Application of autoregressive methods to multigate spectral analysis

Multigate analysis is known to be capable of detecting accurate blood veloc ity profiles from human vessels. Experimental systems so far presented in t he literature use time-domain frequency estimations and, more recently, the fast Fourier transform (FFT) for real-time analysis of Doppler signals fro m multiple range cells. This experimental study is aimed at evaluating the application of an autoregressive (AR) method (Burg algorithm) to multigate Doppler analysis. Both in vitro and in vivo results were collected with a c ommercial Duplex scanner coupled with a prototype multigate unit developed in our laboratory. The same multigate signals are, thus, processed accordin g to both the FFT and the Burg algorithms. The related spectral and maximum frequency profiles are reported and statistically compared. AR, implemente d with the Burg algorithm, is demonstrated to be a way to perform multigate spectral analysis with reduced spectral variance, suitable for maximum vel ocity profile extraction through a simple threshold. (C) 2000 World Federat ion for Ultrasound in Medicine & Biology.