The chest X-ray (CXR) or chest radiograph remains the most commonly ordered imaging study in medicine, yet paradoxically is often the most complex to learn, recall, and master effective and accurate interpretation. The chest radiograph includes all thoracic anatomy and provides a high yield, given the low cost and single source. This guide presents a structured lexicon for use by readers to reproducibly describe radiographic abnormalities of the chest detected on plain film CXRs. The lexicon is designed to provide readers with clinically significant differentiation of abnormalities detected. The content is structured to relate specific combinations of distinct radiographic findings to classes/groupings of pathological etiologies of those findings. Recognizing the individual findings and identifying their combination or lack of combination with other individual findings allows readers to create effective differential diagnoses that can then be further evaluated using other imaging procedures and/or non-radiographic clinical information. The book includes hundreds of images, including radiographs, CTs, graphics, and analogous models to help teach otherwise complex processes and radiographic principles.