Age-related changes of multi-parametric quantitative imaging across the adult lifespan in the lumbar vertebra.

The DFA-MEGRE approach successfully generates multiple qualitative and quantitative imaging maps of the lumbar spine within a clinically feasible scan time.

• The method produces qualitative T1W, PDW, T2*W, water, and fat maps as well as quantitative PD, T1, R2*, PDFF, and QSM maps.
• Scan time for whole lumbar spine coverage with DFA-MEGRE was approximately 6.5 minutes.
• The approach requires three repetitions of GRE acquisition using dual flip angles.
• Six in-phase echoes from dual flip angles were used for T1 and PD quantifications, while water, fat, R2*, PDFF, and QSM maps were obtained from six echoes with FA = 15°.

The DFA-MEGRE method demonstrated strong correlations between measured and true values in phantom validation for both PD and R2* quantification.

• Strong correlations were found between measured PD and true PD values.
• Strong correlations were found between measured R2* and true R2 values.
• Validation was performed using a phantom prior to in vivo application.
• Correlation analysis was applied to validate the accuracy of the proposed method for parameter quantification.

All five quantitative parameters (PD, T1, R2*, PDFF, and QSM) showed age-related quadratic changes in the lumbar vertebra across the adult lifespan.

• The study included 41 healthy volunteers ranging in age from 18 to 71 years old.
• Correlation analysis was performed on all five quantitative parameters versus age.
• Age-related changes followed a quadratic (non-linear) pattern for all five parameters.
• Region-of-interest (ROI) analysis was performed on the vertebra for all volunteer data.

The DFA-MEGRE approach was proposed as an extension of dual flip angle chemical shift-encoded multi-echo GRE acquisition for simultaneous multi-parametric quantification.

• The method combines dual flip angle acquisition with chemical shift-encoded multi-echo GRE in a single framework.
• Three repetitions of GRE acquisition are required for the complete DFA-MEGRE protocol.
• The approach enables simultaneous quantification of PD, T1, R2*, PDFF, and QSM from a single acquisition framework.
• The authors note the method can be extended to other parts of the body beyond the spine.

The multi-parametric quantitative imaging parameters demonstrated potential for longitudinal study and disease assessment in the spine.

• The age-related changes observed across five quantitative parameters support their use in tracking spinal changes over time.
• The study included adults across a broad age range (18–71 years) to characterize normal aging trajectories.
• The authors conclude the parameters 'have great potential for longitudinal study and disease assessment in the spine.'
• The quadratic nature of age-related changes suggests non-linear biological processes in vertebral tissue across adulthood.