Contrast agent which are not used for CT scan:

Ans. B. CO2Ref Sumer Sethi 6th/20; Radiology 6 Imaging by Thayalan159; Dahne Radiology Manual 7th/1147-48Radiocontrast agents are a type of medical contrast medium used to improve the visibility of internal bodily structures in X-ray-based imaging techniques such as computed tomography (CT), radiography & fluoroscopy.Radiocontrast agents are typically iodine or barium compounds.When an agent improves visibility of an area, it is called "contrast enhancingGadolinium is a key component of the contrast material most often used in magnetic resonance (MR) exams.Saline (salt water) and air are also used as contrast materials in imaging exams.Barium sulfate contrast media continue to be the preferred agents for opacification of the gastrointestinal tract for conventional fluoroscopic examinationsThe current use of iodinated water-soluble contrast media is primarily limited to select situationsTwo commercid water-soluble iodinated high-osmolality contrast media (HOCMs) specifically designed for enteric opacification are in common use. Gastrografin and, Gastroview