How does the frequency of an ultrasound exam affect penetration depth?

The frequency of ultrasound waves significantly influences the penetration depth of the sound into tissue. Lower frequencies have longer wavelengths, which allows them to penetrate deeper into the body. This is because lower frequency sound waves encounter less attenuation (i.e., loss of energy) as they travel through tissues, thus maintaining their strength over greater distances.

In contrast, high-frequency ultrasound waves have shorter wavelengths that result in greater attenuation, limiting their penetration depth. While higher frequencies can provide better resolution due to their ability to produce more detailed images, this advantage comes at the cost of decreased penetration depth. Therefore, understanding the relationship between frequency and penetration is crucial for selecting the appropriate ultrasound settings based on the clinical scenario.

The assertion that frequency does not affect penetration depth is incorrect, as it is a fundamental principle of ultrasound physics. The statement regarding increased frequency always reducing resolution is misleading because increased frequency indeed enhances resolution but sacrifices penetration depth. Thus, lower frequencies are optimal for deeper imaging, while higher frequencies are suited for superficial structures.