CT imaging uses X-rays in conjunction with computing algorithms to image a variety of soft tissues in the body. Computed tomography or CT scan (previously known as CAT scan, the "A" standing for "axial") uses a high amount of ionising radiation in the form of X-rays in conjunction with a computer to create images of both soft and hard tissues. These images look as though the patient was sliced like bread (thus, "tomography"-- "tomo" means "slice").
CT is acquired in the axial plane, while coronal and sagittal images can be rendered by computer reconstruction. Radiocontrast agents are often used with CT for enhanced delineation of anatomy.
Intravenous contrast allows 3D reconstructions of arteries and veins. Although radiographs provide higher resolution for bone X-rays, CT can generate much more detailed images of the soft tissues. CT exposes the patient to more ionizing radiation than a radiograph.