Phase-specific turbulence index derived from vector flow imaging for identifying intraplaque neovascularization in...

To investigate the association between phase-specific turbulence index (Tur) derived from vector flow imaging (VFI) and intraplaque neovascularization (IPN) in carotid atherosclerotic plaques, and to evaluate its potential value as a noninvasive hemodynamic biomarker for IPN assessment.

In this prospective study, 108 carotid plaques were analyzed. Tur was measured using VFI at peak systole and end-diastole at three locations relative to the plaque: upstream, the thickest region, and downstream. Intraplaque neovascularization was assessed by superb microvascular imaging (SMI) and classified as negative or positive. Least absolute shrinkage and selection operator (LASSO) regression was used for exploratory predictor selection, and an exploratory predictive model was internally validated using receiver operating characteristic analysis, calibration curves, and bootstrap resampling.

Among the 108 plaques, 82 (75.9%) were IPN-positive and 26 (24.1%) were IPN-negative. The downstream Tur during end-diastole was significantly lower in IPN-positive plaques compared with IPN-negative plaques (P = 0.008). An exploratory multivariable model incorporating diastolic blood pressure, downstream end-diastolic Tur, plaque length, plaque thickness, female sex, and plaque location showed acceptable internal discrimination, with an area under the receiver operating characteristic curve (AUC) of 0.830, and acceptable calibration. After bootstrap correction, the bias-corrected C-statistic was 0.768.

Reduced downstream end-diastolic Tur was associated with IPN in carotid plaques. Phase-specific Tur derived from VFI may provide a potential noninvasive hemodynamic marker for IPN assessment.