title: A comparison of the quality of image acquisition between the incident dark field and sidestream dark field video-microscopes.
abstract: BACKGROUND
  The 'Cytocam' is a third generation video-microscope, which enables real time visualisation of the in vivo microcirculation. Based upon the principle of incident dark field (IDF) illumination, this hand held computer-controlled device was designed to address the technical limitations of its predecessors, orthogonal polarization spectroscopy and sidestream dark field (SDF) imaging. In this manuscript, we aimed to compare the quality of sublingual microcirculatory image acquisition between the IDF and SDF devices.
  
  
  METHODS
  Using the microcirculatory image quality scoring (MIQS) system, (six categories scored as either 0 = optimal, 1 = acceptable, or 10 = unacceptable), two independent raters compared 30 films acquired using the Cytocam IDF video-microscope, to an equal number obtained with an SDF device. Blinded to the origin of the films, the raters were therefore able to score between 0 and 60 for each film analysed. The scores' distributions between the two techniques were compared.
  
  
  RESULTS
  The median MIQS (95% CI) given to the SDF camera was 7 (1.5-12), as compared to 1 (0.5-1.0) for the IDF device (p < 0.0001). Of the six categories assessed by the MIQS, nearly one fifth of the SDF videos were scored as unacceptable for pressure (20%), content (20%), and stability (17%), with focus scoring deficiently 13% of the time. High agreement between the two raters scoring values was evident, with an intra-class correlation coefficient (ICC) of 0.96 (95% CI: 0.94, 0.98).
  
  
  CONCLUSIONS
  These results demonstrate that the quality of sublingual microcirculatory image acquisition is superior in the Cytocam IDF video-microscope, as compared to the SDF video-microscope.
authors.affiliation: University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London, W1T 7HA, UK. e.gilbert@ucl.ac.uk.
authors.forename: Edward
authors.initials: E
authors.lastname: Gilbert-Kawai
authors.affiliation: University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London, W1T 7HA, UK. jonny.coppel@gmail.com.
authors.forename: Jonny
authors.initials: J
authors.lastname: Coppel
authors.affiliation: Statistical Support Service, Population, Policy and Practice Programme, Institute of Child Health, University College London, London, England. v.bountziouka@ucl.ac.uk.
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Bountziouka
authors.affiliation: Department of Intensive Care, Erasmus MC University Hospital Rotterdam, 3000, Rotterdam, The Netherlands. c.ince@amc.uva.nl.
authors.forename: Can
authors.initials: C
authors.lastname: Ince
authors.affiliation: University College London Centre for Altitude Space and Extreme Environment Medicine, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London, W1T 7HA, UK. daniel.martin@ucl.ac.uk.|Division of Neonatology, Erasmus MC-Sophia Children's Hospital, Wytemaweg 80, P.O. Box 2060, 3000 CB, Rotterdam, Netherlands. daniel.martin@ucl.ac.uk.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martin
mesh_terms: D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008833:Microcirculation; D018715:Microscopy, Video; D014059:Tongue / Q000098:blood supply