Figure 8.

The MRF T₁ and T₂ measurements with and without separation and reference T₂ measurements before and after exercise. A, The recovery curve of water T₂ (in milliseconds) from MRF (blue) and MSE measurements (red) averaged over a region of interest in the GM in 1 volunteer. There is a systematic difference between the water T₂ values measured with the 2 techniques, but the offset is more or less constant over time. Hence, the recovery curve measured with MRF follows the same trend as the curve measured with the reference protocol. The dashed line indicates the period during which exercise was performed. B,C, The MRF measurements with and without water–fat separation before and after exercise. The recovery curves of T₁ (B) and T₂ (C) (in milliseconds) averaged over a region of interest in the GM in another volunteer. With water–fat separation (blue), T₁ increases by approximately 35 ms and T₂ decreases by approximately 6 ms compared to without water–fat separation (red). These changes are observed along the entire curves, showing the systematic error in the presence of fat. The recovery curves show smooth behavior. The dashed line indicates the period during which exercise was performed