Provided is an ultrasound transducer for irradiating a subject with ultrasound and receiving an ultrasound echo reflected from the subject. The ultrasound transducer includes a plurality of piezoelectric elements configured to emit ultrasound according to input of an electric signal and convert ultrasound incident from outside into an electric signal, and a mask portion provided between the plurality of piezoelectric elements and a radiation surface of the ultrasound on the ultrasound transducer. The mask portion is configured to: mask any divided region among a plurality of divided regions obtained by dividing an elevation direction orthogonal to a plane parallel to a scanning direction of the ultrasound; reflect the ultrasound in a direction different from a propagation direction of the ultrasound on the masked division region; and allow the ultrasound to pass in the propagation direction in the plurality of divided regions except the masked divided region.

An illustrative device for creating images via ultrasonic pulses comprises an electronics chamber and a probe head. The electronics chamber comprises a motor with an output shaft. The probe head is attached to the electronics chamber. The probe head includes a liquid-filled chamber that comprises an ultrasonic transducer configured to transmit and receive ultrasonic pulses and a mirror configured to reflect the ultrasonic pulses. The mirror is configured to rotate. The output shaft of the motor and the mirror are rotationally coupled.

Devices and methods for obtaining a real-time, three-dimensional image of a body part, particularly a blood vessel. A catheter has a chamber in its tip. The chamber contains an ultrasound transducer and reflector which generally face each other and rotate about a common axis. The transducer element on the transducer and the reflective face on the reflector are both tilted off-axis. The difference in angular velocity generally creates a phase shift between the transducer and the reflective face. The phase shift allows the transducer and the reflective face to actively scan a three-dimensional volume that is generally bounded interiorly by a hyperboloid and exteriorly by the effective range of the ultrasound beam. The transducer and reflector may rotate at constant speeds or nonconstant speeds as well in the same direction or in opposite directions.