Ultrasonic pulsed echo tomography using narrow aperture phased array

This method is based on the Radon transform of echoes using narrow aperture phased array (NAPA). When the NAPA is used, the echoes are expressed as the summation of the wavelets that are returned from the scatterers on the arc. It means that a series of the echoes as a sector scanning is a projection of reflectivity coefficient distribution on the hemispherical surface. Here, the authors discuss the spatial resolution between NAPA-CT and conventional B-mode image by numerical calculation. As a result, for both of lateral direction and the direction of elevation NAPA-CT has better resolution than the conventional B-mode image.