Medicare National Coverage Determinations (NCD) Manual (Pub. 100-03), Ch. 1 § 20.17
Noninvasive Tests of Carotid Function
20.17 - Noninvasive Tests of Carotid Function
(Rev. 1, 10-03-03)
CIM 50-37
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