Recursive fourier-based high-frame rate imaging

The high-frame-rate (HFR) imaging method developed in 1997 used broad beams such as steered plane waves or limited-diffraction beams to illuminate an object, and then received echo signals are used to reconstruct images with Fourier transform. This method can be used in fast ultrasound cardiac imaging, flow velocity vector imaging, elasticity imaging, strain and strain rate imaging, and functional imaging. However, when multiple transmissions are used to reconstruct a frame of image to increase image field of view and improve image quality, image frame rate is reduced. To achieve the highest image frame rate limited only by the ultrasound round-trip time while multiple transmissions are used to reconstruct each frame of image, a recursive method is used. In this method, images reconstructed from each transmission are weighted with a constant that is between 0 and 1, and then added to the most recently reconstructed image. Experiments were performed with a tissue-mimicking phantom to demonstrate the efficacy of the method. Results show that high-quality images can be reconstructed at the highest image frame rate that is usually achievable only when one transmission is used to reconstruct a frame of image.