The Bernoulli effect describes the reduction in pressure that occurs with an increase in velocity of fluid flow.

See also Bernoulli Equation, and Maximum Velocity.

The Bernoulli equation states that the total fluid energy along a streamline of fluid of flow is constant. This is a form of the more general law of energy conservation.

See also Bernoulli Effect.

From Bracco Research S. A., Geneva, Switzerland
BG1135 is a polymer-shelled new ultrasound contrast agent under development. The air-filled microsphere has a rigid, 100 nm thick polymeric shell and a mean diameter of 2.9 μm with 99% less than 8 μm.
The destruction mechanism of BG1135 is unique among microbubbles. The microbubbles of BG1135 appear to acquire a small shell defect, allowing the filling gas to stream out and creating a new gas bubble, but leaving the old shell intact. No significant differences between the diameters of the shells can be measured before and after insonation even though the agent is fragmented.

Bi-directional flow is measured in positive and negative directions.

See also Bi-directional Illumination, and Color Doppler Imaging.

For the flowprobe a vessel is positioned between transducers which generate wide beams of ultrasound to fully illuminate the vessel. The ultrasound beams alternately intersect the flowing blood in upstream and downstream directions. The flowmeter derives an accurate measure of the changes in transit time influenced by the motion of the blood.

See also Bi-directional Flow.