Quantitative Susceptibility Mapping in Vivo in the Rat Brain

Ludovic de Rochefort¹, Aurlie Delzor¹, Martine Guillermier¹, Diane Houitte¹, Marion Chaigneau¹, Nicole Dglon¹, Philippe Hantraye¹, Vincent Lebon¹

Molecular and cellular imaging is seeing a growing interest, but applicability to MRI relies on the ability to be specific, sensitive and quantifiable. Superparamagnetic iron oxides are good candidates as they produce a strong magnetic field creating signal voids in gradient echo images. Quantitative susceptibility mapping (QSM) additively uses the magnetic field to quantify the magnetic sources. In this study we apply QSM in the preclinical context of the rat brain using a reconstruction algorithm that includes unwrapping, removing background effects and inverting the field map. The technique demonstrates its ability to quantify SPIO amounts injected in the brain.