When looking at a PA (Posterior-Anterior) Chest X-ray, look for the following characteristics:
A highly cited and helpful paper for understanding these lines is the published in the New England Journal of Medicine . It provides clear visual examples and concise explanations of the anatomic basis for each line type. Key Characteristics of Kerley C Lines kerley c line
Kerley C lines represent a reticular pattern of interlobular septal thickening due to interstitial pulmonary edema. While less specific and more subtle than their A and B counterparts, their identification on a plain chest radiograph is a valuable sign of elevated left atrial pressure. Clinicians and radiologists should maintain a high index of suspicion for these lines in patients presenting with dyspnea and known cardiac disease. When looking at a PA (Posterior-Anterior) Chest X-ray,
: They are often interpreted as Kerley B lines seen "en face" (head-on) rather than from the side, or as general thickening of the fine anastomotic lymphatics. While less specific and more subtle than their
To identify Kerley C lines, it is essential to distinguish them from the other variants: Appearance Significance Long, unbranching, diagonal Parahilar (upper lobes) Distension of anastomotic lymphatics. B Lines Short, horizontal, parallel Peripheral bases (costophrenic angles) Thickened subpleural interlobular septa. C Lines Reticular, "spider-web" Short/Mesh Central and basal zones Overlapping B lines or diffuse infiltration. D Lines Same as B lines Retrosternal space Best seen on lateral radiographs. Clinical Significance and Etiology
A Kerley C line is a short, fine, linear opacity seen in the lungs. It represents the thickening of interlobular septa (the connective tissue walls between the lung's air sacs) due to fluid, cells, or fibrosis.