(LVO) Ultrasound contrast agents improve the echocardiography assessment of left ventricular function and the low sensitivity of changes in left ventricular ejection fraction (LVEF). In addition, harmonic imaging techniques and automated border detection (ABD) together with contrast enhanced left ventricular opacification increase endocardial border delineation (EBD) and the results compared to native echocardiography.

Linear scattering occur from specular reflectors or tissue, in which the echo is an accurate copy of the incident ultrasound pulse. If the phase or amplitude of the transmitted sound is altered, the phase or amplitude of the echo will be also altered.
Non-linear scatterers, such as microbubbles, do not follow these rules.

The array of elements of microconvex probe is curved with a certain radius. Microconvex probes have a much smaller contact surface, which improves the coupling between the transducer and the skin surface even in complicated areas as the supraclavicular or jugular fossa. Microconvex probes, with large aperture and selection of transmission frequencies are also used in gynecological diagnostic.

See also Transvaginal Echography, Endocavitary Echography and Transrectal Ultrasonography.

A narrow or tuned Bandwidth describes a small frequency spectrum of pulses. With the Fourier transformation method a pulse or amplifier can be subscribed with its bandwidth. It is usually expressed with a 6dB drop of maximum amplitude, subscribing the bandwidth between the edges of the curve.
The selection of bandwidth is essential for achieving certain test results; narrow bandwidth for highly sensitive scans or broad banded for high resolution scans. The fast Fourier transformation uses beside the echo amplitude evaluation method the capability of the echo frequency / bandwidth information.

Non-linear scattering describes in physics the conversion of a photon from one wavelength to one or more other wavelengths. In ultrasound, non-linear scattering is the generation of an echo containing higher harmonics. In the case of a microbubble, the oscillation is asymmetric with time, producing echoes with even harmonics.

See also Cross-section Scattering.