Correction of RF Inhomogeneities in FLASH-Based T1 Mapping Using Unified Segmentation

Nikolaus Weiskopf¹, Antoine Lutti¹, Gunther Helms², John Ashburner¹, Chloe Hutton¹

Quantitative T1 mapping based on variable flip angle acquisitions requires precise knowledge of the local flip angle and is therefore usually combined with RF transmit mapping methods. RF transmit mapping is not readily available and requires extra scan time. We propose a method to correct for RF inhomogeneities that does not require measured RF maps. The method uses the unified segmentation and bias correction approach implemented in SPM8 to simultaneously estimate and correct for the RF inhomogeneities from the T1 maps. The model-based approach is shown to reduce the bias in T1 maps by more than 50%.