The majority of the devices mentioned henceforth are referred to by the manufacturing vendor (current to the date of this publication). Overall, WSI hardware, and in particular the WSI device itself, is the primary focus of this review. The objectives of this work are: (1) to offer an up-to-date technical comparison of currently available WSI hardware (2) to provide a perspective on the function of individual WSI system hardware components for addressing demands in pathology (3) to bridge the gap between vendor technical jargon and practical applications in pathology settings (4) to aid in the pathology departmentвЂ™s/practiceвЂ™s WSI device selection and (5) to speculate on the further evolution of these tools as related to future pathology practice. There has been a paucity of recent publications that review the features of WSI devices and their components.

Since then, WSI devices have become increasingly commoditized, with a growing number of models undergoing studies for near-term US FDA 510(k) clearance and European Union ConformitГ© EuropГ©enne (EU CE) mark approval. In 2017, the Philips Intellisite Pathology Solution (PIPS) was the first WSI system to be granted a United States Food and Drug Administration (FDA) De Novo pathway classification for the primary digital diagnosis of formalin-fixed paraffin-embedded tissue (FFPE) within surgical pathology. The WSI has been used for multiple applications, including education, remote teleconsultation, tumor boards/multidisciplinary conferences, biobanking, archiving, image analysis, and, more recently, primary diagnosis. Starting with the commercial availability of the Aperio (Leica) T1 in 2001, each successive generation of WSI devices has been demarcated by graduated improvements in multiple functions, including scan speed, throughput, image quality, slide capacity, telepathology capabilities, and z-stacking. The WSI device hardware itself has advanced through multiple generations since the introduction of the first virtual microscopes more than 20 years ago. From the rise of telepathology (1980s) to the advent of WSI (2000s) and its pairing with artificial intelligence and machine-learning algorithms (late 2010s), DP has quickly become a central focus to AP laboratories. Although DP solutions have been used with particular fervor throughout the pandemic, these tools have been progressively garnering merit in the practice of pathology since their inception in the 1970s. Global disruption of routine anatomic pathology (AP) procedures in clinical and academic settings ignited deeper exploration into the role of DP as a вЂњsafeguard to clinical services and pathology-based research,вЂќ as well as the expanded employment of WSI as an educational tool. The coronavirus disease-2019 (COVID-19) pandemic brought forth renewed insights into the widespread applicability of digital pathology (DP) solutions, namely that of whole slide imaging (WSI) systems. This analysis of assorted modern WSI devices offers essential, valuable information for successfully selecting and implementing a digital WSI solution for any given pathology practice. Components such as objective lens type and magnification, scanning camera, illumination, and slide capacity were evaluated with respect to scan time, throughput, accuracy of scanning, and image quality. This review focuses on integral hardware components of 43 market available and soon-to-be released digital WSI devices utilized throughout the world. Contemporary whole slide imaging (WSI) devices include technological advances that help address some of the challenges facing modern pathology, such as increasing workloads with fewer subspecialized pathologists, expanding integrated delivery networks with global reach, and greater customization when working up cases for precision medicine. Digital pathology (DP) has disrupted the practice of traditional pathology, including applications in education, research, and clinical practice.

Modern pathology