PA Anatomy: Imaging Overview-Radiography

Radiographs (or computed radiography, abbreviated CR) are projection images, meaning that all of the different tissues of the imaged organ are superimposed on the final 2D image

1) recognize each type of imaging and physical property--NOT a slice, gives a view of an entire region with many structures superimposed on each other, physical property is tissue DENSITY (molecular weight of the average tissue within an imaged pixel, which is the sum of all the tissue encountered by the beam as it passes through the body region)

2) radiation--uses ionizing radiation, at a relatively low dose

3) technical factors are mostly related to the particular PROJECTION (what direction the x-ray beam enters the body)

4) WHITE areas are called 'opacities' or 'densities' and BLACK areas are called 'lucencies', or 'low density areas'

5) types of disease that are best displayed: bone diseases or injuries, broad overview of a large anatomic area, acute problems such as trauma (images can be done very quickly and portably)

6) types of disease that are not well demonstrated: soft tissues such as organs, tendons, ligaments, lymph nodes, or the central nervous system