Table 2

MRI findings in primary cerebral involvement of rheumatic diseases and opportunistic CNS infection⁸ ¹⁵ ¹⁸ ²¹ ²³ ⁵² ⁵³ ^66–⁶⁸

MRI findings	NPSLE	Primary CNS vasculitis	Wegener’s granulomatosis	Neuro-Behçet	Neurosarcoidosis	PML	HSV encephalitis	Bacterial meningitis	Brain abscess
GDTPA, gadolinium-DTPA.
Normal	13–50%	0–50%	50%	30%	11%	Only in the early phase	Rare	?	Rare

Territorial infarction	15–30%	Frequently (e.g. middle cerebral artery)	15–20%	18%	Rare	–	–	–	–

In T₂ hyperintense lesions of the cortex	0–9% Reversible	Rare	Cerebral granulomas (homogeneous, ring enhancement)	36–66% Mes-, diencephalic, 26% isolated brain stem or basal ganglia	30% Multiple or solitary supra- and/or infratentorial, rarely brain stem or cerebellum	56% Thalamus, 32% posterior fossa	Haemorrh. necrosis temporal, insula, thalamus, hippoc., subfrontal	–	Frequent

White matter lesions (WML)	30–75% Subcortical > deep white matter > periventricular	Frequent infarcts often in the deep white matter	50% Periventricular, subcortical	16% Para- and periventricular	40% Peri- and paraventricular, subcortical, confluent	100% Subcortical, 93% parieto-occipital, 92% bilateral, 94% confluent, no mass effect	–	–	Frequent, capsule with low intensity signal, indistinct margins between abscess and surrounding

GDTPA enhancement of WML or cortical lesions	Only active lesions	Active lesions	Active lesions	Often but only active lesions	Often nodular or annular enhancement	<10% Enhancement of the periphery	Often	–	Strong contrast enhancement

Atrophy	10–60%	Chronic stage	42%	20% Brain stem	?	69%	–	–	–

Other		Rarely meningeal enhancement	2–30% Focal or diffuse meningeal/dural thickening	spinal cord lesions	38–57% Nodular or diffuse meningeal enhancement, 28% optic nerve enhancement	58% Infratentorial (e.g. brain stem), no perifocal oedema	Often brain oedema associated with the lesions	Meningeal enhance., nodular lesions	Mass effect