Oral Cholecystogram (OCG):This is a diagnostic test. The patient ingests iodine-containing pills over one or two consecutive nights. The iodine is absorbed from the intestines into the bloodstream, filtered by the liver, and then expelled into the bile. The high concentration of iodine in the bile highlights the gallbladder. Iodine is used in OCG due to its density and ability to block x-rays, effectively outlining gallstones that typically allow x-rays to pass through and are usually not visible on standard x-rays. If the gallbladder does not appear on an OCG, it suggests a potential gallbladder condition. The OCG is particularly useful for identifying gallstones that are strongly suspected but not detectable by ultrasound.
