Fast and Background Free Super-Resolution Ultrasound Based on Fluctuation Statistics

Dynamic contrast-enhanced ultrasound (DCEUS) imaging enables the measurement of blood flow within the vasculature of the imaged tissue. The resolution of classic ultrasound scans is limited by the wavelength of the transmitted pulse in the axial direction and by the aperture of the transducer in the lateral dimension. In the past few years, different methods for achieving super-resolution using contrast-enhanced ultrasound were proposed ([1], [2], [3]). Currently, the temporal resolution is the main limitation of all ultrasound super-resolution methods. Similarly, acquisition of images with resolution below the diffraction limit is of great concern in the field of optical fluorescent microscopy. Recently, a method called super resolution optical fluctuation imaging (SOFI) [4] was introduced, in which the spatial resolution is improved over the diffraction limit, while maintaining good temporal resolution. The improvement is achieved by using the statistics of the blinking fluorophores. In this work, these statistical tools are applied to DCEUS signals in order to produce fast super-resolution acoustic scans. The scan duration required for the proposed method is a second or less while current super resolution images require acquisition duration of several minutes. As a result, the proposed method can be applied during a breath-hold, while the others demand precise registration in order to compensate for motion artifacts in a clinical setting.