X-rays are a form of ionizing radiation that can penetrate the body to form an image on film. Structures that are dense (such as bone) will appear white, air will be black, and other structures will be shades of gray depending on density. X-rays can provide information about obstructions, tumors, and other diseases.
Review Date 4/27/2023
Updated by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.