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. Author manuscript; available in PMC: 2014 Feb 1.
Published in final edited form as: J Magn Reson Imaging. 2012 Sep 25;37(2):457–470. doi: 10.1002/jmri.23823

Table 2.

Experimental Results

Subject exp.# VL* VL/TLC <F> Sham background SD** Physiol. SD**
Mean SD**
HS1 1 5.75 0.82 0.8 0.39 0.13 0.37
2 3.2 0.46 1.5 0.42 0.14 0.40
3 3.15 0.45 1.5 0.42 0.14 0.40
HS2 1 3.19 0.42 1.7 0.42 0.12 0.40
2 3.24 0.43 1.4 0.58 0.24 0.53
3 3.29 0.44 1.8 0.48 0.2 0.44
4 4.94 0.66 1.0 0.35 0.14 0.32
HS3 1 2.89 0.47 1.7 0.38 0.12 0.36
2 2.91 0.47 1.3 0.48 0.14 0.46
3 2.93 0.47 1.7 0.38 0.09 0.37
4 3.93 0.63 1.3 0.29 0.12 0.26
HS4 1 1.51 0.41 2.1 0.74 0.35 0.65
2 1.96 0.53 1.8 0.51 0.28 0.43
3 1.91 0.52 1.9 0.41 0.25 0.32
4 1.88 0.51 1.7 0.54 0.22 0.49
1++ 1.51 0.41 0.2 0.1 0.08 0.06
2 1.51 0.41 0.7 0.3 0.02 0.3
3 1.51 0.41 1.0 0.4 0.05 0.4
HS5 1 1.91 0.39 2.4 0.6 0.35 0.49
2 1.88 0.38 2.2 0.61 0.19 0.58
3 2.61 0.53 1.4 0.27 0.08 0.26
4 1.93 0.39 1.9 0.54 0.14 0.52
5 1.68 0.34 2.1 0.53 0.37 0.38
6 2.61 0.53 1.5 0.29 0.08 0.28
7 1.71 0.34 1.6 0.8 0.22 0.77
HS6 1 2.58 0.26 2.97 0.72 0.1 0.71
2 3.01 0.31 2.22 0.45 0.12 0.43
HS7 1 2.01 0.23 3.41 0.68 0.08 0.68
2 1.57 0.18 3.74 1.16 0.11 1.15
HS8 1 2.92 0.39 2.2 0.69 0.15 0.67
2 2.97 0.39 2.3 0.72 0.19 0.69
3 4.46 0.59 1.7 0.41 0.1 0.40
*

VL is the estimated lung volume at which the experiment was performed. It is the sum of RV (or sub-RV in the case of the divers), xenon and corresponding oxygen and air.

**

SD stands for standard deviation. In case of F it corresponds to the total standard deviation σtotal, in the case of the sham background – it is the contribution of the noise to the total heterogeneity, σnoise, and finally the SD physiological, σphysiol, refers to the contribution of physiological heterogeneity to σtotal and is calculated using Eqn 27. For HS6 and HS7 (the world-class divers) the sham SD was estimated from the part of the images where there was no signal from the lung (corners of the FOV) because at the time we did not collect extra data for the noise estimation.

++

The data in red is collected at 3T at tdiff of 20 (exp. #1), 44 (exp. #2) and 62 (exp. #3) ms. Note that F parameter in this case should be approximately one half of the value measured at 0.2T because of the saturation (3T) and inversion (0.2T) pulses used during contrast generation.