title: Carotid stenosis assessed with a 4-dimensional semiautomated Doppler system.
abstract: OBJECTIVE
  The purpose of this study was to compare peak systolic velocities (PSVs) and the degree of stenosis obtained with a real-time 3-dimensional (ie, 4-dimensional) Doppler ultrasound scanner (Encore PV; VueSonix Sensors Inc, Wayne, PA) to conventional Doppler ultrasound imaging of the carotid arteries (common [CCA], internal [ICA], and external [ECA]). A secondary goal was to assess Encore volume flow measurements.
  
  
  METHODS
  Seventy patients referred for clinical carotid ultrasound participated in this pilot study. Peak systolic velocities of the CCA, ECA, and ICA were obtained bilaterally. The degree of stenosis in the ICA was calculated based on the ICA PSV and ICA/CCA PSV ratio. The Encore detects all 3-dimensional blood flow velocity vectors within 10-s longitudinal volumes of the ICA, ECA, and CCA. On the Encore, a reader determined the centerline of the vessels. The PSV and volume flow were then automatically calculated. The flow measurement error was obtained by comparing the CCA flow to the ICA and ECA flow. Data were compared using linear regression, intraclass correlation coefficients (ICCs), and Bland-Altman analysis.
  
  
  RESULTS
  Due to technical difficulties, only 59 patients (323 vessel segments) were available for analysis. There was good agreement between methods for assessing the degree of stenosis based on the ICA PSV (ICC = 0.83; P < .0001) and, to a lesser degree, on the ICA/CCA PSV ratio (ICC = 0.65; P < .0001). Peak systolic velocity measurements obtained with conventional ultrasound and the Encore correlated in all vessels (r >or= 0.32; P < .002), and Bland-Altman analysis showed reasonable variations. The Encore mean volume flow error +/- SD was -4.1% +/- 66.4% and was not biased (P = .57).
  
  
  CONCLUSIONS
  A new semiautomated 4-dimensional Doppler device is comparable to conventional Doppler ultrasound for assessment of carotid stenosis.
authors: Department of Radiology, Division of Ultrasound, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA. flemming.forsberg@jefferson.edu
authors: Flemming
authors: F
authors: Forsberg
authors: Alan D
authors: AD
authors: Stein
authors: Daniel A
authors: DA
authors: Merton
authors: Kathryn J
authors: KJ
authors: Lipcan
authors: Donald
authors: D
authors: Herzog
authors: Laurence
authors: L
authors: Parker
authors: Laurence
authors: L
authors: Needleman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001185:Artificial Intelligence; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D015150:Echocardiography, Doppler / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity