Spinal arteriovenous malformation: evaluation of change in venous oxygenation with susceptibility-weighted MR imaging after treatment.
OBJECTIVE
To evaluate the efficacy of susceptibility-weighted (SW) magnetic resonance (MR) imaging for the assessment of the posttreatment change in oxygen saturation in the draining vein in patients with spinal arteriovenous malformation (AVM).


METHODS
The study protocol was approved by the institutional review board, and written informed consent was obtained from all subjects. SW imaging was performed in 11 patients with spinal AVM before and after surgical or endovascular treatment. Eleven healthy subjects were included as a control group. A four-grade response scale was used for the visual assessment of the anterior spinal vein (ASV). For quantitative analysis, the phase value of the ASV was measured and oxygen saturation was calculated. Nonparametric multigroup comparison for visual assessment and one-way analysis of variance for quantitative measurement of oxygen saturation were used as statistical tests for comparison among three groups (pretreatment patients, posttreatment patients, and control subjects).


RESULTS
Complete shunt occlusion in all patients was confirmed by using conventional angiography. For visual assessment, the average score of the pretreatment group was significantly less than that of the posttreatment and control groups. For quantitative analysis, the average oxygen saturation of the pretreatment group was significantly higher than that of the posttreatment and control groups, while no significant difference was observed between the posttreatment and control groups.


CONCLUSIONS
After treatment, normalization of increased oxygen saturation was noninvasively observed by using SW imaging in patients with spinal AVM. SW imaging can be a useful tool for the assessment of treatment efficacy in patients with spinal AVM. (c) RSNA, 2010.
Fujima
Noriyuki
N
Departments of Radiology and Neurosurgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Kudo
Kohsuke
K
Terae
Satoshi
S
Hida
Kazutoshi
K
Ishizaka
Kinya
K
Zaitsu
Yuri
Y
Asano
Takeshi
T
Yoshida
Daisuke
D
Tha
Khin Khin
KK
Haacke
E Mark
EM
Sasaki
Makoto
M
Shirato
Hiroki
H
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015901:Angiography, Digital Subtraction; D016022:Case-Control Studies; D020785:Central Nervous System Vascular Malformations / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D003287:Contrast Media; D010100:Oxygen