Estimation of presampling modulation transfer function in synchrotron radiation microtomography

TL;DR

This paper presents a method to estimate the spatial resolution of synchrotron radiation microtomographs by measuring the modulation transfer function using high-precision surfaces and a tilted reconstruction technique.

Contribution

It introduces a novel approach combining the slanted edge method with tilted reconstruction to accurately estimate the MTF in microtomography.

Findings

MTFs estimated from step response functions match those from square-wave patterns.

Flat surfaces with nanometer roughness can be used to determine spatial resolution.

The method accounts for x-ray refraction influences in MTF evaluation.

Abstract

The spatial resolution achieved by recent synchrotron radiation microtomographs should be estimated from the modulation transfer function (MTF) on the micrometer scale. Step response functions of a synchrotron radiation microtomograph were determined by the slanted edge method by using high-precision surfaces of diamond crystal and ion-milled aluminum wire. Tilted reconstruction was introduced to enable any edge to be used as the slanted edge by defining the reconstruction pixel matrix in an arbitrary orientation. MTFs were estimated from the step response functions of the slanted edges. The obtained MTFs coincided with MTF values estimated from square-wave patterns milled on the aluminum surface. Although x-ray refraction influences should be taken into account to evaluate MTFs, any flat surfaces with nanometer roughness can be used to determine the spatial resolutions of microtomographs.