Final answer:
Time gain compensation (TGC) is the control used to enhance far field echoes and diminish near field echoes in ultrasonic imaging systems. It ensures a uniform image quality by compensating for the loss of signal strength at greater depths and reducing the strength of signals closer to the probe.
Step-by-step explanation:
The system control that will simultaneously enhance far field echoes and diminish near field echoes is known as Time gain compensation (TGC). TGC is a feature used in ultrasonic imaging systems, such as ultrasound machines. It compensates for the loss of energy as sound waves travel through tissue, by amplifying the signals received from deeper within the body. This is important because without TGC, echoes from deeper structures would appear fainter compared to those closer to the probe, making the image quality non-uniform. Conversely, TGC reduces the amplification of signals that are received from structures closer to the probe, ensuring that the near field echoes do not overwhelm the image. This allows for a clearer and more balanced image, providing better diagnostic information.