title: Correlation between Doppler velocities and duplex ultrasound carotid cross-sectional percent stenosis.
abstract: OBJECTIVE
  Cross-sectional imaging is being increasingly proposed as a suitable tool to characterize carotid plaques. The aim of this work was to correlate the Doppler velocity parameters with the cross-sectional percent stenosis (CPoS) of internal carotid artery (ICA) and to identify the cutoff values of these parameters in five progressive classes of stenosis area severity (ie, 40%-49%, 50%-59%, 60%-69%, 70%-79%, 80%-90%).
  
  
  METHODS
  High-quality scans from 90 patients (mean age, 74 ± 9 years) with 43%-90% ICA stenosis were analyzed. ICA peak-systolic (PSV) and end-diastolic (EDV) velocities were measured at maximum stenosis level. Total ICA area and residual lumen (RL) were measured to derive the CPoS. A simple physical model described by the equation Velocity = Flow rate/Area was considered. Effectively, the CPoS is expected to negatively correlate with the inverse of velocity parameters, assuming flow rate to be constant. Multiple stepwise regression analyses were used to investigate the relationships between velocity and echographic measures.
  
  
  RESULTS
  With CPoS as the dependent variable, the first significant regressor was the inverse ICA-EDV (r(2) = 0.64; P < .0001) followed by inverse ICA-PSV (r(2) = 0.43; P < .0001). ICA-EDV mean values throughout five progressive classes of stenosis were: 28 cm/second for 40%-49% stenosis, 35 cm/second for 50%-59%, 43 cm/second for 60%-69%, 69 cm/second for 70%-79%. and 103 cm/second for 80%-90%. ICA-PSV mean values were: 97 cm/second for 40%-49%, 110 cm/second for 50%-59%, 136 cm/second for 60%-69%, 224 cm/second for 70%-79%, and 286 cm/second for 80%-90%.
  
  
  CONCLUSIONS
  ICA-EDV is the parameter that better correlates with CPoS. Nevertheless, ICA-PSV maintained a highly significant correlation with CPoS. Moreover, the categorization of Doppler parameters in five progressive classes of severity of stenosis could provide physicians with an easily accessible tool in clinical practice, complementary to the morphological evaluation of cross-sectional stenosis.
authors: Department of Neurosciences, Ophthalmology and Genetics, Clinical Neurophysiology Unit, University of Genoa, Via De Toni, 5, 16132 Genoa, Italy.
authors: Guido
authors: G
authors: Rodriguez
authors: Dario
authors: D
authors: Arnaldi
authors: Claudio
authors: C
authors: Campus
authors: Debora
authors: D
authors: Mazzei
authors: Michela
authors: M
authors: Ferrara
authors: Agnese
authors: A
authors: Picco
authors: Francesco
authors: F
authors: Famà
authors: Barbara M
authors: BM
authors: Colombo
authors: Flavio
authors: F
authors: Nobili
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D004301:Doppler Effect; D006801:Humans; D008954:Models, Biological; D058226:Plaque, Atherosclerotic; D012720:Severity of Illness Index; D018616:Ultrasonography, Doppler, Duplex