Virtual 3D Microscopy Using Multiplane Whole Slide Images in Diagnostic Pathology

Abstract

To reproduce focusing in virtual microscopy, it is necessary to construct 3-dimensional (3D) virtual slides composed of whole slide images with different focuses. As focusing is frequently used for the assessment of Helicobacter pylori colonization in diagnostic pathology, we prepared virtual 3D slides with up to 9 focus planes from 144 gastric biopsy specimens with or without H pylori gastritis. The biopsy specimens were diagnosed in a blinded manner by 3 pathologists according to the updated Sydney classification using conventional microscopy, virtual microscopy with a single focus plane, and virtual 3D microscopy with 5 and 9 focus planes enabling virtual focusing. Regarding the classification of H pylori, we found a positive correlation between the number of focus planes used in virtual microscopy and the number of correct diagnoses as determined by conventional microscopy. Concerning H pylori positivity, the specificity and sensitivity of virtual 3D microscopy using virtual slides with 9 focus planes achieved a minimum of 0.95 each, which was approximately the same as in conventional microscopy. We consider virtual 3D microscopy appropriate for primary diagnosis of H pylori gastritis and equivalent to conventional microscopy.

Concordance between whole-slide imaging and light microscopy for routine surgical pathology

“…These issues have been previously identified in studies using video imaging of histologic slides [23][24][25][26][27][28]. The problem with visualization of bacteria can be addressed through the capture of multiple focal planes at the time of scanning (ie, z-stacking) [13]. The importance of intranuclear detail remains an issue, and additional studies comparing the impact of ×40 magnification would be useful.…”

“…However, their data sets were either limited or highly focused on single-tissue/case types. Although providing important groundwork, these studies have not established equivalence between WSI and light microscopy (LM) for general diagnostic purposes [3,6,[11][12][13]. The result of a recent concordance study using the same pathologist to review both LM and WSI supported the premise that WSI is a reliable diagnostic tool [9].…”

International Clinical Guidelines for the Adoption of Digital Pathology: A Review of Technical Aspects

“…When applying JPEG2000, a compression ratio between 20:1 and 32:1 does not seem to impact diagnosis [47,48], although this figure may vary for different clinical applications [2,25]. JPEG2000 is a highly efficient compression technique, with better image quality for a resulting smaller image file.…”

“…Scanning at ×40 magnification with multiple z-axis planes may come very close to the performance of glass slides, even for the detection of H. pylori , and other (renal/prostate) biopsies may also benefit from it, although this means a significant increase in scanning time and image size [25,34,47]. …”

Pathowiki

“…B. Zoomify (www.zoomify.com) wird das nichtproprietäre JPEG2000-Format verwendet. Die Vorteile von JPEG2000 gegenüber JPEG sind bereits in vorangegangenen Publikationen beschrieben worden [6][7][8][9][10][11]. Tuominen u. Isola [8] haben die höhere Leistungsfähigkeit eines JPEG2000-Servers im direkten Vergleich zu einem JPEG-basierten System (Zoomify) nachgewiesen.…”