Abstract: An endoscopic ultrasound probe for use in transesophageal echo cardiography comprises a rotatable ultrasound transducer array for obtaining two-dimensional cross-sectional images along a variety of scan planes. The array is formed of a plurality of transducer elements and rotates about an axis perpendicular to the plane of the transducer elements. The rotating array defines a circular region of rotation and has a surface area which substantially matches the area of the circular region of rotation within the probe. More specifically, the elements of the array have varying mechanical lengths such that the rotatable array may have a circular shape, a substantially circular shaped or an N-sided polygonal shape where N is an integer greater than four.