Quantitative myelin water imaging using short TR adiabatic inversion recovery prepared echo-planar imaging...

Area of Science:

• Neuroimaging
• Biomarker Discovery
• Medical Physics

Background:

• Myelin alterations are key indicators of neurological damage.
• Myelin water imaging (MWI) quantifies myelin content using the myelin water fraction (MWF).
• Short TR adiabatic inversion recovery (STAIR) is an effective sequence for MWF calculation.

Purpose of the Study:

• To develop and evaluate a novel clinical transitional myelin water imaging (MWI) technique.
• To combine STAIR preparation with echo-planar imaging (EPI) for rapid data acquisition (STAIR-EPI).
• To assess myelin loss in multiple sclerosis (MS) lesions and normal-appearing white matter (NAWM).

Main Methods:

• Acquisition of STAIR-EPI sequences in seven healthy volunteers and seven MS patients.
• Measurement of apparent myelin water fraction (aMWF) in normal white matter (NWM), MS lesions, and NAWM.
• Comparison of aMWF values between healthy controls and MS patients.

Main Results:

• STAIR-EPI images revealed lower signal intensities in MS lesions compared to NAWM.
• Significantly lower aMWF in MS lesions (3.6 ± 1.3%) and NAWM (8.6 ± 1.2%) compared to NWM (10 ± 1.3%) (P < 0.001).
• The technique demonstrated sensitivity to myelin loss in both lesional and non-lesional white matter in MS.

Conclusions:

• The STAIR-EPI technique is a viable method for detecting myelin loss in MS.
• This technique can be implemented across various MRI scanner vendors.
• STAIR-EPI offers a promising tool for clinical assessment of demyelinating diseases.