MRI findings suggestive of tumefactive demyelinaitng lesions (TDL):
(1) one or more white matter lesions > 2 cm in diameter that are hyperintense on T2-weighted images
(2) low mass effect relative to size
(3) little vasogenic edema
(4) incomplete (open-ring) enhancement, often more pronounced on the medial aspect
(5) vessel-like structures running through the center of the lesion(s) on T2-weighted images
(6) low relative cerebral blood flow volume
A highly specific finding (Kim et al) was CT hypoattenuation of an MRI-enhancing lesion.
MRI findings that are nonspecific and shared with other CNS lesions such as gliomas:
(1) ill-defined or irregular border
(2) some mass effect
(3) perilesional edema
(4) central necrosis
(5) variable enhancement
(6) variable signal intensity on T2-weighted images
(7) involvement of gray matter
