System and Method for Improved Lung Fourier Decomposition Magnetic Resonance Imaging

A magnetic resonance imaging (MRI) system, comprising:

• a magnet system configured to generate a polarizing magnetic field about at least a portion of a subject arranged in the MRI system;
• a plurality of gradient coils configured to establish at least one magnetic gradient field to the polarizing magnetic field;
• a radio frequency (RF) system configured to apply an RF field to the subject and to receive magnetic resonance signals therefrom;
• a computer system programmed to:
• direct the MRI system to acquire a time series of images depicting a subject's lungs while the subject is breathing, each image in the time series of images having a plurality of voxels located within a field-of-view;
• register each image in the time series of images to a reference image;
• obtain geometric information indicative of proton density changes in each voxel in the field-of-view due to inhalation and exhalation from the registration;
• correct proton density values in each voxel in the time series of images using the obtained geometric information, the corrected proton density values being indicative of changes in proton density due to changes in gas volume in the subject's lung;
• produce a Fourier spectrum for each voxel in the field-of-view, each Fourier spectrum including a signal peak associated with a frequency of the subject's breathing rate, by Fourier transforming the corrected time series of images;
• extract the signal peak in each voxel that is associated with a frequency of the subject's breathing rate from the produced Fourier spectra;
• and
• produce an image indicative of ventilation in the subject using the extracted signal peaks.