The graphic representation of the ultrasound frequency shift or velocity range and amplitude can be depicted as a histogram.

The perfect image quality is dependent on some assumptions of the propagation of ultrasound waves in tissues after generating in an imaging system. These assumptions are important for the developing of optimal ultrasound imaging systems.
A lot of steps can be taken to prevent artifacts and to improve image quality, for example beamforming is used to focus the ultrasound beam, and contrast agents decrease the reflectivity of the undesired interfaces or increase the backscattered echoes from the desired regions.

See also Coded Excitation, Validation and Refraction Artifact, Q-Value, Ultrasound Phantom, Dead Zone, Narrow Bandwidth.

(AE) Induced acoustic emission is an effect of ultrasound contrast agents, presenting the interaction between the agent and the incident ultrasound wave.
Microbubbles break down in high-amplitude diagnostic ultrasound energy. The bubble rupture produces a transient pressure wave, which results in a characteristic mosaic pattern from tissues containing the agent. It is important to note that the color patterns of induced acoustic emission do not represent flow signals.

M-mode (Motion-mode) ultrasound shows the motion of cardiac structures. M-mode echocardiography records the amplitude and rate of motion of a moving structure in real time by repeatedly measuring the distance of the object from the single transducer at a given moment. The single sound beam is transmitted and reflected signals are displayed as dots of varying intensities, creating lines across the screen. It yields a one-dimensional image, sometimes called an 'ice pick' view of the heart.
M-mode echocardiography is used to detect valvulopathies (calcifications, etc.) and cardiomyopathies (dyskinesis, aneurysm, etc.).

See also Bicycle Stress Echocardiography, Transthoracic Echocardiography, and Transesophageal Echocardiography.

(Vmax) The maximum velocity is the highest velocity found with significant amplitude within the sampled region normally for use in Bernoulli type gradient estimations.