RT Journal Article
SR Electronic
T1 Toward Normal Perfusion after Radiosurgery: Perfusion MR Imaging with Independent Component Analysis of Brain Arteriovenous Malformations
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1636
OP 1644
VO 25
IS 10
A1 Guo, Wan-Yuo
A1 Wu, Yu-Te
A1 Wu, Hsiu-Mei
A1 Chung, Wen-Yuh
A1 Kao, Yi-Hsuan
A1 Yeh, Tzu-Chen
A1 Shiau, Cheng-Ying
A1 Pan, D. Hung-Chi
A1 Chang, Yue-Cune
A1 Hsieh, Jen-Chuen
YR 2004
UL http://www.ajnr.org/content/25/10/1636.abstract
AB BACKGROUND AND PURPOSE: Brain perfusion is disturbed by cerebral arteriovenous malformations (AVMs). Our study was conducted to determine the radiosurgical effects on this disturbed perfusion.METHODS: MR perfusion imaging with independent component analysis was performed in five healthy subjects and 19 patients with AVM before and after radiosurgery (every 6 months up to 2 years). Perfusion map relative cerebral blood volume (rCBV), cerebral blood flow (rCBF), and mean transient time (rMTT) were assessed. Regions of interest (ROIs) on AVM target sections were defined as follows: N, AVM nidus; H, the rest of the ipsilateral hemisphere; P, immediately posterior to the nidus; A, immediately anterior to the nidus; Ar, anterior remote; Pr, posterior remote. Similar ROIs in the contralateral hemisphere (N1, H1, P1, A1, Pr1, and Ar1) served as internal references. Perfusion ratios of ROI–ROI1 were defined. Nonparameteric Mann-Whitney U tests and generalized linear models were used for statistical analysis.RESULTS: Before radiosurgery, patients’ H/H1 rCBV and rCBF ratios were significantly higher than those of healthy subjects (P < .005), indicating AVM steal. Three types of perilesional perfusion disturbance were observed. From the first postradiosurgical follow-up at 6 months, N/N1 rCBV and rCBF ratios gradually decreased to 1.0 (both P < .001), whereas rMTT ratios gradually increased to 1.0 (P < .015); H/H1, A/A1, and P/P1 rCBV and rCBF ratios decreased after radiosurgery (P < .005), indicating reversal of steal toward normal perfusion.CONCLUSION: Initial high transnidal flow and perinidal perfusion disturbances were demonstrated. They gradually changed toward normal perfusion after radiosurgery. This explains, in part, the pathophysiologic factors of AVM and therapeutic effects.