Phantom and in vivo study of the look–locher T 1 mapping method

Abstract

This paper describes and tests the LL-EPI method for obtaining quantitative T 1 estimates in a few seconds thereby allowing dynamic T 1 studies. It is shown that the method works even when there is an inflow into the imaged volume, e.g., in a vessel. No calibration is needed. The method has been tested in a phantom study with several different scan parameter set-ups, with and without inflow. The method shows robustness and individual scan parameters and inflow rates do not influence the ability to calculate the Gd-DTPA concentration. Linearity prevail between the measured 1/T 1 and the Gd-DTPA concentration in the range 150 < T 1 < 2500 ms. In a dynamic Gd-DTPA phantom study, it was shown that the dynamic LL-EPI T 1 mapping technique was three times more sensitive than the signal from a T ∗ 2-weighted EPI sequence. In an in vivo study, dynamic T 1 mapping of the Gd-DTPA uptake in a meningioma was performed. Inspection of the uptake curves indicates that the method is feasible in clinical perfusion studies.