Recently, there have been numerous reports on the application of non-thermal ultrasound energy for treating various diseases in combination with drugs. Furthermore, the introduction of
microbubbles and nanobubbles as carriers/enhancers of drugs has added a whole new dimension to
therapeutic ultrasound. Non-thermal mechanisms for effects seen include various forms of energy due to cavitation, acoustic streaming, micro jets and radiation force which increases possibilities for targeting tissue with drugs, enhancing
drug effectiveness or even chemically activating certain materials. Examples such as enhancement of
thrombolytic agents by ultrasound have proven to be beneficial for
acute stroke patients and peripheral
arterial occlusions. Non-invasive low intensity focused ultrasound in conjunction with anti-
cancer drugs may help to reduce
tumor size and lessen recurrence while reducing severe
drug side effects. Chemical activation of drugs by ultrasound energy for treatment of
atherosclerosis and
tumors is another new field recently termed as "Sonodynamic
therapy". Lastly, advances in molecular imaging have aroused great expectations in applying ultrasound for both diagnosis and
therapy simultaneously.
Microbubbles or nanobubbles targeted at the molecular level will allow medical doctors to make a final diagnosis of a disease using ultrasound imaging and then immediately proceed to a
therapeutic ultrasound treatment.