Model-constrained reconstruction accelerated with Fourier-based undersampling for hyperpolarized [1-¹³ C] pyruvate...

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Metabolic Imaging
• Medical Physics

Background:

• Dynamic MRI with hyperpolarized [1-¹³ C]-pyruvate enables metabolic imaging.
• Acquisition speed is a limitation for dynamic MRI.
• Accelerating MRI acquisition is crucial for improved clinical utility.

Purpose of the Study:

• To introduce and validate Model-constrained reconstruction with Fourier-based undersampling (MoReFUn) for accelerating dynamic MRI.
• To assess the accuracy and reliability of MoReFUn in reconstructing metabolic information.
• To evaluate MoReFUn's performance across various datasets, including phantoms and patient data.

Main Methods:

• MoReFUn utilizes pharmacokinetic model constraints to resolve spatial aliasing caused by undersampling.
• The method was tested on a numerical phantom for accuracy validation under different signal-to-noise ratio (SNR) and undersampling conditions.
• MoReFUn was evaluated on in vitro phantom data and retrospective undersampled prostate cancer patient data.

Main Results:

• Successful reconstruction was achieved across all tested datasets using MoReFUn.
• Image details of pyruvate and lactate time series were preserved with minimal increase (<10%) in mean square residual error at reduction factors up to 8.
• Quantitative estimation of pyruvate-to-lactate conversion rate in prostate cancer data showed high accuracy (<10% error) at a reduction factor of 2.

Conclusions:

• MoReFUn is an effective and reliable technique for accelerating dynamic MRI acquisition.
• The method enables high-fidelity metabolic imaging using hyperpolarized [1-¹³ C]-pyruvate.
• MoReFUn holds promise for improving the efficiency of metabolic MRI in clinical settings.