- To compensate for attenuation, it is possible to amplify the signal intensity of the returning echo. The degree of receiver amplification is called the gain. Increasing the gain will amplify only the returning signal and not the transmit signal. An increase in the overall gain will increase brightness of the entire image, including the background noise. Preferably, the time gain compensation (TGC) is adjusted to selectively amplify the weaker signals returning from deeper structures (1).
- It is difficult to visualize a needle inserted at a steep angle (> 45 degrees to the skin surface) (1).
References: - Ultrasound for regional anesthesia:Â link. [ accessed May 15th 2013 ]
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