Time-resolved lung perfusion- and ventilation-weighted MRI by Wavelet Analysis

Introduction Non-contrast-enhanced assessment of the pulmonary function remains a challenge in the developement of suitable MR techniques. Recently a Fourier Decomposition (FD) MRI was proposed to obtain regional lung perfusion and ventilation-related information during a single acquisition series [1, 2]. The method utilizes rapid acquisition of time-resolved MR-data using a Steady-State Free Precession (SSFP) sequence and allows for a spectral separation of respiratory and cardiac signal changes caused by lung parenchyma contraction and blood pulsation. We propose an alternative post-processing method based on the Wavelet Analysis (WA). The Wavelet transform allows for a robust analysis of physiological signals, which most often show a non-stationary behavior [3]. Signal contribution from the respiratory and cardiac cycles can be separated in the time-scale plane. The aim of this study was to show feasibility of the proposed method.