An exhaustive criterion for estimating quality of images in electrical impedance tomography with application to clinical imaging

• This study proposes a versatile criterion to estimate performance of EIT systems.
• The PSF is measured based on scattering of energy over the entire domain.
• This criterion regards all aspects of image measurement.
• It takes the positioning of the distributed artifacts into consideration.
• This criterion is more tolerant than existing criteria in measuring the PSF.

This study proposes a versatile criterion for estimating quality of images in electrical impedance tomography. The point spread function (PSF) is calculated throughout the domain based on the scattering of energy as responses to a small anomaly spirally moved from the centre to the boundary. The proposed PSF is a measure of weighted spatial variance (WSV) of the conductivity over the whole domain. For each element, the weighting factor is a normalized multiplication of the area of that element by its square intensity. The WSV collectively incorporates all image attributes, i.e., spatial resolution, artifact, amplitude response, positioning error and shape deformation. The location of artifacts, which significantly influences reconstructed images in reality, is taken into account as well. The results illustrate that the proposed measure is more tolerant than existing criteria in evaluating performance of EIT systems in both theory and practice.