X-rays refers to a type of light ray that is useful for clinical work of various parts of the body, because they show the presence and position of bones, fractures, and foreign bodies. A clinical disadvantage of X-rays, and specifically X-ray films of the brain, is that there is little differentiation between the brain structures and the cerebrospinal fluid, making the clinical use of this procedure ineffective.
Lexicon of Psychology - Terms, Treatments, Biographies,