Efficiency is defined as the ratio of the acoustic power generated to the total electrical power input. Efficiency varies with frequency and is expressed as a percentage.

The usual applications of endocavitary echography (also called internal echography / endoscopic ultrasound (EUS)) are examinations of the pelvic organs through internally introduced probes, which give a more precise and correct image.
Transrectal ultrasound is a well established method for rectal or prostate carcinoma assessment.
A transvaginal echography uses a small transducer that is inserted directly into the vagina.
Used are high-frequency (10-12 MHz) for superficial organs, endocavitary echography, and intraoperative laparoscopic ultrasound. A sterile cover is slipped over the probe, which is then covered with lubricating ultrasound gel and placed in the cavitary (see Equipment Preparation).

See also Endoscopic Ultrasound, Prostate Ultrasound, Interventional Ultrasound, Transurethral Sonography, Vaginal Probe, Rectal Probe.

(EUS) Endoscopic ultrasound uses a small probe that is inserted in the rectum either through a proctoscope or by itself. During the test biopsies of any suspicious areas are possible. The usual necessary preparation is an enema to empty the rectum. Endoscopic ultrasound provides additional information about rectal polyps, rectal cancer, perianal infection, and sphincter muscle injuries and improves the selection of patients for local excision.
Transrectal echography using a high-frequency transducer is a well established method for preoperative rectal carcinoma assessment.
Endoscopic scanning is limited by the ultrasound physics (depth and axial resolution) of the endocavitary probe. Therefore, the combination of endoscopic and transcutaneous ultrasound is most favorable.

Environmental protection in ultrasound imaging involves adopting practices and technologies that minimize the environmental impact associated with the use of ultrasound equipment and disposables.

Here are some key considerations:

By focusing on energy efficiency, digitalization, waste management, equipment lifespan, and education, healthcare facilities can make significant strides towards reducing their carbon footprint and the environmental impact of ultrasound imaging practices.

See also Ultrasound System Performance, Equipment Preparation, Ultrasound Accessories and Supplies and Sonographer.

From Biosound Esaote, Inc.;
'The Caris Plus combines the power of a conventional mainframe ultrasound system with an extraordinarily portable design. The result − High-performance ultrasound diagnostics in the most compact, most portable CFM system available anywhere. Powerful state-of-the-art microelectronics and wide-band multi-frequency technology ensure exceptional 2D, Doppler and CFM performance that can be taken where they're needed.'

Specifications for this system will be available soon.