ECO COLOR DOPPLER: This noninvasive test bounces high-frequency sound waves off blood cells to measure blood flow. In order to properly diagnose CCSVI, a specialized type of ultrasound probe, called a “transcranial probe,” is required. For CCSVI diagnosis, both ‘extracranial’ and ‘transcranial’ ultrasonography is recommended, as this approach covers both the veins in the head, neck, and upper chest. An experienced duplex ultrasonographer can accurately assess whether or not blood is refluxing back into the central nervous system, or flowing at abnormal rates. Accurate data acquisition and interpretation is highly operator dependent.