Commonly, Cervical¹> Thoracic
Multiple Lesions

Spinal cord oedema is typically seen in the acute phase of MS myelitis,
potentially mimicking neoplastic myelopathies². In chronic MS, the
coalescence of multiple short lesions can mimic longitudinally extensive
transverse myelitis (LETM).
LETM should prompt search for alternative aetiology.

Enhancement is present in most acute lesions;
the pattern is variable, usually homogeneous or patchy.
Often minimal enhancement and subtle or vague enhancement
is the most common pattern. Ring enhancement is seen in
about one-third of enhancing cord lesions in MS².
With both MS and NMO/NMOSD, the enhancement often
resolves within 2–3 months³.

Spinal Cord atrophy correlates with
duration of disease.
As oedema resolves, chronic MS T2-hyperintense
spinal cord lesions may appear smaller but
typically do not resolve completely².
 

                          Image from Ref 1

   Image from Ref 3

                                                                                                              Image from Ref 3

Typical apple core lesion of chronic MS¹.

Focal cord atrophy in longstanding MS¹.

MOG: Sagittal T2-hyperintense line (white arrowhead) surrounded by hazier T2 hyperintensity (yellow arrowheads). 
On axial sequences, the T2 hyperintensity is highly restricted to the gray matter forming an H sign (red arrowhead).
Postgadolinium sagittal images demonstrate no gadolinium enhancement.

NMO: Hyperintense extensive lesion with prominent swelling (yellow arrowheads) and axial T2 lesion with diffuse central signal                        
abnormality not confined to gray matter (red arrowhead).

MS: Short T2-hyperintense lesion at the C2 level extending one vertebral segment in length (yellow arrowhead) with accompanying faint ring
enhancement (blue arrowhead). 
On axial sequences, the lesion is located in the periphery of the cord in the right dorsal column (red arrowhead).

Lesions are typically peripheral, and wedge-shaped or
round and affect less than half of the crosssectional area
of the cord1. Gray matter involvement more evident in
the spinal cord than the brain¹.
80% of lesions are dorsal and lateral and 20% are anterior⁴.
Image show focal wedge shaped lesion of posterior columns.