Kerley C lines are a lesser-known but important radiographic sign of interstitial pulmonary edema. Unlike the more commonly recognized Kerley A and B lines, C lines are fine, reticular opacities predominantly seen in the lower and mid-zones of the lungs. This paper reviews their historical context, anatomical-pathological correlation, radiographic identification, and clinical relevance, emphasizing their role in the early detection of elevated pulmonary capillary wedge pressure.
If you suspect Kerley C lines on an X-ray, check the following:
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 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.
Here is a comprehensive guide to understanding and identifying Kerley C lines.