Susceptibility Weighted Imaging and Susceptibility Mapping (SWIM): A New Means to Visualize Veins and Quantify Susceptibility

Introduction: Susceptibility weighted imaging (SWI) has been used for some time as a means to enhance venous vessels using high pass filtered phase images [1,2]. However, efficacy of SWI processing relies especially on an asymmetric voxel aspect ratio [3] and to a slight extent on the relative orientation of the head and the main magnetic field. Therefore, when SWI is collected as high resolution isotropic data, the conventional processing will fail. To overcome this problem and make the venous vessel depiction independent of these factors, we propose using a form of susceptibility mapping to produce an image of veins from SWI data [1] which we refer to here as SWIM (susceptibility weighted imaging and mapping).