In modern clinical practice, digital pathology has a crucial role and is increasingly a technological requirement in the scientific laboratory environment. The advent of whole-slide imaging, availability of faster networks, and cheaper storage solutions has made it easier for pathologists to manage digital slide images and share them for clinical use. In parallel, unprecedented advances in machine learning have enabled the synergy of artificial intelligence and digital pathology, which offers image-based diagnosis possibilities that were once limited only to radiology and cardiology. Integration of digital slides into the pathology workflow, advanced algorithms, and computer-aided diagnostic techniques extend the frontiers of the pathologist's view beyond a microscopic slide and enable true utilisation and integration of knowledge that is beyond human limits and boundaries, and we believe there is clear potential for artificial intelligence breakthroughs in the pathology setting. In this Review, we discuss advancements in digital slide-based image diagnosis for cancer along with some challenges and opportunities for artificial intelligence in digital pathology.

https://www.thelancet.com/pdfs/journals/lanonc/PIIS1470-2045(19)30154-8.pdf

Digital pathology and artificial intelligence

Introduction to Digital Image Analysis in Whole-slide Imaging: A White Paper from the Digital Pathology Association.

Context.— Whole slide imaging (WSI) represents a paradigm shift in pathology, serving as a necessary first step for a wide array of digital tools to enter the field. Its basic function is to digiti...

/pdf/a-practical-guide-to-whole-slide-imaging-a-white-paper-from-3gb83qshfy.pdf

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

Whole slide imaging is being used increasingly in research applications and in frozen section, consultation and external quality assurance practice. Digital pathology, when integrated with other digital tools such as barcoding, specimen tracking and digital dictation, can be integrated into the histopathology workflow, from specimen accession to report sign-out. These elements can bring about improvements in the safety, quality and efficiency of a histopathology department. The present paper reviews the evidence for these benefits. We then discuss the challenges of implementing a fully digital pathology workflow, including the regulatory environment, validation of whole slide imaging and the evidence for the design of a digital pathology workstation.

/pdf/digital-pathology-in-clinical-use-where-are-we-now-and-what-4l8ko6ywue.pdf

Digital pathology in clinical use: where are we now and what is holding us back?

PURPOSEDigital pathology (DP), referring to the digitization of tissue slides, is beginning to change the landscape of clinical diagnostic workflows and has engendered active research within the ar...

https://ascopubs.org/doi/pdf/10.1200/CCI.18.00157

HistoQC: An Open-Source Quality Control Tool for Digital Pathology Slides.

We propose a workflow for color reproduction in whole slide imaging (WSI) scanners, such that the colors in the scanned images match to the actual slide color and the inter-scanner variation is minimum. We describe a new method of preparation and verification of the color phantom slide, consisting of a standard IT8-target transmissive film, which is used in color calibrating and profiling the WSI scanner. We explore several International Color Consortium (ICC) compliant techniques in color calibration/profiling and rendering intents for translating the scanner specific colors to the standard display (sRGB) color space. Based on the quality of the color reproduction in histopathology slides, we propose the matrix-based calibration/profiling and absolute colorimetric rendering approach. The main advantage of the proposed workflow is that it is compliant to the ICC standard, applicable to color management systems in different platforms, and involves no external color measurement devices. We quantify color difference using the CIE-DeltaE2000 metric, where DeltaE values below 1 are considered imperceptible. Our evaluation on 14 phantom slides, manufactured according to the proposed method, shows an average inter-slide color difference below 1 DeltaE. The proposed workflow is implemented and evaluated in 35 WSI scanners developed at Philips, called the Ultra Fast Scanners (UFS). The color accuracy, measured as DeltaE between the scanner reproduced colors and the reference colorimetric values of the phantom patches, is improved on average to 3.5 DeltaE in calibrated scanners from 10 DeltaE in uncalibrated scanners. The average inter-scanner color difference is found to be 1.2 DeltaE. The improvement in color performance upon using the proposed method is apparent with the visual color quality of the tissue scans.

https://www.spiedigitallibrary.org/journals/journal-of-medical-imaging/volume-1/issue-2/027501/Color-accuracy-and-reproducibility-in-whole-slide-imaging-scanners/10.1117/1.JMI.1.2.027501.pdf

Color accuracy and reproducibility in whole slide imaging scanners.

Real-time deformable registration of multi-modal whole slides for digital pathology

This invention pertains to a method for microscopically imaging a sample, with a digital scanner comprising a sensor including a 2D array of pixels and to a digital scanning microscope carrying out this method. It is notably provided a method for microscopically imaging a sample with a scanner comprising a sensor including a 2D array of pixels in an XY coordinate system, the axis Y being substantially perpendicular to the scan direction, wherein the scanner is arranged such that the sensor can image an oblique cross section of the sample, and wherein the method comprises the steps of: • activating a first sub-array of the 2D array of pixels, the first sub-array extending mainly along the Y axis at a first X coordinate (X1), • creating a first image by imaging a first area of the sample by means of the first sub-array of pixels. According to aspects of the invention, it is further proposed a scanner carryout this method and using the same 2D array sensor for imaging and auto-focusing purpose.

Sensor for microscopy.

The invention relates to a spot generator (10) having: -an entrysurface (12) for receiving an incident light beam (20) and an exit surface (14) for transmitting the light beam, the entry surface defining an entryside (16) and the exit surface defining an exit side (18). According to the invention, the spot generator is designed to modulate the incident light beam to generate on the exit side a first plurality (22) and a second plurality (24) of separate light spots, each light spot belonging to the first plurality having a first angular spectrum and each light spot belonging to the second plurality having a second angular spectrum different than the first angular spectrum. Advantageously, the spot generator comprises a periodic binary phase structure. The invention further relates to a multi-spot scanning microscope and to a method of imaging a microscopic sample.

Bas Hulsken

Papers

Color accuracy and reproducibility in whole slide imaging scanners.

Real-time deformable registration of multi-modal whole slides for digital pathology

Sensor for microscopy.

Multi-modal spot generator and multi-modal multi-spot scanning microscope

A quantitative approach to evaluate image quality of whole slide imaging scanners.