Diagnostic medical ultrasound system and method for using a sparse array

Abstract

A method and system for obtaining ultrasound data with a sparse array of transducer elements is provided. About one wavelength of a highest operating frequency separates the center of each transducer element from any adjacent transducer element. While this spacing may generate grating lobes, the beamformer of the ultrasound system is configured to filter and isolate information at a harmonic of a fundamental transmit frequency. The resultant two-way beam pattern is less effected by the grating lobes. The image generated as a function of the harmonic information has few artifacts created as a function of the sparse spacing of the transducer elements. Given a set number of beamformer transmit channels, the sparse spacing may allow for a larger aperture width with few artifacts as a result of sparse element spacing. The larger aperture width generates a narrower beam in the azimuthal dimension of a one-dimensional transducer. By generating a narrower beam, better azimuthal resolution may be obtained. Alternatively, the number of transmit channels may be reduced to provide a beam width that is the same or similar to a beam generated with a conventional phased array where transducer elements have a one-half of the wavelength spacing of the fundamental frequency. By using fewer transmit channels to obtain the same beam width, the space required by electrical traces connecting the transducer elements to the beamformer is reduced. The reduced required space is beneficially used on catheter or intravascular transducers.