In silico and in vitro investigation of induced magnetic susceptibility effects due to different size of intramammary-like calcifications in an external magnetic field

This is the authors' abstract. We don't add key points for this paper.

Susceptibility-weighted imaging (SWI) is a promising MRI technique for localizing and characterizing intramammary calcifications. However, no clinically established breast SWI protocol currently exists, and susceptibility effects caused by breast calcifications remain insufficiently studied due to a lack of realistic imaging phantoms and validated simulation models. This study aimed to systematically investigate magnetic susceptibility effects both in silico and in vitro , considering various sizes and shapes of calcifications using in vivo imaging protocol parameters. In silico and in vitro models were developed to evaluate susceptibility effects of spherical intramammary calcifications. The simulation placed single spherical calcifications at the Field of View center to compute magnetic field distribution to generate MR-like images. Manually produced blackboard spheres ( d = 3 − 8 mm ) as in vitro samples were examined using a 3D multi-echo gradient-echo pulse sequences at 1.5 T, with varying echo times (TE) and spatial resolutions ( 0.3 mm 3 and 0.5 mm 3 ). Sample localization and volumetric accuracy were assessed in magnitude and SW images. Intramammary calcifications can be simulated according to cylindrical and spherical geometry-dependent approaches in a cube-shaped voxel. Higher spatial resolution ( 0.3 mm 3 ) and TEs near the Breast's T 2 * relaxation time enhanced volumetric accuracy and localization of calcifications. Simulation and phantom results aligned well, despite differences in sample positioning, air pockets and local magnetic field inhomogeneities. For the first time, dedicated in silico models were aligned with in vitro phantoms to analyze susceptibility effects caused by intramammary calcifications, highlighting the clinical potential of SWI and the need for improved phantom designs.