The main advantage of ultrasound is that certain structures can be observed without using radiation. However, ultrasound is energy and there are ultrasound safety regulations, because two bioeffects of ultrasound are heat and cavitation. Ultrasound is a mechanical energy in which a pressure wave travels through tissue. Reflection and scattering back to the transducer are used to form the image. As sound energy is transmitted through the tissue, some energy is reflected and some power is absorbed.
Possible physical effects with ultrasound:
The ultrasound safety is based on two indices, the mechanical index (MI) and the thermal index (TI). The WFUMB guidelines state that ultrasound that produces temperature rises of less than 1.5°C may be used without reservation. They also state that ultrasonic exposure causing temperature rises of greater than 4°C for over 5 min should be considered potentially hazardous. This leaves a wide range of temperature increases which are within the capability of diagnostic ultrasound equipment to produce and for which no time limits are recommended. However, it has not been determined that medical ultrasound causes any adverse reaction or deleterious effect.
The American Institute of Ultrasound in Medicine states that as of 1982, no independently confirmed significant biologic effects had been observed in mammalian tissue below (medical usage) 100mW/cm2.

See also Ultrasound Regulations and Ultrasound Radiation Force.

From GE Healthcare.;
(CV Ultrasound) Vivid 3 - 'Vivid family system designed to address customer requests for another level of cardiovascular performance, and offer an even wider range of clinical applications in vascular, pediatrics and the OR. From color flow imaging with super-high frame rates to DICOM connectivity, the new Vivid 3 offers a wealth of technological innovations that enhance image quality, productivity and patient care.'

Specifications for this system will be available soon.

From GE Healthcare.;
'Vivid 7 Dimension, a premier cardiovascular ultrasound system from GE Healthcare, expands on the strength of a powerful imaging platform to offer new, innovative technology of dimensional proportions.'

From GE Healthcare.;
'The incredible Vivid i system establishes a completely new level of cardiovascular performance that gives clinicians the freedom to get diagnostic results outside of the echo lab.'

From GE Healthcare.;
'GE is defining a new age of ultrasound. We call it Volume Ultrasound. GE's Voluson 730 Expert is a powerful system that enables real-time techniques for acquiring, navigating and analyzing volumetric images so that you can make clinical decisions with unprecedented confidence.'