When performing venous imaging, it is very important to compress the veins in the transverse view. If compression is performed in the longitudinal view, the vein may roll away from the transducer possibly creating a false-negative examination. When performing Doppler spectral analysis or color Doppler, the angle between the beam and the vessel should be below 68 degrees. This is essential to obtain an adequate Doppler shift. The Doppler gate should be placed in the center of the vessel. When there is nonobstructing or recanalized thrombosis, the Doppler gate should be placed within the remaining vessel lumen for flow detection. The vessels are assessed for the five Doppler features in the longitudinal view.
The common femoral, superficial femoral, profunda femoral, sapheno-femoral junction, and greater saphenous veins are examined in the supine position. The examination begins at the level of the common femoral at the inguinal ligament. A generous amount of gel is applied to the thigh along the expected course of the common and superficial femoral veins. Every vessel is examined centimeter by centimeter in both the transverse and longitudinal views. The veins are examined for compressibility with light transducer pressure in the transverse view. Pulsed Doppler or color Doppler should be performed in the longitudinal view throughout the exam, and is very valuable if there is a question regarding vessel identification (arterial vs vein). The examination should begin in the transverse view so the common femoral vein, common femoral artery, vessel duplication, and anatomic variations can be located. The common femoral vein is followed distally from the sapheno-femoral junction.
The common femoral vein will divide into the profunda femoral (deep femoral) and the superficial femoral vein. Only the first 1-2 centimeters of the profunda veins can usually be examined due to it’s depth and the profunda femoral vein maybe hard to compress because of depth and the muscle mass in the thigh. The superficial femoral vein is followed distally to just above the patella where it enters the adductor canal.
The popliteal vein can be examined in the supine or dependent position. The transducer is placed behind the knee in the popliteal space. The popliteal vein and popliteal artery are identified. The popliteal vein is usually more superficial than the popliteal artery.
Once the popliteal vein has been examined in the transverse and longitudinal views, the transducer should be moved higher in the popliteal space into the distal posterior thigh to follow the popliteal vein up through the adductor canal and the distal superficial femoral vein. Firm transducer pressure will be needed because of the vessels’s depth. To examine the calf the patient can be placed in a dependent position with legs resting on the operator’s lap. If the patient is unable to sit, the leg can be imaged in the supine position. To image the posterior tibial veins the transducer is placed just superior to the medial malleolus. The posterior tibial veins are identified as paired structures on either side of the posterior tibial artery.
transverse view - lower calf
transverse view - mid calf
longitudinal view - lower calf
longitudinal view - mid calf
The posterior tibial vessels are followed proximally to the tibial peroneal trunk in the transverse and longitudinal views. The tibial peroneal trunk is examined proximally to the popliteal space where the popliteal vein is identified. The lesser saphenous and gastrocnemius veins can be examined from the popliteal space. The gastrocnemius vessels are examined from the popliteal space to their end point deep within the calf muscle. The lesser saphenous vein is the more superficial vessel in the popliteal space and can be examined from the popliteal space to the lateral malleolus from the posterolateral aspect of the calf. The lesser saphenous may continue proximally from the popliteal space to the mid thigh. The peroneal veins are examined from the lateral aspect of the calf. The transducer is placed over the popliteal vein and moved distally on the lateral aspect of the calf. Distal to the tibial trunk the transducer is placed between the fibula and tibia, the peroneal vessels are examined distally to the lateral malleolus
While in this view, sets of soleal vessels can sometimes be examined. To examine the anterior tibial vessels the transducer is placed on the anterior aspect of the calf just lateral to the tibia. The anterior tibial vessels can be located just below the patella as they pair off from the tibial-peroneal trunk. The anterior tibial vessels can be examined distally to the anterolateral aspect of the ankle