Bubble specific imaging methods rely usually on non-linear imaging modes. These contrast imaging techniques are designed to suppress the echo from tissue in relation to that from a microbubble contrast agent.
Stimulated acoustic emission (SAE) and phase / pulse inversion imaging mode (PIM) are bubble specific modes, which can image the tissue specific phase.
In SAE mode bubble rupture is seen as a transient bright signal in B-mode and as a characteristic mosaic-like effect in velocity 2D color Doppler.
PIM are Doppler modes and detect non-linear echoes from microbubbles. In pulse inversion imaging modes the transducer bandwidth extends, resulting in improved spatial resolution and more contrast.

See also Contrast Pulse Sequencing, Microbubble Scanner Modification, Narrow Bandwidth, Contrast Medium, Dead Zone.

To calculate the echo position, a constant sound speed of 1538.5 m/sec is assumed. Tissue penetration is frequency depended, if the frequency increases, the imaging depth decreases. The range resolution defines the depth. Ultrasound propagating in tissue is attenuated due to scattering and absorption. The attenuation is proportional to depth and frequency and is typically in the range from 0.5 to 1 dB/(MHz cm).

See also Attenuation Coefficient, Proximity Sensor, and Echo Ranging.

Hitachi Medical Systems America Inc.;
The EUB-525 is a mid-size ultrasound system with a full feature set. Capable of B-mode, M-mode, Doppler, color flow and color angiography it performs a variety of tasks in a simple and straightforward fashion. This system produces high quality images with excellent clarity and detail.

Enhancement artifacts occur if decreasing of the echo amplitude is not equal with penetration depth caused by inhomogeneous tissue layers and fluids like cysts or air-filled regions. The enhancement artifact appears as a hyperintense (hyperechoic) signal. The attenuation of the ultrasound wave in fluids is much lower as the attenuation in other tissues, therefore tissues distal to fluid are enhanced. Artificial enhancement may also be found distal to a homogeneous solid tumor surrounded by adipose tissue, due to the comparatively high attenuation in fat.

See also Boundary Layer, and Half-Value Layer.

From Hitachi Medical Corporation (HMC), sales, marketing and service in the US by Hitachi Medical Systems America Inc.
The HI VISION™ 5500 - EUB-5500 fully digital ultrasound system delivers the latest generation of signal processing technology, sophisticated transducer design, and a host of features and options for advanced imaging capabilities across a wide range of clinical situations. This system is compatible with all Pentax ultrasound endoscopes.