Ultrasound imaging is excellent for diagnosing cysts and other fluids in soft tissue. For ultrasound imaging or ultrasonography, different modes are used to examine the arterial/venous system, heart, pancreas, urinary system, ovaries, spinal cord, joints and more.
Power levels, frequencies used, amplification, and beamforming determine the clarity of the image. These things are controlled by the sonographer, interacting with the properties of the ultrasound machine.

Various imaging modes:

Echoes of deep lying structures within the body do not always come from the latest emitted sound pulse and can produce an aliasing artifact. Aliasing lowers the frequency components when the pulse repetition frequency is less than 2 times the highest frequency of a Doppler signal. This artifact can be problematical at Spectral or Color Doppler examinations.
Aliasing of the data displayed in pulsed wave technology is utilized as a benefit in determining transitions from laminar to turbulent flow.

See also Ultrasound Imaging Modes.

Reflux sonography, as an alternative to micturating cystography (MCU), evaluates vesico-ureteral reflux (VUR), a common problem in children. Contrast enhanced pulse-inversion imaging shows best results. During the instillation of an ultrasound contrast agent into the bladder, (as for a conventional MCU) the lower ureters and renal pelves are scanned transabdominally as the bladder is filled to stimulate micturition.
Advantages for reflux sonography are a high sensitivity and the avoidance of X-rays. A disadvantage is the poorer depiction of the posterior urethra. However, for girls and for all follow-up studies, the ultrasound MCU has become standard in many pediatric ultrasound departments.

See also Urologic Ultrasound, Kidney Ultrasound, Ultrasound Safety, Ultrasound Imaging Modes.

Sonazoid™ is an ultrasound contrast agent (UCA) consisting of stabilized gas microbubbles in an aqueous suspension. Sonazoid™ has overcome the stability problems of first generation USCA and can produce myocardial perfusion images. Myocardial imaging using ultrasound contrast agents provides diagnosis of chronic heart disease and assessment of the coronary arteries and of the coronary blood flow reserve.
Sonazoid™ is taken up by healthy Kupffer cells in the liver and spleen, but break down in high amplitude ultrasound imaging modes such as color Doppler imaging. The bubble rupture produces a transient pressure wave, which results in a characteristic mosaic color pattern from tissues containing the microbubbles (induced acoustic emission). Liver tumors without Kupffer cells will not display the mosaic pattern and can therefore be identified easily.

A thyroid ultrasound evaluates the size and shape of the thyroid gland and parathyroid glands. A thyroid ultrasound can show nodules, cysts, tumors, and an enlargement, but a sonogram cannot determine the function of the thyroid. Ultrasound guides the placement of the needle during a thyroid fine needle aspiration biopsy.

See also Sonographic Features, Ultrasound Imaging Modes, Anechoic, Beam Width Artifact and Enhancement Artifact.