Juan Parra-Robles1, Martin H. Deppe1, Xiaojun Xu1, Helen Marshall1, Jim M. Wild1
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom
In this work, the effect of diffusion time on 3He ADC is investigated through experiments with healthy human volunteers. The results of this work show that the short-range ADC of 3He gas in human lungs decreases with increasing diffusion time, while its degree of non-monoexponentiality remained constant in the range 1.4-2.5 ms. The results demonstrate that the cylinder model produces inaccurate estimates of the airway dimensions as a consequence of incompletely accounting for the diffusion-time dependence in the model equations.