Radiation-induced arteritis: thickened wall with prominent enhancement on cranial MR images report of five cases and comparison with 18 cases of Moyamoya disease.
OBJECTIVE
To evaluate magnetic resonance (MR) imaging findings of radiation-induced cranial arteritis regarding arterial wall thickening and degree of enhancement, as well as to compare the findings with those of idiopathic moyamoya disease.


METHODS
We reviewed cerebral MR images in five patients with radiation-induced large cerebral arteritis. All patients had undergone irradiation 2-25 years prior to this study. Conventional nonenhanced MR, MR angiographic, and contrast material-enhanced MR images were evaluated. Special attention was paid to wall enhancement of the affected arteries (distal internal carotid artery). Wall enhancement was staged in three levels by two neuroradiologists. We also reviewed MR images in 18 patients with primary moyamoya disease for comparison and analyzed them statistically (Fisher exact test).


RESULTS
Wall thickening and prominent ring enhancement of the wall of the affected large cerebral arteries were observed in all (five of five) patients with radiation-induced arteritis. In contrast, wall thickening and prominent ring enhancement of the wall of the occluded arteries either were not seen (13 of 18 patients) or were faint (five of 18 patients) in patients with moyamoya disease. Contrast enhancement of the arterial walls in patients with radiation-induced arteritis was significantly more prominent than in patients with moyamoya disease (P =.003).


CONCLUSIONS
MR images of wall thickening and prominent ring enhancement of the wall of affected large cerebral arteries may be a diagnostic clue in differentiating radiation-induced arteritis from moyamoya disease.
Aoki
Shigeki
S
Department of Radiology, University of Tokyo Hospital, 7-3-1 Hongo, Bunkyoku, Tokyo 113-8655, Japan. saoki-dis@h.u-tokyo.a.cjp
Hayashi
Naoto
N
Abe
Osamu
O
Shirouzu
Ichiro
I
Ishigame
Keiichi
K
Okubo
Toshiyuki
T
Nakagawa
Keiichi
K
Ohtomo
Kuni
K
Araki
Tsutomu
T
D000293:Adolescent; D000328:Adult; D001167:Arteritis / Q000209:etiology* / Q000473:pathology*; D002536:Cerebral Arteries / Q000473:pathology / Q000528:radiation effects*; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000473:pathology*; D011832:Radiation Injuries / Q000473:pathology; D011878:Radiotherapy / Q000009:adverse effects*; D012189:Retrospective Studies
D003287:Contrast Media