Empirical findings relating sample volume size to diagnostic accuracy in pulsed Doppler cerebrovascular studies

Ultrasonic duplex scanning has a sensitivity of 97% in detecting disease of the carotid bulb. However, the specificity is much less, being 37%. The error in distinguishing normal arteries from those with minimal disease appears to be in part related to the size of the sample volume of the pulsed Doppler. This paper addresses the importance of the features of scan head design in relation to distinguishing normal and diseased arteries.