Paediatric Chest Exposures

Exposure

A correctly exposed radiograph should demonstrate pulmonary vessels in the central two-thirds of the lung fields without evidence of blurring. The trachea and major bronchi should also be visible as should the intervertebral disc spaces of the lower thoracic spine through the heart.

Respiration

Failure to achieve satisfactory inspiration is a common problem when radiographing children. In young children, the phase of respiration can be assessed by observing the rise and fall of the abdomen. The shape of the paediatric chest alters with growth and therefore the assessment of adequate inspiration by rib counting also changes. Adequate inspiration is important in order to visualise the lung fields clearly and to avoid the impression of cardiomegaly and prominent pulmonary vasculature.

Exposure factors and radiation protection

A fast film/screen combination 400–800 speed should be used in paediatric chest radiography combined with an exposure time of less than 10 ms to reduce the risk of movement unsharpness. The use of automatic exposure control (AEC) is not recommended for infants and small children due to the relatively large size of the chamber compared to the area of interest and the difficulty of positioning the chamber to an appropriate anatomical area.The kilovoltage (kV) selected is influenced by the size of the child. A relatively high kV should be used to reduce the radiation dose. The use of a grid or Bucky is not appropriate for chest radiography on small children. However, it may be used when imaging large adolescents.

Go back to paediatric radiography main page