For BNR 2:1 to 5:1, how fast should you move the ultrasound head?

For BNR 2:1 to 5:1, how fast should you move the ultrasound head?

• A. 0.5 cm/sec
• B. 1 cm/sec
• C. 2 cm/sec
• D. 4 cm/sec

Answer: (B)

When using therapeutic ultrasound, the speed you move the head affects how evenly energy is applied across the treatment area, especially when the beam isn’t perfectly uniform. A beam nonuniformity ratio in the range of 2:1 to 5:1 means there are hotspots within the beam. Moving the transducer at about 1 cm per second helps energy blur over the area more evenly and reduces the risk of concentrating too much energy in any one spot. If you go faster, some areas may not receive enough energy due to uneven distribution; if you go slower, hotspots could overheat tissue. So the best balance for this BNR range is a slow, steady pace of 1 cm/sec.

When using therapeutic ultrasound, the speed you move the head affects how evenly energy is applied across the treatment area, especially when the beam isn’t perfectly uniform. A beam nonuniformity ratio in the range of 2:1 to 5:1 means there are hotspots within the beam. Moving the transducer at about 1 cm per second helps energy blur over the area more evenly and reduces the risk of concentrating too much energy in any one spot. If you go faster, some areas may not receive enough energy due to uneven distribution; if you go slower, hotspots could overheat tissue. So the best balance for this BNR range is a slow, steady pace of 1 cm/sec.