Reflection takes places when some of the energy of the sound wave is averted back toward the transducer. Reflection will occur only if the borders of two different tissues have different impedances; otherwise, transmission occurs. Recall that the incident intensity is the intensity of a sound beam as it leaves the transducer prior to coming into contact with tissue. The transmitted intensity is the forward propagation of the intensity of the incident beam after hitting that boundary. Normal incidence is when the incident sound beam comes into contact with the boundary at a 90-degree angle. During
diagnostic imaging, there are few differences in the impedance of soft-tissue
boundaries; therefore, more than 99% of the incident beam will be transmitted. To summarize, with normal incidence and identical impedances of the media, all of the incident beam's intensity will be transmitted. Keep in mind that the incident and transmitted intensities must always equal 100%. Oblique incidence and reflection (or transmission) are hard to conclude because they tend to be complex.
Reflection takes places when some of the energy of the sound wave is averted back toward the transducer. Reflection will occur only if the borders of two different tissues have different impedances; otherwise, transmission occurs. Recall that the incident intensity is the intensity of a sound beam as it leaves the transducer prior to coming into contact with tissue. The transmitted intensity is the forward propagation of the intensity of the incident beam after hitting that boundary. Normal incidence is when the incident sound beam comes into contact with the boundary at a 90-degree angle. During
diagnostic imaging, there are few differences in the impedance of soft-tissue
boundaries; therefore, more than 99% of the incident beam will be transmitted. To summarize, with normal incidence and identical impedances of the media, all of the incident beam's intensity will be transmitted. Keep in mind that the incident and transmitted intensities must always equal 100%. Oblique incidence and reflection (or transmission) are hard to conclude because they tend to be complex.