Quantitative Synthetic MRI in Body Imaging: Technical Basis, Current Applications, and Future Directions.

Area of Science:

• Medical Imaging
• Quantitative MRI
• Biomarker Discovery

Background:

• Quantitative synthetic MRI (SyMRI) allows simultaneous acquisition of T1, T2, and proton density maps.
• SyMRI moves beyond qualitative MRI, offering objective tissue biomarkers and potentially improving workflow efficiency.
• While neuroimaging is its primary focus, SyMRI applications in body imaging are rapidly expanding.

Purpose of the Study:

• To review the technical basis of body SyMRI, including 2D and 3D approaches.
• To summarize current evidence of SyMRI applications in various body regions.
• To discuss the potential and limitations of SyMRI in clinical practice.

Main Methods:

• Focus on the 2-dimensional QRAPMASTER/multidynamic multiecho (MDME) framework.
• Discussion of the newer 3-dimensional quantification using an interleaved Look-Locker acquisition sequence with T2 preparation pulse (QALAS) approach.
• Review of existing literature on SyMRI in breast, prostate, gynecologic, rectal, head and neck, and musculoskeletal imaging.

Main Results:

• SyMRI is technically feasible across multiple body imaging applications.
• SyMRI shows promise for lesion characterization, tumor grading, prognostic assessment, and treatment response evaluation.
• SyMRI parameters can provide added value when combined with other imaging techniques and clinical data.

Conclusions:

• Current evidence for body SyMRI is limited by small, heterogeneous studies, often using 2D methods.
• Multicenter prospective validation and standardization of quantitative workflows are crucial for future progress.
• Broader evaluation of newer 3D SyMRI methods is needed to realize its full potential in body imaging.