Which of the following imaging works based on the principle of piezoelectric effect?

Ans. A. USG* The ultrasound image is based on mechanical oscillations of the crystal excited by electrical pulses (piezoelectric effect). Numerous crystals are assembled to form the transducer. Based on the pulse-echo principle occurring with ultrasound piezoelectric crystals, ultrasound transducers convert electricity into sound.* The ultrasound waves are sent from the transducer (pulse) and propagate through different tissues and then they come back (echo) and converted back into electrical impulses by the transducer crystals and are further processed in order to form the ultrasound image presented on the screen. That is called as pulse-echo principle.