Which type of transducer should you select to produce the narrowest slice thickness throughout the image plane?

• A. 1.5D multirow array
• B. a phased array with a small footprint
• C. a tightly curved curvilinear array
• D. a mechanical sector

Answer: (A)

To obtain the narrowest slice thickness across the image plane, you need precise control of the beam in the elevational direction. A 1.5D multirow array achieves this by using multiple rows of elements and electronic focusing in the elevational dimension. This configuration creates a much thinner elevational beamwidth that can be adjusted with depth, so the slice thickness stays small throughout the field of view.

In contrast, a phased array with a small footprint can steer and focus laterally well, but its elevational aperture is limited, so the slice thickness tends to be thicker and less uniform across depth. A tightly curved curvilinear array improves lateral coverage and near-field focusing but doesn’t provide the same level of elevational control as a true multirow, so the slice thickness isn’t consistently the thinnest across the image plane. A mechanical sector relies on a fixed, sweeping beam with no electronic elevation focusing, which typically results in a thicker, less uniform slice.

So the 1.5D multirow array stands out because its elevational electronic focusing across multiple rows delivers the thinnest, most uniform slice thickness throughout the image.