Magnetic resonance fingerprinting for simultaneous renal T₁ and T2* mapping in a single breath-hold

Purpose: To evaluate the use of magnetic resonance fingerprinting (MRF) for simultaneous quantification of T₁ and T*₂ 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 T*₂. 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 T*₂ 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 T*₂ 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 T*₂. Baseline images in vivo were free of artifacts and relaxation times yielded good agreement with conventional methods and literature (deviation T₁:7 ± 4%, T*₂:6±3%). Conclusions: In this feasibility study, the proposed renal MRF sequence resulted in accurate T₁ and T*₂ quantification in a single breath-hold.