![]() The panel also considered various technical aspects of carotid US and methods for quality assessment, and identified several important unanswered questions meriting future research. However, the correlation between conventional angiography and PSV shows considerable scattering. The conclusion should state an estimated degree of ICA stenosis as reflected in these categories. Background: Peak systolic velocity (PSV) is measured with pulse-wave (PW) Doppler with angle correction in patients with internal carotid artery stenosis (ICAS). Study limitations should be noted when they exist. Fifth, the final report should discuss velocity measurements and grayscale and color Doppler findings. Fourth, ICA should be diagnosed as normal when ICA PSV is less than 125 cm/second and no plaque or intimal thickening is visible, less than 50% stenosis when ICA PSV is less than 125 cm/second and plaque or intimal thickening is visible, 50 to 69% stenosis when ICA PSV is 125 to 230 cm/second and plaque is visible, > or =70% stenosis to near occlusion when ICA PSV is more than 230 cm/second and visible plaque and lumen narrowing are seen, near occlusion when there is a markedly narrowed lumen on color Doppler US, and total occlusion when there is no detectable patent lumen on grayscale US and no flow on spectral, power, and color Doppler US. Two additional parameters (the ICA-to-common carotid artery PSV ratio and ICA end diastolic velocity) may also be used when clinical or technical factors raise concern that ICA PSV may not be representative of the extent of disease. Third, ICA peak systolic velocity (PSV) and the presence of plaque on grayscale and/or color Doppler images are primarily used in the diagnosis and grading of ICA stenosis. Second, the degree of stenosis determined at grayscale and Doppler US should be stratified into the categories of normal (no stenosis), less than 50% stenosis, 50 to 69% stenosis, > or =70% stenosis to near occlusion, near occlusion, and total occlusion. Key elements of the statement include the following: First, all internal carotid artery (ICA) examinations should be performed with grayscale, color Doppler, and spectral Doppler US. The panel's consensus statement is believed to represent a reasonable position on the basis of analysis of available literature and panelists' experience. All rights reserved.The Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts in the field of vascular ultrasonography (US) to come to a consensus regarding Doppler US for assistance in the diagnosis of carotid artery stenosis. The results of this study suggest that the introduction of vector Doppler methods in commercial machines may finally be considered mature and capable of overcoming the angle-dependent overestimation typical of the standard spectral Doppler approach.Īngle independent Blood velocity estimation Carotid artery hemodynamics Real-time velocity measurement Spectral Doppler Vector Doppler.Ĭopyright © 2015 World Federation for Ultrasound in Medicine & Biology. Inter- and intra-operator repeatability measurements performed in a group of 8 healthy volunteers provided equivalent results for all of the methods (coefficients of variability in the range 2.7%-6.9%), even though the sonographers were not familiar with the VD methods. Analysis of the results obtained from 15 internal carotid arteries led to similar conclusions, indicating significant overestimation of peak systolic velocity with the spectral Doppler method. Application of Bland-Altman analysis to comparison of either VD technique with the spectral Doppler method provided a 21%-25% average difference with ± 13%-15% limits of agreement. The peak systolic velocities measured in 22 healthy common carotid arteries by the two VD techniques were very close (according to Bland-Altman analysis, the average difference was 3.2%, with limits of agreement of ± 8.6%). Although the two VD techniques were completely different (using the transmission of focused beams and plane waves, respectively), the measurement results indicate that these techniques are nearly equivalent. In this study, blood peak systolic velocities in the common and internal carotid arteries of both healthy volunteers and patients with internal carotid artery stenosis were measured by two vector Doppler (VD) methods and compared with measurements obtained with the conventional spectral Doppler approach. Although severely affected by the angle dependency, carotid artery peak systolic velocity measurements are widely used for assessment of stenosis.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |