Abstract: Catheter for echographic imaging within a cavity, comprising a proximal end situated to the outside of the patient, a distal end situated close to the tissues which are to be investigated, and a body connecting these two ends, the distal end comprising a guide wire and a capsule which is transparent to ultrasound and in which are accommodated a fixed piezoelectric transducer and a mirror for deflecting the ultrasonic wave and driven by means of rotation accommodated in the said capsule, this catheter being characterized in that the said mirror (30) is placed directly, without torque transmission shaft, on the surface of the rotor (34) of a microactuator constituting the said means of rotation.