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 15 – Velocity criteria to quantify renal artery stenosis both native and after stenting Degree of stenosis Renal artery PSV Renal aortic ratio Renal artery EDV Intrarenal flow Renal artery PSV after stenting Renal aortic ratio after stenting Normal < 200 cm/s < 3.5 < 150 cm/s AT < 70 ms < 390 cm/s < 5 < 60% ≥ 200 cm/s < 3.5 < 150 cm/s AT < 70 ms < 390 cm/s < 5 ≥ 60% ≥ 200 cm/s ≥ 3.5 < 150 cm/s AT < or ≥ 70ms > 390 cm/s ≥ 5 ≥ 80% ≥ 200 cm/s ≥ 3.5 ≥ 150 cm/s AT ≥ 70 ms tardus/ parvus flow ≥ 390 cm/s ≥ 5 Occlusion - - - Might have tardus/ parvus flow - - AT: acceleration time; EDV: end-diastolic velocity; PSV: peak systolic velocity. Table 15 summarizes the criteria recommended by DCI-BSC for hemodynamically significant RAS (> 60%). All references to these criteria are detailed in the guideline. 2 Renal artery occlusion might be suggested if the vessel flow is not seen during color flow imaging and/or power Doppler, and not detected with pulsed wave Doppler, associated with a longitudinal diameter of the ipsilateral kidney < 8.5 cm. Follow-up after renal revascularization is not part of the scope of this publication and can be found in the DCI guidelines. 2 3.4.4. Limitations of the Renal Artery Study Listed on table 12. 3.4.5. Essential Information to Include in the Medical Report • Report if there were technical difficulties during the examination. • Inform the presence or absence of atherosclerotic disease or signs of fibromuscular dysplasia. • Lesion site. • Measurement of stenosis. • Measurement of renal artery PSV and EDV. • Measurement of aortic PSV. • Measurement of pulsatility index (PI) and RI in intraparenchymatous arteries (preferably the segmental artery). • Measurement of kidney size. 4. Lower-Limb Arteries VUS can evaluate peripheral arterial diseases (PADs) with high accuracy, enabling the anatomical and functional assessment of arterial lesions, in addition to identifying the location, extension, and hemodynamic repercussion of stenosis or occlusion. 54,55 4.1. Clinical Indications • Anatomic diagnosis of stenosis or occlusion in the stenotic PAD in symptomatic patients considered for revascularization. 56-59 • Follow-up of the progression of stenotic disease previously diagnosed. • Surgical therapeutic planning for patients diagnosed with PAD. 60,61 •Diagnosis and follow-up of peripheral arterial aneurysms. 62 •Diagnosis,follow-up,andtreatmentofpseudoaneurysms. 63,64 • Evaluation of autogenous or synthetic vascular grafts, with follow-up and diagnosis of complications. 65-67 • Monitoring of arterial sites submitted to percutaneous intervention, such as angioplasty, thrombolysis, thrombectomy, atherectomy, and stenting . 68-71 • Confirmation of significant arterial abnormalities detected by another imaging method. • Evaluation of vascular and perivascular abnormalities, such as masses, aneurysms, pseudoaneurysms, dissections, thrombosis, embolism, vascular malformation, and arteriovenous fistula (AVF). • Evaluation of arterial integrity in trauma. • Evaluation of artery compression syndromes, such as popliteal artery entrapment. 4.2. Examination Protocol (Table 16) 4.3. Diagnostic Criteria Stenosis: measure PSV at the lesion site (V2) and 1 to 4 cm proximal to the lesion (V1) and calculate the velocity ratio (V2/ V1). Obtain the spectral curve with an angle ≤ 60 o parallel to the turbulent flow axis (Figure 9). The degree of stenosis should be classified according to table 17. 60,61 Other criteria that can assist in grading stenosis are: prolonged AT in distal arteries, which could indicate hemodynamically significant lesions in proximal segments. Occlusion: lack of flow in any lower-limb arterial segment, even with scan parameters that detect low-velocity flows. Presence of typical preocclusive waveform (high peripheral resistance, low peak systolic velocity, and lack of diastolic flow). Collateral vessels can be found in occluded pre- and post-segment (refilling point). The post-occlusive spectrum is characterized by monophasic waveform, with reduced PSV and prolonged AT ( parvus/tardus pattern). Hypoechoic image with concave interface in colored flow and spectrum in standard pre-occlusive staccato suggests thromboembolism (Table 18). 828