TY - CHAP M1 - Book, Section TI - PLAIN FILMS: BASICS A1 - GUPTA, PRASHANT A1 - HEDGIRE, SANDEEP A1 - ZIA, AIZA A1 - HASAN, NADEEN ABU A1 - HARISINGHANI, MUKESH A2 - Butler, Kathryn L. A2 - Harisinghani, Mukesh PY - 2015 T2 - Acute Care Surgery: Imaging Essentials for Rapid Diagnosis AB - X-rays are high-energy electromagnetic waves that have been used in diagnostic imaging since their discovery in 1896 by Wilhelm Conrad Roentgen. They consist of electromagnetic components oscillating in orthogonal planes. For routine clinical use, a finely controlled x-ray beam of known energy and quantity is targeted toward the site of interest.1 An x-ray tube in its most elementary form consists of a tube filament and target (Figure 1–1). The tube filament (cathode) emits electrons when heated. A target (anode) emits x-rays when struck by these high-energy electrons. In diagnostic radiology, these x-rays pass through a patient and are attenuated to various degrees based on the density of the tissue. They then strike an image detector, leading to formation of an image. On the processed image the “lighter” areas are the attenuated x-rays, with “darker” areas of the film corresponding to areas of less attenuation. Bone, the densest tissue, appears bright white on plain film, while soft tissue is of intermediate attenuation, and air appears black (Table 1–1). SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accesssurgery.mhmedical.com/content.aspx?aid=1110747338 ER -