Reliability of visual assessment of non-contrast CT, CT angiography source images and CT perfusion in patients with suspected ischemic stroke. oleh Tom van Seeters, Geert Jan Biessels, Joris M Niesten, Irene C van der Schaaf, Jan Willem Dankbaar, Alexander D Horsch, Willem P T M Mali, L Jaap Kappelle, Yolanda van der Graaf, Birgitta K Velthuis, Dust Investigators