Table 3

The contribution of brain MRI

DiseaseFindings on brain MRI
InfarctionNormal, unless other process present
HaemorrhageNormal +/−subarachnoid haemorrhage
MST2 white matter hyperintensities, Dawson fingers, periventricular lesions, juxtacortical lesions, T2 hyperintense lesions in the optic nerves may be present if optic neuritis has occurred.
NMOSD—aquaporin-4 antibody positive (43%–70%)Periependymal lesions in deep grey matter structures, corpus callosum (‘arch bridge pattern’), area postrema. Large and/or confluent white matter lesions. When optic neuritis has occurred, long lesions in the optic nerve involving the posterior nerve and chiasm may differentiate NMOSD.
NMOSD—MOG antibody positiveMay mimic aquaporin-4 antibody NMOSD features, with significant overlap of features. ‘Fluffy’ lesions may occur.
Systemic lupus erythematosusLacunar infarcts, cortical infarcts, white matter haemorrhages and large territorial infarcts have been noted in patients with systemic lupus erythematosus; more so if they have associated antiphospholipid syndrome. Note: patients with systemic lupus erythematosus may have associated aquaporin-4 antibody positive NMOSD.
Sjögren’s syndromeMRI may show non-specific subcortical and periventricular T2 hyperintensities. Acute punctate infarcts.
Other autoimmune disordersNon-specific findings/normal
ADEMMultiple white matter T2 hyperintensities with incomplete ‘open-ring’ enhancement
ParaneoplasticMay mimic inflammatory or demyelinating lesions. NMOSD may also coexist with malignant conditions (causality not established) and so features on MRI may also be in keeping with this diagnosis.
SarcoidLeptomeningeal enhancement occurs in 40% of patients (especially basilar) and may lead to hydrocephalus in 5%–12% of patients. T2 hyperintense intraparenchymal lesions that typically enhance. Involvement of pituitary gland, hypothalamus and cavernous sinus may also occur.
MetabolicTypical degeneration of white matter manifesting as extensive T2 hyperintense areas in the periventricular white matter (most common in vitamin B12 deficiency)
MalignancyNormal/concurrent malignancy (both in primary and metastatic)
  • ADEM, acute disseminated encephalomyelitis; MOG, myelin oligodendrocyte glycoprotein; MS, multiple sclerosis; NMOSD, neuromyelitis optica spectrum disorder.