Quicktime virtual reality technology in light microscopy to support medical education in pathology

From Scope to Screen: The Evolution of Histology Education

Histology, the branch of anatomy also known as microscopic anatomy, is the study of the structure and function of the body's tissues. To gain an understanding of the tissues of the body is to learn the foundational underpinnings of anatomy and achieve a deeper, more intimate insight into how the body is constructed, functions, and undergoes pathological change. Histology, therefore, is an integral element of basic science education within today's medical curricula. Its development as a discipline is inextricably linked to the evolution of the technology that allows us to visualize it. This chapter takes us on the journey through the past, present, and future of histology and its education; from technologies grounded in ancient understanding and control of the properties of light, to the ingenuity of crafting glass lenses that led to the construction of the first microscopes; traversing the second revolution in histology through the development of modern histological techniques and methods of digital and virtual microscopy, which allows learners to visualize histology anywhere, at any time; to the future of histology that allows flexible self-directed learning through social media, live-streaming, and virtual reality as a result of the powerful smart technologies we all carry around in our pockets. But, is our continuous pursuit of technological advancement projecting us towards a dystopian world where machines with artificial intelligence learn how to read histological slides and diagnose the diseases in the very humans that built them?

Augmented Reality Technology Using Microsoft HoloLens in Anatomic Pathology

Context

Augmented reality (AR) devices such as the Microsoft HoloLens have not been well used in the medical field.

Objective

To test the HoloLens for clinical and nonclinical applications in pathology.

Design

A Microsoft HoloLens was tested for virtual annotation during autopsy, viewing 3D gross and microscopic pathology specimens, navigating whole slide images, telepathology, as well as real-time pathology-radiology correlation.

Results

Pathology residents performing an autopsy wearing the HoloLens were remotely instructed with real-time diagrams, annotations, and voice instruction. 3D-scanned gross pathology specimens could be viewed as holograms and easily manipulated. Telepathology was supported during gross examination and at the time of intraoperative consultation, allowing users to remotely access a pathologist for guidance and to virtually annotate areas of interest on specimens in real-time. The HoloLens permitted radiographs to be coregistered on gross specimens and thereby enhanced locating important pathologic findings. The HoloLens also allowed easy viewing and navigation of whole slide images, using an AR workstation, including multiple coregistered tissue sections facilitating volumetric pathology evaluation.

Conclusions

The HoloLens is a novel AR tool with multiple clinical and nonclinical applications in pathology. The device was comfortable to wear, easy to use, provided sufficient computing power, and supported high-resolution imaging. It was useful for autopsy, gross and microscopic examination, and ideally suited for digital pathology. Unique applications include remote supervision and annotation, 3D image viewing and manipulation, telepathology in a mixed-reality environment, and real-time pathology-radiology correlation.

Exploring virtual reality technology and the Oculus Rift for the examination of digital pathology slides

Background:

Digital slides obtained from whole slide imaging (WSI) platforms are typically viewed in two dimensions using desktop personal computer monitors or more recently on mobile devices. To the best of our knowledge, we are not aware of any studies viewing digital pathology slides in a virtual reality (VR) environment. VR technology enables users to be artificially immersed in and interact with a computer-simulated world. Oculus Rift is among the world's first consumer-targeted VR headsets, intended primarily for enhanced gaming. Our aim was to explore the use of the Oculus Rift for examining digital pathology slides in a VR environment.

Methods:

An Oculus Rift Development Kit 2 (DK2) was connected to a 64-bit computer running Virtual Desktop software. Glass slides from twenty randomly selected lymph node cases (ten with benign and ten malignant diagnoses) were digitized using a WSI scanner. Three pathologists reviewed these digital slides on a 27-inch 5K display and with the Oculus Rift after a 2-week washout period. Recorded endpoints included concordance of final diagnoses and time required to examine slides. The pathologists also rated their ease of navigation, image quality, and diagnostic confidence for both modalities.

Results:

There was 90% diagnostic concordance when reviewing WSI using a 5K display and Oculus Rift. The time required to examine digital pathology slides on the 5K display averaged 39 s (range 10–120 s), compared to 62 s with the Oculus Rift (range 15–270 s). All pathologists confirmed that digital pathology slides were easily viewable in a VR environment. The ratings for image quality and diagnostic confidence were higher when using the 5K display.

Conclusion:

Using the Oculus Rift DK2 to view and navigate pathology whole slide images in a virtual environment is feasible for diagnostic purposes. However, image resolution using the Oculus Rift device was limited. Interactive VR technologies such as the Oculus Rift are novel tools that may be of use in digital pathology.

Shifting gears higher--digital slides in graduate education--4 years experience at Semmelweis University

Background

The spreading of whole slide imaging or digital slide systems in pathology as an innovative technique seems to be unstoppable. Successful introduction of digital slides in education has played a crucial role to reach this level of acceptance. Practically speaking there is no university institute where digital materials are not built into pathology education. At the 1st. Department of Pathology and Experimental Cancer Research, Semmelweis University optical microscopes have been replaced and for four years only digital slides have been used in education. The aim of this paper is to summarize our experiences gathered with the installation of a fully digitized histology lab for graduate education.

Methods

We have installed a digital histology lab with 40 PCs, two slide servers - one for internal use and one with external internet access. We have digitized hundreds of slides and after 4 years we use a set of 126 slides during the pathology course. A Student satisfaction questionnaire and a Tutor satisfaction questionnaire have been designed, both to be completed voluntarily to have feed back from the users. The page load statistics of the external slide server were evaluated.

