When the depth of view is set to 15.4 cm, PRF is ______.

When the depth of view is set to 15.4 cm, PRF is ______.

• A. 2,500 Hz
• B. 10,000 Hz
• C. 5,000 Hz
• D. 15,000 Hz

Answer: (C)

PRF is tied to how long it takes for sound to travel to the furthest imaging depth and back, since a new pulse is sent only after echoes from that depth return. The relationship is PRF = c / (2d), where c is the speed of sound in tissue (about 1540 m/s) and d is the depth of view. With a depth of 15.4 cm (0.154 m), PRF ≈ 1540 / (2 × 0.154) = 1540 / 0.308 ≈ 5000 Hz. So the PRF is about 5000 Hz. This inverse relationship means deeper imaging lowers PRF, while shallower imaging raises it.

PRF is tied to how long it takes for sound to travel to the furthest imaging depth and back, since a new pulse is sent only after echoes from that depth return. The relationship is PRF = c / (2d), where c is the speed of sound in tissue (about 1540 m/s) and d is the depth of view.

With a depth of 15.4 cm (0.154 m), PRF ≈ 1540 / (2 × 0.154) = 1540 / 0.308 ≈ 5000 Hz. So the PRF is about 5000 Hz. This inverse relationship means deeper imaging lowers PRF, while shallower imaging raises it.