Magnetic resonance fingerprinting for simultaneous renal T 1 and T 2 * mapping in a single breath-hold.

Purpose To evaluate the use of magnetic resonance fingerprinting (MRF) for simultaneous quantification of T1 and T2* in a single breath-hold in the kidneys. Methods The proposed kidney MRF sequence was based on MRF echo-planar imaging. Thirty-five measurements per slice and overall 4 slices were measured in 15.4 seconds. Group matching was performed for in-line quantification of T1 and T2*. Images were acquired in a phantom and 8 healthy volunteers in coronal orientation. To evaluate our approach, region of interests were drawn in the kidneys to calculate mean values and standard deviations of the T1 and T2* times. Precision was calculated across multiple repeated MRF scans. Gaussian filtering is applied on baseline images to improve SNR and match stability. Results T1 and T2* times acquired with MRF in the phantom showed good agreement with reference measurements and conventional mapping methods with deviations of less than 5% for T1 and less than 10% for T2*. Baseline images in vivo were free of artifacts and relaxation times yielded good agreement with conventional methods and literature (deviation T1:7 +/- 4%, T2*:6 +/- 3%). Conclusions In this feasibility study, the proposed renal MRF sequence resulted in accurate T1 and T2* quantification in a single breath-hold.