Color Doppler

There are three types of Doppler ultrasound:

• Color Doppler uses a computer to convert Doppler measurements into an array of colours to show the speed and direction of blood flow through a blood vessel.
• Power Doppler is more sensitive than colour Doppler and capable of providing greater detail of blood flow, especially when blood flow is of low velocity. Power Doppler, however, does not help the radiologist determine the direction of blood flow, which may be important in some situations.
• Spectral Doppler displays blood flow measurements graphically, in terms of the distance travelled per unit of time, rather than as a colour picture. It can also convert blood flow information into a distinctive sound that can be heard with every heartbeat.