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

Abstract

Purpose: To evaluate the use of magnetic resonance fingerprinting (MRF) for simultaneous quantification of $T_1$ and $T_2^{\ast }$ 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 $T_1$ and $T_2^{\ast }$ . 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 $T_1$ and $T_2^{\ast }$ times. Precision was calculated across multiple repeated MRF scans. Gaussian filtering is applied on baseline images to improve SNR and match stability.

Results: $T_1$ and $T_2^{\ast }$ times acquired with MRF in the phantom showed good agreement with reference measurements and conventional mapping methods with deviations of less than 5% for $T_1$ and less than 10% for $T_2^{\ast }$ . Baseline images in vivo were free of artifacts and relaxation times yielded good agreement with conventional methods and literature (deviation $T_1:7\pm 4\%$ , $T_2^{\ast }:6\pm 3\%$ ).

Conclusions: In this feasibility study, the proposed renal MRF sequence resulted in accurate $T_1$ and $T_2^{\ast }$ quantification in a single breath-hold.

Keywords: $T_1$ mapping; $T_2^{*}$ mapping; magnetic resonance fingerprinting; quantitative kidney imaging.