Transmission media for ultrasonography

Demonstration of organ structures by ultrasonography is sometimes limited due to the gaseous contents of the gastrointestinal tract. Fluids or semifluids which have a variable acoustic transmission may be used to allow passage of the ultrasound through the obstructing boundaries. These material should not have too low an attenuation relative to soft tissues because then the fixed swept gain curve will cause an effective amplication of the posterior echoes. The materials should also not be too attenuating, thus limiting patient penetration. Various liquid transmission media were tested in their ability to eliminate gas deposits in the gastrointestinal tract. Meat soup was found effective in the stomach and Metamucil was found effective in the colon.