PT  - JOURNAL ARTICLE
AU  - T. Nishii
AU  - A.K. Kono
AU  - M. Nishio
AU  - N. Negi
AU  - A. Fujita
AU  - E. Kohmura
AU  - K. Sugimura
TI  - Bone-Subtracted Spinal CT Angiography Using Nonrigid Registration for Better Visualization of Arterial Feeders in Spinal Arteriovenous Fistulas
AID  - 10.3174/ajnr.A4435
DP  - 2015 Aug 06
TA  - American Journal of Neuroradiology
4099  - http://www.ajnr.org/content/early/2015/08/06/ajnr.A4435.short
4100  - http://www.ajnr.org/content/early/2015/08/06/ajnr.A4435.full
AB  - BACKGROUND AND PURPOSE: Pretreatment diagnosis for the location of shunts and arterial feeders of spinal arteriovenous fistulas is crucial. This study aimed to evaluate the utility of subtracted CT angiography imaging by using nonrigid registration (R-CTA) in patients with spinal arteriovenous fistulas compared with conventional CTA imaging.MATERIALS AND METHODS: The records of 15 consecutive subjects (mean age, 65 years; 2 women) who had undergone CTA and digital subtraction angiography for clinically suspected spinal arteriovenous fistula were reviewed. From CTA images obtained at the arterial and late arterial phases, warped images of the late arterial phase were obtained by using nonrigid registration that was adjusted to the arterial phase images. R-CTA images were then obtained by subtracting the warped images from the arterial phase images. The accuracies of using nonrigid registration and conventional spinal CTA and the time required for detecting arterial feeders in spinal arteriovenous fistulas were analyzed for each patient with DSA results as a standard reference. The difference between R-CTA and conventional spinal CTA was assessed by the Welch test and the McNemar χ2 test.RESULTS: R-CTA had a higher accuracy compared with conventional spinal CTA (80% versus 47%, P = .025). The time for interpretation was reduced in R-CTA compared with conventional spinal CTA (45.1 versus 97.1 seconds, P = .002).CONCLUSIONS: Our subtracted CTA imaging by using nonrigid registration detects feeders of spinal arteriovenous fistulas more accurately and quickly than conventional CTA.AbbreviationsANTsAdvanced Normalization Tools softwareC-CTAconventional spinal CTAR-CTAbone-subtracted spinal CTA using novel nonrigid registrationSAVFspinal arteriovenous fistulaSyNsymmetric diffeomorphic image normalization algorithm