Converting whole slide images from DICOM to ScanScope Virtual Slide-like TIFF: a practical workaround for teaching,...

Pathology Departments in their digitalization transition are encouraged to adopt the Digital Imaging and Communications in Medicine (DICOM) format for routine diagnosis. However, DICOM adoption is still emerging, with several viewing platforms not supporting this format, which limits its use for collaborative diagnosis, teaching, and research purposes. In this manuscript, an open-source, Python-based solution, with detailed explanations, is proposed to convert DICOM whole slide image files obtained from various vendors to ScanScope Virtual Slide (SVS)-like files, matching the format used by Aperio, Leica Biosystems. The conversion is lossless, preserving native image quality, and supports single-plane brightfield and singleplex fluorescence images. The native Python script is presented, as well as a Windows- and macOS-compatible executable designed for a routine usage without coding experience. This solution was tested with 70 DICOM slides coming from five major vendors (Leica, 3DHistech, Roche, Hamamatsu, and Olympus/Evident). The mean time for slide conversion was about 18 s for a file of approximately 1 gigabyte with an institutional workstation, but could be reduced to about 3 s with a more efficient workstation. Converted WSI were successfully opened with three SVS-compatible software programs. The solution has been successfully implemented in the author's institution, and address a practical issue currently faced by pathologists and researchers in sharing and using their digitized slides.