Peripheral Vascular Disease - Diagnosis

Diagnosis

Upon suspicion of PVD, the first-line study is the ankle brachial pressure index (ABPI/ABI). When the blood pressure readings in the ankles is lower than that in the arms, blockages in the arteries which provide blood from the heart to the ankle are suspected. An ABI ratio less than 0.9 is consistent with PVD; values of ABI below 0.8 indicate moderate disease and below 0.5 imply severe ischemic disease, alternatively 0.4 is used as a threshold.

It is possible for conditions which stiffen the vessel walls (such as calcifications that occur in the setting of chronic diabetes) to produce false negatives usually, but not always, indicated by abnormally high ABIs (> 1.3). Such results and suspicions merit further investigation and higher level studies.

If ABIs are abnormal the next step is generally a lower limb doppler ultrasound examination to look at site and extent of atherosclerosis. Other imaging can be performed by angiography, where a catheter is inserted into the common femoral artery and selectively guided to the artery in question. While injecting a radiodense contrast agent an X-ray is taken. Any flow limiting stenoses found in the x-ray can be identified and treated by atherectomy, angioplasty or stenting.

Modern multislice computerized tomography (CT) scanners provide direct imaging of the arterial system as an alternative to angiography. CT provides complete evaluation of the aorta and lower limb arteries without the need for an angiogram's arterial injection of contrast agent.