Rapid B₁-Insensitive MR Fingerprinting for Quantitative Kidney Imaging.

Area of Science:

• Medical Imaging
• Biophysics
• Radiology

Background:

• Magnetic Resonance Fingerprinting (MRF) enables rapid, simultaneous tissue parameter quantification.
• Kidney imaging requires efficient techniques for accurate T1 and T2 mapping.

Purpose of the Study:

• To evaluate a rapid kidney MRF technique at 3.0 T.
• Assess the technique's performance in phantoms, healthy volunteers, and patients.

Main Methods:

• Developed a 15-second kidney MRF acquisition with low flip angles and spiral trajectory.
• Validated in vitro with phantoms and in vivo with 10 healthy volunteers and 3 pediatric ARPKD patients.
• Utilized multiple magnetization preparation schemes including T1, T2, and fat suppression.

Main Results:

• Excellent agreement between MRF and spin-echo T1/T2 values in phantoms (R² > 0.99).
• Precise in vivo T1 and T2 maps in healthy volunteers, consistent with literature values.
• Good reproducibility in ARPKD patients (<3% difference) and insensitivity to B1 field inhomogeneities.

Conclusions:

• A novel kidney MRF method provides accurate in vivo T1 and T2 maps at 3.0 T.
• The technique allows for single breath-hold acquisition with improved precision.
• No B1 correction is required, simplifying clinical application.