Enabling machine learning in X-ray-based procedures via realistic simulation of image formation. - Unberath, Mathias; Zaech, Jan-Nico; Gao, Cong; Bier, Bastian; Goldmann, Florian; Lee, Sing Chun; Fotouhi, Javad; Taylor, Russell; Armand, Mehran; Navab, Nassir (International Journal of Computer Assisted Radiology & Surgery, 2019)