title: Quantitative evaluation of healthy epidermis by means of multiphoton microscopy and fluorescence lifetime imaging microscopy.
abstract: OBJECTIVE
  Multiphoton microscopy (MPM) enables the assessment of unstained living biological tissue with submicron resolution, whereas fluorescence lifetime imaging microscopy (FLIM) generates image contrast between different states of tissue characterized by various fluorescence decay rates. The aim of this study was to compare the healthy skin of young individuals with that of older subjects, as well as to assess the skin at different body sites, by means of MPM and FLIM.
  
  
  METHODS
  Nineteen elderly patients were examined on the outer side of the forearm, whereas 30 young individuals were assessed on the dorsal and volar sides of the forearm and on the thigh.
  
  
  RESULTS
  Cell and nucleus diameters, cell density and FLIM vary according to the epidermal cell depth and the skin site. In elderly subjects, epidermal cells show morphologic alterations in shape and size, with smaller cell and nucleus diameters; the number of basal cells is decreased, whereas the mean fluorescence lifetimes at both the upper and the lower layers increase.
  
  
  CONCLUSIONS
  This study provides quantitative and qualitative data on normal epidermis at different skin sites at different ages and represents a reference for the clinician attempting to understand the effectiveness of MPM and FLIM in discriminating diseased states of the skin from normal ones.
authors.affiliation: Department of Dermatology, University of Modena and Reggio Emilia, Modena, Italy. 84498@studenti.unimore.it
authors.forename: Elisa
authors.initials: E
authors.lastname: Benati
authors.forename: Valerio
authors.initials: V
authors.lastname: Bellini
authors.forename: Stefania
authors.initials: S
authors.lastname: Borsari
authors.forename: Christopher
authors.initials: C
authors.lastname: Dunsby
authors.forename: Chiara
authors.initials: C
authors.lastname: Ferrari
authors.forename: Paul
authors.initials: P
authors.lastname: French
authors.forename: Mario
authors.initials: M
authors.lastname: Guanti
authors.forename: Davide
authors.initials: D
authors.lastname: Guardoli
authors.forename: Karsten
authors.initials: K
authors.lastname: Koenig
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pellacani
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ponti
authors.forename: Simona
authors.initials: S
authors.lastname: Schianchi
authors.forename: Clifford
authors.initials: C
authors.lastname: Talbot
authors.forename: Stefania
authors.initials: S
authors.lastname: Seidenari
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D046169:Dermoscopy / Q000379:methods*; D000078404:Epidermal Cells; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015595:Skin Aging / Q000473:pathology*; D055815:Young Adult