Magnetic resonance imaging of the cervical spinal cord in multiple sclerosis at 7T

Abstract

Background:

The clinical course of multiple sclerosis (MS) is mainly attributable to cervical and upper thoracic spinal cord dysfunction. High-resolution, 7T anatomical imaging of the cervical spinal cord is presented. Image contrast between gray/white matter and lesions surpasses conventional, clinical T₁- and T₂-weighted sequences at lower field strengths.

Objective:

To study the spinal cord of healthy controls and patients with MS using magnetic resonance imaging at 7T.

Methods:

Axial (C2–C5) T₁- and T₂*-weighted and sagittal T₂*-/spin-density-weighted images were acquired at 7T in 13 healthy volunteers (age 22–40 years), and 15 clinically diagnosed MS patients (age 19–53 years, Extended Disability Status Scale, (EDSS) 0–3) in addition to clinical 3T scans. In healthy volunteers, a high-resolution multi-echo gradient echo scan was obtained over the same geometry at 3T. Evaluation included signal and contrast to noise ratios and lesion counts for healthy and patient volunteers, respectively.

Results/conclusion:

High-resolution images at 7T exceeded resolutions reported at lower field strengths. Gray and white matter were sharply demarcated and MS lesions were more readily visualized at 7T compared to clinical acquisitions, with lesions apparent at both fields. Nerve roots were clearly visualized. White matter lesion counts averaged 4.7 vs 3.1 (52% increase) per patient at 7T vs 3T, respectively (p=0.05).