An automated system for whole microscopic image acquisition and analysis

Abstract

The field of anatomic pathology has experienced major changes over the last decade. Virtual microscopy (VM) systems have allowed experts in pathology and other biomedical areas to work in a safer and more collaborative way. VMs are automated systems capable of digitizing microscopic samples that were traditionally examined one by one. The possibility of having digital copies reduces the risk of damaging original samples, and also makes it easier to distribute copies among other pathologists. This article describes the development of an automated high-resolution whole slide imaging (WSI) system tailored to the needs and problems encountered in digital imaging for pathology, from hardware control to the full digitization of samples. The system has been built with an additional digital monochromatic camera together with the color camera by default and LED transmitted illumination (RGB). Monochrome cameras are the preferred method of acquisition for fluorescence microscopy. The system is able to digitize correctly and form large high resolution microscope images for both brightfield and fluorescence. The quality of the digital images has been quantified using three metrics based on sharpness, contrast and focus. It has been proved on 150 tissue samples of brain autopsies, prostate biopsies and lung cytologies, at five magnifications: 2.5×, 10×, 20×, 40×, and 63×. The article is focused on the hardware set-up and the acquisition software, although results of the implemented image processing techniques included in the software and applied to the different tissue samples are also presented.

Implementation of a real‐time reference and calibration grid platform for improved screening – mapping in Pap test slides

“…In pathology, the screening process under bright‐field microscopy utilizes tissue continuity for a step‐by‐step eye‐based examination of the corresponding slides . In contrast to tissue sectioning procedure, cytological slides are characterized by a biphasic cell pattern.…”

“…In pathology, the screening process under bright-field microscopy utilizes tissue continuity for a step-by-step eye-based examination of the corresponding slides. 1 In contrast to tissue sectioning procedure, cytological slides are characterized by a biphasic cell pattern. They demonstrate areas with different cellularity (cell density) and completely empty spaces due to the nature of the scraping procedure and randomized cell deposition on the slide.…”

An Overlapping and Integral Blurry Evaluation Method to Optimize Tissues Scanning from Microscope

“…Due to the tilt of the mechanical stage produced by the increasing assemble tolerances, that causes blurriness in small zones of the WSI. This inconvenient, although on a lesser scale, is still an issue of expensive microscopes [12]. Different researchers have stated algorithms to detect the blurry zones and to conduct the autofocus of the microscope.…”

A Practical Guide to Whole Slide Imaging: A White Paper From the Digital Pathology Association

“…3 Whole slide imaging uses slide scanners that consist of 4 main components: light source, slide stage, objective lenses, and a high-resolution camera for image capture. [4][5][6] Scanning of other materials, such as cytology slides and other specimens (eg, plant material), is also possible, although not described in depth here. 7,8 Whole Slide Scanning Whole slide scanners capture images of tissue sections tile by tile or in a line-scanning fashion.…”

“…16 Digitizing of tissue slides at even higher resolution (360/363 or 3100, under oil) is now available via select scanners, but is typically only recommended for specific use cases such as blood smears. 6,14,17 A select number of scanners are available that can accommodate both dry scanning and oil immersion during the digitization process. 4 Different scanner models vary not only in their scanning modality, but also in their slide-loading capacity and scan time.…”