title: Gradient field microscopy for label-free diagnosis of human biopsies [Invited].
abstract: We introduce a label-free method for detecting high-grade prostatic intraepithelial neoplasia (HGPIN) in unstained biopsies. We image this condition based on the identification of basal cells in biopsies that otherwise would resemble prostate cancer by unassisted histologic examination. Gradient field microscopy (GFM) is used as a label-free imaging method which increases the contrast of a transparent sample by taking the first-order phase derivative that is very sensitive to rapid refractive index changes. GFM is able to image the basal cell layers in HGPIN biopsies because of their rapid refractive index changes at the periphery of small glandular structures.
authors.affiliation: Quantitative Light Imaging Laboratory, Department of Electrical and Computer Engineering, Beckman Institute for Advanced Science & Technology, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, USA.
authors.forename: Taewoo
authors.initials: T
authors.lastname: Kim
authors.forename: Shamira
authors.initials: S
authors.lastname: Sridharan
authors.forename: André
authors.initials: A
authors.lastname: Kajdacsy-Balla
authors.forename: Krishnarao
authors.initials: K
authors.lastname: Tangella
authors.forename: Gabriel
authors.initials: G
authors.lastname: Popescu
mesh_terms: D001706:Biopsy / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008853:Microscopy / Q000379:methods*; D019048:Prostatic Intraepithelial Neoplasia / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*; D012031:Refractometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling