The Relationship between 3He ADC and Lung Volume
Bierhals A, Yablonskiy D, Conradi M, Woods J, Chang Y, Gierada D, Lutey B
3He diffusion MRI has the likely application of characterizing alveolar spaces in health and disease. Recent comparisons to morphometry in healthy and diseased lungs has more rigidly validated the 3He ADC as indicating alveolar size. The relationship between 3He diffusivity and lung volume, however, is largely unknown. We imaged three volunteers and four normal donor lungs (rejected for transplantation) at multiple inflation volumes and determined that ADC is a weak, linear function of lung volume in the range of normal inspiration. For a volume of 0.5 times the lungs TLC, ADC is reduced to 78% of its value at TLC.