High-level programming languages, designed in 1964, Beginner's All-purpose Symbolic Instruction Code.

If available, some graphic aids can be helpful to show image orientations.
1) A graphic icon of the labeled primary axes (A, L, H) with relative lengths given by direction sines and system of coordinates as if viewed from the normal to the image plane can help orient the viewer, both to identify image plane orientation and to indicate possible in plane rotation.
2) In graphic prescription of obliques from other images, a sample original image with an overlaid line or set of lines indicating the intersection of the original and oblique image planes can help orient the viewer. The location in the R/L and P/A directions can be specified relative to the axis of the scanner.
The F/H location can be specified relative to a convenient patient structure.
The orientation of single oblique slices can be specified by rotating a slice in one of the basic orientations toward one of the other two basic orthogonal planes about an axis defined by the intersection of the 2 planes.
Double oblique slices can be specified as the result of tipping a single oblique plane toward the remaining basic orientation plane, about an axis defined by the intersection of the oblique plane and the remaining basic plane. In double oblique angulations, the first rotation is chosen about the vertical image axis and the second about the (new) horizontal axis. Angles are chosen to have magnitudes less than 90° (for single oblique slices less than 45°); the sign of the angle is taken to be positive when the rotation brings positive axes closer together.

An anion is a negative charged ion; the atom has more electrons than protons. Anions are attracted from the positively charged anode. This is a basic part for producing radiation in the x-ray tube.

(ALARA) 'As low as reasonably achievable' is a precautionary principle that should be part of basic radiation safety considerations in protection to the exposure as well as in other technologies of the medical, the nuclear and the industrial fields.
ALARA is based on three principles: Justification means that possible exposure to humans should yield a sufficient benefit to society to justify the risks of the radiation exposure. The ICRP in 1977 states that 'all exposures shall be kept as low as reasonably achievable, economic and social factors being taken into account'. The radiation exposure must be reduced to the lowest level possible, considering the costs of such a limitation in dose.

An atom is the basic particle of matter, the smallest (~10^-8cm) particle of a chemical element. Atoms consist of a nucleus with neutrons, positive charged protons and orbiting negative charged electrons. The chemical properties of elements are defined largely by the number of protons in the nucleus. The number of electrons is similar to the number of protons. An atom is ionized when the number of electrons is not equal to the number of protons; the resulting electrical charge depends on the difference between the number of protons and the number of electrons.

See Rutherford-Bohr Atom Model, Ionization.