What is the name of the control used to compensate for attenuation related to path length?

The control used to compensate for attenuation related to path length is referred to as TGC, which stands for Time Gain Compensation. This adjustment allows the sonographer to enhance the brightness of echoes received from deeper structures that experience greater attenuation due to the increased distance the ultrasound waves must travel.

Ultrasound waves lose energy as they pass through tissues, and this attenuation can result in weaker signals from deeper structures. TGC allows the sonographer to adjust the gain at different depths, essentially increasing the gain for the echoes coming from deeper areas while maintaining appropriate levels for shallower structures. This control varies the amplification of the signal based on the time it takes for echoes to return, effectively compensating for the natural decline in echo strength with distance.

The other available options do not specifically address the compensation for path length attenuation in this manner. Gain refers generally to the overall signal amplification and does not differentiate between depths. Dynamic range pertains to the range of echo amplitudes that can be processed, and focus controls the beam width and depth resolution but does not directly affect signal strength based on path length.