title: Myocardial blood flow measurements in rats with simple pulsing contrast echocardiography.
abstract: Relationship between contrast intensity and ultrasound (US) pulsing interval has been utilized to quantify myocardial blood flow (MBF) during myocardial contrast echocardiography (MCE). We tested if an MCE method employing a simple pulsing sequence during intravenous contrast infusion has the ability to quantify MBF in rats. We performed MCE in 17 rats using a 5- to 12-MHz broadband transducer during microbubble infusion via the femoral vein. Acoustic density (AD) from the anterior wall of the left ventricle imaged in the short axis plane was plotted against the frame number after shortening the pulsing interval (PI) from 1:20 to 1:1 end-systolic ECG gating. The relation between AD and frame number was fitted to a decay function. The rate of the AD decay was decreased during dipyridamole infusion, but was increased by causing coronary stenosis. The AD during long PI imaging remained unchanged during the interventions. Estimated MBF by MCE after correction by heart rate exhibited a close correlation (r = 0.83) with the present "gold standard" of colored microsphere-derived MBF. Thus, the decay rate of the contrast intensity obtained with the high-frequency transducer after abrupt shortening of PI during intravenous microbubble infusion may provide for noninvasive measurement of MBF in rats.
authors.affiliation: Kagawa Medical University School of Medicine, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Oshita
authors.forename: Koji
authors.initials: K
authors.lastname: Ohmori
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Isao
authors.initials: I
authors.lastname: Kondo
authors.forename: Hiroto
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Takagi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Wada
authors.forename: Kazushi
authors.initials: K
authors.lastname: Yukiiri
authors.forename: Katsufumi
authors.initials: K
authors.lastname: Mizushige
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kohno
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology*; D004452:Echocardiography / Q000379:methods*; D005260:Female; D008297:Male; D008863:Microspheres; D023421:Models, Animal; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology; D011673:Pulsatile Flow; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D003287:Contrast Media