Results

The digital histology lab served ~900 students and ~1600 hours of histology practice. The questionnaires revealed high satisfaction with digital slides. The results also emphasize the importance of the tutors' attitude towards digital microscopy as a factor influencing the students' satisfaction. The constantly growing number of page downloads from the external server confirms this satisfaction and the acceptance of digital slides.

Conclusions

We are confident, and have showed as well, that digital slides have got numerous advantages over optical slides and are more suitable in education.

Lossy compression in diagnostic virtual 3-dimensional microscopy--where is the limit?

Data compression is inevitable to reduce the huge data amounts of virtual slides, especially in virtual 3-dimensional (3D) microscopy. Lossy compression influences the image quality and leads to recognizable compression artifacts above a compression ratio of 20:1 in JPEG2000 format. To test out whether higher compression ratios are acceptable in diagnostic pathology, we prepared virtual 3D slides of gastric biopsy specimens with or without Helicobacter pylori gastritis using 5 different compression ratios as follows: 20:1, 40:1, 50:1, 75:1, and 200:1. The virtual 3D slides were diagnosed in a blinded manner by 3 pathologists according to the updated Sydney classification. The results showed no significant differences using virtual 3D slides with any compression of up to 200:1. We conclude that compression ratios higher than those commonly used can be applied in virtual microscopy, even in diagnostic applications.

Web-based interactive 3D visualization as a tool for improved anatomy learning

Despite a long tradition, conventional anatomy education based on dissection is declining. This study tested a new virtual reality (VR) technique for anatomy learning based on virtual contrast injection. The aim was to assess whether students value this new three-dimensional (3D) visualization method as a learning tool and what value they gain from its use in reaching their anatomical learning objectives. Several 3D vascular VR models were created using an interactive segmentation tool based on the "virtual contrast injection" method. This method allows users, with relative ease, to convert computer tomography or magnetic resonance images into vivid 3D VR movies using the OsiriX software equipped with the CMIV CTA plug-in. Once created using the segmentation tool, the image series were exported in Quick Time Virtual Reality (QTVR) format and integrated within a web framework of the Educational Virtual Anatomy (EVA) program. A total of nine QTVR movies were produced encompassing most of the major arteries of the body. These movies were supplemented with associated information, color keys, and notes. The results indicate that, in general, students' attitudes towards the EVA-program were positive when compared with anatomy textbooks, but results were not the same with dissections. Additionally, knowledge tests suggest a potentially beneficial effect on learning.

Use of digital video for documentation of microscopic features of tissue samples

CONTEXT

Digital photography is commonly used to document microscopic features of tissue samples, but it relies on the capture of arbitrarily selected representative areas. Current technologic advances permit the review of an entire sample, some even replicating the use of a microscope.

OBJECTIVE

To demonstrate the applicability of digital video to the documentation of histologic samples.

DESIGN

A Canon Elura MC40 digital camcorder was mounted on a microscope, glass slide-mounted tissue sections were filmed, and the unedited movies were transferred to a Apple Mac Pro computer. Movies were edited using the software iMovie HD, including placement of a time counter and a voice recording.

RESULTS

The finished movies can be viewed in computers, incorporated onto DVDs, or placed on a Web site after compression with Flash software. The final movies range, on average, between 2 and 8 minutes, depending on the size of the sample, and between 50 MB and 1.6 GB, depending on the intended means of distribution, with DVDs providing the best image quality.

CONCLUSIONS

Digital video is a practical methodology for documentation of entire tissue samples. We propose an affordable method that uses easily available hardware and software and does not require significant computer knowledge. Pathology education can be enhanced by the implementation of digital video technology.

Virtuelle Mikroskopie

Only recently fast-paced developments in computer technology allowed for the digitization of complete histologic slides. The resulting virtual slides may be viewed via webbrowser by any number of pathologists or students independent of time and location. Usage of a virtual microscope simply requires a computer workstation with a fast internet connection, which opens this technology to a broad public. A virtual microscopy system consists of three components: acquisition, server and client. Such systems are under development by different commercial and academic bodies worldwide. We have developed a virtual microscope system called vMic (http://www.vmic.unibas.ch) which provides virtual slides of very high image quality. Several successfully held online slide seminars and a histology course for students in dentistry are freely accessible in the internet. With the commercial availability of ultra rapid and easy-to-use slide scanners and the fast improvements of technology virtual microscopy will offer many applications in teaching, research and diagnostics. Thanks to additional functionalities, real microscopes will most likely be replaced by computer workstations in a couple of years.

Factors to keep in mind when introducing virtual microscopy

Digitization of glass slides and delivery of so-called virtual slides (VS) emulating a real microscope over the Internet have become reality due to recent improvements in technology. We have implemented a virtual microscope for instruction of medical students and for continuing medical education. Up to 30,000 images per slide are captured using a microscope with an automated stage. The images are post-processed and then served by a plain hypertext transfer protocol (http)-server. A virtual slide client (vMic) based on Macromedia's Flash MX, a highly accepted technology available on every modern Web browser, has been developed. All necessary virtual slide parameters are stored in an XML file together with the image. Evaluation of the courses by questionnaire indicated that most students and many but not all pathologists regard virtual slides as an adequate replacement for traditional slides. All our virtual slides are publicly accessible over the World Wide Web (WWW) at http://vmic.unibas.ch . Recently, several commercially available virtual slide acquisition systems (VSAS) have been developed that use various technologies to acquire and distribute virtual slides. These systems differ in speed, image quality, compatibility, viewer functionalities and price. This paper gives an overview of the factors to keep in mind when introducing virtual microscopy.