Chengbo Wang1, John P. Mugler, III1,2, Eduard E. de Lange1, Talissa A. Altes1
1Radiology, University of Virginia, Charlottesville, VA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
Global long-time-scale helium-3 ADC values as a function of diffusion time were measured in 29 healthy volunteers and 14 subjects with COPD. The percentage difference in group mean ADC versus diffusion time had a well-defined maximum at a diffusion time of approximately 1 s, suggesting that this diffusion time affords the best ability to discriminate COPD and healthy subjects. Furthermore, the percentage difference between the two groups at the long-time scale (110%-150%) was much greater than that found at the short-time-scale (commonly, 20%-100%), which supports the premise that long-time-scale diffusion is more sensitive to COPD than short-time-scale diffusion.