Diagnosis

Your doctor will carefully examine you and ask questions about your symptoms and health history. However, because most people with popliteal artery entrapment syndrome (PAES) are young and usually healthy, diagnosing the condition can sometimes be challenging. The findings from a physical exam usually are normal.

Your doctor will rule out other causes of leg pain, including muscle strains, stress fractures, chronic exertional compartment syndrome and peripheral artery disease, which results from clogged arteries.

Tests used to rule out other conditions and diagnose PAES include the following:

• Ankle-brachial index (ABI) measurement is usually the first test done to diagnose PAES. Blood pressure measurements are taken in your arms and legs during and after walking on a treadmill. The ABI is determined by dividing ankle pressure by arm pressure. The blood pressure in your legs should be higher than that in your arms. But if you have PAES, your ankle pressure drops during exercise.
• Duplex ultrasound of the calf uses high-frequency sound waves to determine how fast blood is flowing through the leg arteries. This noninvasive test may be done before or after exercise or while you flex your foot up and down, which puts your calf muscle to work.
• Magnetic resonance angiography (MRA) shows the calf muscle that is trapping the artery. It can also reveal how much of the popliteal artery is narrowed. You may be asked to flex your foot or press it against a board during this test. Doing so helps your doctor determine how blood is flowing to your lower leg.
• CT angiography also shows which leg muscle is causing the artery entrapment. As with MRA, you may be asked to change the position of your foot during this test.
• Catheter-based angiography allows your doctor to see how blood is flowing to and from the lower leg in real time. It's done if the diagnosis is still unclear after other, less invasive imaging tests.