Efficient estimation of gadolinium-based contrast agent concentration using transient-state keyhole MR-STAT

Area of Science:

• Medical Imaging
• Biophysics
• Radiology

Background:

• Fast quantitative MRI (qMRI) enables multi-parameter quantification in brief scan times.
• Integrating qMRI into clinical protocols requires efficient post-contrast agent imaging.
• Current methods for tracking contrast agent concentration are time-prohibitive.

Purpose of the Study:

• To develop and validate an accelerated multi-parametric method for time-efficient estimation of Gadolinium-based contrast agent (GBCA) concentrations.
• To enable faster tracking of contrast agent dynamics in clinical MRI settings.

Main Methods:

• An accelerated 2D MR-STAT protocol was designed using transient-state acquisitions and Cartesian keyhole acceleration.
• GBCA concentrations were quantified in phantoms with varying gadobutrol concentrations (0.05–0.9 mM) based on reconstructed T1 values.
• Method validation involved linear regression analysis, synthetic patient data, and a hybrid human/phantom study.

Main Results:

• The accelerated MR-STAT protocol (undersampling factor of 4) accurately measured T1, T2, and GBCA concentrations.
• A strong linear relationship was observed between estimated and reference GBCA concentrations (slope=1.034, intercept=0.009).

Conclusions:

• A multi-parametric approach was developed for quantitative gadolinium concentration assessment in vitro and in a hybrid setup.
• The accelerated MR-STAT protocol measures gadobutrol concentrations (0.05–0.9 mM) within clinically applicable scan times.
• Further in vivo validation is required for this promising quantitative MRI technique.