What are lung nodules? "A lung nodule is a small, solid, rounded mass of tissue in the lungs that can be seen on a chest computed tomography (CT) scan or X-ray as a white spot," explains Samir ...

Dense materials like bones and metal appear white on the X-ray, while air in the lungs appears black. Soft tissues, including muscles and fat, show up in shades of grey. In some cases, contrast ...