Accurate and precise in vivo liver 3D T₁ mapping at 3T

To develop an accurate and precise liver 3D $$ mapping method using only scanner-agnostic sequences.

While the spoiled gradient-recalled echo sequence is widely available on clinical scanners, variable flip angle $$ mapping methods based on this sequence provide biased $$ estimates, with the largest systematic error arising from $$ inhomogeneities. To correct for this, the flip angle was mapped using a 2D gradient-echo double-angle method approach. To correct for the confounding effect of fat on liver $$ and $$ , Dixon and fat saturation techniques were used in combination with the variable flip angle and the $$ map acquisitions, respectively. The $$ and $$ mapping methods were validated with a $$ -phantom against gold standard methods. An intra- and inter-repeatability study was conducted at 3T in 10 healthy individuals' livers.

The developed 3D $$ mapping method achieved an excellent agreement with the gold standard, with a weighted root mean squared normalized error below 2.8%. In vivo, a median $$ standard deviation of 31 ms and an interquartile range of [27, 39] ms was achieved across all measurements, including the intra- and inter-repeatability study data. A within-subject standard deviation for $$ of 21 ± 5 ms had a corresponding repeatability coefficient of 60 ms. The measured $$ values agree well with MOLLI and SASHA $$ mapping methods, with average $$ differences of 5%.

Accurate and precise 3D $$ liver measurements can lead the way to the wider adoption of a clinically feasible $$ measurement as a marker of hepatic fibro-inflammation.