Access Restriction

Author De Pieri, G. ♦ Rovai, D. ♦ Mazzarisi, A. ♦ Landini, L. ♦ Lombardi, M. ♦ Distante, A. ♦ Taddei, L. ♦ Benassi, A. ♦ L'Abbate, A.
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©1988
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science ♦ Technology ♦ Medicine & health
Subject Keyword Radio frequency ♦ Veins ♦ Instruments ♦ RF signals ♦ Integral equations ♦ Ultrasonic imaging ♦ In vitro ♦ Echocardiography ♦ Containers ♦ Probes
Abstract The linear relationship between dose of contrast agent and radio-frequency (RF) signal constitutes a means of noninvasive evaluation of intracardiac flows by contrast echocardiography. To assess the concentration of echo-contrast agents by ultrasound, a commercially available echocardiographic instrument was modified. The RF signal (unprocessed backscattered signal) corresponding to a region of interest inside the 2-D echo image was sampled in real time and transferred online to a personal computer. The relationship between different doses of contrast agent and RF signal was tested in an in vitro system of circulation. In the range of doses between 0.25 and 1.5 ml of contrast a linear correlation was found between dose and RF (r=0.92). At higher doses (1.75-2.0) ml, the dynamic converter used in this modified echo instrument produced a significant distortion of the signal. The system also made it possible to study the spontaneous decay of the echo contrast agent. The spontaneous T/sub 1/2/ (68 s) is long enough to allow flow evaluation.<<ETX>>
Description Author affiliation: CNR Clinical Physiol. Inst., Pisa, Italy (De Pieri, G.; Rovai, D.; Mazzarisi, A.; Landini, L.; Lombardi, M.; Distante, A.; Taddei, L.; Benassi, A.; L'Abbate, A.)
ISBN 081861949X
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research ♦ Reading
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1988-09-25
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Size (in Bytes) 233.21 kB
Page Count 4
Starting Page 211
Ending Page 214

Source: IEEE Xplore Digital Library