About Non-Invasive Vascular Assessments (NIVA)

Non-invasive vascular assessment (NIVA) is a type of exam that uses Doppler ultrasound to evaluate the circulatory system.

Ultrasound, also called sonography, is an exam that uses sound waves to obtain images of the inside of the body. These high-frequency sound waves are far above the range of human hearing. Sound waves are aimed at a particular area of the body. The different body tissues reflect the waves back in varying degrees. The echoed waves are recorded and displayed as a continuous real-time image on a computer monitor. Since the images are real-time, ultrasound has the benefit of allowing the radiologist to see organs in motion, such as the movement of heart valves and blood flow.

Doppler ultrasound is able to provide information in various formats: audible sounds, continuous color images of the blood flow, and graphs showing changes in blood velocity. This makes it particularly useful for assessing the function the circulatory system.

NIVA is used to check for many conditions including:

  • Aneurysms (ballooning arteries), such as an abdominal aortic aneurysm
  • Blood clots
  • Poor circulation
  • Varicose Veins

Types of NIVA Exams

Following are the three types of NIVA exams:

  • Extremity Arterial NIVA evaluates the flow of blood from your heart to your legs or arms.
  • Carotid NIVA evaluates the carotid and vertebral arteries in the neck for obstructions.
  • Extremity Venous NIVA checks for blood clots in the legs or arms.

Risks Involved in a NIVA

No radiation is used in this examination and there are no known health risks.

Scheduling, Insurance and Preparation


Contact your personal physician for a referral for this exam. Then call 720-493-3700 to schedule.

Insurance Coverage

Non-invasive vascular assessments are usually covered by insurance when ordered by a physician. Check with your insurance company to be sure. Please bring your insurance card with you to your exam.

Conditions to Let Us Know About

There are no conditions that you need to report prior to this exam.

Preparation Guidelines

NIVA exams require no advanced preparation. You may eat and drink as normal. Take all prescribed medications.

What to Expect

During the Exam

Non-invasive vascular assessments vary depending on the area of the body being imaged. However, here is generally what will happen:

  1. You may need to partially disrobe or change into a gown, depending on the type of NIVA you are receiving. You may use a secure locker for your personal items during your exam.
  2. The sonographer will explain the procedure and answer any questions you have.
  3. The sonographer will position you on a table and apply a clear, warm gel to the skin. This gel helps the sound waves penetrate into your body.
  4. The sonographer will move the transducer (a handheld device that produces and records sound waves) across the area to be imaged while watching a continuous image on a computer screen. He or she will periodically listen to the sound of your blood flow. At certain times you may be asked to hold your breath. The technologist may also compress certain spots during the exam. You won’t feel any pain during the procedure, but you may feel some mild discomfort.
  5. The sonographer will help you remove any remaining gel.
  6. You will change back into your clothes if necessary.

The sonographer may leave the room to show images to a radiologist. The radiologist may come in during the exam to watch the NIVA or perform part of the exam personally.

A NIVA can take from 20 minutes to two hours, depending on the type and purpose of the exam.

Arterial NIVA

Part of an arterial NIVA includes placing blood pressure cuffs at different levels on your arms or legs to measure blood flow and pressure.

If this exam is being performed on your legs, your physician may order that it be done with exercise. If exercise is required, you will walk on a treadmill for a specific amount of time, and then your blood flow and pressure will be measured again.

After the Exam


You can return to your normal activities immediately after your NIVA exam.

Exam Results

A board-certified radiologist experienced in the interpretation of non-invasive vascular assessments will analyze the data and results from your exam. The results will be reported to your physician. Your physician will pass the results onto you.

During the exam, our radiologists and technologists will be happy to answer questions about the exam itself; however, they will not immediately provide you with the results of your exam.

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