An interleaved flip angle multi-slice acquisition method for 2D variable flip angle T1 mapping

Motivation: Magnetization transfer (MT) effect has been demonstrated to be a significant factor that results in the estimation bias and reduced reproducibility of single pool T1 mapping by 3D variable flip angle (VFA) method. Goal(s): Reduce the estimation bias of 2D VFA T1 mapping method while improving its reproducibility using different protocols with a simple single-pool relaxometry model. Approach: Interleave the variable flip angles for multi-slice 2D acquisition to balance the MT effect between acquisitions without SAR increase. Results: Both simulations and in vivo experiments showed improved accuracy and reproducibility of 2D VFA T1 mapping with our proposed method. Impact: It has been reported that 2D VFA T1 mapping encounters biased estimation and low reproducibility issues. Improving estimation accuracy and reducing estimation variance can help promote the clinical application of 2D VFA T1 mapping.