The objective of this program is the domonstration of acoustical holography imaging in a clinical setting. The diagnostic usefulness of holographic images of soft tissue structures and organs in the human body, particularly the abdomen, will be evaluated. The clinical demonstration involves a series of experiments including imaging of normal animal and human organs in-vitro, living animals, sick patients, and healthy pregnant women. The clinical demonstration will make use of an acoustical holography system developed by Actron Industries, Inc. Actron will supply the system to the University at no cost to the grant. The acoustical holography system records a hologram of a large ( approximately 30 cm x 30cm x 30 cm) patient volume in-vivo with high resolution (approximately 2.5 mm) using a single short pulse (approximately 150 microseconds) of ultrasound. A holographic movie is made using a low repetition rate of 4 pulses per second, ensuring a safe average acoustical power level of 8 mW/cm2. This movie is reconstructed in a viewer where the image in focus consists of a 30 cm diameter field of view with approximately 3 mm depth of focus. Because the image is recorded in a hologram, any 3 mm thick plane throughout the 30 cm depth can be brought into focus in the viewing system long after recording. A final important feature of the system is the ease and reliability with which images may be obtained by X-ray technicians with minimal additional training thus facilitating the transferability of the technology to the other clinical settings.