The Methodology for Accessing the Accuracy of Apparent Diffusion Coefficient Determining

Abstract

One of the criteria for MRI neoplasms assessing is the apparent diffusion coefficient, which is calculated from the diffusion-weighted images. It is a measured parameter and is characterized by some error. A phantom including substances with self-diffusion limited to varying degrees was developed for quality assurance of diffusion-weighted images. The purpose of this work was to develop a methodology for determining the accuracy of methods and controls. The work included identification of errors sources and evaluation of each of them according to the results of numerical and phantom experiments. The method of MR-spectrometry has been used to evaluate the systematic error caused by the phantom control substances. The result of the evaluation of the phantom scan is an estimate of the magnitude of the random error determined by the operation of the tomograph. In addition, the effect of temperature variations on the measurements was evaluated. 11 experiments on tomographs of 5 different manufacturers were conducted. The accuracy of determining the apparent diffusion coefficient by each of them, as well as the comparison of the devices among themselves, showed a 16% variation.