Diagnosis methods for PAD
PAD patients may be asked to undergo the (mostly non-invasive) common tests below to diagnose their disease and its staging, and to allow for repeated objective measurements over time to detect improvement or deterioration of their PAD, or to confirm that a revascularization (procedure done to restore the blood supply to their leg) was successful.
These tests / examinations may include (but are not limited to):
Patient’s legs and feet are examined by the doctor while fully exposed to detect any changes in skin color and texture (thin and shiny skin, hair loss and trophic skin changes, tissue loss, ulceration and gangrene, skin pallor), and blood flow indicators are externally examined - decreased blood pressure or pulse absence / irregularities, in the leg.
Patient’s blood tests help indicate the risk factors for PAD development (lipid profile, cholesterol, coagulation tests). It can also detect blood indicators for organ injury or the worsening of peripheral blood supply by measuring levels of homocysteine (the building blocks for proteins), and C-reactive protein (CRP) (produced by the body in response to inflammation); when both of these are present in high levels in the blood this can be associated with atherosclerosis.
ABI/TBI (Ankle/Toe-Brachial Pressure Index)
This is a common, non-invasive test with high sensitivity and specificity in identifying healthy individuals or those diagnosed with PAD, if the result of the ABI exceeds the normal ranges. ABI is the ratio calculated from the blood pressure measured by an inflated cuff placed on the patients’ ankle/toe and compared to the blood pressure measured with by an inflated cuff placed on the patients’ arm.
DUS (Duplex ultrasonography)
This is a common, non-invasive ultrasound imaging of the leg suspected with PAD. This imaging approach shows blood vessels structure with blood flow and allows estimation of the vessel diameter and level and velocity of blood flow. DUS is a useful tool to define the locations of lesions/blockages in the artery.
A minimally-invasive examination done by injection of contrast agents into the artery via a catheter inserted at the groin area with X-rays (fluoroscopy) imaging. This allows for viewing the blood flow up from the common femoral artery to the artery in question with the specific blockage, and downstream until the foot. Although fluoroscopy by X-ray is the most used imaging method for PAD angiography, the doctor may use other imaging modalities prior to the invasive angiography, such as Computerized Tomography Angiography (CTA) or Magnetic Resonance Angiography (MRA), which are both non-invasive. If invasive diagnosis is used it enables the physician to treat the lesion in the same session.
Walking Impairment Questionnaire (WIQ)
This questionnaire is a validated subjective tool to detect changes in the daily walking ability of PAD patients. This questionnaire is filled out by the patient and evaluates the patient’s walking ability, with a focus on walking distance, walking speed and the ability to climb stairs.
A commonly used clinical staging system for describing PAD, this can be used as an objective scale to allow doctors to describe and discuss PAD patients using a common terminology. It has seven stages, from Stage 0 (asymptomatic) to Stage 6 (severe ischemic ulcers or gangrene).