Bias correction for phase-based cr-MREPT using low resolution B1+ magnitude

Area of Science:

• Medical Imaging
• Biophysics
• Electrical Engineering

Background:

• Full-form Magnetic Resonance Electrical Properties Tomography (MREPT) relies on B1+ magnitude and phase data.
• Phase-based MREPT methods offer faster acquisition and higher SNR but are prone to concave bias.
• This bias arises from neglecting the gradient of B1+ magnitude (∇|B1+|) within the region of interest.

Purpose of the Study:

• To re-derive the core equation for phase-based MREPT without the simplifying assumption of negligible ∇|B1+|.
• To propose and validate a novel correction method integrated directly into the MREPT equation system.

Main Methods:

• Re-derivation of the phase-based MREPT central equation.
• Integration of a correction for ∇|B1+| into the equation system.
• Validation using both simulated and experimental MREPT data.

Main Results:

• The proposed method effectively corrects the concave bias observed in phase-based MREPT.
• Significant improvements in overall image quality were achieved.
• The correction method utilizes a low-resolution |B1+| map, minimizing additional imaging time.

Conclusions:

• The developed correction method enhances the accuracy of conductivity imaging in MREPT.
• The approach offers a practical solution to overcome limitations of existing phase-based techniques.
• The method can even use simulated |B1+| magnitude, eliminating the need for extra MREPT scans.