Pulmonary diffusing capacity: assessment with oxygen-enhanced lung MR imaging preliminary findings.

PURPOSE To determine differences in the signal intensity (SI) time courses at oxygen-enhanced magnetic resonance (MR) lung imaging in healthy volunteers and patients with pulmonary diseases and to correlate these differences with pulmonary diffusing capacity. MATERIALS AND METHODS Seventeen patients with pulmonary diseases and 11 healthy volunteers underwent oxygen-enhanced MR imaging while they breathed room air and 100% oxygen. A turbo spin-echo sequence with global or section-selective inversion pulses was used. For postprocessing, SI slope maps during the breathing of 100% oxygen were calculated. Mean SI slope and SI change values were compared with the diffusing capacity of the lung for carbon monoxide (DLCO). RESULTS The SI slopes were significantly different for patients and volunteers (P < or = .05, Mann-Whitney U test). Linear correlations were detected between the DLCO and SI slopes for the section-selective inversion pulse (r(2) = 0.81) and the global inversion pulse (r(2) = 0.74). A lower correlation was associated with the SI change for the section-selective pulse (r(2) = 0.04; global pulse, r(2) = 0.81). Regional differences were seen in the SI slope and SI change maps. These differences correlated with findings on radiographs and computed tomographic scans. CONCLUSION The SI slope during the breathing of 100% oxygen allows spatially resolved assessment of the pulmonary diffusion capacity.