ABC | Volume 112, Nº6, June 2019

Statement Vascular Ultrasound Statement from the Department of Cardiovascular Imaging of the Brazilian Society of Cardiology – 2019 Arq Bras Cardiol. 2019; 112(6):809-849 Table 5 – MESA table: 15 individuals of both genders, aged 65 to 84 years, of white, black, Chinese, or Hispanic ethnicity Mean IMT RCCA Percentile White man White woman Black man Black woman Age Age Age Age 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 %25 0.52 0.57 0.65 0.72 0.51 0.55 0.65 0.72 0.58 0.61 0.71 0.74 0.55 0.60 0.65 0.71 %50 0.62 0.68 0.77 0.83 0.58 0.65 0.75 0.83 0.67 0.74 0.85 0.85 0.64 0.71 0.76 0.83 %75 0.71 0.81 0.92 0.97 0.67 0.76 0.87 0.93 0.80 0.92 0.99 1,02 0.74 0.81 0.92 0.96 Percentile Chinese man Chinese woman Hispanic man Hispanic woman Age Age Age Age 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 %25 0.54 0.56 0.62 0.66 0.55 0.54 0.59 0.67 0.53 0.60 0.65 0.71 0.51 0.57 0.65 0.63 %50 0.64 0.70 0.73 0.79 0.60 0.63 0.71 0.77 0.62 0.67 0.78 0.81 0.58 0.69 0.76 0.78 %75 0.73 0.83 0.92 0.98 0.70 0.77 0.84 0.96 0.73 0.82 0.90 0.92 0.67 0.77 0.87 0.92 Mean IMT LCCA Percentile White man White woman Black man Black woman Age Age Age Age 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 %25 0.54 0.57 0.67 0.71 0.50 0.55 0.63 0.70 0.56 0.63 0.69 0.72 0.54 0.59 0.63 0.68 %50 0.63 0.69 0.81 0.85 0.58 0.64 0.73 0.80 0.69 0.75 0.82 0.85 0.63 0.67 0.76 0.78 %75 0.78 0.82 0.95 1,00 0.67 0.75 0.85 0.94 0.81 0.92 0.99 1,02 0.73 0.80 0.90 0.91 Percentil Chinese man Chinese woman Hispanic man Hispanic woman Age Age Age Age 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 45-54 55-64 65-74 75-84 %25 0.55 0.57 0.62 0.69 0.49 0.52 0.58 0.64 0.55 0.61 0.68 0.72 0.51 0.58 0.62 0.68 %50 0.63 0.70 0.72 0.84 0.58 0.63 0.71 0.76 0.64 0.72 0.80 0.86 0.58 0.68 0.72 0.77 %75 0.73 0.84 0.86 0.97 0.67 0.72 0.87 0.94 0.75 0.85 0.98 0.97 0.68 0.79 0.86 0.91 RCCA: right common carotid artery; LCCA: left common carotid artery; IMT: intima-media thickness. Wave characteristics depend on the type of local flow, as well as changes in blood velocity resulting from conditions proximal and distal to the measurement site. In the internal carotid artery (ICA), the resistance of flow velocity waveforms is usually of low. In the external carotid artery (ECA), the resistance of velocity waveform is high, while in the common carotid artery (CCA), it is intermediate between ICA and ECA 13 (Figure 4). Measure the velocities in the proximal and distal segments of CCA. To evaluate the velocity ratio in the quantification of ICA stenosis, assess CCA at approximately 2 cm from the bifurcation, preferably in a rectilinear segment, without plaques. 4 Analyze ICA in the proximal and middle segments, since atherosclerotic lesions usually affect the proximal 2 cm. The cursor must be parallel to the vessel wall, with a volume sample smaller than the lumen, and positioned in its center and toward the flow, so the insonation angle is ≤ 60 o (Figure 5). 1,26 After identifying the stenosis with B-scan and/or color Doppler, document the spectral tracing in this point, and pre-stenotic and post-stenotic regions. The velocity evaluation given by the spectral tracing must include the peak systolic velocity (PSV) and end-diastolic velocity (EDV) in CCA and ICA. Systolic and diastolic velocities provide the following relationships (ratios): PSV ICA/PSV CCA, PSV ICA/EDV CCA, and EDV ICA/EDV CCA. Subocclusions are diagnosed based on the narrowing of the vessel lumen using color/power Doppler, with thin flow (string sign or trickle flow); however, it might be associated with high, low, or undetectable velocities, which occasionally hinders the diagnosis. 1 In turn, carotid occlusions can be diagnosed with ultrasound as the absence of patent lumen in grayscale and undetected flow with color/power Doppler and/or spectral Doppler, in addition to the presence of high-resistance flow 816