Figure 4

Quantitative T2 mapping results from a T2 phantom with actual T2 = 62 ms. Without RF chopping (o's0, recovering signal contaimates consecutive slice acquisition resulting in elevated T2 estimates. Estimating this recovery term via a T2-fit with baseline offset yields uniform, but erroneous values across slices. With RF chopping (x's) the T2-contrast is better preserved across slices and a simple 2-parameter fit yields the correct T2 values. A 3-parameter fit gives resonable estimates but suffers error from the reduced degrees-of-freedom in the fit, sub-optimal TE times to estimate the baseline and sensitivity to nois.