(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.

From Fukuda Denshi Co., Ltd.;
'Phased array probes made available for High resolution imaging of full cardiovascular examinations.
By adding Linear and Convex probes, the examination areas are extended to Abdominal and OB/GYN applications.
B-mode (1, 2 displays), M, and B/M-modes can be individually shown.
Optional Doppler unit available for observation of Blood flow information in pulsed and continuous wave Doppler.
Portable with IP (Image Processing), Full Keyboard, and track ball are standard.'

From Fukuda Denshi Co., Ltd.;
'Fully software controlled Image Processing (F-XT technology)
Color Doppler & Power Doppler display available
Autofocus function for transmission
High-resolution SVGA display
Cine memory with 128 frames
Wide band Probe for multi frequency function
6-step STC adjustment
DICOM-compatible Ethernet port
3.5-inch 640MB drive for image filing'

The focal zone is the region within the transmitted sound beam in which the beam narrows to its minimum size. The lateral resolution is best within the focal zone of the beam.

From Philips Medical Systems;
'Clinicians are demanding smaller, higher performing systems specifically designed to meet their clinical and operational challenges. The new Philips HD11 system provides an uncompromising platform, plus advanced options in a highly mobile and easy-to-use system.'