This coefficient is a quantification of the energy intensity loss of waves (electromagnetic or mechanical) due to attenuation. In ultrasound imaging it is the relative energy intensity loss per traveled centimeter. The ultrasound attenuation coefficient is measured in units of dB/cm. The attenuation coefficient in soft tissues is nearly proportional to the ultrasound frequency. The attenuation coefficient is doubled when the frequency is doubled.
This coefficient (dB/cm) divided by the frequency (MHz) is almost constant in a given tissue.

Berlex Laboratories has been integrated into Bayer HealthCare, and operates as an integrated specialty pharmaceuticals business under a new name, Bayer HealthCare Pharmaceuticals.
The company is developing and making specialized medicines for treating multiple sclerosis, dermatological disorders, female health concerns, cancer and is creating new diagnostic imaging techniques. Berlex Laboratories, Inc. was a pioneer in the imaging market. It introduced a broad range of imaging agents. Its contribution began in 1988 with the introduction of the world's first magnetic resonance imaging agent, Magnevist® (gadopentetate dimeglumine) injection. Berlex Laboratories, Inc. was an US affiliate of Bayer Schering Pharma AG Germany.

In 1987 Esaote SpA began marketing its products in the United States through Biosound Inc.. In 1990 Esaote SpA acquired Biosound Inc.. Biosound Esaote today also distributes the veterinarian derivates from Esaote Pie Medical in the United States.

'BIOSOUND ESAOTE is an ISO9001/EN46001 certified major medical corporation operating as part of the international Esaote Group. With its parent company, Esaote, S.p.A. based in Genoa, Italy, ISO-9000 certified research and development and manufacturing facilities in Florence and Genoa, and North American headquarters in Indianapolis, the Esaote Group develops diagnostic ultrasound and magnetic resonance imaging (MRI) equipment for the worldwide medical community.'

Ultrasound Related Product Lines:

Ultrasound Systems:

Digital systems use discrete numerical values or non-numeric symbols for input, processing, transmission, storage, or display rather than being composed of variable voltage, acoustic field or electromagnetic field.

See also Digital Imaging and Communications in Medicine and Analog to Digital Converter.

A filter in electronics is a circuit that only passes certain signals. In ultrasound is a filter a device to suppress acoustic or electromagnetic waves of certain frequencies, letting other frequencies pass, e.g. high pass filter, low pass filter. The high pass filter is the wall filter (also called thump filter) used in Doppler devices to eliminate low frequency Doppler shifts caused by clutter. For blood flow measurement, a low pass filter is often used to strip out high frequency noise, leaving only the biological components of interest. Frame averaging is a form of a low pass filter.