کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9587343 | 1393236 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Measurements and modeling of long range 3He diffusion in the lung using a “slice-washout” method
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
In healthy lung tissue, pulsed-gradient-spin-echo (PGSE) methods reveal apparent diffusion coefficients (ADC) of the order 0.20 cm2 sâ1; for diffusion times of â2 ms. For these short diffusion times the ADC is only sensitive to structures approximately (2Dt)1/2 â 0.6 mm in size. Recent work, using magnetic tagging of the longitudinal magnetization has revealed much smaller ADC values for longer length scales. In this work, the in vivo ADC from within the air-spaces, was measured using a new technique. The signal from a series of images was analyzed from a slice that was repeatedly imaged. Diffusion tends to “top-up” the non-renewable polarization within the slice, which leads to a non-exponential decay in image signal. Image data were compared to 1D finite-difference simulations of diffusion to calculate a long range ADC value. The results yield values of the order 0.034 cm2 sâ1, which are nearly an order of magnitude smaller than those reported by PGSE measurements at shorter diffusion times.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetic Resonance - Volume 174, Issue 1, May 2005, Pages 28-33
Journal: Journal of Magnetic Resonance - Volume 174, Issue 1, May 2005, Pages 28-33
نویسندگان
Stanislao Fichele, Martyn N.J. Paley, Neil Woodhouse, Paul D. Griffiths, Edwin J.R. van Beek, Jim M. Wild,