(FDA) An agency of the US federal government established by Congress in 1912 and presently part of the US Department of Health and Human Services. The FDA gives classifications of medical devices according to potential risks and controls the safety of marketed drugs.

See also Class I II III Devices, Phase 1 2 3 4 Drug Trials and US FDA 510k Document.

From Philips Medical Systems;
'Clinicians are demanding smaller, higher performing systems specifically designed to meet their clinical and operational challenges. The new Philips HD11 system provides an uncompromising platform, plus advanced options in a highly mobile and easy-to-use system.'

Huygens principle states that an expanding sphere of waves behaves as if each point on the wave front were a new source of radiation of the same frequency and phase. The principle explains how a flat ultrasound transducer can transmit a narrow ultrasound beam, which in the near field is confined to the dimensions of the transducer surface.
Spherical wavelets are emitted from numerous point sources on the transducer surface. They interfere to form a narrow, slightly converging beam of ultrasound in the near field. The wavefronts in the beam are nearly parallel. A precondition for this interference is that the transducer surface is much larger than the ultrasound wavelength.

See also Interference Artifact.

Ultrasound contrast agents (USCAs) improve the sensitivity of various ultrasound applications. They usually stay within the vascular space and can be injected several times. Nevertheless the contrast enhancement is limited caused by physiologic clearance and bubble destruction.

Different injection techniques to improve the imaging:
Continuous infusion yield a steady-state concentration of the USCAs, greater examination time with optimal enhancement, avoid bloom and possibly other artifacts. Continuous infusion also allows the sonographer to optimize the effective dose individually during the examination.

See also Power Modulation.

From GE Healthcare.;
Versatile High Performance System 'The LOGIQ 5 Expert ultrasound system delivers the premium performance advantage of TruScan architecture in a versatile high performance package. Advanced capabilities for outstanding clinical performance are available with the efficiency and productivity needed to meet clinical demands.'