Radiologic Examination—Plain Films
There are a number of indirect diagnostic approaches which can be used to detect cancer. The most common of these methods is known as radiology or roentgenography. Radiology refers to photography by means of roentgen rays, which are electromagnetic radiation of extremely short wave length with great penetrating powers in matter opaque to light. X-rays are produced when high energy beams of electrons strike matter. An X-ray photograph is a negative (like a camera film) rather than a positive (like a print).
Words ending in "-graphy" refer to the act of recording studies of various parts of the body. Words ending in "-gram" refer to the resulting record while "-graph" refers to either the instrument for recording or the resulting record.