The goal in diagnostic imaging is to use the _______ that still provides images to the depth of the structures of clinical interest.

• A. Lowest frequency
• B. Highest frequency
• C. Medium frequency
• D. A frequency dependent on tissue

Answer: (B)

In diagnostic imaging, you want to maximize image quality by using the highest frequency that can still reach the depth of interest. Higher frequency gives better resolution because the ultrasound wavelength is shorter, so edges and small details are clearer. But higher frequency also attenuates more quickly, meaning it doesn’t penetrate as far. So the goal is to pick the tallest frequency that nonetheless provides adequate penetration to image the structures you’re after.

Using the lowest frequency would reach deeper structures but with poorer resolution, which can miss small or subtle abnormalities. A medium frequency is a compromise, not exploiting the best possible resolution for the depth you need. Saying the frequency is dependent on tissue isn’t the target idea here—the practical aim is to balance depth of penetration with resolution by choosing the highest usable frequency for the given depth.