ABSTRACT
Ultrasonic B-mode real-time imaging can be combined with Doppler in a scanner so that the scanner is capable of providing not only anatomical information but also blood flow data. Both sets of information are displayed simultaneously. A cursor line is typically superimposed on the B-mode image to indicate the direction of the Doppler beam. An FFT algorithm is used to compute the Doppler spectrum that is displayed in real time. This type of scanner is called a duplex scanner; a duplex image is shown in Figure 5.6. Alternatively, blood flow data can be displayed in real time and superimposed with the B-mode image if the data acquisition rate and image processing algorithms are sufficiently fast.
