Differentiation of parenchymal lung disorders with in vitro proton nuclear magnetic resonance

We investigated in vitro NMR properties of bleomycin-induced alveolitis and pulmonary fibrosis in 18 Lewis rats (6 controls). When alveolitis or fibrosis had developed, animal lungs were excised and examined histologically and gravimetrically and their T1 and T2 were determined by a NMR spectrometer at 10.7 MHz and 37 degrees C. Clinical diagnosis was confirmed histologically in each case. The NMR signal intensities were significantly elevated in both disease states (P less than 0.001). Both T1 and T2 values of alveolitic lungs were about the same as in controls, but were significantly decreased in fibrotic lungs (P less than 0.01). Changes in T1 and T2 correlated well (P less than 0.001) with changes in water content of diseased lungs.