What is the ideal Beam Nonuniformity Ratio (BNR)?

The ideal Beam Nonuniformity Ratio (BNR) is considered to be 1:1. This ratio indicates that the ultrasound beam is completely uniform throughout its cross-section, meaning that the intensity of the ultrasound energy is evenly distributed. A BNR of 1:1 signifies that there are no areas of varying intensity, which leads to consistent and effective treatment across the entire treated area.

In comparison, higher ratios such as 3:1, 6:1, or 10:1 suggest increasing levels of nonuniformity within the ultrasound beam, meaning that there are significant variations in intensity. These higher BNRs may lead to the potential for uneven tissue heating, increasing the risk of damaging the tissues or causing discomfort during treatment. Therefore, a BNR of 1:1 is ideal for ensuring safe and effective ultrasound therapy.