3 research outputs found
A Modified Synthetic Aperture Focussing Technique Utilising the Spatial Impulse Response of the Ultrasound Transducer
Get PDFIn B-mode imaging, lateral resolution is impeded by the size and shape of the ultrasound beam used to create the image. For improved lateral resolution, a focussing method that utilises a beam model calculated using the Fraunhofer far field approximations to enhance the Synthetic Aperture Focussing Technique (SAFT) is proposed. The Beam Model Weighted Synthetic Aperture Focussing Technique (BMW-SAFT) method uses an approximation of the beam model to weight the focussing algorithm and adjust the aperture size based on distance from the transducer. Through application to simulated data the method is compared with the conventional SAFT, where the proposed algorithm is found to provide significant improvements over the conventional SAFT methods
Resolution enhancement of ultrasonic B-mode images
Get PDFThe use of ultrasonic array imaging systems is now commonplace throughout the NDT industry, but interpretation of the images produced by such systems can be a time-consuming process, which is further complicated by the inherent suboptimal resolution of such images. This paper proposes a three-step processing chain: noise-to-signal ratio (NSR) deconvolution, beam model weighted synthetic aperture focusing technique (BMW-SAFT) and statistical background noise removal (SBNR) image noise removal, which can be used to significantly enhance the temporal and spatial resolution of these systems. A validated simulation model is used to generate B-scan image data. Conventional Wiener filter deconvolution and SAFT methods are compared to those proposed, with results indicating a significant improvement
