What does the sum of reflected intensity and transmitted intensity equal?

The sum of reflected intensity and transmitted intensity equals the incident intensity. When ultrasound waves encounter a boundary between two different media, some of the sound energy is reflected back into the first medium, while some is transmitted into the second medium.

The incident intensity refers to the total power of the ultrasound waves before they interact with any interfaces. According to the law of conservation of energy, the total energy (or intensity) of the incident sound wave must equal the energy that is reflected plus the energy that is transmitted. Therefore, the mathematical representation can be expressed as:

Incident Intensity = Reflected Intensity + Transmitted Intensity.

This principle is foundational in understanding how ultrasound waves interact with tissues and structures in sonography, influencing image formation and interpretation. Understanding this relationship is crucial for interpreting ultrasound data and assessing the properties of different tissues based on their acoustic impedances.