Phantom and in vivo study of the Look-Locher T1 mapping method

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, (C) 1999 Elsevier Science Inc.