Impact of single phase CT angiography collateral status on functional outcome over time: results from the MR CLEAN Registry. - Jansen IG; Mulder MJ; Goldhoorn RB; Boers AM; van Es AC; Yo LS; Hofmeijer J; Martens JM; van Walderveen MA; van der Kallen BF; Jenniskens SF; Treurniet KM; et al. (Journal of neurointerventional surgery, 2019)