Digital Pathology FAQs

Courtesy of the Digital Pathology Association.

Answers to many key questions you may have been afraid of asking.

1. Q: Is digital pathology FDA approved for primary diagnosis?  

A: No, digital pathology is not FDA approved for primary diagnosis.  However, several manufacturers have received 510(k) clearances or specific uses.  Please refer to theregulatory page for more information.  

2. Q: What CPT codes can apply to digital pathology?

 A: (Reference chart below) 

*No manufacturers at this time are FDA approved for primary diagnosis. Refer to the Regulatory page for more information.  
** Some manufacturers have obtained 510(k) clearances for manual and/or quantitative analysis of Immunohistochemistry and/or FISH.  Please refer to the 510(k) clearance list [link to page] and the Regulatory page for more information.

3. Q: Do I need to validate my digital pathology system for clinical use? 
A: It is recommended by the College of American Pathologists (CAP), a CLIA accredited organization, that all institutions or practices considering the implementation of digital pathology for clinical diagnostic purposes must carry out their own validation.  For more information please refer to the Regulatory page.

 4. Q: Do I need to preform a validation if I am only doing the professional component (PC) of the diagnosis? 

A: It is recommended by the College of American Pathologists (CAP), a CLIA accredited organization, that all institutions or practices considering the implementation of digital pathology for clinical diagnostic purposes must carry out their own validation. However, it is up to the institution or practice who has implemented the digital pathology system to determine the scope of the validation study; specifically what will and will not be included as an intended use. Refer to the institution preforming the technical component (TC) for information on their validation of the digital pathology system and weather it is validated for the professional component (PC) of a primary or secondary diagnosis.

5. Q: How can digital pathology benefit patients? 
A: Often pathologists do not meet the patients they serve.  However, digital pathology provides the tools and innovation necessary to bridge the gap between a patient, their diagnosis, and their pathologist.  Digital pathology can illustrate and document key findings within a patient diagnosis to promote better communication between pathologists, other physicians, and patients.  Examples include a digital image imbedded into the pathology report, the delivery of a prognostic score based on computer assisted quantitative analysis, whole slide images of a patient case being discussed at a tumor board, or simply improving the turnaround time of a patient diagnosis.

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 including HIPPA compliance, 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: Are whole slide images DICOM compatible? 
A: Yes, however digital pathology solution manufacturers must support DICOM Supplement 145: Whole Slide Microscopic Image IOD and SOP Classes, finalized by the DICOM Standards Committee, and Working Group 26 for Pathology in 2010.

10. Q: Is digital pathology HIPAA compliant? 
A: The metadata associated with a whole slide image, but not the whole slide image itself, can contain protected health information (PHI) which is at the center of HIPAA compliancy.  However, most digital pathology manufacturers can support a HIPAA compliant solution by encrypting PHI sensitive metadata such as slide labels, hospital / patient / case / specimen information, etc.  Furthermore, procedures must be in place to protect PHI within the digital pathology system to reduce the risk of unauthorized access to the computer system.

11. 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.

12. Q: Can whole slide images be integrated with my Laboratory Information System (LIS) or a snapshot put into my pathology report? 
A: Yes, the current state of integration between digital pathology systems (DPS) and anatomic pathology laboratory information systems (APLIS) provide pathologists with access to images and image analysis data from within the APLIS or the DPS. This information is then available to the Patient Report. More detailed information on this topic can be found in the DPA white paper “Interoperability between Anatomic Pathology Laboratory Information Systems and Digital Pathology Systems.”