Digital pathology imaging has advanced from the single field, static imaging systems, through dynamic remote microscope systems, to automated full-slide scanning solutions. Several companies, including InterScope Technologies, have released digital slide scanner solutions, with several others near release. Despite the advantages made in automation and scanning speed, the limiting factor continues to be image quality. Several autofocusing or prefocusing methodologies have been implemented and are well suited for detecting and following low-frequency variations in the focal plane due to global tissue or slide features. However, high-frequency variations are present in the tissue samples primarily due to tissue folds, tears, or tissue composition. High-frequency changes can also occur when multiple tissue sections are placed on a single slide. These focal plane changes are particularly evident in microarray slides where multiple biopsies of the same or different tissue types are placed on the same slide. These high-frequency changes result in pockets of tissue areas being out of focus in virtual slides. This can be traced back to the pockets of tissue extending beyond the depth of field of the imaging optics. No matter how good the autofocusing technique or the imaging sensor, these pockets will never be in focus with conventional optics. InterScope Technologies has teamed with CDM Optics to integrate Wavefront Coding into a full-slide, digital scanner. Wavefront Coding can be used to extend the depth of field of conventional optics. This extension will effectively eliminate the outlying pockets, and result in a significantly higher quality virtual slide image. Integration of Wavefront Coding is a straight-forward process, and as such, extended depth-of-field, virtual slides can be generated and evaluated in the Phase I effort. Extended depth of field imaging will not only improve the overall image quality; it will allow InterScope's digital slide scanner to go beyond the current three minute per slide scan rate to reach the all important subminute per slide scan times. Both are required for wide spread adoption of virtual slides.
Thesaurus Terms: digital imaging, high throughput technology, image enhancement, image processing, technology /technique development biomedical automation, three dimensional imaging /topography, time resolved data biotechnology, computer program /software
