Modern medical practice has seen many advances in imaging over the past ten years. Magnetic Resonance Imaging, CT scanning and Ultrasound investigations have all been added to the repertoire of normal practice. However, the humble chest X-ray remains a crucial first line investigation - particularly for acute medical admissions. Many chest X-rays are requested for a specific purpose e.g. confirmation of pneumonia, but the image may reveal features of previously unsuspected disease of another body system. Digital storage of X-ray images means that a chest X-ray may be viewed at any computer...