Patent Application
20080024860
1. Field of the Invention
The present invention relates to a device and method for wide-field and high resolution imaging. Particularly, the present invention is directed to a system having wide-field and high resolution imaging capability.
The present invention is particularly suitable for imaging skin cancer, e.g., as a rapid bedside guide to tumor excision. The invention is useful for providing enhanced imaging of epithelial tumors, inflammatory disorders, or other pathological conditions, including nonmelanoma skin cancer. However, the subject device and method may be used for imaging and analyzing surface, structural, spectral, functional, fluorescence, Raman, bio-chemical, polarization and other similar characteristics of any object when the combination of wide field imaging and high resolution is required.
2. Description of Related Art
Advances in the development of optical imaging modalities have facilitated efforts to employ these techniques for noninvasive detection and treatment guidance of different pathological conditions. In general, the turbidity of tissue creates major challenges for optical in vivo spectroscopy and imaging. However, reflectance and fluorescence imaging techniques, like multi-spectral polarized light macro-imaging and confocal microscopy are well suited for skin cancer detection and demarcation. Confocal reflectance microscopy was introduced to the field of dermatology in the 1990s. Since then, it has been used to study different skin disorders.
Confocal microscopy is a technique where the specimen is pointwise illuminated by a focused beam of light. An image is recorded by scanning the beam focus through a plane in the specimen, and the reflected light from the specimen is focused onto a small detector aperture. The light source, the illuminated spot and the detector aperture are placed in optically conjugated focal planes. “Optical sectioning” occurs as out-of-focal-plane back-scattered light is rejected by a pinhole placed in front of a detector. Optical sectioning makes it possible to record images of thin layers within tissue. Confocal microscopy allows imaging within turbid media with high resolution (lateral resolution of about 1 μm, and axial resolution (section thickness) of about 3-5 μm), which is comparable to histology. The major disadvantage of confocal microscopy as a detection and guidance tool for cancer surgery is its small field of view, which is typically, up to about 0.3 mm. To examine an entire suspected cancerous area using confocal microscopy (CM), a sequence of images must be captured and stitched together. This process takes time and motion artifacts may distort the resulting image.
Multi-spectral polarized light imaging (MSPLI) is a simple and inexpensive technique for skin tumor imaging. The technique provides the means to differentiate effectively between endogenous (blood, melanin, etc.) and exogenous (dye) chromophores absorbing in different spectral domains, and is capable of obtaining superficial images (at a resolution of about 3-50 μm-lateral, 5-0200 μm-axial in the visible spectral range) of thick tissue layers. Such imaging is relatively insensitive to small shifts in the position of the imaged object, and combination of the large field-of-view and sufficient lateral resolution enables rapid examination of large surfaces, thus facilitating tumor margin delineation. However, morphology of individual cells and fine structures cannot be resolved using MSPLI. Thus, the multi-spectral polarized light imaging approach can benefit from combination with a high-resolution technique, such as confocal reflectance microscopy, which can be used by a pathologist in the cases when high-resolution images of small suspicious areas are required. Such combination may become a powerful tool for cancer detection and demarcation.
The purpose and advantages of the present invention will be set forth in and apparent from the description that follows. Additional advantages of the invention will be description and claims hereof, as well as from the appended drawings.
The present technology relates to a novel device that combines a wide-field, low-resolution imaging modality and a high-resolution, narrow-field imaging modality, which preferably share a common light source and hardware control unit. One preferred embodiment includes a combination of confocal microscopy with wide-field CCD (charge-coupled device) imaging. By combining these two imaging devices, a high resolution wide-field imaging is effectively achieved. CCD imaging, for example, the technique of multi-spectral polarized light imaging (MSPLI), enables rapid inspection of a superficial tissue layer over large surfaces, but does not provide information on cellular microstructure. Confocal microscopy (CM) allows imaging within turbid media with resolution comparable to that of histology, but suffers from a small field of view. Typically, pathologists use microscopes at low power and high power, to view the margins of pathology and cell features, respectively. Therefore, the present technology, which can combine, for example, MSPLI and CM can guide cancer surgery more rapidly, and at lower cost than conventional histopathology.
