MULTI-parametric MR imaging with fLEXible design (MULTIPLEX).

Area of Science:

• Magnetic Resonance Imaging
• Medical Physics
• Radiology

Background:

• Multi-parametric MRI offers rich tissue characterization but often requires lengthy acquisition times.
• Existing methods may compromise resolution, accuracy, or flexibility for comprehensive data acquisition.

Purpose of the Study:

• To introduce MULTIPLEX, a novel gradient echo (GRE)-based method for single-scan 3D multi-parametric MRI.
• To achieve high resolution, signal-to-noise ratio (SNR), accuracy, efficiency, and acquisition flexibility.

Main Methods:

• The MULTIPLEX method utilizes a comprehensive design with dual-repetition time (TR), dual flip angle (FA), and multi-echo acquisitions.
• Optional flow modulation is incorporated for advanced imaging capabilities.
• Evaluation involved system phantoms and human brain scans, with quantitative analysis of parametric maps.

Main Results:

• A single MULTIPLEX scan generates multiple image sets, including T1 maps, proton density (PD) maps, and quantitative susceptibility mapping (QSM).
• Quantitative errors for T1, T2*, and PD mapping were under 5% in phantoms and consistent with literature in brain scans.
• High-resolution (0.68 × 0.68 × 2 mm³) whole-brain coverage was achieved in approximately 7.5 minutes with rapid processing (<1 minute).

Conclusions:

• The MULTIPLEX method demonstrates significant potential for efficient and comprehensive multi-parametric MRI.
• Its ability to acquire diverse quantitative information in a single, fast scan enhances its utility in clinical and research settings.