3He diffusion MRI of the lung.
OBJECTIVE
MR imaging of the restricted diffusion of laser-polarized 3He gas provides unique insights into the changes in lung microstructure in emphysema.


RESULTS
We discuss measurements of ventilation (spin density), mean diffusivity, and the anisotropy of diffusion, which yields the mean acinar airway radius. In addition, the use of spatially modulated longitudinal magnetization allows diffusion to be measured over longer distances and times, with sensitivity to collateral ventilation paths. Early results are also presented for spin density and diffusivity maps made with a perfluorinated inert gas, C3F8.


METHODS
Techniques for purging and imaging excised lungs are discussed.
Conradi
Mark S
MS
Department of Physics, Washington University, Saint Louis, MO 63130, USA. msc@wuphys.wustl.edu
Yablonskiy
Dmitriy A
DA
Woods
Jason C
JC
Gierada
David S
DS
Jacob
Richard E
RE
Chang
Yulin V
YV
Choong
Cliff K
CK
Sukstanskii
Alex L
AL
Tanoli
Tariq
T
Lefrak
Stephen S
SS
Cooper
Joel D
JD
D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D011653:Pulmonary Diffusing Capacity; D011656:Pulmonary Emphysema / Q000175:diagnosis / Q000503:physiopathology