Radiation dose reduction in paediatric fluoroscopy using added filtration.

Studies on a water phantom indicate that the insertion of extra tube filtration combined with the removal of the antiscatter grid can reduce the total energy imparted from paediatric fluoroscopy by a factor of more than four when automatic exposure control is used. The omission of the grid is responsible for up to 40% of the reduction while the addition of 0.7 mm steel filtration is found to account for a further reduction in energy imparted of between 57% and 70%, for depths of water simulating small patients of 6-16 cm thickness. For all contrast paediatric examinations the reduction in image quality was considered to be small and the diagnostic information unimpaired with the filter in place.