Final answer:
Edge enhancement, increase in receiver gain, and zoom are the controls that a sonographer can apply to help delineate a subtle liver mass.
Step-by-step explanation:
One control that a sonographer can apply to help delineate a subtle liver mass is edge enhancement.
Edge enhancement is a digital processing technique that enhances the edges of structures in an image, making them more distinct and easier to identify.
By applying edge enhancement, the sonographer can highlight the boundaries of the liver mass, making it more visible.
Another control that can be used is increase the receiver gain.
The receiver gain controls the amplification of the received ultrasound signals.
By increasing the receiver gain, the sonographer can make the subtle liver mass more apparent in the image.
Lastly, zoom can also be applied to help delineate a subtle liver mass.
Zooming in on the area of interest allows for a closer examination of the liver mass, enabling better visualization of its details.