Small encapsulated gas bubbles (diameters of micrometers) that can be used as CONTRAST MEDIA, and in other diagnostic and therapeutic applications. Upon exposure to sufficiently intense ultrasound, microbubbles will cavitate, rupture, disappear, release gas content. Such characteristics of the microbubbles can be used to enhance diagnostic tests, dissolve blood clots, and deliver drugs or genes for therapy.

A subfield of acoustics dealing in the radio frequency range higher than acoustic SOUND waves (approximately above 20 kilohertz). Ultrasonic radiation is used therapeutically (DIATHERMY and ULTRASONIC THERAPY) to generate HEAT and to selectively destroy tissues. It is also used in diagnostics, for example, ULTRASONOGRAPHY; ECHOENCEPHALOGRAPHY; and ECHOCARDIOGRAPHY, to visually display echoes received from irradiated tissues.

The application of high intensity ultrasound to liquids.

Substances used to allow enhanced visualization of tissues.

Liquid perfluorinated carbon compounds which may or may not contain a hetero atom such as nitrogen, oxygen or sulfur, but do not contain another halogen or hydrogen atom. This concept includes fluorocarbon emulsions and fluorocarbon blood substitutes.

The use of focused, high-frequency sound waves to produce local hyperthermia in certain diseased or injured parts of the body or to destroy the diseased tissue.

The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.

The branch of physics that deals with sound and sound waves. In medicine it is often applied in procedures in speech and hearing studies. With regard to the environment, it refers to the characteristics of a room, auditorium, theatre, building, etc. that determines the audibility or fidelity of sounds in it. (From Random House Unabridged Dictionary, 2d ed)

Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.

Water-soluble proteins found in egg whites, blood, lymph, and other tissues and fluids. They coagulate upon heating.

Blocking of a blood vessel by air bubbles that enter the circulatory system, usually after TRAUMA; surgical procedures, or changes in atmospheric pressure.

Any device or element which converts an input signal into an output signal of a different form. Examples include the microphone, phonographic pickup, loudspeaker, barometer, photoelectric cell, automobile horn, doorbell, and underwater sound transducer. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)

The use of molecularly targeted imaging probes to localize and/or monitor biochemical and cellular processes via various imaging modalities that include RADIONUCLIDE IMAGING; ULTRASONOGRAPHY; MAGNETIC RESONANCE IMAGING; FLUORESCENCE IMAGING; and MICROSCOPY.

Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.

Sulfur hexafluoride. An inert gas used mainly as a test gas in respiratory physiology. Other uses include its injection in vitreoretinal surgery to restore the vitreous chamber and as a tracer in monitoring the dispersion and deposition of air pollutants.

High-amplitude compression waves, across which density, pressure, and particle velocity change drastically. The mechanical force from these shock waves can be used for mechanically disrupting tissues and deposits.

Tailored macromolecules harboring covalently-bound biologically active modules that target specific tissues and cells. The active modules or functional groups can include drugs, prodrugs, antibodies, and oligonucleotides, which can act synergistically and be multitargeting.

A versatile contrast medium used for DIAGNOSTIC X-RAY RADIOLOGY.

Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.

The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)

A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.

The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)