Arteries Visible pulsations from arteries are observed when compression is applied with the transducer to soft tissue. The amount of compression necessary for this depends on many variables, including the blood pressure, size and depth of the artery, and proximity of the artery to bone. Adjusting the amount of transducer compression to elicit visible pulsations is the fastest way to identify arteries. In some cases it is necessary to apply Doppler. Arteries have thicker walls than veins and do not have valves. Almost every peripheral nerve has a long running path with accompanying artery or vein.
FIGURE 21.1 Short-axis view of the axillary artery in the axilla viewed with power Doppler.
Femoral artery
Lateral circumflex femoral artery
FIGURE 21.2 Power Doppler imaging of the femoral artery and lateral circumflex femoral artery. The lateral artery overlies the femoral nerve and is a potential site for bleeding complications.
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Arteries
ABSTRACT
Arteries can be identified by their thick walls and round shape. Transducer compression must be adjusted to elicit visible pulsations. Power Doppler is useful to identify small arteries that accompany peripheral nerves.
KEYWORDS
visible pulsations power Doppler
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Arteries
Superficial cervical artery
A Brachial plexus
B FIGURE 21.3 Superficial cervical artery is observed overlying the brachial plexus during interscalene block. (A) B-mode sonogram. (B) Power Doppler.
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Structures
Femoral artery
Femoral vein
FIGURE 21.4 Long-axis view of femoral artery running under the sartorius muscle in the midthigh proximal to the adductor canal. The femoral vein also is seen in long-axis view. The femoral artery serves as a landmark for saphenous nerve block in the midthigh.
Arteries
A
B
C FIGURE 21.5 Arteries normally have a uniform caliber. In this case, aneurysmal dilatation of the axillary artery was detected. Short-axis views in the normal segment (A) and dilated segment (B) are shown, together with the long-axis view (C). Axillary block was performed away from this site where the artery appeared to be normal.