, which have been remapped and resampled, into the corresponding coordinate system index location of the three-dimensional table, and then, calculate the image intensity and index location of the unknown voxels by means of tri-linear interpolation or non-linear interpolation based the neighboring known image intensity as a reference. As a result, lost voxels of single image can be rebuilt and patched, and the depth resolution of the image can be increased. The accuracy to fuse three dimensional images in a microscope system is increased by the present invention.
While the invention has been described by way of examples and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications.
This application is a Continuation-In-Part of application Ser. No. 12/336,306, filed Dec. 16, 2008.
Number | Date | Country | |
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Parent | 12336306 | Dec 2008 | US |
Child | 12726933 | US |