If you want to improve spatial resolution directly without changing the transducer size, which adjustment is most direct?

• A. Use a higher frequency transducer with the trade-off of increased attenuation
• B. Use a lower frequency to reduce attenuation
• C. Increase frame rate by increasing pulse repetition frequency
• D. Increase transducer diameter to reduce beam width

Answer: (A)

Using a higher frequency transducer is the most direct way to improve spatial resolution without changing the transducer size. Higher frequency waves have a shorter wavelength, which directly enhances axial resolution because you can distinguish two closely spaced points along the beam path more precisely. It also helps lateral resolution for a given aperture because beam width is tied to wavelength; shorter wavelengths mean a narrower beam. The trade-off is greater attenuation, so penetration depth is reduced and signal from deeper structures may be weaker. The other adjustments don’t directly sharpen spatial detail: increasing frame rate improves temporal resolution rather than spatial detail; using a lower frequency reduces spatial resolution even though it attenuates less; and increasing transducer diameter would narrow the beam and improve lateral resolution, but that changes the transducer size, which isn’t allowed here.