Dose response of the intravascular contrast agent gadofosveset trisodium in MR perfusion imaging of the myocardium using semiquantitative evaluation.

ABSTRACT

PURPOSE: To evaluate appropriate injection protocols for gadofosveset at 1.5 and 3 T magnetic resonance imaging (MRI) for semiquantitative myocardial perfusion analysis. MATERIALS AND METHODS: Eighteen young healthy volunteers were subjected to first-pass perfusion cardiac scans at 1.5 and 3 T MRI using three different injection protocols for gadofosveset (0.00375, 0.0075, and 0.0150 mmol/kg bodyweight) and two perfusions. At both field strengths a T1-weighted saturation recovery turboFLASH sequence with parallel imaging was employed. Peak signal-to-noise ratio (SNR), maximum contrast enhancement ratio (CER), peak-baseline difference, and upslope values were assessed. Moreover, sectors with dark banding artifacts were evaluated. RESULTS: Significant differences of the upslope values for first compared to second perfusion could be observed for the medium- and high-dose groups at 1.5 T (P < 0.01), but not at 3 T. Sectors with dark banding artifacts during first perfusion occurred significantly more often at the highest dose of gadofosveset compared to the lowest dose at 1.5 T (P = 0.04) and 3 T (P < 0.01). CONCLUSION: The best injection protocol for semiquantitative perfusion analysis at 1.5 T is 0.00375 mmol/kg, as higher doses lead to lower upslope values during the second perfusion. At 3 T 0.0075 mmol/kg should be used to avoid dark banding artifacts.