(CCI) A major limitation of the use of ultrasound contrast agents is the problem that signals from the microbubbles are mixed with those from tissue, so that the distribution of the microbubbles is not optimally displayed either in Doppler or gray scale.
Coherent contrast imaging is a high frame rate implementation of inverting the phase of alternate sound pulses and summing the resulting echoes. The symmetrical signals from linear reflectors are cancelled leaving those from non-linear scatterers, with the advantage that the cancellation is performed without the need to transmit two pulses per image line so that bubble destruction is minimized. Coherent contrast imaging yields best results in the vascular phase of phospholipid microbubbles (such as Definity and SonoVue).

See also Coherence.

Duplex ultrasonography (duplex scan) consists of two ultrasound modalities to study blood flow and the perivascular tissue. This includes B-mode / gray scale imaging used in combination with spectral Doppler / pulsed-wave Doppler.
The real-time visualization of the vessels and tissue by the B-mode component improves the PW Doppler positioning and the direction of blood flow can be inferred. The angle between the direction of the PW Doppler signal and the estimated direction of blood flow can be measured.
Duplex techniques are available on phased array, linear array, and mechanical scanners. A phased array probe is able to create nearly simultaneous images and flow information. A linear array transducer can also do this if the Doppler probe is attached separately to one end of the scanhead. A mechanical transducer freeze the image; the crystals must be static to produce a Doppler image. The first two transducers are therefore the best choice for Duplex.

See also Compound B-Mode, and Duplex Scanner.

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.

From Hitachi Medical Corporation (HMC), sales, marketing and service in the US by Hitachi Medical Systems America Inc.;
Powerful, flexible, and fast, the HI VISION™ 8500 - EUB-8500 diagnostic ultrasound scanner combines leading edge technologies with user-oriented operation for exceptional imaging and functionality.
Available exclusively on the 8500, SonoElastography provides a new perspective on the physical properties of tumors and masses by determining and displaying the relative stiffness of tissue.

From Hitachi Medical Corporation (HMC);
The HI VISION™ 6500 - EUB-6500 high resolution digital ultrasound system offers advanced clinical imaging, enhanced operating efficiency, and remarkable clinical flexibility, all in robust and versatile configuration that simply represents a better clinical solution in a variety of real-world, real-work arenas.