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Published on: February 17, 2013
Toward normal perfusion after radiosurgery: perfusion MR Imaging with independent component analysis of brain
Wan-Yuo Guo1, Yu-Te Wu, Hsiu-Mei Wu
1Department of Radiology, Taipei Veterans General Hospital, No, 201, Section II, Shih-Pai Road, 112 Taipei, Taiwan, ROC.
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.
Insights
Radiosurgery normalizes brain perfusion in patients with arteriovenous malformations (AVMs). This study shows reduced AVM steal and improved blood flow after treatment, indicating radiosurgery
Area of Science:
- Neuroimaging
- Radiosurgery
- Cerebrovascular Diseases
Background:
- Cerebral arteriovenous malformations (AVMs) disrupt normal brain perfusion.
- Understanding these perfusion disturbances is crucial for effective treatment.
Purpose of the Study:
- To evaluate the effects of radiosurgery on disturbed brain perfusion in AVM patients.
- To analyze changes in cerebral blood volume, flow, and transit time post-treatment.
Main Methods:
- MR perfusion imaging with independent component analysis was used.
- Perfusion parameters (rCBV, rCBF, rMTT) were assessed in defined regions of interest before and after radiosurgery.
- Statistical analysis included Mann-Whitney U tests and generalized linear models.
Main Results:
- Pre-radiosurgery, AVM patients exhibited significantly higher rCBV and rCBF ratios, indicating "AVM steal."
- Post-radiosurgery, AVM nidus perfusion ratios normalized, and perinidal perfusion disturbances reversed towards normal.
- These changes suggest a significant therapeutic effect of radiosurgery on AVM-related perfusion abnormalities.
Conclusions:
- Radiosurgery effectively addresses high transnidal flow and perinidal perfusion disturbances in AVMs.
- The observed normalization of perfusion post-treatment provides insight into AVM pathophysiology and radiosurgery efficacy.
