Meeting Banner
Abstract #3993

The Influence of Diffusion Time on the Measurement of the Short-Range 3He Diffusivity in Human Lungs

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.