Optimizing pseudo-spiral sampling for abdominal DCE MRI using a digital anthropomorphic phantom.

Area of Science:

• Medical Imaging
• Radiology
• Biophysics

Background:

• Dynamic Contrast-Enhanced MRI (DCE MRI) requires k-space undersampling for efficient data acquisition.
• Pseudo-spiral (PS) sampling offers a method for k-space undersampling on a Cartesian grid following a spiral trajectory.

Purpose of the Study:

• To optimize pseudo-spiral (PS) k-space sampling patterns for abdominal DCE MRI.
• To enhance the accuracy and precision of pharmacokinetic parameter estimation in DCE MRI.

Main Methods:

• An anthropomorphic digital phantom simulated contrast agent dynamics in abdominal organs and PDAC.
• 704 sampling and reconstruction strategies were evaluated using variable density, halfscan, and compressed sensing.
• Optimal strategies were assessed for image quality and parameter accuracy in healthy volunteers and a PDAC patient.

Main Results:

• The optimal PS reconstruction involved a PS-diffuse based pattern with quadratic readout distribution, no random shuffling, a 0.8 halfscan factor, and 0.05 total variation regularization.
• This strategy yielded sharper images with reduced artifacts in healthy volunteers compared to suboptimal methods.
• High-quality DCE images were obtained in a PDAC patient using the optimized sampling strategy.

Conclusions:

• An optimal PS sampling strategy for abdominal DCE MRI was identified using a digital phantom.
• The feasibility and effectiveness of this optimized strategy were demonstrated in a PDAC patient.