3D Visual Guide to Lines and Stripes in Chest Radiography.

Chest radiography continues to be the first-line imaging modality for evaluation of the chest. Interpretation is based on the understanding of complex three-dimensional (3D) structural relationships, which are translated into a two-dimensional (2D) plane. These 2D projections form multiple "lines and stripes" on chest radiographs, representing the interfaces between the pulmonary parenchyma, pleura, and normal mediastinal structures. Given the subtlety of overlying tissue and the need to mentally synthesize planar images into three dimensions, structural relationships may be difficult to appreciate. An understanding of these relationships forms the basis of recognizing pathologic conditions and providing an accurate differential diagnosis, which can assist in targeted appropriate further workup. On a 2D radiograph, this means recognizing the normal lines and stripes as well as their appearance when effaced or displaced. Once this abnormality is identified, a focused differential diagnosis can be generated, which can be further narrowed on the basis of other factors, such as patient history or ancillary findings. Three-dimensional cinematic rendering is an innovative tool that can help radiologists grasp these anatomic relationships and discern subtle findings at radiography. This technique allows improved visualization of structures such as the pleura that are difficult to appreciate with traditional imaging modalities. The authors provide an updated review of lines and stripes on chest radiographs, using 3D cinematic rendering as a teaching tool. RSNA, 2023 Quiz questions for this article are available in the supplemental material.