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.