The RCS is a normal lucent (dark) area seen on a lateral chest film, positioned immediately behind the sternum and directly in front of the ascending aorta and heart shadow.
. PubMed Central (PMC) (.gov) +2 Comparison of Kerley Lines In clinical practice, Kerley lines (named after radiologist Peter Kerley ) are categorized by their location and orientation: Type Appearance Location on X-ray Primary Cause Kerley A Long (2–6 cm), diagonal Mid-to-upper lung zones, radiating from hilum Lymphatic distension or fibrosis Kerley B Short (1–2 cm), horizontal Lung bases, perpendicular to the pleura Interstitial edema (classic CHF sign) Kerley C Fine, criss-cross Throughout lung fields (reticular pattern) Overlapping A/B lines or diffuse infiltration Kerley D Identical to Kerley B Retrosternal clear space (Lateral view) Pulmonary fibrosis or interstitial edema Clinical Importance Finding Kerley D lines on a lateral X-ray is often an early indicator of kerley d lines
Kerley lines are linear opacities seen on chest imaging, representing thickened interlobular septa due to fluid, cellular infiltration, or fibrosis. They are classified as: The RCS is a normal lucent (dark) area
| Condition | Differentiating Features | |-----------|--------------------------| | Congestive heart failure | Cardiomegaly, cephalization, rapid improvement with diuretics | | Lymphangitic carcinomatosis | Nodular septal thickening, hilar/mediastinal adenopathy, known malignancy | | Interstitial pneumonia | Ground-glass opacities, traction bronchiectasis | | Asbestosis | Associated pleural plaques, lower lobe predominant fibrosis | They are classified as: | Condition | Differentiating