The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

collimation

1. In microscopy, the process of making light rays parallel; the process of aligning the optical axis of the optical system to the reference mechanical axes or surfaces of the instrument, or the adjustment of two or more optical axes with respect to each other.

2. In radiology, the elimination of the peripheral (more divergent) portion of an x-ray beam by means of metal tubes, cones, or diaphragms interposed in the path of the beam.

3. In nuclear medicine, the use of a perforated absorber to restrict the field of view of a detector and reduce scatter; the use of an absorber with converging or diverging perforations will also change the camera’s angle of view.