Feasibility of ASL spinal bone marrow perfusion imaging with optimized inversion time

Area of Science:

• Radiology
• Medical Imaging
• Physiology

Background:

• Spinal bone marrow (SBM) perfusion assessment is crucial for understanding various physiological and pathological conditions.
• Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a common method for evaluating perfusion, but it involves contrast agents.
• Flow-sensitive alternating inversion recovery (FAIR) offers a potential alternative for SBM perfusion measurement without contrast agents.

Purpose of the Study:

• To evaluate the correlation between FAIR and DCE-MRI for SBM perfusion quantification.
• To determine the optimal inversion time (TI) for SBM FAIR perfusion imaging.
• To assess the reproducibility of the SBM FAIR perfusion technique.

Main Methods:

• FAIR perfusion imaging was performed on volunteers to optimize TI by measuring signal intensity changes (ΔM) and signal-to-noise ratio (SNR).
• Reproducibility was assessed through repeat SBM FAIR experiments in a subset of volunteers.
• Correlation analysis was conducted between FAIR-derived blood flow (BFASL) and DCE-MRI parameters (Ktrans, Kep, Ve) in subjects.

Main Results:

• An optimal TI of approximately 1200 msec was identified, maximizing ΔM and SNR for SBM FAIR perfusion.
• The SBM FAIR perfusion protocol demonstrated good reproducibility with a low within-subject coefficient of variation (3.28%).
• BFASL showed significant correlations with Ktrans (P < 0.001) and Kep (P = 0.004), but not with Ve (P = 0.082).

Conclusions:

• 1200 msec is the optimal TI for high-quality SBM ASL perfusion imaging using FAIR.
• The SBM FAIR perfusion protocol is reproducible and reliable for blood flow measurement.
• FAIR is a feasible technique for SBM blood flow assessment, showing strong correlation with DCE-MRI parameters.