Table 1.
Sequence parameters at 1.5T and 3T.
Fig 1.
Registration of the 1.5T to the 3T series.
Registration between the corresponding 1.5T and 3T series was performed to achieve voxel wise comparability. A: Overlay of 1.5T and 3T images before registration. B: Overlay image of 1.5T and 3T images after successful registration. Note the increasing structural similarity index (SSIM) of 0.15 before to 0.56 after the registration, which is indicating a successful registration step.
Fig 2.
Respiratory outliers outside the maximum or minimum respiratory level were excluded by removing images outside the intersection of the diaphragm tracking curves of the 1.5T and 3T series. Furthermore, the acquisition time of both series was equalized by truncating the 3T series.
Fig 3.
Exemplary PREFUL derived perfusion- and ventilation-weighted maps of a 30-year-old female participant at 1.5T and 3T.
Notice the differing scaling.
Fig 4.
Histogram analysis of the normalized Q- and RVent- values of all participants.
The Q- and RVent-values were normalized by division by the 95th percentile of each distribution.
Table 2.
Functional parameters of all participants.
Table 3.
Skewness and kurtosis of Q and RVent of all participants.
Table 4.
SNR and CNR results of all participants.
Fig 5.
A) The mean average of QDP ((QDP 1.5T –QDP 3T)/2) is 7.39% and the mean difference (QDP 1.5T –QDP 3T) (solid red lines) is 4.29% with a SD of 3.54%. The upper and lower 95% confidence intervals mean ± 1.96*SD (dashed red lines) are 11.23% and -2.64%. B) The mean average of VDP is 4.04% and the mean difference is 1.23% with a SD of 2.76%. The confidence intervals are 6.64% and -4.18%. C) The mean average of VQM is 89.44% and the mean difference is -5.15% with a SD of 2.45%. The confidence intervals are -0.35% and -9.95%. D) The mean average of QQuant is 314 ml/min/100ml and the mean difference is 54 ml/min/100ml with a SD of 246 ml/min/100ml. The confidence intervals are 537 and -428 ml/min/100ml.