To achieve these and other advantages and in accordance with the purpose of the subject technology, as embodied, the subject technology includes a device for wide-field and high resolution imaging of an object surface includes first and second imaging modalities, a lens associated with the second imaging modality. The first imaging modality has a high resolution imaging means with a first observation line, such as an optical axis in the event that the imaging modality is optical. It will be understood that non-optical imaging modalities can also be used including but not limited to acoustic (e.g., ultrasonic), terahertz and the like, for example.
The second imaging modality is arranged in an image plane at a first angle with respect to an object plane and has a second observation line and a wider imaging field than the first imaging modality. The lens associated with the second imaging modality is arranged in a lens plane at a second angle with respect to the object plane, where the second angle being equal to about one-half of the first angle. The first and second imaging modalities are mutually arranged such that the first and second optical axes intersect at a point on the object plane.
The first imaging modality can include a confocal microscope including an objective lens, a multi-photon microscope, a high-resolution CCD imaging device or another high-resolution imaging device.
Devices in accordance with the present technology can be capable of adjusting to a first configuration, in which the second imaging modality is capable of capturing an image and/or to a second configuration, in which the first imaging modality is capable of capturing a high-resolution image. The first imaging modality can be capable of imaging both an object surface as well as beneath the object surface. The first and second imaging modalities can be supported by a supporting structure, such supporting structure providing rigidity, providing support to the device components, and/or enabling the device to be moved with respect to the object surface. The second modality and the lens can be pivotally supported by the device.
Illumination can be provided and configured to provide illumination of an object through optics of the confocal microscope. The optics of the confocal microscope can provide illumination for confocal microscopic images captured by the first imaging modality and images captured by the second imaging modality.
The second imaging modality can be arranged at about 55 degrees, with respect to an object plane, with the lens being at a bisector of that angle, at about 27.5 degrees with respect to the object plane.
The second imaging means can include a CCD camera and/or can be capable of rotating about the observation line (e.g., optical axis) of the first imaging modality to facilitate imaging of the object surface. The second imaging modality can further be capable of multimodal imaging and can utilize imaging techniques such as reflectance, fluorescence, Raman, multi-photon and harmonic generation imaging, for example. The second imaging modality can include an image splitter splitting light received by the second imaging modality into a plurality of light paths and a plurality of sensors for receiving light from each light path.
The subject technology also includes a system for providing wide-field and high resolution images. In accordance with one embodiment, the system includes a first imaging modality, which is a first high-resolution imaging modality, a second imaging modality arranged in an image plane at a first angle with respect to an object plane and a computer system operatively associated with the first and second imaging modalities. The computer system can include a processor and executable code being adapted and configured to capture a first image by way of the second imaging modality, receive instructions to image with the first imaging modality, a selected region of the first image, and capture a second image of the selected region, via the first imaging modality, in accordance with the instructions.
The system can further comprise an objective lens with a first observation line (e.g., for example, an optical axis) associated with the first imaging modality, the second imaging modality having a second observation line (e.g., an optical axis), and a lens associated with the second imaging modality, arranged in a lens plane at a second angle with respect to the object plane, the second angle being equal to about one-half of the first angle. The first and second imaging modalities can be mutually arranged such that the first and second optical axes intersect at a point on the object plane.
The subject technology further includes a method of wide-field and high resolution imaging of an object. In accordance with one embodiment, the method includes providing a device having a first imaging modality including high-resolution imaging means and a first observation line and a second imaging modality arranged in an image plane at a first angle with respect to an object plane, with the second imaging modality having a second observation line. The method further includes positioning the first and second imaging modalities in an imaging region of an object surface of which an image is desired, such that the first and second optical axes mutually intersect in the imaging region, illuminating the imaging region via confocal optics of the first imaging modality, capturing a first image of the imaging region with the second imaging modality, identifying a first sub-region of interest within the first image of the imaging region, capturing a second image of the first sub-region with the first imaging modality, and analyzing the second image.
Methods in accordance with the subject technology can further include identifying a second sub-region of interest, capturing a third image of the second sub-region with the first imaging modality, and analyzing the third image. Identification of the first and second sub-regions of interest can occur concurrently, prior to capturing of the second and third images.
