Fig. 4

Measuring regional iron load in a 39-year-old man with relapsing-remitting multiple sclerosis (A, B) in periventricular lesions and measuring iron load in corresponding locations in a healthy 44-year-old male control subject. A represents an axial three-dimensional fluid-attenuation inversion recovery (3D FLAIR) film of the patient demonstrating two periventricular lesions (right and left). The 3D FLAIR film was overlayed on the quantitative susceptibility map as depicted in image B and the transparency was set to 50% to visualise both the quantitative susceptibility mapping (QSM) and the 3D FLAIR images. Two regions of interest (ROIs), shown as red and violet circles, were placed in the periventricular lesions and the ROIs were analysed on the QSM image. C Represents a corresponding axial 3D FLAIR cut of a healthy man. Similar steps were performed to measure iron in approximate locations corresponding to the MS periventricular lesions