Axial resolution is the minimum separation between two interfaces located in a direction parallel to the beam (objects above and below each other) so that they can be imaged as two different interfaces. The axial space resolution directly relates with the wave frequency, but higher frequencies have lower penetration into tissues.
The axial resolution is inversely proportional to the frequency of the transducer depending on the size of the patient. The higher the frequency the lower the axial resolution in large patients. This state results from the rapid absorption of the ultrasound energy with lower penetration. Lower frequencies are utilized to increase depth of penetration.

See also Damping.

[This entry is marked for removal.]

From POINT Biomedical Corp
BiSphere™ is a technology for drug delivery applications by ultrasound. BiSpheres™ consists of microparticles comprising a shell of an outer layer of a biologically compatible material and an inner layer of biodegradable polymer. The core of the microbubbles contains a filling gas, liquid, or solid for use in drug delivery or as a contrast agent for ultrasonic contrast imaging. The contrast agent particles are capable of passing through the capillary systems of a subject. The drug-loaded biSpheres™ would be administered intravenously and freely circulate throughout the body, while the drug encapsulated within would remain biologically unavailable. The drug would only be released when the biSpheres become flooded when passing through an externally directed ultrasound field.
The use of biSpheres™ to transport agents to specific sites within the body is expected to substantially increase local efficacy while decreasing systemic side effects or adverse reactions. The biSpheres™ may also serve to protect labile agents from metabolism or degradation. The noninvasive release of a protected, encapsulated agent can be controlled by ultrasound imaging to a depth of 20-30 cm from the skin surface.
The flexibility in size control in the biSphere™ technology has enabled the construction of submicron ultrasound contrast agents suitable for lymphatic imaging, with a diameter in the submicron range. This agent, while much smaller in size than CardioSphere®, is based on the BiSphere configuration: a shell within a shell enclosing a gas. The inner layer, made from a biodegradable polymer, provides the physical structure and controls the acoustic response. The outer layer functions as the biological interface. Each of these layers has been independently tailored to fulfill the specific requirements for lymphatic imaging.

A C-scan ultrasound can be displayed in 2D or 3D ultrasound technique. C-scan systems can generate images which are parallel to the surface of the skin (coronal). 2D plane images, usually in gray scale, are recordable at different depths, maintaining high quality subsurface information.

From SIUI Inc.;
'The SIUI CTS-200 is one of few 'linear only' units to be developed with a digital scan converter to process all incoming signals. With a digital processor, not only is the incoming signal processed faster but less noise is introduced into the signal path. The images are cleaner, crisper than you have experienced, even in machines at many times the price.'
'CTS-200 is suitable to a wide range of examination of liver, gallbladder, kidney, spleen, pancreas, thyroid gland, breast, uterus, urinary bladder, OB/GYN, etc. It is a portable ultrasound scanner of high performance.'

From SIUI Inc.;
'The CTS-285 is designed for the diagnosis of liver, gallbladder, kidney, pancreas, thyroid, breast, uterus, bladder, ovary, etc. It is a portable versatile ultrasound scanner with convex and linear array scanning.'