Acute limb ischemia (ALI)

Acute (<2 wk), severe hypoperfusion of the limb characterized by these features: pain, pallor, pulselessness, poikilothermia (cold), paresthesias, and paralysis.


Angiography is an X-ray procedure that is used to visualize the inside, or lumen, of blood vessels and organs of the body. A radiopaque dye is introduced into the blood vessels to act as a contrast agent and make the vessels stand out.

Ankle-brachial index (ABI)

A test that compares the blood pressure in the arms with the blood pressure in the ankles. Doctors perform ABI to determine if a patient has Peripheral Artery Disease (PAD). You can find the ABI by dividing the systolic blood pressure of the ankle by the systolic blood pressure of the arm. A result of 1 or greater indicates that there is no blockage, between 0.91 – 0.99 indicates borderline PAD, and below 0.91 indicates a PAD diagnosis.

Below the knee (BTK)

BTK refers to the parts of the leg below the knee. Peripheral Artery Disease is most commonly found BTK in the tibiopedal vessels.

Critical limb ischemia (CLI)

CLI is a severe form of Peripheral Artery Disease that results in pain in the feet or legs, even at rest. Other symptoms of CLI include sores that will not heal on the legs or feet and a reduced pulse in the legs or feet. Patients that are experiencing the symptoms of CLI should seek an evaluation for PAD.

Chronic limb-threatening ischemia (CLTI)

CLTI is a severe blockage of the arteries that results in inadequate blood flow to the extremities. It can cause damage to the tissues and even result in the loss of a limb. CLTI will not improve on its own and requires medical attention.

Computed tomography angiography (CTA)

Computed Tomography (CT) scans are a form of medical imaging used in radiology to make cross-sectional images of the body. Patients receive an injection of a special dye then a CT scan is used to observe the blood vessels. The IV contrast dye makes the blood vessels stand out during imaging.

Dual antiplatelet therapy (DAPT)

Blood clots are formed when platelets in the blood clump together and can lead to a heart attack. There is a class of medication called antiplatelet agents that inhibit platelets from clumping. Patients at risk of heart attack or stroke – or have suffered a heart attack or stroke — are treated with two antiplatelet agents to prevent blood clots.

Drug-coated balloon (DCB)

A doctor inserts a catheter into the patient’s blood vessels, and a device with a small balloon tip is advanced through the arteries until it reaches the narrowed area. The doctor inflates the anti-proliferative medication-coated balloon, causing the plaque on the artery walls to flatten.

Drug-eluting stent (DES)

Stents open peripheral or coronary arteries to improve blood flow. Drug-eluting stents have a coating of medicine that prevents cell proliferation, which can cause narrowing.

Direct oral anticoagulation (DOAC)

Anticoagulants prevent blood clots from forming and may prevent blood clots that already exist from increasing in size. DOACs are a newer class of medication that has advantages over traditional anticoagulants, like warfarin.

Digital subtraction angiography (DSA)

An interventional radiology technique that allows for the visualization of blood vessels to detect problems with blood flow. The procedure involves the insertion of a catheter into an artery. Then there is an injection of contrast dye that allows for a clear picture of the blood vessels. A process that digitally subtracts the first image from the second provides a clearer view of the blood vessels.

Duplex ultrasound (DUS)

DUS is a type of ultrasound providing a look at the rate of blood flow and the structure of veins. DUS involves two modes of ultrasound – Doppler and B-mode. It helps diagnose arteriosclerosis of the arms or legs, blood clots, and venous insufficiency.

Frequency-domain optical coherence tomography (FD-OCT)

OCT is a noninvasive imaging method that captures two and three-dimensional images with micrometer resolution. FD-OCT generates a depth profile by using a Fourier transform to resolve depth reflections of the interference patterns from light that is reflected with a fixed optical delay at various depths.

High on-treatment platelet reactivity (HTPR)

When patients that are under antiplatelet therapy have a higher-than-expected platelet reactivity. This can expose them to an increased risk of a major adverse cardiovascular event. HTPR to dual antiplatelet therapy can predict unfavorable outcomes in patients that have coronary artery disease.

Intravascular ultrasound (IVUS)

IVUS is a diagnostic test that can see inside of blood vessels with the use of sound waves. An ultrasound wand is attached to a catheter. The doctor inserts the catheter into an artery, and a computer creates images by detecting how the sound waves reflect off the blood vessels.

Single antiplatelet therapy (SAPT)

Antiplatelet can stop platelets from sticking together and forming a blood clot. SAPT is when a patient is treated with a single antiplatelet agent to prevent blood blots.

Spectral-domain optical coherence tomography (SD-OCT)

SD-OCT is an interferometric imaging technique that uses either a spectrometer to spatially separate wavelength contributions or a narrowband tunable laser swept linearly during spectral fringe data acquisition. The reference arm is stationary, allowing for high-speed OCT imaging.

Toe-brachial index (TBI)

TBI is a method for measuring arterial disease involving the measurement of brachial systolic pressures in both arms and arterial pressures in the largest toe. If a person has an ABI greater than 1.3, a TBI could offer an alternative examination. TBI is also an indicator of progress after an angioplasty.

Transcutaneous oxygen pressure (TcPO²)

A noninvasive test that can help determine the level of oxygen in the tissue beneath the skin. TcPO² assesses the partial press of oxygen diffusing through the skin and records the capacity for the vascular system to deliver oxygen. Many consider TcPO² to be the most reliable test to determine the potential for a wound to heal.

Wound, ischemia, and foot infection (WiFi)

Wound, ischemia, and foot infection (WiFi) is a classification system that categorizes the risk factors for amputation. The system has a scale of none (0), mild (1), moderate (2), and severe (3).  A visual representation of WiFi involves three intersecting rings of the three risk factors: wound, ischemia, and foot infection.