1. Q: How does digital pathology benefit drug development?
A: Digital Pathology streamlines the drug development process through discovery, preclinical, and clinical trials by enabling pathologists to more efficiently illustrate, communicate, and collaborate on crucial findings in tissue based toxicity and efficacy studies. A few benefits of digital pathology include high throughput scanning of glass slides, quantitative analysis of whole slide images, immediate web based consultations with expert pathologists, and secure archival of pathology data.
2. Q: Are digital pathology systems GLP and CFR compliant?
A: No, but you can create a validation plan to establish a GLP and CFR compliant environment to work with your digital pathology system. Please refer to the life science regulatory page for additional information or the DPA white paper “Validation of a Digital Pathology System in the Regulated Non-clinical Environment.”
3. Q: Do I need to validate my digital pathology system for use in a GLP study or for clinical trials?
A: Yes, please refer to the life science regulatory page for additional information or the DPA white paper “Validation of a Digital Pathology System in the Regulated Non-clinical Environment.”
4. Q: Are slide scanners calibrated to insure the integrity of the image data?
A: All digital pathology systems have a calibration process to insure the scanner produces consistent, high quality whole slide images. However the calibration technique and process will be different for each manufacturer. Therefore, discuss the calibration process with your digital pathology provider.
5. Q: Do I have to calibrate images when used with image analysis software?
A: If your image analysis software is compatible with proprietary whole slide image formats (formats are different for each manufacturer) then no calibration is needed. However, if you are working with an unsupported format or with a static “snapshot” from a whole slide image, then yes you will have to manually calibrate the image for accurate image analysis results.
6. Q: Is viewing a whole slide image on a computer monitor the same as viewing a glass slide under a microscope?
A: Many pathologists believe the viewing experience of a whole slide image is better then a microscope. When you look through the eye pieces of a microscope you have a limited field of view and can only view one slide. With digital pathology you can see more slides and more of the tissue all at once. In addition you can move the slide around, change objectives, and even focus up and down through the tissue - just like a microscope!
7. Q: What is the file size of a whole slide image and how should they be managed?
A: Most scanners support capture resolutions of 0.5 microns/pixel (effective viewing magnification: 20X) or 0.275 microns per pixel (effective viewing magnification: 40X). The image file associated with a 20X scan of a 15mmx20mm tissue specimen is as large as 3.6GB and a 40X scanned image can be as large as 14.5GB. The images are compressed to more manageable sizes (25:1 compression or greater) such that there is an optimization between image quality, image file size, network bandwidth usage, and server and client resource utilization. For example, the 20X scan could be stored in a JPEG2000-compression file of size 144MB. The 40X image described above could be stored in a JPEG2000-compressed file of size 576MB. Digital Pathology images are about 10X that of Radiology images and will require more storage management through their useful life cycle. For more information on how they should be managed please refer to the DPA white paper “Archival and Retrieval in Digital Pathology Systems.”
8. Q: Is cloud (SaaS) storage secure and fast for digital pathology?
A: Yes, cloud technology or Storage as a Service (SaaS) is growing in popularity and offers some significant benefits for primary storage and for replication of data. Cloud based storage can lower storage costs, maintain or improve security and data integrity, improve flexibility, and expand capacity when capacity resources are strained. More information on cloud replication of data is provided in the DPA white paper “Archival and Retrieval in Digital Pathology Systems.”
9. Q: How long does it take to scan a glass slide?
A: Scan time is calculated by the time it takes to acquire the high resolution whole slide image of the tissue represented on the glass slide; most manufacturers have scan times under 3 minutes a slide. Scan time will typically include the overview image, focus, and acquisition of the whole slide image at either 0.5 microns/pixel (effective viewing magnification: 20X) or 0.275 microns per pixel (effective viewing magnification: 40X). Scan time does not take into account post processing time, which is the time it may take to compress the image and transfer the image to a data management solution for viewing of the whole slide image remotely. Other variables that contribute to variation in scan time include tissue size, capture resolution, if z-plane scanning is added, brightfield versus fluorescence, and the manufacturers specification since scan time will vary from scanner to scanner.