Motion-corrected 4D-Flow MRI for neurovascular applications.

Area of Science:

• Medical Imaging
• Biophysics
• Neuroscience

Background:

• Neurovascular 4D-Flow MRI is crucial for cerebrovascular hemodynamics.
• Motion artifacts can significantly bias hemodynamic measurements, particularly in aging populations.

Purpose of the Study:

• Develop and validate a 3D self-navigation method for retrospective rigid motion correction in neurovascular 4D-Flow MRI.
• Assess the method's efficacy in phantom, volunteer, and clinical aging studies.

Main Methods:

• Employed a 3D radial trajectory with pseudorandom ordering and multi-resolution low-rank regularization.
• Achieved high spatiotemporal resolution self-navigators from undersampled data.
• Validated using simulations, phantoms, volunteers, and clinical data from aging studies.

Main Results:

• Motion correction enhanced vessel conspicuity, reduced blurring, and decreased variability in quantitative measures.
• Significant improvements observed in cerebral artery blood flow rates, pulsatility index, and lumen areas post-correction.
• Demonstrated reduction in motion-induced overestimation of hemodynamic markers.

Conclusions:

• The developed 3D self-navigation approach effectively corrects rigid motion in neurovascular 4D-Flow MRI.
• This method improves the reliability of hemodynamic characterization in aging adults and other at-risk populations.
• Reduces measurement bias, leading to more accurate clinical assessments.