Diameter‐based measurements of the degree of carotid artery stenosis using ultrasonography

Abstract

Flow velocity measurement by duplex ultrasonography (DUS) is widely accepted as a preoperative method for grading carotid stenoses. Diameter-based grading is used for angiographic methods, but so far the experience is limited regarding diameter-based grading using DUS. In 101 cases with different degrees of carotid stenoses, we compared diameter-and velocity-based grading using DUS and evaluated variability and reproducibility for diameter measurements in 38 of the stenoses. In 18% of the cases, suboptimal image quality with calcifications and acoustic shadowing precluded diameter measurements. In the remaining 83 cases, the agreement between velocity-based and diameter-based grading for distinction between significant and non-significant stenosis was 69% with a kappa value of 0.40. Repeated measurements of diameters showed a coefficient of variation of 10% and intraclass coefficients of correlation of 0.9. We conclude that diameter measurement with DUS can be performed with high reproducibility in most patients with carotid stenosis. These measurements can then be used for calculations of the degree of stenosis, to supplement velocity-based grading. The moderate agreement between diameter-based and flow velocity-based grading cannot easily be explained. Discrepancies probably constitute a mixture of methodological errors and hemodynamic factors and need further evaluation.

Doppler Study of the Left Common Carotid Artery With Preocclusive Stenosis

“…Increased velocities in the stenosis indicate narrowing, but the appearance of collateral flow and decreased poststenotic flow velocity indicate a more than 70% stenosis. 25 The patient in this case report had no history of hypertension, diabetes, or dyslipidemia or any other chronic disease. In this context, a study was conducted by the American Heart Association, and it was reported that critical carotid artery stenosis is more often present in patients with coronary artery disease, while the association of risk factors has been demonstrated for diabetes, hypertension, and dyslipidemia.…”

“…Increased velocities in the stenosis indicate narrowing, but the appearance of collateral flow and decreased poststenotic flow velocity indicate a more than 70% stenosis. 25…”

Application of ultrasound in the evaluation of internal carotid artery stenosis

“…At the same time, the combination of spectral Doppler technology and other indicators such as blood flow velocity is more conducive to accurate evaluation of the degree of stenosis, especially to improve the diagnostic accuracy of moderate or above stenosis. Some scholars at home and abroad have isolated two-dimensional ultrasound and CDFI detection, and the consistency of the classification of stenosis degree between the classification based on pipe diameter and the classification based on flow rate is only about 60% 28 .The accuracy of the diagnosis of ICAS degree by themselves was low 29 . In most patients with carotid artery stenosis, the diameter method has a high repeatability, but there are differences due to the difference in the twodimensional section evaluated by the examiner.…”