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BackgroundShock wave therapy (SWT) is an acoustic technology clinically used for the non-invasive treatment of ischemic heart disease (IHD). Therapeutic ultrasound (TUS) has more recently been developed for the same indication, although its effects on reperfusion and angiogenesis have yet to be directly compared to those of SWT.Methods and resultsTUS and SWT acoustic parameters were matched, and their ability to promote angiogenesis and reperfusion in a rat hindlimb ischemia model was compared. After left femoral artery excision, 3-weekly TUS, SWT or sham treatments (n=10 rats each) of the left hindlimb were performed for 2 weeks. Laser Doppler perfusion imaging demonstrated improved perfusion with TUS (66±4% L:R hindlimb perfusion, mean±SEM, P=0.02), but not with SWT (59±4%, P=0.13) compared with sham (50±4%). Immunohistochemistry of CD31 demonstrated increased microvascular density with TUS (222.6 vessels/high-power field, P=0.001) and SWT (216.9, P=0.01) compared to sham-treated rats (196.0). Tissue vascular endothelial growth factor mRNA levels were elevated in the left hindlimb of TUS-, but not SWT- or sham-treated rats.ConclusionsDirect comparison demonstrates that TUS is more effective than SWT at promoting reperfusion, whereas both therapies promote angiogenesis in ischemic gastrocnemius muscle. These results suggest that TUS may be more effective than SWT for the treatment of IHD and peripheral arterial disease.

Ultrasound (US) has gained widespread use in diagnostic cardiovascular applications. At amplitudes and frequencies typical of diagnostic use, its biomechanical effects on tissue are largely negligible. However, these parameters can be altered to harness US's thermal and non-thermal effects for therapeutic indications. High-intensity focused ultrasound (HIFU) and extracorporeal shock wave therapy (ECWT) are two therapeutic US modalities which have been investigated for treating cardiac arrhythmias and ischemic heart disease, respectively. Here, we review the biomechanical effects of HIFU and ECWT, their potential therapeutic mechanisms, and pre-clinical and clinical studies demonstrating their efficacy and safety limitations. Furthermore, we discuss other potential clinical applications of therapeutic US and areas in which future research is needed.

Ultrasound imaging is useful for monitoring high-intensity, focused ultrasound (HIFU) therapy but interference on the ultrasound image, caused by HIFU excitation, must be avoided. A method to synchronize HIFU excitation with ultrasound imaging is described.

High-intensity, focused ultrasound (HIFU) surgical applicators are described and discussed.

The variations of the total peroxide yield, together with the variations of the cavitation noise spectrum and with the variations of the temperature inside the collapsing bubbles when adding small amounts of an anionic surfactant in water is examined. Because of its known effects on the cavitation field, sodium dodecyl sulfate (SDS) is analyzed which shows that it modifies the coalescence phenomena.

Research is done on low concentrations of short chain aliphatic alcohols and organic acids and bases, which suppress single-bubble sonoluminescence (SBSL) in water. In conclusion butyric acid and propylamine behave in the same manner, but only in their neutral forms, indicating that the SBSL suppression is due to processes occurring within the bubble.

Sonoluminescence refers to the mechanical production of light from sound through a process called cavitation. The process is highly robust and synchronized, indicating numerous technological applications.

Ultrasonic diagnosis was performed in an in vitro experiment to study the occurence of transient cavitation, the speedy build-up and collapse of a gas-filled cavity. The experiment used a Hewlett-Packard clinical diagnostic scanner to probe water with 30 MegaHertz (MHz) pulses. Observations revealed cavitation in water with polystrene spheres at 2.5 MHz in the M-mode and Doppler mode coinciding with negative acoustic pressure of 1.1 MegaPascals or more.