Kidneys, CT scan. Coloured 3-D computed tomography (CT) scan of kidneys in frontal view. The image shows the abdominal aorta (top centre to bottom) which supplies blood to the kidneys (red). Behind the kidneys are the bones of the lower vertebrae and the iliac crests of the pelvis (lower left and lower right). This image was produced using a multi-slice CT scanner, which uses a thin X-ray beam create 'slices' of the patient's body. A computer reconstructs the slices into coloured 3-D images. A contrast agent, injected into the patient, enables blood vessels to be detected by the scanner. This image was created using OsiriX medical imaging software which allows users to navigate through animated fly-throughs of the data.