Radiology Practice Test 2026 - Free Radiology Practice Questions and Study Guide

A radiopaque structure appears white, light, and shades of gray on a radiograph. This is due to the ability of the radiopaque material to absorb X-rays more effectively than surrounding tissues. As a result, fewer X-rays reach the film or digital sensor, causing those areas to appear lighter on the image. Dense structures such as bones, contrast agents, and some foreign objects exhibit this radiopaque characteristic, which allows for clear differentiation from less dense, more radiolucent tissues that appear darker.

The options that suggest black and dark shades represent radiolucent structures, which allow more X-rays to pass through and therefore appear darker. Colors like blue, green, and red, and hues like yellow and orange are not typically used in the context of radiographic imaging, as those colors do not correlate with the density and radiographic characteristics critical to interpretation.