An aesthetic imaging and treatment system for use in cosmetic treatment, the system comprising: a hand wand comprising: a first controlling device operably controlling an ultrasonic imaging function for providing an ultrasonic imaging; a second controlling device operably controlling an ultrasonic treatment function for providing an ultrasonic treatment; a movement mechanism configured to direct ultrasonic treatment in a linear sequence of individual thermal lesions; a control module; and at least a first and a second removable transducer module, respectively being an emitter-receiver module, a handle with an integrated receptacle for insertion of the at least first or second removable transducer module on one end and an electrical cable for attachment to the control module on the other end, wherein said first and second transducer modules are configured for both ultrasonic imaging and ultrasonic treatment, wherein said first and second transducer modules are configured for interchangeable coupling to the hand wand at the integrated receptacle, wherein said first transducer module is configured to apply ultrasonic therapy to a first layer of tissue, wherein said second transducer module is configured to apply ultrasonic therapy to a second layer of tissue, wherein the second layer of tissue is at a different depth than the first layer of tissue, wherein said first and second transducer modules are configured to be operably coupled to at least one of said first controlling device, said second controlling device and said movement mechanism, wherein the movement mechanism is configured for travel through a liquid-tight seal with a magnetic coupling, and wherein the emitter-receiver module (200; 200') comprises a transducer, which is movable within the emitter-receiver module, wherein the movement mechanism includes a stepper motor, a scotch yoke with a movement member and the magnetic coupling on a distal end of the movement member, wherein the magnetic coupling helps move the transducer. a hand wand comprising: a first controlling device operably controlling an ultrasonic imaging function for providing an ultrasonic imaging; a second controlling device operably controlling an ultrasonic treatment function for providing an ultrasonic treatment; a movement mechanism configured to direct ultrasonic treatment in a linear sequence of individual thermal lesions; a control module; and at least a first and a second removable transducer module, respectively being an emitter-receiver module, a handle with an integrated receptacle for insertion of the at least first or second removable transducer module on one end and an electrical cable for attachment to the control module on the other end, wherein said first and second transducer modules are configured for both ultrasonic imaging and ultrasonic treatment, wherein said first and second transducer modules are configured for interchangeable coupling to the hand wand at the integrated receptacle, wherein said first transducer module is configured to apply ultrasonic therapy to a first layer of tissue, wherein said second transducer module is configured to apply ultrasonic therapy to a second layer of tissue, wherein the second layer of tissue is at a different depth than the first layer of tissue, wherein said first and second transducer modules are configured to be operably coupled to at least one of said first controlling device, said second controlling device and said movement mechanism, wherein the movement mechanism is configured for travel through a liquid-tight seal with a magnetic coupling, and wherein the emitter-receiver module (200; 200') comprises a transducer, which is movable within the emitter-receiver module, wherein the movement mechanism includes a stepper motor, a scotch yoke with a movement member and the magnetic coupling on a distal end of the movement member, wherein the magnetic coupling helps move the transducer.