T1 Contrast-Augmented Single-Spoke Real-Time 4D MRI

Motivation: 4D MRI is a powerful technique for free-breathing volumetric imaging, holding great potential for application in MRI-guided radiotherapy. Traditional 4D MRI typically requires explicit motion detection and data binning for respiratory-resolved reconstruction and commonly employs fast steady-state MRI acquisition, which may not yield optimal contrast. Goal(s): This work proposes a novel T contrast-augmented, free-breathing, real-time 4D MRI technique. Approach: The proposed technique improves image contrast through highly-accelerated inversion recovery-prepared acquisition and reconstruction of real-time 4D images at a sub-second temporal resolution without requiring explicit motion compensation. Results: T1 contrast-augmented real-time 4D MRI demonstrated improved image contrast over conventional 4D MRI with steady-state acquisition. Impact: The contrast-augmented real-time 4D MRI technique proposed in this work can improve image contrast for free-breathing imaging without requiring explicit motion detection, data binning and respiratory motion compensation. It holds great potential for various applications, such as MRI-guided radiotherapy.