title: Automated Cell Detection and Morphometry on Growth Plate Images of Mouse Bone.
abstract: Microscopy imaging of mouse growth plates is extensively used in biology to understand the effect of specific molecules on various stages of normal bone development and on bone disease. Until now, such image analysis has been conducted by manual detection. In fact, when existing automated detection techniques were applied, morphological variations across the growth plate and heterogeneity of image background color, including the faint presence of cells (chondrocytes) located deeper in tissue away from the image's plane of focus, and lack of cell-specific features, interfered with identification of cell. We propose the first method of automated detection and morphometry applicable to images of cells in the growth plate of long bone. Through ad hoc sequential application of the Retinex method, anisotropic diffusion and thresholding, our new cell detection algorithm (CDA) addresses these challenges on bright-field microscopy images of mouse growth plates. Five parameters, chosen by the user in respect of image characteristics, regulate our CDA. Our results demonstrate effectiveness of the proposed numerical method relative to manual methods. Our CDA confirms previously established results regarding chondrocytes' number, area, orientation, height and shape of normal growth plates. Our CDA also confirms differences previously found between the genetic mutated mouseSmad1/5CKOand its control mouse on fluorescence images. The CDA aims to aid biomedical research by increasing efficiency and consistency of data collection regarding arrangement and characteristics of chondrocytes. Our results suggest that automated extraction of data from microscopy imaging of growth plates can assist in unlocking information on normal and pathological development, key to the underlying biological mechanisms of bone growth.
authors.affiliation: Department of Orthopaedic Surgery, University of California, Los Angeles, California 90095, USA.
authors.forename: Maria-Grazia
authors.initials: M
authors.lastname: Ascenzi
authors.affiliation: Department of Orthopaedic Surgery, University of California, Los Angeles, California 90095, USA.
authors.forename: Xia
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Orthopaedic Surgery, University of California, Los Angeles, California 90095, USA.
authors.forename: James I
authors.initials: JI
authors.lastname: Harding
authors.affiliation: Department of Mathematics, University of California, Los Angeles, California 90095, USA.
authors.forename: Emily N
authors.initials: EN
authors.lastname: Beylerian
authors.affiliation: Department of Mathematics, University of California, Los Angeles, California 90095, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: de Silva
authors.affiliation: Department of Mathematics, University of California, Los Angeles, California 90095, USA.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Gross
authors.affiliation: Department of Mathematics, University of California, Los Angeles, California 90095, USA.
authors.forename: Hannah K
authors.initials: HK
authors.lastname: Kastein
authors.affiliation: Department of Orthopaedic Surgery, University of California, Los Angeles, California 90095, USA.
authors.forename: Weiguang
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Orthopaedic Surgery, University of California, Los Angeles, California 90095, USA.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Lyons
authors.affiliation: Department of Mathematics, University of California, Irvine, California 92697, USA.
authors.forename: Hayden
authors.initials: H
authors.lastname: Schaeffer
keywords: Anisotropic diffusion; Retinex; cell detection; growth plate; mouse