MODEL RELEASED. Analysing X-rays. Radiologist examines X-rays of a chest and other parts of the body, & makes notes by speaking into a dictaphone. Radiography is an important diagnostic technique. A radiograph is like a photographic 'negative' - the light areas represent an absence of X-rays on the film. X-rays are high-energy electromagnetic waves. They can penetrate soft tissue but are absorbed in heavier materials such as bone.