When performing a duplex ultrasound to assess the popliteal artery, it's easy to miss segments if you don't know what you're doing. In this video, from our Ultrasound Masterclass, we'll cover a methodical approach to locating a stenosis and give you some essential tips to ensure you don't miss anything.
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Prior to the duplex ultrasound and prepare the patient for the examination, warn them that the exam initially requires the probe to be placed in their groin. Have them lay supine on the table, tuck a towel or washcloth into their underwear to keep the gel off as the patient to bend their knee a tiny bit to relax it out to the side in a frog leg position.
Too much bend at the knee can make it difficult to find the popliteal artery. Every formal image is required to include 2d color and Doppler. Thus at each segment, perform those steps. Remember machines a lot of color and Doppler on the same screen. First, we will be the Mickey Mouse view of the CFA and transverse plane.
Started in the mid to slightly lateral inguinal crease and slide in the crease medially toward the inner thigh and you will cross it. Remember transfers images are not recorded. They are used to locate arteries as well as aneurisms. Turn your probe 90 degrees clockwise. Remember, this will move the notch toward the patient's head and obtain a longitudinal view.
In longitudinal view, look for plaque or aneurism on 2d and color, then Doppler for a waveform. Evaluate the profaned off the bifurcation and then the proximal, mid and distal SFA. Ideally, track the arteries slowly in longitudinal view with color to continuously evaluate the entire artery. This takes practice because you can slide off the artery and miss a segment but it's the most effective way to locate a stenosis.
If you slide off, you can go back into transverse and locate the artery again. Did not just spot check the upper mid and distal thigh stenosis can be missed in between the segments you checked waveforms will help locate where the blockage is even if you don't actually see it on duplex. Next, evaluate further down the leg. Pick up the probe and place it behind the knee.
Evaluate the entire popliteal artery behind the knee by moving the probe down as far as possible until the calf vessels bifurcate. Again, this will produce a 2d black and white and color images and wave form. It's as simple as that.