Linear transducers consist of a straight, flat array of crystals that produce a rectangular field of view, with a wide, flat footprint. They are typically high-frequency transducers, providing high spatial resolution but more limited penetration.Sector (phased-array) transducers consist of an array of crystals that rapidly produce ultrasound waves and thus yield images with high temporal resolution; a small, squarefootprint; a pie-shaped field of view; and some loss of spatial resolution. These transducers are most commonly used in echocardiography but can be used in other areas as well.