The amplitude is the signal height. The amplitude of the ultrasound echo is proportional to the difference of the acoustical impedance caused by different tissue layers. The amplitude decreases with increasing penetrationdepth of a homogeneous tissue.
See also Color Amplitude Imaging.
The Doppler signal from any range gate is proportional to the number of red blood cells moving through during the periods of its read out, so the amplitude (or loudness) works as an indicator of the number of blood cell reflectors.
High Doppler amplitudes are generated by large pulsed Doppler or color Doppler imagingrange gates and large vessels.
See also Amplitude Map, Color Amplitude Imaging.
Amplitude shading is a method of reducing the side lobe levels in a transducerarray. The shading usually causes the main beam to broaden by applying different voltages to the elements of the array.
See also Analog Output Signal.