In 1895, physicist Wilhelm Roentgen discovered X-rays during an experiment with a cathode tube. He observed invisible rays passing through cardboard, causing another screen to glow. Unsure of their nature, he named them X-rays, a discovery that later earned him a Nobel Prize.

X-rays are a form of electromagnetic radiation with higher energy than visible light. They are produced when high-energy electrons hit a metal component, releasing energy. X-rays can penetrate many materials, making them useful for medical imaging, but they can also cause mutations, which is why lead aprons are used for protection.

X-rays interact with matter by colliding with electrons. Their absorption or scattering depends on the material's density and atomic number. Dense materials and elements with higher atomic numbers, like calcium in bones, absorb X-rays more effectively, appearing white on film. Softer tissues, with lower density and atomic numbers, allow more X-rays to pass through, darkening the film.

Traditional 2D X-ray images have limitations as they sum all interactions along the path. To get a more detailed internal view, doctors use Computed Tomography (CT) scans. This Nobel Prize-winning invention involves taking X-ray views from multiple angles to construct a detailed 3D image, which helps in determining the exact position and shape of anomalies like tumors.

A CT scanner sends a fan or cone of X-rays through the patient to an array of detectors while rotating around the body, often in a spiral trajectory. This process generates detailed cross-sectional data, allowing doctors to identify anatomical features, tumors, blood clots, infections, and even historical medical conditions in mummies, demonstrating CT scans' significant impact on medical diagnostics and saving lives.