(5) The processing of the exposed film is more critical than in conventional
radiography. Time-temperature development in fresh solutions of proper strength is
imperative. Safe lighting must conform to proper standards of darkroom illumination.
The film emulsion must be fresh and have unimpaired quality.
c. X-ray Unit. A full-wave rectified x-ray unit of sufficient capacity and equipped
with a rotating anode tube is preferred. With this type of unit, it is possible to minimize
the effects of motion unsharpness by the use of shorter exposure times.
d. Positioning. Positioning of the part is the same as for routine radiography.
Modification in positioning or in the alignment of the CR may be necessary to
circumvent overlying bone or other structures that may obscure the site of interest.
e. Basic Technique. The basic technique factors given below (see table 4-2)
should prove of value as a starting procedure and are listed solely for the guidance of
the x-ray specialist. They are based on the average-sized adult using a full-wave
rectified unit and par speed intensifying screens. If a trial exposure is indicated to
determine the characteristic behavior of the x-ray unit or intensifying screens, a small
portion of the site to be demonstrated should be selected and the surrounding areas
marked off with suitable radiopaque materials prior to making the exposure.
Examination of the test exposure should enable the x-ray specialist to make the
necessary adjustments. If the exposed area on the film is excessively dense, the mAs
(milliamperes-seconds) value should be reduced; if it is blank or devoid of image details,
the kVp should be increased. The following techniques should prove useful as those
suitable for average adult exposures.
Hand and wrist
Elbow and ankle
Table 4-2. Basic technical factors.