Septal Lines On | Chest X Ray [better]

: The most common and clinically recognizable type. They appear as short (1–2 cm), thin, horizontal lines at the lung bases, running perpendicular to the pleural surface. They are a classic sign of interstitial pulmonary edema .

Septal lines in lung | Radiology Reference Article - Radiopaedia

: These are longer (2–6 cm) and course diagonally from the outer lung toward the hilum (the central part of the lung). They represent thickening of the deeper septa and are typically seen in more severe cases of pulmonary congestion.

: These are short, fine lines that create a spider-web or reticular pattern at the lung bases. They are often considered the "en face" view of other septal lines, meaning they are seen head-on rather than from the side. Clinical Significance and Causes septal lines on chest x ray

There are three types, but are the most commonly referenced in everyday reading:

Septal lines on a chest X-ray, often called , are thin, linear opacities that indicate the thickening of the interlobular septa in the lungs. These septa are thin sheets of connective tissue that separate the functional units of the lung, called secondary pulmonary lobules. While normally invisible on a radiograph, they become prominent when fluid, cells, or fibrous tissue accumulate within them. Types of Septal (Kerley) Lines

The presence of septal lines is a critical diagnostic marker for several conditions, primarily those affecting the heart or the lymphatic system: : The most common and clinically recognizable type

In a patient with acute dyspnea, almost always point to elevated left atrial pressure (e.g., congestive heart failure), often appearing before overt alveolar edema (i.e., before diffuse airspace opacities). Their presence helps distinguish cardiogenic from noncardiogenic pulmonary edema (e.g., ARDS) – though not absolute, septal lines are much more common in cardiogenic causes.

: Fine, reticular (spiderweb-like) lines that are neither central nor peripheral. They are often considered a superposition of many B lines viewed from the front. Common Causes

Septal lines in lung | Radiology Reference Article - Radiopaedia Septal lines in lung | Radiology Reference Article

The appearance of these lines usually indicates an underlying pathology:

Pleura: No significant effusion.