Steering angle varied pattern for ultrasound imaging with a two-dimensional array

摘要

Methods and systems for varying a pattern as a function of steering angle for medical imaging with a multidimensional array are provided. Transmit waveform, delay, phase or apodization patterns in addition to delays, phases or apodization for focusing are used with a multidimensional array. By applying a periodic variation perpendicular to the steering direction, the effects of grating lobes due to the variation may be reduced. Along the steering direction, additional offsets are not provided, but may be provided. This different or non-existent offsets provide less grating lobe clutter. The transmit aperture is adjusted to be parallel to a direction of steering of non-normal transmit scan line or scan lines. The variation pattern is selected to result in enhancement or isolation of one or more frequency bands from one or more other frequency bands, such as isolation of second harmonic information from fundamental transmit frequency information.