You are using a 5 MHz, 40 mm linear array transducer to image a structure. What is the width of the image?

You are using a 5 MHz, 40 mm linear array transducer to image a structure. What is the width of the image?

• A. 20 mm
• B. 40 mm
• C. 60 mm
• D. 80 mm

Answer: (B)

In ultrasound, the width of a linear-array image is determined by the physical width of the transducer’s active aperture. The frequency affects resolution and penetration, not how wide the image appears. So with a 40 mm wide array, the lateral field of view—and thus the image width—is about 40 mm. The other options would require a different transducer aperture or zoom, which isn’t specified here.

In ultrasound, the width of a linear-array image is determined by the physical width of the transducer’s active aperture. The frequency affects resolution and penetration, not how wide the image appears. So with a 40 mm wide array, the lateral field of view—and thus the image width—is about 40 mm. The other options would require a different transducer aperture or zoom, which isn’t specified here.