Methods in accordance with the subject technology can further include illuminating the imaging region with a first frequency of light while capturing the first image and illuminating the sub-region with the first frequency of light while capturing the second image. Further, the method can include additionally illuminating the imaging region with a second frequency of light while capturing a third image of the imaging region and illuminating the sub-region with the second frequency of light while capturing a fourth image of the sub-region.
Alternatively, the above-method can include illuminating the imaging region with polychromatic light while capturing a fifth image of the imaging region and illuminating the sub-region while capturing a sixth image of the sub-region.
The foregoing first and second images can be individual images, or sets of images, for example, taken simultaneously with different imaging modes. The foregoing analysis can be performed to find abnormal cell growth in skin of a patient. The identification of the one or more sub regions can be performed automatically by a computer system, or manually by an operator, such as a doctor or technician. Analysis of the second image can also be performed automatically by a computer system, or by an operator.
In accordance with still another aspect of the subject technology, a system is provided, including a first imaging modality capable of providing a high-resolution image, and which can include a confocal microscope or other high-resolution imaging device, a second imaging modality capable of providing a macroscopic image, and a computer system operatively associated with the first and second imaging modalities. The computer system can include a processor and executable code being adapted and configured to receive instructions from a user to capture a macroscopic first image of an object, capture a first image of the object by way of the second imaging modality, display the first image for a user to view, receive input selecting a first region of the first image, corresponding to a first region of the object, to be imaged with the first imaging modality, send instructions to adjust the first imaging modality to a position in which an image of the first region can be captured, and capture a second image of the first region, via the first imaging modality.
The computer system can further include a processor and executable code are further adapted and configured to store the first and second captured images. The computer system can also be configured to receive input selecting a second region of the first image, corresponding to a second region of the object, to be imaged with the first imaging modality, send instructions to adjust the first imaging modality to a position in which an image of the second region can be captured, and capture a third image of the second region, via the first imaging modality. In accordance with the subject technology, the computer system can further include a processor and executable code are further adapted and configured to receive input selecting a third region of the first image, corresponding to a third region of the object, to be imaged with the first imaging modality, send instructions to adjust the first imaging modality to a position in which an image of the third region can be captured, and capture a fourth image of the third region, via the first imaging modality.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide a non-limiting explanation of the subject technology.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with a color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the method and system of the invention.
Reference will now be made in detail to the present preferred embodiments of the invention, an example of which is illustrated in the accompanying drawings. The method and corresponding steps of the subject technology will be described in conjunction with the detailed description of the system.
For purpose of explanation and illustration, and not limitation, a view of an exemplary embodiment of a system 100 in accordance with the present technology is illustrated in
The present technology includes both a device and a method for effectively obtaining high-resolution wide-field optical imagery, which cannot be achieved with previously known devices or methods. This is achieved by combining a pair of imaging modalities: a wide-field relatively low-resolution imaging modality and a high-resolution, relatively narrow-field imaging modality, which preferably share a common light source. Either monochromatic or polychromatic light source can be employed, including, but not limited to, lasers, LEDs, discharge lamps, incandescent lamps, and the like. The illumination wavelength can be in the range between 10 nm and 1 mm. The detected radiation can be elastically scattered, fluorescent, Raman, non-linearly formed (e.g., second harmonic), or generated as a result of another physical phenomenon in the imaged object.
In one preferred embodiment, the wide-field modality is polarization-enhanced elastic/fluorescent imaging with a CCD sensor, and the high-resolution modality is confocal microscopy. Both modes can be controlled by a computer or a similar control device. In such an arrangement, the user is preferably able to switch seamlessly between the first and second imaging modalities. The high-resolution modality can be automatically positioned at the point of interest selected by the user within the field-of-view of the wide-field modality, with subsequent image acquisition by the high-resolution modality from a region near that point. Alternatively, the point of interest to be imaged with the high-resolution imaging modality can be automatically selected by a computer, based on predetermined identifyable characteristics, such as predetermined surface features.
