In vivo Hahn spin-echo decay (Hahn-T2) observation of regional changes in the time course of oleic acid lung injury.
We studied the time course of changes in the Hahn spin-echo decay (Hahn-T2) in lungs of spontaneously breathing living rats at 1 hour, 3 hours, and 7 days following oleic acid injection. Motion artifacts were minimized by using the motion-insensitive interleaved rapid line scan (ILS) imaging technique. Prior to injury, the lungs exhibited two resolvable exponential Hahn-T2 components. One and 3 hours after injury the decay showed a regionally nonuniform behavior, which was fit with one, two, or three exponential components. The short and medium components increased at 1 and 3 hours after injection. The third, much longer, component is probably due to intraalveolar pulmonary edema. After 7 days the Hahn decay was similar to that observed before injury, probably reflecting resolution of the edema. Our data suggest that Hahn-T2 measurements can be used to characterize the time course and regional distribution of lung injury in living animals.
Shioya
S
S
Department of Physics, University of Utah, Salt Lake City 84112, USA.
Christman
R
R
Ailion
D C
DC
Cutillo
A G
AG
Goodrich
K C
KC
Morris
A H
AH
D000818:Animals; D016477:Artifacts; D005260:Female; D007091:Image Processing, Computer-Assisted; D008168:Lung / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D019301:Oleic Acid; D011654:Pulmonary Edema / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D019301:Oleic Acid