Spectral broadening in conventional and harmonic Doppler measurements with gaseous contrast agents

Author

Shi, William T. ; Forsberg, Flemming ; Oung, Harry

Author_Institution

Dept. of Radiol., Thomas Jefferson Univ. Hosp., Philadelphia, PA, USA

Volume

2

fYear

1997

fDate

5-8 Oct 1997

Firstpage

1575

Abstract

Gaseous contrast agents can be used to enhance conventional Doppler measurements and to create new harmonic Doppler modalities. The effect of bubble destruction on both conventional and harmonic Doppler spectra was studied using an in vitro, pulsatile flow system. Similar spectrograms were observed for low levels of insonification (below 0.62 MPa) in both conventional and harmonic Doppler measurements of the same flow. As the acoustic output was increased (up to 1.8 MPa) the spectrograms showed marked spectral broadening, especially for harmonic Doppler. The spectral broadening was caused by transit time effects resulting from the destruction of insonated bubbles. This finding was confirmed by performing a similar experiment on stationary polymer-coated microbubbles suspended in a gel phantom. In conclusion, the effect of bubble destruction should be taken into account in both conventional and harmonic Doppler measurements with gaseous contrast agents

Keywords

Doppler broadening; Doppler measurement; biomedical ultrasonics; blood flow measurement; bubbles; pulsatile flow; 0.62 MPa; 1.8 MPa; bubble destruction effect; conventional Doppler measurements; gaseous contrast agents; gel phantom; harmonic Doppler measurements; harmonic Doppler modalities; in vitro pulsatile flow system; insonated bubbles; stationary polymer-coated microbubbles; transit time effects; Computed tomography; Doppler measurements; Frequency; Imaging phantoms; In vitro; Power harmonic filters; Pulse amplifiers; Spectrogram; Transducers; Ultrasonic imaging;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1997. Proceedings., 1997 IEEE

Conference_Location

Toronto, Ont.

ISSN

1051-0117

Print_ISBN

0-7803-4153-8

Type

conf

DOI

10.1109/ULTSYM.1997.663297

Filename

663297