Evaluating single-point quantitative magnetization transfer in the cervical spinal cord: Application to multiple...

Area of Science:

• Neuroimaging
• Biophysics
• Radiology

Background:

• Spinal cord (SC) damage in multiple sclerosis (MS) causes clinical deficits.
• Conventional MRI lacks specificity for early macromolecular tissue changes in MS SC.
• Quantitative magnetization transfer (qMT) offers high-resolution indices sensitive to macromolecular composition.

Purpose of the Study:

• Evaluate potential biases of the single-point qMT model in MS patients.
• Assess the variability of qMT constraints in patient and control cohorts.
• Determine the clinical feasibility of single-point qMT for MS white matter pathology.

Main Methods:

• Acquired single-point qMT measurements in the cervical SC of MS patients and controls.
• Evaluated differences in qMT constraints (k_mf, T_2fR_1f, T_2m) between cohorts.
• Compared macromolecular to free pool size ratio (PSR) between healthy volunteers, MS lesions, and normal-appearing white matter.

Main Results:

• No significant differences in PSR were found between control- and patient-derived qMT constraints (p > 0.149).
• White matter PSR in healthy volunteers significantly differed from MS lesions (p < 0.005) and normal-appearing white matter (p < 0.02).
• Single-point qMT demonstrated significant differences in PSR between healthy and affected white matter in MS.

Conclusions:

• Single-point qMT is a valuable tool for quantitative assessment of white matter pathology in MS.
• The method provides clinically feasible scan times for high-resolution imaging.
• This technique can detect macromolecular changes preceding overt lesion detection in MS.