1. Department of Radiology; Veterinary Faculty; University of Utrecht; Yalelaan 10, de Uithof 3584 CM Utrecht The Netherlands
2. Department of General and Large Animal Surgery; Veterinary Faculty; University of Utrecht; Yalelaan 12, de Uithof 3584 CM Utrecht The Netherlands
3. Westeinde Hospital; Lijnbaan 32 2512 VA The Hague The Netherlands