T1 mapping of the entire lung parenchyma: Influence of the respiratory phase in healthy individuals

J Magn Reson Imaging. 2005 Jun;21(6):759-64. doi: 10.1002/jmri.20319.

Abstract

Purpose: To determine the effect of respiratory phase on the T1 values of the entire lung.

Materials and methods: We calculated T1 relaxation time on a pixel-by-pixel analysis of a series of Snapshot FLASH tomograms acquired after a single inversion pulse. Two sets of coronal T1 maps were acquired, one in full suspended inspiration and one in suspended expiration.

Results: The average of the mean T1 values over the entire lung in inspiration was 1199+/-117 msec, the average of the mean T1 values in expiration was 1333+/-167 msec. This difference was statistically significant, at P=0.005. In inspiration the average coefficient of variation was 182+/-56 msec, in expiration it was 153+/-41 msec. This difference was not statistically significant.

Conclusion: T1 measurements of the entire lung are feasible. Our findings underline the need for a close monitoring of the inspirational status during MR examinations of the thorax, notably when T1 measurements of the lung are performed.

MeSH terms

  • Adult
  • Chi-Square Distribution
  • Feasibility Studies
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Lung / physiology*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Respiratory Mechanics / physiology*
  • Statistics, Nonparametric