An array microscope for ultrarapid virtual slide processing and telepathology. Design, fabrication, and validation study

ArticleinHuman Pathlogy 35(11):1303-14 · December 2004with23 Reads
DOI: 10.1016/j.humpath.2004.09.002 · Source: PubMed
This paper describes the design and fabrication of a novel array microscope for the first ultrarapid virtual slide processor (DMetrix DX-40 digital slide scanner). The array microscope optics consists of a stack of three 80-element 10 x 8-lenslet arrays, constituting a “lenslet array ensemble.” The lenslet array ensemble is positioned over a glass slide. Uniquely shaped lenses in each of the lenslet arrays, arranged perpendicular to the glass slide constitute a single “miniaturized microscope.” A high-pixel-density image sensor is attached to the top of the lenslet array ensemble. In operation, the lenslet array ensemble is transported by a motorized mechanism relative to the long axis of a glass slide. Each of the 80 miniaturized microscopes has a lateral field of view of 250 microns. The microscopes of each row of the array are offset from the microscopes in other rows. Scanning a glass slide with the array microscope produces seamless two-dimensional image data of the entire slide, that is, a virtual slide. The optical system has a numerical aperture of N.A. = 0.65, scans slides at a rate of 3 mm per second, and accrues up to 3,000 images per second from each of the 80 miniaturized microscopes. In the ultrarapid virtual slide processing cycle, the time for image acquisition takes 58 seconds for a 2.25 cm2 tissue section. An automatic slide loader enables the scanner to process up to 40 slides per hour without operator intervention. Slide scanning and image processing are done concurrently so that post-scan processing is eliminated. A virtual slide can be viewed over the Internet immediately after the scanning is complete.
    • "All of the images are 24-bit color high resolution images ranging in size from 527 MB (13165 × 14000) to 3.23 GB (39912 × 29032). Each image is identified with pathology or satellite together with an index, e.g., pathology 1 or satellite 3. Recent technological developments in digital pathology allow rapid processing of pathology slides using array microscopes [24]. The resulting high-resolution images (referred to as virtual slides) can then be reviewed by a pathologist either locally or remotely over a telecommunications network. "
    [Show abstract] [Hide abstract] ABSTRACT: Image sizes have increased exponentially in recent years. The resulting high-resolution images are often viewed via remote image browsing. Zooming and panning are desirable features in this context, which result in disparate spatial regions of an image being displayed at a variety of (spatial) resolutions. When an image is displayed at a reduced resolution, the quantization step sizes needed for visually lossless quality generally increase. This paper investigates the quantization step sizes needed for visually lossless display as a function of resolution, and proposes a method that effectively incorporates the resulting (multiple) quantization step sizes into a single JPEG 2000 codestream. This codestream is JPEG 2000 Part 1 compliant and allows for visually lossless decoding at all resolutions natively supported by the wavelet transform as well as arbitrary intermediate resolutions, using only a fraction of the full-resolution codestream. When images are browsed remotely using the JPEG 2000 Interactive Protocol (JPIP), the required bandwidth is significantly reduced, as demonstrated by extensive experimental results.
    Full-text · Article · Jul 2016
    • "The use of dermatological consultation based on VS has been reported by Massore et al. [8,12], followed by Mooney et al. [9]. The application of telediagnosis in the field of pathology is relatively advanced, and significant contributions to the development of telepathology have been made by Weinstein et al. in the USA beginning in the early 1980s232425, Kaiser et al. in Europe [26,27], and by Sawai et al. in Japan from the early 1990s [28]. Along with the shift from static to robotic images and from analog to digital lines, recent developments in IT led to the emergence of the worldwide use of VS, especially in the fields of diagnosis and education [29,30] , followed by diagnostic developments such as automated diagnosis of histological screening via the Internet [31]. "
    [Show abstract] [Hide abstract] ABSTRACT: BackgroundAn online consultation system using virtual slides (whole slide images; WSI) has been developed for pathological diagnosis, and could help compensate for the shortage of pathologists, especially in the field of dermatopathology and in other fields dealing with difficult cases. This study focused on the performance and future potential of the system.MethodIn our system, histological specimens on slide glasses are digitalized by a virtual slide instrument, converted into web data, and up-loaded to an open server. Using our own purpose-built online system, we then input patient details such as age, gender, affected region, clinical data, past history and other related items. We next select up to ten consultants. Finally we send an e-mail to all consultants simultaneously through a single command. The consultant receives an e-mail containing an ID and password which is used to access the open server and inspect the images and other data associated with the case. The consultant makes a diagnosis, which is sent to us along with comments.Because this was a pilot study, we also conducted several questionnaires with consultants concerning the quality of images, operability, usability, and other issues.ResultsWe solicited consultations for 36 cases, including cases of tumor, and involving one to eight consultants in the field of dermatopathology. No problems were noted concerning the images or the functioning of the system on the sender or receiver sides. The quickest diagnosis was received only 18 minutes after sending our data. This is much faster than in conventional consultation using glass slides. There were no major problems relating to the diagnosis, although there were some minor differences of opinion between consultants. The results of questionnaires answered by many consultants confirmed the usability of this system for pathological consultation. (16 out of 23 consultants.)ConclusionWe have developed a novel teledermatopathological consultation system using virtual slides, and investigated the usefulness of the system. The results demonstrate that our system can be a useful tool for international medical work, and we anticipate its wider application in the future.Virtual slidesThe virtual slides for this article can be found here:
    Full-text · Article · Dec 2012
    • "Twenty breast core biopsy surgical pathology cases (half benign and half malignant cases verified by the original report and second confirmatory review by a Board Certified pathologist not in the study) were digitized using the DMetrix DX-40 virtual slide processor (DMetrix, Inc, Tucson, AZ). The processor scans images at 0.47 μm per pixel resolution [29]. The low magnification digitized images were stored in JPEG format and displayed on an IBM (IBM Corp, Armonk, NY) T221 9 mega-pixel (3840 x 2400) color liquid crystal display (22.2-in diagonal area (16:10 aspect ratio), 0.12 mm pixel pitch, contrast ratio 400:1, brightness 235 cd/m 2 , 170 degree viewing angle). "
    [Show abstract] [Hide abstract] ABSTRACT: The goal of this study was to examine and characterize changes in the ways that pathology residents examine digital whole slide images as they progress through the residency training. A series of 20 digitized breast biopsy whole slide images (half benign and half malignant biopsies) were individually shown to 4 pathology residents at four points in time-at the beginning of their first, second, third, and fourth years of residency. Their task was to examine each image and select three areas that they would most want to zoom in on in order to view the diagnostic detail at higher resolution. Eye position was recorded as they scanned each whole slide image at low magnification. The data indicate that with each successive year of experience, the residents' search patterns do change. Overall, with time, it takes significantly less time to view an individual slide and decide where to zoom, significantly fewer fixations are generated overall, and there is less examination of nondiagnostic areas. Essentially, the residents' search becomes much more efficient. These findings are similar to those in radiology, and support the theory that an important aspect of the development of expertise is improved pattern recognition (taking in more information during the initial Gestalt or gist view) as well as improved allocation of attention and visual processing resources. Progression in improvements in visual search strategies was similar, but not identical, for the 4 residents.
    Full-text · Article · Jul 2012
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