A phased array transducer uses a group of piezoelectric elements arranged in a small footprint that are fired with precisely timed electronic delays to steer and focus the ultrasound beam. This design produces a sector-shaped (fan or pie-slice) image that starts narrow at the skin surface and widens with depth. The small footprint makes phased array probes ideal for imaging between the ribs, which is why they are the standard transducer for echocardiography. They are also used in abdominal and transcranial imaging when access is limited. By adjusting the timing of element activation, a phased array can rapidly sweep the beam across a wide field of view, providing real-time imaging of moving structures like the heart.
Sonography Term