The near field of an ultrasound beam is characterized by which intensity pattern?

The near field of an ultrasound beam is characterized by which intensity pattern?

• A. High peaks and valleys of intensity
• B. Uniform intensity
• C. No intensity variation
• D. Constant low intensity

Answer: (A)

In the near field, the ultrasound beam shows an uneven intensity pattern because the waves emitted from the transducer interfere with each other as they propagate. This interference creates regions where the waves reinforce each other (high intensity) and regions where they cancel out (low intensity), producing a pattern of hot spots and nulls. That’s why the near field is characterized by high peaks and valleys of intensity. As you move farther from the transducer into the far field, the beam tends to form a more uniform main lobe, though some residual nonuniformity can remain.

In the near field, the ultrasound beam shows an uneven intensity pattern because the waves emitted from the transducer interfere with each other as they propagate. This interference creates regions where the waves reinforce each other (high intensity) and regions where they cancel out (low intensity), producing a pattern of hot spots and nulls. That’s why the near field is characterized by high peaks and valleys of intensity. As you move farther from the transducer into the far field, the beam tends to form a more uniform main lobe, though some residual nonuniformity can remain.