On Mar. 1, 1974, researchers from the University of Washington (UW) published in Transactions in Biomedical Engineering, the first report of ultrasonic duplex scanning for arterial and venous disorders, an advance that furthered the UW’s leadership in diagnostic ultrasound.

The clinicians and bioengineers at the UW, under the direction of Dr. D. Eugene Strandness, Jr., built a prototype duplex scanner that combined B-mode imaging and pulsed Doppler flow detection in a single instrument.

This work resulted in the University of Washington duplex criteria for carotid artery disease, which have been widely adopted and modified. Subsequent advances in ultrasound technology expanded the applications of duplex scanning to the peripheral arteries and veins, as well as the abdominal vessels.