Single-phase CT angiography: collateral grade is independent of scan weighting

- Bisson, Daniel-Alexandre; Mahmoudian, David; Shatil, Anwar S.; Waggass, Ghouth; Zhang, Liying; Levi, Christopher; Spratt, Neil J.; Lin, Longting; Liebeskind, David; Parsons, Mark; Bivard, Andrew; Aviv, Richard I.