The USCT reference database

Ultrasound Computer Tomography (USCT) is an emerging technology mostly aimed at breast cancer imaging. Following the idea of open science a USCT reference database is established with open and easy to use data and code interfaces. The aim is to promote and facilitate the exchange of available reconstruction algorithms and raw data sets from different USCT devices throughout the growing USCT community. Additionally, the feedback about data and system architecture of the scientists working on reconstruction methods will be published online to help to drive further development of the various measurement setups

Optimized auto-focusing method for 3D ultrasound imaging in NDT

14 páginas, 14 figuras, 1 tablaIn this work, we propose an optimized auto-focusing algorithm to be used with ultrasound matrix arrays for three-dimensional imaging in the presence of interfaces. Its main application is for non-destructive-testing (NDT), where usually two mediums with different propagation velocities are present. The refraction at the interface between those mediums complicates the calculation and the application of the focusing delays, which requires iterative processes that are usually the main bottleneck for high-speed inspections. We tackle this problem by generalizing the virtual array concept previously proposed for linear arrays and plane images to the case of matrix-arrays and three-dimensional (3D) beamforming. Furthermore, we propose a two-dimensional iterative algorithm for exact time-of-flight calculation to the two foci per scan line required by the virtual array. The mathematical formulation for the 3D case is obtained and the time-delay errors are analyzed by simulation. Finally, image quality with the proposed method is compared with that obtained with conventional Total Focusing Method (TFM) and exact delay calculation. The principal conclusion is that the virtual array approach generates images with equivalent quality to those obtained by exact calculation, while it reduces more than two orders of magnitude the computation load.This research was supported by the project PDC2022-133504-I00 founded by MCIN/AEI/10.13039/501100011033 (Spain) and “Next Generation EU”/PRTR (European Union) and by the fellowship CIU founded by MCIU (Spain)

Automatic estimation of surface and probe location for 3D imaging with bidimensional arrays

17 páginas, 22 figuras, 5 tablasUltrasound imaging for Non Destructive Testing is frequently performed in an immersion setup, where water is used as coupling medium between the probe and the component under test. For the computation of the time delays needed for beam-forming, the shape of the component surface and probe location and orientation (PLO) must be known. In this work we develop methods for the automatic detection of the surface and the estimation of PLO for 2D array probes. In particular, the methods developed apply to three types of elementary surfaces which are usually found in industrial and structural components: planes, cylinders and spheres. The methods use the measured surface echoes Time of Flight (TOF) to fit parametric models based on ray propagation and reflection on the surface, giving the coordinates and Euler angles that define the PLO relative to the component under test. Validation experiments with four test specimens representing the three types of surfaces are presented. The accuracy and precision of estimated PLO coordinates and angles are analyzed, and a Total Focusing Method (TFM) imaging example is shown achieving a correct detection of artificial defects in the component for a different PLOs.This research was supported by the projects PDC2022-133504-I00 founded by MCIN/AEI/10.13039/501100011033 (Spain) and ‘‘Next Generation EU’’/PRTR (European Union), by the fellowship PRE2019- 088602 founded by MCIU (Spain) and by the project PID2022- 143271OB-I00, founded MCIN/AEI /10.13039/501100011033/FEDER, U

Matrix array inspections in NDT: 3D imaging with the Virtual Array method

2022 IEEE International Ultrasonics Symposium (IUS), 10-13 October 2022, Venice, ItalyWhile ultrasound testing (UT) with linear transducer arrays is a widely used method in Non-destructive Testing (NDT), the use of matrix arrays is not so widespread in the field. Nevertheless, matrix arrays can be used to do volumetric imaging without the need to displace the transducer. Furthermore, they provide a solution to the lack of resolution in the elevation direction characteristic of linear arrays, and the possibility to steer the beam in every direction in space. In this work, we propose an optimized auto-focusing algorithm to be used with ultrasound matrix arrays for three-dimensional imaging in the presence of interfaces, as is the case in immersion testing frequently used in NDT.Peer reviewe