A comparison of the Accuracy of Ultrasound and Computed Tomography in common diagnoses causing acute abdominal pain - van Randen, A; Laméris, W; Wouter van Es, H; van Heesewijk, H PM; van Ramshorst, B; ten Hove, W; Bouma, W H; van Leeuwen, M S; vam Keulen, E M; Bossuyt, P M; Stoker, J; Boermeester, M Aon behalf of the OPTIMA study group (Eur Radiol, 2011)