Non-Invasive Vascular Testing

Non-invasive vascular testing aims to check for blood flow problems in arteries and veins. Vascular problems or conditions affecting your blood vessels can impact mobility and quality of life. As such, vascular testing is a type of blood flow test to help diagnose your condition and customize a treatment plan that will help relieve pain and regain mobility. 

What Is Vascular Testing? 

Doctors often use a non-invasive vascular diagnostic test to evaluate patients suspected of having peripheral artery disease (PAD). This condition involves the narrowing or blockage of blood vessels that carry blood from the heart to the limbs. Patients with certain risk factors like smoking, diabetes or kidney issues may be referred for non-invasive vascular testing. Symptoms like pain while walking, pain at rest or wounds that don't heal, as well as signs of tissue death or gangrene, also prompt these tests. After a patient has surgery to improve blood flow, vascular tests are done to ensure the disease is not coming back or worsening and to catch new problems.
 

Vascular laboratory testing has two main categories: ultrasound-based imaging and physiological testing. These tests help doctors understand your blood vessel health without making an incision to enter the body, making them non-invasive. The physiologic test refers to evaluating physical and functional aspects of blood flow, such as blood pressure in different body parts, the speed of blood flow and oxygen levels in the blood. Physiologic tests include:

  • Ankle-brachial index - comparing the blood pressure in the ankle with the blood pressure in the arm.
  • Toe-brachial index – comparing the blood pressure in the toes with that of the arm.
  • Wrist-brachial index – measuring blood pressure in the wrist and the upper arm.
  • Segmental pressures – blood pressure measurements taken at multiple segments of the limbs to determine the presence and location of arterial blockages or narrowing.
    • Lower extremity segmental pressures - specifically assess the arteries in the legs. The process involves measuring blood pressure at various levels of the legs, such as the thigh, above the knee, below the knee and at the ankle or foot. 
    • Upper extremity segmental pressures – aims to assess the arteries in the arms. Like the lower extremity test, blood pressure cuffs are placed at different levels of the arms, such as above and below the elbow and potentially at the wrist.
  • Pulse volume recordings (PVR) – checking blood flow through the limbs using special cuffs like those used for blood pressure measurements. Results are shown as waveforms, which doctors will interpret later.
  • Transcutaneous oxygen measurements (TcPO2) – assesses tissue oxygenation levels to evaluate blood flow and arterial health by measuring the oxygen pressure through the skin.

Non-invasive imaging vascular testing includes:

  • Arterial duplex ultrasound – provides detailed images of blood vessels and measures blood flow using grayscale and color doppler to offer insights into the anatomy and function of arteries without discomfort. Similar test types include carotid duplex ultrasound, renal artery ultrasound and venous duplex ultrasound.
  • Computed tomography angiography (CTA) – provides detailed anatomical views of vascular lesions in PAD patients.
  • Magnetic resonance angiography (MRA) – provides clear pictures of blood vessels and can sometimes show how blood flows through them.

The choice of imaging or physiologic vascular testing method depends on the patient's health and diagnostic needs. Your healthcare provider can help explain why you need to undergo certain imaging tests and their pros and cons.

How Is a Vascular Test Done? 

A vascular test is done depending on the type of procedure. For instance, your doctor will use blood pressure cuffs and Doppler ultrasound devices when performing Ankle-Brachial Index, Toe-Brachial Index, Wrist-Brachial Index and Segmental Pressure tests. The cuffs are wrapped around different body parts (ankle, toe, wrist, thigh, above and below the knee and arms) to measure blood pressure at various points. At the same time, a Doppler device helps your doctor listen to the blood flow, identifying areas with potential blockages or narrowed arteries.
 
For PVR, specialized PVR equipment is used with blood pressure cuffs to measure and graph blood flow changes through the limbs. These tools produce waveforms that doctors analyze to determine the presence and severity of vascular issues. For TcPO2, a specialized probe device is used to measure the oxygen level at the skin's surface to assess tissue oxygenation and arterial health, indicating how well blood is delivering oxygen to different parts of the body.
 

On the other hand, vascular imaging tests utilize distinct specialized equipment tailored for each procedure. Arterial duplex ultrasound uses a machine with Doppler technology for detailed vascular imaging. CTA relies on a dedicated CT scanner to provide high-resolution images of blood vessels. Meanwhile, MRA uses specialized MRI equipment designed to capture detailed images of the vascular system.

How Long Does a Vascular Ultrasound Take?

The duration of a vascular ultrasound can vary depending on the specific area being examined and the complexity of the patient's condition. Generally, a standard vascular ultrasound study can take 30 minutes to one hour. However, the procedure might take longer if multiple areas need to be assessed or the examination is particularly detailed. Note that preparation and post-examination procedures could add to the overall time spent at the facility.

Find a Vascular Surgeon in San Antonio, TX

Schedule an appointment with one of our vascular providers today. We'll work with you to develop a personalized treatment plan and get you on the path to healing.

See our Providers

Non-Invasive Vascular Testing Resources

General Vascular Resources

Cardiovascular Services

Continue