Ultrashort Echo Time (UTE) MR Lung Imaging with Respiratory Motion Compensation

Introduction: Conventional gradient-echo based magnetic resonance imaging of lung parenchyma suffers from poor signal-to-noise ratios due to low proton density and short T2* caused by susceptibility gradients between airways and tissue. In addition, respiratory and cardiac motions seriously degrade the achievable image quality. Ultra-short echo time (UTE) MRI has recently gained renewed attention for imaging short T2* species by utilizing a half-echo projection acquisition in combination with half pulse excitation to achieve a echo times well below 100us. UTE MRI has been successfully applied to lung imaging [1-3], but so far the issue of respiratory motion during imaging the lung parenchyma has not yet been addressed. In this work, a respiratory motion-compensated UTE lung MRI technique is presented. This technique combines the self-gating properties of projection imaging [4] with the reconstruction flexibility provided by the golden-angle view-order strategy [5].