Uni- and bidirectional wide angle CT colonography: effect on missed areas, surface visualization, viewing time and polyp conspicuity. - East JE; Saunders BP; Boone D; Burling D; Halligan S; Taylor SA; East, James E; Saunders, Brian P; Boone, Darren; Burling, David; Halligan, Steve; Taylor, Stuart A (European Radiology, 2008)