Anke Balasch^{1}, Patrick Metze^{1}, Tobias Speidel^{2}, and Volker Rasche^{1}

^{1}Department of Internal Medicine II, Ulm University Medical Center, Ulm, Germany, ^{2}Core-Facility Small Animal Imaging, Ulm University, Ulm, Germany

In this study, a two-dimensional ultra-short TE protocol was used to acquire free-breathing data of the lung. The signal intensity in expiration and inspiration were used to derive the fractional ventilation, proton fraction and perfusion of the lung parenchyma.

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Figure 1: Correlation between breathing amplitude and a) fractional ventilation and b) proton fraction is exemplarily shown for a slice thickness of 20mm. The ventilation tends to increase with increasing breathing amplitude (R² = 37%). This behaviour also can be observed in the difference in the proton fraction $$$∆f_P$$$ (expiration minus inspiration) (R²=62%). One dataset has been excluded due to weak SNR in the IN which adulterated the values.

Figure 2: Ventilation, proton fraction and perfusion in end-expiration for a non-smoker and a smoker. The smokers showed significantly higher values for the proton fraction, but no significant changes in ventilation and perfusion.

Table 1: a) Ventilation b) proton fraction and c) perfusion data (mean ± std) for the 2D UTE SG acquisitions at 3T. The proton fraction and perfusion increase from anterior to posterior and correlates with the respiratory phase. In expiration, the values are higher than in inspiration. It is a significant difference between the two respiratory phases (expiration and inspiration). The difference between the two groups in FV and perfusion is not significant. A significant difference was observed for proton fraction between the two groups.