If you’ve ever looked at a chest X-ray and seen a cluster of tiny, horizontal lines at the lung bases, you might have dismissed them as blood vessels or artifact. But to a trained eye, those little lines are a major red flag. They are called Kerley B lines , and they are one of the most classic signs of an overworked heart and fluid-filled lungs.
Next time you scroll through a CXR, don’t just look at the lung fields for pneumonia. Zoom in on those peripheral lower zones. If you see a row of short, horizontal lines—think and B for “Back to the chart to check for heart failure.” Have you missed Kerley B lines before? What’s your go-to sign for early interstitial edema? Let me know in the comments below. kerley b
Let’s break down what these lines are, why they appear, and why radiologists get concerned the moment they spot them. In simple terms, Kerley B lines are thin, linear opacities seen in the periphery of the lungs, most commonly near the costophrenic angles (the bottom corners of the lungs). If you’ve ever looked at a chest X-ray