T1 Mapping: Should We Agree to Disagree?

Mathieu Boudreau¹, Nikola Stikov¹, Bruce G. Pike¹

A recent study reported that three commonly used methods for T₁ mapping (Inversion Recovery, Look-Locker, Variable Flip Angle) measure similar T₁ values in phantoms, but disagree <I>in vivo</I> at 3T (VFA overestimated and LL underestimated relative to IR). This work investigates possible confounding factors that may explain the T₁ trends observed <I>in vivo</I>. Bloch simulations tested the effects of inaccurate B₁ mapping and spoiling on T₁ for all three sequences. These simulations predict a systematic bias in VFA and LL due to these effects, consistent with trends observed <I>in vivo</I>, highlighting the importance of proper calibration with the IR gold standard.