title: In-vivo, cardiac-cycle related intimal displacement of coronary plaques assessed by 3-D ECG-gated intravascular ultrasound: exploring its correlate with tissue deformability identified by palpography.
abstract: BACKGROUND
  ECG-gated image acquisition of intravascular ultrasound (IVUS) has been shown to provide more accurate measurements at different phases of the cardiac cycle.
  
  
  OBJECTIVE
  We sought to explore the ability dynamic assessment of ECG-gated 3-D IVUS to identify deformable regions of coronary plaques, by testing the hypothesis that at a given pressure and region, a faster displacement of the intima would correspond to high strain (soft tissue) regions assessed by palpography.
  
  
  METHODS
  ECG-gated 3-D IVUS and palpograms were acquired using 30 and 20 MHz IVUS imaging catheters respectively. Frames with high and/or low strain spots identified by palpography were randomly selected and the spots were assigned to a respective quadrant within the cross section. A color-blinded side-by-side view was performed to enable the co-localization of the same region. Subsequently, the pressure driven displacement of the intima was established for each quadrant and a binary score (significant displacement or no displacement) was decided.
  
  
  RESULTS
  One hundred and twenty-four quadrants were studied and the prevalence of highly deformable quadrants was low (n=7, 5.6% of the total). The sensitivity, specificity, positive predictive value and negative predictive value of 3-D ECG-gated IVUS to detect deformable quadrants as assessed by palpography were 42.9, 87.2, 16.7, and 96.2% respectively.
  
  
  CONCLUSIONS
  In this pilot in vivo study, the intimal displacement velocity in the radial direction assessed by gray-scale 3-D ECG-gated IVUS failed to correlate with highly deformable regions. However, these preliminary findings suggest that the absence of significant displacement of the intima might be accurate to predict the absence of deformable tissue.
authors.affiliation: Erasmus Medical Center, Thoraxcenter, Rotterdam, The Netherlands.
authors.forename: Gastón A
authors.initials: GA
authors.lastname: Rodriguez-Granillo
authors.forename: Pierfrancesco
authors.initials: P
authors.lastname: Agostoni
authors.forename: Héctor M
authors.initials: HM
authors.lastname: García-García
authors.forename: Pim
authors.initials: P
authors.lastname: de Feyter
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Serruys
mesh_terms: D003287:Contrast Media; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D004562:Electrocardiography; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012680:Sensitivity and Specificity; D017539:Tunica Intima / Q000000981:diagnostic imaging / Q000473:pathology; D018084:Ultrasonography, Interventional
chemical_list: D003287:Contrast Media