CORRECTION OF INTRINSIC SPECTRAL BROADENING ERRORS IN DOPPLER PEAK VELOCITY-MEASUREMENTS MADE WITH PHASED SECTOR AND LINEAR-ARRAY TRANSDUCERS

Commercial duplex ultrasound systems primarily measure peak velocity o f blood flow to provide important information in diagnosing vascular d isease, However, due to errors caused by intrinsic spectral broadening (ISB), the accuracy decreases as the Doppler angle increases, In gene ral, vascular technologists and surgeons keep the Doppler angle under 60 degrees, Even at 60 degrees, ISB can produce an overestimation of p eak velocity as high as 40%, This would indicate the necessity of redu cing the Doppler angle even lower than 60 degrees, Since most vessels in the body run parallel with the skin surface any criteria requiring a Doppler angle of say 45 degrees or less would be difficult to achiev e, Using the transverse Doppler equation as a correction for ISB, in c onjunction with the classical Doppler equation, accurate peak velocity measurements were obtained at Doppler angles as high as 80 degrees, C orrections were made using both phased sector and linear array transdu cers for steered and unsteered beams, However, for beams steered at la rge angles, 20 degrees or more, corresponding to Doppler angles of <70 degrees, the transverse Doppler equation failed to correct ISB errors in measurements made, This may be due to the experimental setup and n ot due to limitations in the transverse Doppler equation.