Table 4. Magnetic Resonance Imaging classification of amyloid-related imaging abnormalities ³⁴ .

ARIA type	Radiographic severity
	Mild	Moderate	Severe
ARIA-E	FLAIR hyperintensity confined to sulcus and/or cortex/subcortex white matter in one location <5 cm	FLAIR hyperintensity 5–10 cm in single greatest dimension, or more than one site of involvement each measuring <10 cm	FLAIR hyperintensity >10 cm with gyral swelling and sulcal effacement. One or more sites may be noted.
ARIA-H microhemorrhages	<4 new incident microhemorrhages	5–9 new incident microhemorrhages	≥10 new incident microhemorrhages
ARIA-H superficial siderosis	One focal area of superficial siderosis	Two focal areas of superficial siderosis	More than two focal areas of superficial siderosis

Abbreviations: FLAIR, fluid-attenuated inversion recovery; ARIA-E, amyloid-related imaging abnormality with edema and effusion; ARIA-H, amyloid-related imaging abnormality with hemosiderin deposits.