Characterization of biological fluids by ultrasound and computed tomography.

Blood and blood products, and solutions of albumin and chondroitin sulfate of varying concentrations were imaged by ultrasound and computed tomography in a phantom having ultrasonic and CT characteristics of liver tissue. Measurements of CT number, ultrasonic absorption, and viscosity were obtained for selected fluids. All fluids, including concentrated solutions of albumin and chondroitin sulfate having high viscosity, were detectable as echofree regions on ultrasound scans. Acoustical enhancement distal to fluids was noted to decrease in prominence with increasing sound absorption in the fluid. On CT scans, fluids with CT numbers close to those of their surroundings were poorly detected.