Which transducer type is best suited to cardiac imaging?

• A. Mechanical sector
• B. Linear array
• C. Phased array
• D. Convex array

Answer: (C)

Cardiac imaging benefits from a transducer that can quickly and flexibly form a sector-shaped image through a tight chest window. The phased array transducer excels here because its many small elements are electronically steered and focused to sweep angles without moving the transducer, producing a wide, real-time sector with high frame rates. This electronic steering, combined with a compact footprint that fits between the ribs, lets you rapidly switch among apical, parasternal, and subcostal views and angle toward different walls and valves as the heart beats. Mechanical sector transducers rely on moving a single element, which is bulkier and slower and offers limited steering. Linear array transducers provide high resolution but create a rectangular field and don’t naturally give the wide sector needed for heart imaging. Convex arrays offer a broader curved field and are versatile for some applications, but they don’t match the phased array’s agility and optimal steering for the heart.