'ALOKA, the innovator in ultrasound is the longest operating ultrasound company in the world with its main headquarters located in Tokyo, Japan.
The history of ALOKA began in 1950 when the medical equipment department of Japan Radio Company became the independent company, Medical and Physical Institute Co., Ltd.
In 1960, we developed the world's first commercially available diagnostic ultrasound system.
In 1976, our company name changed to ALOKA, which, in ancient Sanskrit, means 'Ray of Hope'.
ALOKA's ultrasound systems have been sold in the United States through distributors since the early 70s. Some of our major distributors included Johnson & Johnson Ultrasound and Corometrics Medical Systems, Inc., which also provided service for the ALOKA equipment.
In 1986 the first ALOKA office was opened in the United States.
And on January 1, 1991, ALOKA America began direct sales of ultrasound units.
All US sales, distribution and service are provided through our US headquarters located in Wallingford, Connecticut . In addition, we have sales, service and clinical applications representatives strategically located throughout the country to provide exceptional service to our customers.'

In November 2010 Hitachi Medical announced the acquisition of ALOKA.

Ultrasound Systems:

(AALs) Acoustically active lipospheres and ultrasound are under development to deliver bioactive molecules to the vascular endothelium. The AALs are similar to both ultrasound contrast agents and drug-delivering liposomes. They can carry bioactive substances using biologically inert shells and deliver those substances when disrupted by ultrasound.
The lipospheres consist of a small gas microbubble surrounded by a thick oil shell and are enclosed by an outermost lipid layer. The gas bubble contained in these vehicles makes them acoustically active, similar to ultrasound contrast agents. Acoustically active lipospheres can be nondestructively deflected using ultrasound radiation force, and fragmented with high intensity ultrasound pulses. Their lipid-oil complex can carry bioactive substances at high concentrations. An optimized sequence of ultrasound pulses can deflect the AALs toward a vessel wall then disrupt them, painting their contents across the vascular endothelium.

See also Filling Gas, and MRX 115.

An image artifact is any image attribute, which is not present in the original imaged object. An image artifact is sometime the result of an improper operation of the imager, and in other times a consequence of natural processes or properties of the human body.
Artifacts in diagnostic ultrasound are a reflection or an echo, which appears on the display and represents the real anatomical structure not correctly. An artifact can be a false, multiple or misleading information introduced by the imaging system or by interaction of ultrasound with the adjacent tissue.

Artifacts in ultrasound can be classified as to their source like e.g.:
Image artifacts can occur in each medical ultrasound. Then an interpretation of the image is complicated and can eliminate the structural information of objects looking for.

See also Ultrasound Imaging Procedures.

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.

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.