CMS Noninvasive Tests of Carotid Function Form

Noninvasive tests of carotid function aid physicians in studying and diagnosing carotid disease. There are varieties of these tests which measure various anatomical and physiological aspects of carotid function, including pressure (systolic, diastolic, and pulse), flow, collateral circulation, and turbulence.

For operational purposes, it is useful to classify noninvasive tests of carotid function into direct and indirect tests. The direct tests examine the anatomy and physiology of the carotid artery, while the indirect tests examine hemodynamic changes in the distal beds of the carotid artery (the orbital and cerebral circulations).

It is important to note that the names of these tests are not standardized. Following are some of the acceptable tests, recognizing that this list is not inclusive and that local medical consultants should make determinations:

Direct Tests

• Carotid Phonoangiography
• Direct Bruit Analysis
• Spectral Bruit Analysis
• Doppler Flow Velocity
• Ultrasound Imaging including Real Time
• B-Scan and Doppler Devices

Indirect Tests

• Periorbital Directional Doppler Ultrasonography
• Oculoplethysmography
• Ophthalmodynamometry