title: Feasibility and precision of transcutaneous very-high resolution ultrasound for quantification of arterial structures in human neonates - comparison with conventional high resolution vascular ultrasound imaging.
abstract: BACKGROUND
  Non-invasive transcutaneous very-high resolution ultrasound (VHRU, 25-55 MHz) has recently been developed to quantify superficial vascular structures in humans. The performance of the method has yet not been evaluated in vivo in neonates. The aim of the study was to compare VHRU with conventional high-resolution ultrasound (HRU, 7-12 MHz), and to assess the feasibility and precision of VHRU in this population.
  
  
  METHODS
  150 images from central elastic (common carotid, CCA) and peripheral muscular (brachial, BA; femoral, FA) arteries were obtained in 25 neonates of different gestational ages (range 33 + 0 to 41 + 5 gestational weeks) and weights (range 1570-4950 g) with VHRU, and the use of HRU for comparison assessed in five.
  
  
  RESULTS
  Images were captured from CCAs with 35 MHz, FAs using 35 and 55 MHz, and BAs using 55 MHz. 12 MHz was unable to assess FAs and BAs, and the CCA IMT was grossly overestimated compared with 35-55 MHz. IMTs of the smallest BAs and FAs were beyond the axial resolution of VHRU (<0.05 mm), thus immeasurable. For VHRU, the intra-, inter- and test-retest coefficients of variation (CV) were for LDs (range 1.44-2.62 mm, CVs between 1.6 and 4.8%), IMATs (range 0.141-0.161 mm, CVs between 8.8 and 19.9%), and IMTs (range 0.062-0.165 mm, CVs between 12.8 and 24.8%) for the different arteries.
  
  
  CONCLUSIONS
  VHRU is feasible, accurate and precise in the assessment of superficial proximal conduit arteries but unable to assess the abdominal aorta in human neonates HRU-derived neonatal conduit arterial wall layer thicknesses are below the ultrasound axial resolution.
authors.affiliation: University of Helsinki, and Helsinki University Hospital, Helsinki, Finland. Electronic address: johnny.sundholm@helsinki.fi.
authors.forename: Johnny K M
authors.initials: JK
authors.lastname: Sundholm
authors.affiliation: University of Helsinki, and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Rasmus F W
authors.initials: RF
authors.lastname: Olander
authors.affiliation: University of Helsinki, and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Tiina H
authors.initials: TH
authors.lastname: Ojala
authors.affiliation: University of Helsinki, and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Sture
authors.initials: S
authors.lastname: Andersson
authors.affiliation: University of Helsinki, and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Taisto
authors.initials: T
authors.lastname: Sarkola
mesh_terms: D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D001724:Birth Weight; D001916:Brachial Artery / Q000000981:diagnostic imaging*; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005263:Femoral Artery / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional / Q000379:methods*
keywords: Biomicroscopy; Child; Intima-media thickness; Neonate; Vascular ultrasound; Very-high resolution ultrasound