Which US probe frequency is recognized for the best penetration of soft tissue?

The frequency of an ultrasound probe has a direct impact on its ability to penetrate soft tissue. Lower frequencies are known for providing better penetration compared to higher frequencies, which tend to give clearer images of superficial structures but have limited depth of penetration.

In this context, a 2 MHz probe frequency is indeed the one recognized for its ability to penetrate soft tissue most effectively. At this lower frequency, sound waves can travel deeper into the tissue, allowing for the visualization of structures that are located further beneath the skin surface. This is especially useful in medical imaging where deeper structures need to be evaluated.

Higher frequencies, such as 5 MHz, 10 MHz, or 15 MHz, are better suited for imaging superficial structures due to their enhanced resolution but they suffer from limited penetration ability as they do not travel as deep into the soft tissues. Thus, the choice of frequency should be based on the clinical scenario, balancing the need for penetration versus image resolution.