title: Study of parameters in focus simulation functions of virtual slide.
abstract: As a special function of Virtual Slide (VS) for thick specimens like cytology slides, multilayer (Z-stack) simulated focus and focus fusion were introduced. From the standpoint of surgical pathologist, the optimum parameters for multilayer focus simulation were examined. First, minimal thickness of the layer was checked by measuring thickness of small cells counting the number of the layers that come into focus. Then the optimal number of layers to scan, total thickness, was tried. Small-sized cell nuclei showed around 2 μm or less thickness. As minimal thickness of one layer for focus simulation, less than 2 μm is required. Papillary cell mass of urothelial carcinoma, aspiration cytology specimen of breast or thyroid, and uterine cervical smear showed different optimal thickness. Cells piling up more than 4 to 5 layer are difficult to make close up observation. Total 15 (to 30) μm thick scan was enough for most specimens. The "focus fusion" image is single layer image synthesized from multiple layer images. Several layer thicknesses were examined, and there was negligible difference between the focus fusion image synthesized from 0.25 and 1 μm thick layers. In the focus fusion image synthesized from 3 μm thick layers, some cells not to come into focus. The "focus fusion" seems to contain all the cells in one plane, and easy for screening. To emphasize the existence of myoepithelial cells in fibroadenoma of breast, or to clarify the 3-dimensional tissue structure, multilayer image was better. From our results, 10 layers with 1.5 μm thick each provide sufficient information in most specimens.
authors.affiliation: Department of Human Pathology, Wakayama Medical University 811-1, Kimiidera, Wakayama City, Wakayama 641-8509, Japan. ichiro-m@wakayama-med.ac.jp
authors.forename: Ichiro
authors.initials: I
authors.lastname: Mori
authors.forename: Takashi
authors.initials: T
authors.lastname: Ozaki
authors.forename: Emiko
authors.initials: E
authors.lastname: Taniguchi
authors.forename: Kennichi
authors.initials: K
authors.lastname: Kakudo
mesh_terms: D003581:Cytodiagnosis / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D010340:Pathology, Surgical / Q000379:methods*; D019113:Telepathology / Q000379:methods*; D014584:User-Computer Interface