b. Tissue Density and Tissue Contrast. Radiography of an infant's chest
normally requires a higher range of x-ray intensity in relation to a given part-size than in
the case of an adult. This is mainly due to the difference in the ratio of aerated to non-
aerated tissue in the thoraces of infants and adults. The opposite is the case for the
other parts of the body; that is, for a given part-size, less exposure energy normally is
required for a very young patient. The foregoing facts should be carefully evaluated
when it is necessary to modify tabular exposure techniques that are based on factors
scaled for routine radiography of adults.
c. Motion. The greatest obstacle to overcome in the normal course of pediatric
radiography is the adverse effect of motion--whether voluntary or involuntary. In a
young child (and especially in an infant), respiratory and cardiovascular motions are
much more rapid than in the average adult patient. The most effective method for
overcoming this limiting factor is by reduction of the exposure time.
d. Susceptibility to Infection. The x-ray specialist should always wash his
hands thoroughly before handling any pediatric patient. If suffering from a minor
respiratory complaint, he should wear a mask.
4-14. RADIOGRAPHIC PROCEDURE
a. Preliminary Procedure. The selection of technique factors, films, work-up of
identification material, and other necessary preparations should be completed before
the patient is brought into the exposure room. This will enable the x-ray specialist to
give his full attention to the handling of the patient. Calling the ward for pediatric
patients should be deferred until it is certain they can be given immediate attention.
(1) For the most part, the positioning procedure for pediatric patients should
conform to the essential technical considerations prescribed for the standard positions
with respect to a given examination.
(2) Awkward positions should be avoided. Whenever possible, advantage
should be taken of unorthodox angulations or positions of the x-ray tube.
(3) Unless otherwise indicated, examination of the extremities for a given
view should b done bilaterally, preferably by simultaneous exposure on the same film.
(4) In chest examinations, it is advisable to make two films, one at
inspiration and one at expiration.