What is the main advantage of using a 1.5D or multirow array transducer?

• A. Narrow slice thickness over a large part of the scanned volume
• B. Increased penetration
• C. Improved axial resolution
• D. Faster frame rates

Answer: (A)

The key benefit is improved elevational resolution: the ability to form a much thinner slice in the elevational (slice) direction across a wide region of the scanned volume. A 1.5D or multirow array adds rows of elements and electronic focusing in the elevational direction, which narrows the beam in that dimension. That means the slice thickness stays small over a large part of the image, reducing partial-volume artifacts and giving sharper, more accurate cross-sectional detail through the volume. Penetration depends mainly on frequency and tissue, axial resolution comes from pulse length and bandwidth, and frame rate is influenced by the amount of data and focusing; these are not the primary advantages of elevationally focused multirow arrays, making the improved slice thickness the standout feature.