Because imaging probes use backing material and have a wide bandwidth they are often referred to as ______.

Because imaging probes use backing material and have a wide bandwidth they are often referred to as ______.

• A. Broadband
• B. High-q
• C. Low-q
• D. Non-imaging

Answer: (C)

The concept here is how damping affects a transducer’s bandwidth through its quality factor. Imaging probes include backing material to damp the crystal’s vibrations, which shortens the pulse and reduces ringing. That damping broadens the frequency response, so the transducer responds across a wide range of frequencies. The quality factor, Q, is defined as the center frequency divided by the bandwidth; a broader bandwidth means a smaller Q. So imaging probes with wide bandwidth are described as having a low quality factor. This low-Q characteristic is what enables the short pulses and improved axial resolution needed for good imaging. High-Q would imply a narrow bandwidth, which isn’t characteristic of these probes, and non-imaging doesn’t describe the damping-broadband property.

The concept here is how damping affects a transducer’s bandwidth through its quality factor. Imaging probes include backing material to damp the crystal’s vibrations, which shortens the pulse and reduces ringing. That damping broadens the frequency response, so the transducer responds across a wide range of frequencies. The quality factor, Q, is defined as the center frequency divided by the bandwidth; a broader bandwidth means a smaller Q. So imaging probes with wide bandwidth are described as having a low quality factor. This low-Q characteristic is what enables the short pulses and improved axial resolution needed for good imaging. High-Q would imply a narrow bandwidth, which isn’t characteristic of these probes, and non-imaging doesn’t describe the damping-broadband property.