RACER-GRASP: Respiratory-weighted, aortic contrast enhancement-guided and coil-unstreaking golden-angle radial sparse...

Area of Science:

• Medical Imaging
• Magnetic Resonance Imaging
• Radiology

Background:

• Dynamic contrast-enhanced (DCE) MRI is crucial for liver imaging.
• Standard GRASP (Golden-angle RAdial Sparse Parallel) MRI has limitations in motion compensation and artifact reduction.
• Optimizing DCE MRI techniques is essential for accurate liver diagnosis.

Purpose of the Study:

• To develop and evaluate RACER-GRASP, a novel DCE MRI technique for liver imaging.
• To enhance GRASP by incorporating automatic contrast bolus timing, respiratory motion compensation, and coil unstreaking.
• To improve overall imaging performance in liver MRI examinations.

Main Methods:

• RACER-GRASP utilizes aortic contrast enhancement (ACE) guided sorting and respiratory-weighted sparse reconstruction.
• Coil unstreaking weights k-space data to minimize streaking artifacts from individual coils.
• Technique was compared against standard GRASP in healthy volunteers and liver patients.

Main Results:

• RACER-GRASP significantly improved overall image quality (3.25 vs. 3.85) and hepatic vessel sharpness (3.58 vs. 4.0).
• Residual streaking artifact levels were reduced (3.23 vs. 3.94) with RACER-GRASP.
• Automatic arterial phase timing was successfully enabled by the RACER-GRASP technique.

Conclusions:

• RACER-GRASP enhances standard GRASP for free-breathing DCE liver MRI.
• The technique's ACE-guided sorting, motion suppression, and coil unstreaking improve imaging performance.
• RACER-GRASP offers superior image quality and artifact reduction in liver MRI.