Diagrams showing the different micro-CT designs for imaging animal models. In the systems shown in image (A, 1 and 2), the animal is placed in the centre of the set-up and the gantry carrying the detector and the X-rays source is rotated around it. This is the common setup used in in vivo preclinical imaging. A fan-shaped beam system fitted with a single-slice detector and cone beam system fitted with flat-panel detector are displayed in (A, 1 and 2), respectively. In the system (B), the specimen is placed on a stand that rotates within its own axis in the course of the beam. Image (C) shows a multimodality scanner in which the CT is integrated with PET and SPECT systems (Inveon System Siemens Medical Solutions, Knoxville, TN, USA). This versatile system allows unified PET, SPECT and CT data acquisition. The CT system has an automated zoom control which allows the operator to adjust the field of view and magnification.