Effects of endotoxin lung injury on NMR T2 relaxation

✍ Scribed by Antonio G. Cutillo; Pei H. Chan; David C. Ailion; Suetaro Watanabe; Kurt H. Albertine; Carl H. Durney; Christopher. B. Hansen; Gernot Laicher; Randall. F. Scheel; Alan H. Morris

• Book ID: 102957505
• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 854 KB
• Volume: 39
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1910390205

✦ Synopsis

Abstract

The effects of endotoxin injury on lung NMR relaxation times (T~1~, CPMG T~2~, and Hahn decay constant (Hahn T~2~)) were studied in excised unperfused rat lungs. Blinded histologic examination showed no clear‐cut separation between endotoxin and control lungs. Morphometric lung tissue volume density and gravimetric lung water content did not differ significantly between the two groups. In contrast, the values of the fast, intermediate, and slow T~2~ components, obtained by multiexponential analysis of the CPMG decay curve, increased markedly after endotoxin administration, with minimal overlap between endotoxin and control values. The response of Hahn T~2~ was, in general, in the same direction as that of CPMG 7~2~; however, Hahn T~2~ may be more affected by measurement errors and may be less sensitive to the presence of lung injury. t~1~ showed minimal changes after injury. The present data suggest that CPMG 7~2~ measurements can consistently detect the presence of lung injury even when conventional histologic, morphometric, and gravimetric studies provide negative or equivocal results, and that the CMPG T~2~ method is superior, in this respect, to the Hahn decay method. T~1~ does not appear to be sensitive to lung injury in the absence of significant lung water accumulation.