DC-gated high resolution three-dimensional lung imaging during free-breathing.

PURPOSE

To use the acquisition of the k-space center signal (DC signal) implemented into a Cartesian three-dimensional (3D) FLASH sequence for retrospective respiratory self-gating and, thus, for the examination of the whole human lung in high spatial resolution during free breathing.

MATERIALS AND METHODS

Volunteer as well as patient measurements were performed under free breathing conditions. The DC signal is acquired after the actual image data acquisition within each excitation of a 3D FLASH sequence. The DC signal is then used to track respiratory motion for retrospective respiratory gating.

RESULTS

It is shown that the acquisition of the DC signal after the imaging module can be used in a 3D FLASH sequence to extract respiratory motion information for retrospective respiratory self-gating and allows for shorter echo times (TE) and therefore increased lung parenchyma SNR.

CONCLUSION

The acquisition of the DC signal after image signal acquisition allows successful retrospective gating, enabling the reconstruction of high resolution images of the whole human lung under free breathing conditions.