Which of the following parameters can be adjusted to enhance the contrast resolution of an image?

Dynamic range is a crucial parameter that can be adjusted to enhance the contrast resolution of an ultrasound image. It refers to the ratio of the largest to the smallest intensity of echoes that can be processed and displayed. By adjusting the dynamic range, the sonographer can optimize the range of echoes that are displayed, which improves the visibility of subtle differences in tissue densities.

A wider dynamic range allows for more shades of gray to be presented in an image, thereby enhancing the ability to distinguish between tissues with similar acoustic properties. Conversely, a narrow dynamic range can limit the amount of detail visible in an image, making it more difficult to discern between different structures or pathologies that may have similar echogenicity.

While the other parameters like output power, pulse repetition frequency, and frequency of the transducer play significant roles in image generation and quality, they do not have the same direct impact on contrast resolution as dynamic range does. Output power influences brightness and signal strength, pulse repetition frequency affects frame rate and temporal resolution, and frequency of the transducer affects spatial resolution but does not directly adjust the way contrast is displayed in an image.