To propose and preliminarily evaluate a rapid method with potential clinical applicability for correcting the B1+ spatial variation in quantitative abdominal MRI.

The 3D VFA method allows rapid quantification of the T1 relaxation time and is particularly suitable for abdominal imaging, but requires mapping of the B1+ field throughout the 3D volume, which is often not available on clinical MRI scanners. The proposed method, called B1MM, combines a rapid 2D mapping of the B1+ field with modelling of the excitation coil properties to generate a B1+ mapping over a large 3D volume. The method was first validated on phantoms and a healthy volunteer against reference T1-mapping techniques. The method was then applied to simultaneously estimate PDFF, T1, and T2* in the liver, abdominal muscles, and fat of six patients with steatosis using a VFA-based two-compartment model. The six patients were scanned on a 1.5 T clinical MRI (Magnetom Sola, Siemens Healthineers, Erlangen) with a total protocol duration of 25 s. A comparison of the results with and without angle correction and with the literature was performed.

In both phantoms and the volunteer, angle correction brought T1 values close to the reference. In the six patients, as expected, angle correction had no effect on PDFF or T2*, but it markedly reduced T1 variability and improved T1 measurement accuracy. In addition, the total acquisition time is considerably reduced, which improves patient comfort.

Quantitative MRI

Flip angle correction

VFA

Breath-hold

PDFF

T1

T2*

© 2026 The Authors. Published by Elsevier Inc.