title: Spatiotemporal Image Correlation and Volumetric Impedance Indices in the Neonatal Brain: Proof of Concept and Preliminary Reproducibility.
abstract: OBJECTIVE
  Changes in tissue perfusion can be critically important in the vulnerable neonate, but they are very difficult to assess at the bedside. Spatiotemporal image correlation (STIC) sonography is an exciting concept that allows assessment of blood flow by rearranging and merging multiple 2-dimensional color images to create serial 3-dimensional images showing regional blood flow throughout the cardiac cycle. Variations in tissue blood flow may reflect tissue impedance and perfusion. The aim of this study was to demonstrate that it is possible to use STIC images to evaluate tissue impedance in the neonatal brain.
  
  
  METHODS
  Spatiotemporal image correlation data sets were acquired by cranial sonography in 19 neonates. Offline data analysis was performed by using virtual organ computer-aided analysis. With the use of STIC images from different phases of the cardiac cycle, impedance indices were calculated, based on maximum (systolic), minimum (diastolic), and mean virtual organ computer-aided analysis values, in the same way that resistive indices are calculated in 2-dimensional sonography.
  
  
  RESULTS
  Volumetric indices for tissue impedance were obtained for all neonates. Intraclass correlation coefficients (95% confidence intervals) for volumetric impedance indices were as follows: systolic/diastolic ratio, 0.793 (0.615-0.906); pulsatility index, 0.790 (0.609-0.905); and resistive index, 0.783 (0.598-0.901). Interclass correlation coefficients for image processing and analysis were as follows: systolic/diastolic ratio, 0.868 (0.692-0.947); pulsatility index, 0.904 (0.772-0.962); and resistive index, 0.914 (0.794-0.966).
  
  
  CONCLUSIONS
  This study shows that STIC data sets can be used to calculate volumetric impedance indices in the neonatal brain. Preliminary assessment shows that this technique appears reliable and allows evaluation of regional tissue impedance in the neonate.
authors: Departments of Newborn Care (T.S., J.L.O.) and Maternal-Fetal Medicine (A.W.), Royal Hospital for Women, Randwick, New South Wales, Australia; and Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia (T.S., Y.G., L.W., J.L.O., A.W.) tschindl@med.usyd.edu.au.
authors: Tim
authors: T
authors: Schindler
authors: Departments of Newborn Care (T.S., J.L.O.) and Maternal-Fetal Medicine (A.W.), Royal Hospital for Women, Randwick, New South Wales, Australia; and Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia (T.S., Y.G., L.W., J.L.O., A.W.).
authors: Yasmin
authors: Y
authors: Gilbert
authors: Departments of Newborn Care (T.S., J.L.O.) and Maternal-Fetal Medicine (A.W.), Royal Hospital for Women, Randwick, New South Wales, Australia; and Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia (T.S., Y.G., L.W., J.L.O., A.W.).
authors: Linda
authors: L
authors: Wu
authors: Departments of Newborn Care (T.S., J.L.O.) and Maternal-Fetal Medicine (A.W.), Royal Hospital for Women, Randwick, New South Wales, Australia; and Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia (T.S., Y.G., L.W., J.L.O., A.W.).
authors: Ju Lee
authors: JL
authors: Oei
authors: Departments of Newborn Care (T.S., J.L.O.) and Maternal-Fetal Medicine (A.W.), Royal Hospital for Women, Randwick, New South Wales, Australia; and Faculty of Medicine, University of New South Wales, Kensington, New South Wales, Australia (T.S., Y.G., L.W., J.L.O., A.W.).
authors: Alec
authors: A
authors: Welsh
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D001921:Brain / Q000502:physiology*; D000071937:Cerebral Blood Volume / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004453:Echoencephalography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007231:Infant, Newborn; D008297:Male; D055420:Perfusion Imaging / Q000379:methods*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D062211:Spatio-Temporal Analysis
keywords: cranial sonography; neonatology; pediatric ultrasound; power Doppler sonography; spatiotemporal imaging correlation