Enhanced Spinal Cord Lesion Detection in MS Using White-Matter-Nulled 3D MPRAGE with Deep Learning Reconstruction

Spinal cord (SC) lesions are critical in MS diagnosis and progression, yet their detection remains challenging. Conventional sequences such as 2D T2-weighted FSE and STIR have suboptimal sensitivity, both in the cervical and thoracic spine. This study evaluated the diagnostic performance of a new imaging technique for SC lesion detection, the 3D white-matter-nulled (WMn) MPRAGE sequence, compared with conventional MRI sequences.

Thirty-eight patients with MS or clinically isolated syndrome were prospectively evaluated with 3T SC MRI, acquiring 2D T2-weighted FSE, 2D STIR, 3D MPRAGE, and 3D WMn. A deep learning denoising method was applied to 3D WMn to compensate the inherent low signal. Four blinded neuroradiologists independently assessed lesion count, confidence in lesion detection, and image quality (eg, artifacts). Contrast-to-noise ratio (CNR) was also computed for all lesions detected on all sequences. Statistical comparisons were performed across sequences.

In the cervicothoracic spine, the 3D WMn sequence detected significantly more lesions than 2D T2-weighted FSE (+62%; P < .001), STIR (+47%; P < .05), and 3D MPRAGE (+50%; P < .01). In the thoracolumbar spine, the 3D WMn sequence detected significantly more lesions than 2D T2-weighted FSE (+53%, P < .05). The 3D WMn sequence demonstrated a higher CNR and improved lesion conspicuity while exhibiting fewer artifacts than STIR. These advantages contributed to greater rater confidence in lesion detection by using the 3D WMn sequence, with over 75% of strong confidence reported by the 2 most experienced raters, along with the highest interreader agreement.

The 3D WMn sequence associated with deep learning-based denoising significantly improves SC lesion detection, outperforming all conventional sequences. Three-dimensional WMn represents, then, a promising alternative for SC imaging in MS.