Effect of respiratory phases on MR lung signal intensity and lung conspicuity using segmented multiple inversion recovery turbo spin echo (MIR-TSE)

The purpose of this study was to determine the effect of respiratory phase on signal intensity of the lung. Lung images were obtained from eleven heal thy human volunteers using a multiple inversion recovery segmented turbo sp in echo sequence (MIR-TSE). MIR exploits the difference in T-1 between diff erent tissues to effectively null signal contributions from fat and muscle for improved visualization of the lung. The volunteers were asked to perfor m breath-holding on end inspiration or end expiration. There was a signific ant decrease in signal intensity of the lung with average SNR of 7.3 +/- 0. 9 vs. 14.4 +/- 0.8 for coronal slices, and 9.5 +/- 1.5 vs. 16.0 +/- 2.4 for sagittal breath-hold images acquired during end inspiration compared with end expiration. It is concluded that MRI of the lungs should be performed d uring end expiration in order to optimize image quality. Magn Reson Med 43: 760-763, 2000. (C) 2000 Wiley-Liss, Inc.