Human brain quantitative susceptibility mapping at 5 T: A prospective multicenter traveling-subject study with...

Area of Science:

• Neuroimaging
• Biophysics
• Medical Physics

Background:

• Quantitative susceptibility mapping (QSM) measures magnetic susceptibility to assess brain iron.
• QSM is validated across various MRI field strengths but lacks multicenter evaluation at 5 Tesla.
• Standardized protocols are crucial for multicenter QSM performance assessment.

Purpose of the Study:

• To evaluate the multicenter performance of brain QSM at 5 Tesla MRI.
• To establish repeatability and reproducibility benchmarks for 5T QSM.
• To compare 5T QSM results with 3T clinical reference scans.

Main Methods:

• A traveling-subject cohort of six healthy volunteers underwent QSM on six different 5T MRI systems.
• Standardized 3D multi-echo gradient-echo sequences were used, with QSM maps reconstructed via a uniform pipeline.
• Nine bilateral regions of interest were analyzed for repeatability and inter-scanner reproducibility.

Main Results:

• 5T QSM demonstrated high scan-rescan repeatability (ICCs 0.93-0.99).
• Inter-scanner reproducibility at 5T was high for deep gray matter structures, comparable to 3T and 7T multicenter data.
• Good to excellent cross-field agreement between 3T and 5T was observed for several structures, though moderate agreement was noted for others.

Conclusions:

• This study provides the first multicenter benchmark for brain QSM at 5T.
• 5T QSM exhibits high repeatability and reproducibility, suitable for multicenter studies.
• Findings support the use of 5T QSM for brain iron assessment, with careful consideration of cross-field agreement for specific regions.