Abstract: The present invention is directed to an ultrasonic device comprising a plurality of transducer elements arranged in rows and columns and acoustic insulation material maintained between each two adjacent rows of transducer elements. The ultrasonic device comprises (i) a plurality of rows of the transducer elements, each row being disposed on an imaginary circle, (ii) a plurality of circular plates each supporting one of said rows and (iii) spacers for spacing adjacent plates of the plurality of plates at a predetermined space interval, thereby forming a cylindrical array.