Final answer:
Sample size (B) has no effect on the amount of color displayed in a Doppler ultrasound, as it only determines the area sampled. Sample angle, scale settings, and baseline can alter color representation of blood flow velocity and direction.
Step-by-step explanation:
The control that has no effect on the amount of color fill in a chamber or vessel on color Doppler evaluation is B) Sample size. The sample size, also known as the gate size of the color Doppler, dictates the size of the region being sampled but does not directly alter the amount of color, which is indicative of the velocity and direction of blood flow within the vessel or chamber being examined.
Sample angle and Color Doppler scale settings influence the detection and portrayal of flow velocities. The angle of insonation in color Doppler can affect the Doppler shift and thereby the color coding of the flow. Scale settings adjust the range of velocities that can be measured; inappropriate scales can lead to aliasing or underestimation of flow. Color Doppler baseline adjustment can also influence the appearance of the color map, allowing differentiation between different flow directions and velocities.