Effect of Gd-DTPA induCED susceptibility on single-point Dixon fat/water separation

A single-point Dixon (SPD) fat/water separation method is proposed for breast dynamic contrast-enhanced MRI (DCE-MRI) in which field inhomogeneities and phase offsets measured prior to the injection of gadopentate dimeglumine (Gd-DTPA) are used to correct the postinjection images. A breast phantom study was conducted to demonstrate this technique, in which varying excess concentrations of Gd-DTPA (0-3 mM) were introduced into a 25-cm(3) breast lesion. The presence of excess Gd-DTPA in the lesion was found to create magnetic field perturbations of up to 0.35 microT per mM excess Gd-DTPA around the lesion. However, these perturbations had a negligible effect on the quality of the fat/water separation for Gd-DTPA concentrations in the range of, and exceeding, those observed in breast tumors following a standard 0.1 mmole/kg injection. Therefore, we conclude that the preinjection phase data is adequate for the correction of the postinjection images in breast exams.