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 or presence of recent or residual thrombi, every 5 cm, throughout the venous trunk in the femoropopliteal segment by the medial thigh, the infrapatellar segment for the popliteal and trifurcation, the posteromedial leg for calf muscle veins (gastrocnemius, soleus, intergemellar), posterior tibial and fibular veins up to the ankle, as well as superficial veins (great and small saphenous veins along its entire extension). The fibular and soleus veins can be seen in the lateral leg, using the fibula as an anatomical reference. In this case, fibular veins are more superficial in relation to the transducer and posterior tibial veins, deeper. To that end, the patient should change positions, flexing the knee and placing the foot on the bed. Do not neglect this maneuver even in hospitalized patients due to the high prevalence of DVT in segments proximal to fibular veins in this group of individuals. Anterior tibial and foot veins are rarely studied unless there is a sign of local involvement. Investigate iliac veins when the patient has DVT in common femoral veins, and it is not possible to identify the end of the thrombus, or when the flow detected in these veins is continuous or has low amplitude. Alternate between transverse and longitudinal images using color imaging to evaluate flow and, when necessary, spectral Doppler. Save all stages of the examination (videos and still images) digitally. Currently, clinical research protocols of international multicenter studies recommend recording the maneuver of compressing the vein – with and without compression – in the same picture (dual image). In case of thrombus, measure the venous diameter, in determined sites, to evaluate the residual thrombotic mass. 107 Follow the same evaluation protocol for deep and superficial venous systems in upper limbs, middle and distal segments of subclavian veins, and jugular veins. During the follow-up of patients withDVT and recanalization, they preferably should stay in the orthostatic position or, when not possible, sitting for the study of venous reflux. Do not forget that the temperature in the room can significantly influence the performance of these examinations. Cold induces vasoconstriction and should be avoided. The ideal temperature is 22 to 25°C. 6.4.1. Transducers In general, high-frequency (5 to 12 MHz) linear transducers are used for normal-weight and thin patients. In overweight/ obese patients, the study of the adductor canal and even of leg veins in individuals with moderate/severe edema can use transducers of greater depth range, such as convex abdominal ones, whose frequency varies from 3 to 5 MHz. 108 6.4.2. Information for the Report • Presence or lack of signs of deep and/or superficial venous thrombosis. • Information about the characteristics of the thrombus. • Extension of thrombosis: essential and, if possible, with approximate measurements of anatomical reference points, such as the anterior-superior iliac spine, inguinal fold, knee, malleolar or plantar region, axillary fold, elbow fold, and wrist fold. • In case of chronic thrombosis: - Measurements of residual thrombotic masses can be included in the report and/or images, with their locations so that they can be compared later. - Presence of orthostatic reflux. 7. Transcranial Doppler The main purpose of the study called transcranial Doppler (TCD) is to gather hemodynamic information from intracranial trunk arteries non-invasively, using flow insonation with pulsed wave Doppler. 109,110 The skull has always represented a barrier to reach the vessels since US does not penetrate the calcium in bone tissue and there are limited areas (transorbital and transtemporal windows, and foramen magnum) for examination. Also, arteries are located in deeper parts of the brain, making it difficult to obtain proper images and safely collect a sample capable of providing the spectral curves needed to interpret the hemodynamic status registered at a given moment. These unfavorable characteristics determine that a transducer capable of insonating flow in all trunk arteries of anterior and posterior circulations needs to be small and have a low frequency (2.0 MHz or less). CFI safely identifies vessels and analyzes flows. 7.1. Types of Transcranial Doppler • “ Blind” TCD : only uses transducer with pulsed wave Doppler, without B-scan image (Table 24). • TCD with color Doppler : transducer with image from B-scan, pulsed wave Doppler, and CFI associated. • TCD with microbubble contrast : color TCD associated with intravenous infusion of microbubble contrast. • TCD with macrobubbles : color TCD associated with peripheral intravenous infusion of saline or glucose solution mixed with ambient air and shaken (macrobubbles). 7.2. Examination Technique and Protocol The main focus of any TCD examination must be identifying all trunk arteries safely and recording the spectral flow curve of each vessel. Therefore, the usefulness of CFI is indisputable. Currently, using devices exclusively dedicated to “blind” Doppler is warranted in the monitoring of continuous flow during surgeries and in neurointensive units. The basic TCD protocol should include the use of all possible windows to transmit US to intracranial arteries: 109 a) transorbital (right and left) , to insonate carotid siphons and ophthalmic arteries; b) transtemporal (right and left) , to visualize distal internal carotids, anterior cerebral (A1 and A2 segments), middle cerebral (throughout M1 segments and at the beginning of M2), top basilar, and posterior cerebral arteries (throughout P1 and P2 segments); c) transforaminal, to study V4 segments of vertebral and basilar arteries (proximal and middle segments), with the possibility of insonating posterior-inferior cerebellar branches of vertebral arteries. 838