Microbubbles echocardiography

CLINICAL USE OF INJECTED GAS MICROBUBBLES ECHOCARDIOGRAPHY POTENTIAL FOR CANCER DETECTION... 

The fact that the microbubbles are restricted to the vascular space makes them ideal for contrast echocardiography and vascular imaging. Echocardiography is used extensively to assess ischemic heart disease. Contrast-enhanced echocardiography improves visualization of the cavities of the heart, the lumen of arteries and veins, and small vessels within solid organs and perfused tissues. Effective endocardial border delineation allows assessment of global heart function and the detection of coronary insufficiency (Fig. 12). 

Earlier studies (ref. 440-442) with ordinary air microbubbles (without any synthetic surfactant coating) have already shown that echocardiographic contrast produced by microbubbles is useful in the qualitative analysis of blood flow and valvular regurgitation. In addition, quantitative studies (ref. 440) have shown a correlation between individual contrast trajectories on M-mode echocardiography and invasive velocity measurements in human beings. Meltzer et al. (ref. 441) have shown that velocities derived from the slopes of contrast trajectories seen on M-mode echocardiography correlate with simultaneous velocities obtained by Doppler techniques. (This correlation is expected because both measures represent the same projection of the microbubble velocity vector, that is, in the direction of the sound beam.) More detailed studies (ref. 442) confirmed that microbubble velocity obtained from either Doppler echocardiography or M-mode contrast trajectory slope analysis correlates well with actual (Doppler-measured) red blood cell velocity. Thus, these early studies have shown that microbubbles travel with intracardiac velocities similar to those of red blood cells. 

Apart from echocardiography, another promising clinical application of synthetic microbubbles is the ultrasonic monitoring of local blood flow in the abdomen (analogous to the earlier use of gas microbubbles to monitor myocardial perfusion (ref. 443)). Such refined ultrasonic blood flow measurements, utilizing injected... 

A detailed knowledge of the predominant physicochemical/biochemical mechanism by which gas microbubbles are stabilized in aqueous media is of practical importance to numerous and varied fields acoustic and hydrodynamic cavitation, commercial oil recovery, hydraulic and ocean engineering, waste-water treatment, chemical oceanography, meteorology, marine biology, food technology, echocardiography, and the continual medical problem of decompression sickness. Many of these applications... 

Perflutren is an ultrasound agent that consists of per-fluoropropane gas encapsulated in hpid microbubbles. It has been used in patients with suspected cardiac disease and suboptimal basehne echocardiography in doses of 5 pl/kg (n — 85) or 10 pl/kg (n — 84) 42 patients received isotonic saline (14). The magnitude of chnically useful opacification was not dose-dependent, but its duration... 

M. Vannan, T. P. McCreery, Li, Z. Han and E. C. Unger, Ultrasound-mediated transfection of canine myocardium by intravenous administration of cationic microbubble-linked plasmid. /. Am. Soc. Echocardiography, 15(3), 214-218 (2000)... 

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