Enhanced axial and lateral resolution using stabilized pulses

Abstract

Ultrasound B-scan imaging systems operate under some well-known resolution limits. To improve resolution, the concept of stable pulses, having bounded inverse filters, was previously utilized for the lateral deconvolution. This framework has been extended to the axial direction, enabling a two-dimensional deconvolution. The modeling of the two-way response in the axial direction is discussed, and the deconvolution is performed in the in-phase quadrature data domain. Stable inverse filters are generated and applied for the deconvolution of the image data from Field II simulation, a tissue-mimicking phantom, and imaging of a carotid artery, where resolution enhancement is observed. Specifically, in simulation results, the resolution is enhanced by as many as 8.75 times laterally and 20.5 times axially considering the [Formula: see text] width of the autocorrelation of the envelope images.

Single-image Bayesian Restoration and Multi-image Super-resolution Restoration for B-mode Ultrasound Using an Accurate System Model Involving Correlated Nature of the Speckle Noise

“…Most methods assume an identical, independent noise. In the works of Parker and colleagues, [25][26][27] the emphasis was mostly on the resolution enhancement; however, the CNR change was not reported. As mentioned in these papers, the drawback of this is the increased noise.…”

“…In y → , there is also the effect of speckle and electronic noise. Due to the nature of the speckle, the noise formation in medical ultrasound is better modeled with a multiplicative term 11,27,44 ; however, for B-mode ultrasound images, it has been shown that the linear and additive model in Equation (2) is appropriate since B-mode images are subjected to the log compression operation 33,35,36,44 :…”

“…Another line of research (to obtain resolution enhancement beyond the system resolution limits) is by using specialized excitation pulses and apodizations. 25 -27 In the study of Parker, 25 stabilized pulses were introduced. When digitally sampled, these pulses have the property to have stable inverses.…”

“…In the work of Chen and Parker, 26 the proposed method was first applied to Field II simulator and then, in vivo ultrasound scans in the lateral direction only. In another work of Chen and Parker, 27 under some well-accepted assumptions, the received signal was modeled as separable two-dimensional (2D) pulses in the axial and the lateral directions, and the stabilized inverses were estimated to achieve the deconvolution in 2D. In all of them, the deconvolution is in the form of the linear filters, designed for a specific imaging depth.…”

Sub-wavelength lateral detection of tissue-approximating masses using an ultrasonic metamaterial lens

“…A large proportion of current ultrasonic imaging systems utilize phased and linear array emitters combined with beamforming and signal processing techniques. Various metrics are used in literature to quantify the resolution of a system including full width at half maximum (FWHM) and minimum separation detectable (MSD) between adjacent objects [5][6][7][8] . For single element emitters, the FWHM for a focused Gaussian beam is defined as FWHM 1:06λF a ;where F is the focal length, λ is the wavelength, and a is the aperture 9 .…”