Standardization of a Non-Invasive MRI Assessment of Liver Iron Overload Using a Phantom Containing Superparamagnetic Iron Oxide Nanoparticles

Abstract

Background: Liver iron overload is a common diagnosis in patients with frequent blood transfusions. MRI is a promising non-invasive method for assessing liver iron concentration. We have created an MR-compatible phantom to develop a method for the standardization of T2* mapping and following conversion of T2* values (ms) into iron concentration (mg/mL) for an assessment of overload grade. Methods and Results: The standardization process involved the development of an MR-compatible phantom with solutions of paramagnetic iron oxide nanoparticles of various concentrations mimicking various degrees of liver iron overload. Using this phantom, we assessed the repeatability of T2* values obtained on reference MRI scanners (3T and 1.5T) at the D. Rogachev NMRCPHOI on 6 MRI acquisitions with one-week intervals. To assess the reproducibility of the results obtained on other MRI scanners, we compared these measurements with the reference values. Conclusion: The method for the standardization of T2* mapping on various 1.5T and 3T MRI scanners was tested. This method is based on the use of our phantom to validate or calibrate (if necessary) the MRI study protocol. The standardization protocol provided an opportunity to use the empirical formula (revealed in our institute as well as in other studies) for converting T2* values from any MRI scanner into LIC (mg/mL).