Further, if embodied with automatic positioning capability, devices in accordance with the subject technology can precisely automatically center the high-resolution imaging modality, such as a confocal imaging system, at the area of interest selected by analyzing an image captured with the wide-field imaging modality. Accuracy of tissue discrimination will therefore be significantly improved.
With reference to the system 100 as depicted in
In the embodiment of
Reflectance and fluorescence macroscopic images can be acquired using the CCD device 240, which can be coupled to an image-splitter, such as a 4-band image-splitter, and can be operatively associated with a macro-lens 245 (
In one preferred embodiment, positioning a CCD device 240 at a 55° angle, and the CCD lens 245 at a 27.5° angle, each with respect to the object plane 285, significantly improves the image quality (see object 310b
A 4-band amplitude image splitter (not shown) can be employed for simultaneous reflectance and fluorescence polarization image acquisition, via a single or multiple CCD devices or other sensors, as desired. The image splitter can include a collimating lens, to collimate the light coming from an intermediate image, a four-sided highly reflective pupil separating pyramid prism, to split the incident beam in four, and four adjustable mirrors to fold the beams through the optical system (not shown). The purpose of the splitter is to simultaneously produce four images of the object being imaged. The image splitter eliminates artifacts in difference images due to fluctuations of lamp intensity and patient motion, as well as speeding up the image acquisition process. Linearly polarizing filters, neutral density filters, and/or spectral bandpass filters can be introduced into the optical paths of the four spatially-separated beams to study reflectance, fluorescence, and polarization images of the tissue, as desired. Additionally or alternatively, other imaging techniques, such as Raman, multi-photon and harmonic generation imaging techniques can be used.
Moreover, for optimal image acquisition and processing it is preferred that the intensity scales of the reflectance and fluorescence channels do not differ substantially. Reflectance and fluorescence channels can be balanced by the introduction of the neutral density filters into the optical path of reflectance channels. However, throughput of two reflectance and/or two fluorescence channels may vary. To account and compensate for such potential differences at the image processing stage, a calibrated reflectance/fluorescence reference can be placed in the camera field of view. Specifically, a reference sample can be kept in the camera's field of view to account for fluctuations in light and the like. Lateral resolution and the field of view can be controlled by the magnification lenses. Multiple interchangeable lenses can be utilized to allow different magnifications, depending on the dimensions of the area or region under investigation. The macro-imaging field of view is preferably about 20-30 mm (with lateral resolution not worse than 60 μm).
Image acquisition and analysis is accomplished as follows. First, macro-images are acquired. Then, the macro-images are inspected by a physician or an investigator who creates a list in a computer memory or otherwise notes suspicious areas that require closer inspection by, for example, confocal imaging. Such listing can be achieved by pointing at the desired regions using a computer input device such as a mouse, touch screen or digitizing pad, for example. Alternatively, such images can be analyzed and listed by a computer system, based on predetermined search characteristics, such as image characteristics corresponding to a particular type of skin cancer.
As shown in
As can be seen in
If the imaging devices 110 and 240 need to be repositioned with respect to the object surface 270, such movement can be achieved automatically or manually, by an operator. Both imaging modalities are preferably supported by a common physical structure to enable movement over the object surface. Moreover, since the lens 245 and its plane 283 preferably bisect the angle between the object plane 285 and the CCD image plane 281, such adjustment would require adjustment of the angles of the lens 245 and CCD device 240. Accordingly, these elements are preferably pivotally mounted with respect to the aforementioned structure.
Further, since the embodiment of
As can be seen, an operator can have an array of information at his or her fingertips on which to base a diagnosis. The operator can choose which imaging technique(s) to utilize, and can switch between images or imaging techniques, which greatly enhances operator efficiency.
The methods and systems of the present technology, as described above and shown in the drawings, provide for wide-field and high-resolution imaging with superior characteristics. It will be apparent to those skilled in the art that various modifications and variations can be made in the device and method of the present technology without departing from the spirit or scope of the invention. Thus, it is intended that the present invention include modifications and variations that are within the scope of the appended claims and their equivalents.
This application claims priority to U.S. Provisional Patent Application No. 60/818,200 filed Jun. 30, 2007, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60818200 | Jun 2006 | US |
