Fluoroscopy without the grid: a method of reducing the radiation dose.

The anti-scatter grid has been removed from the fluoroscopic set during the course of over 80 contrast examinations performed routinely during the ordinary workload of a busy paediatric radiology department. This manoeuvre approximately halves the radiation dose to the patient during both fluoroscopy and radiography. Our experience suggests that the degree of loss of contrast consequent on the abandonment of the grid is diagnostically acceptable during many examinations performed on children (of all ages), when balanced against the lower radiation dose received. In addition, an assessment has been made of the "contrast improvement factor" of the grids in two fluoroscopic sets in common use, using tissue-equivalent phantoms of various thicknesses. Although the contrast is significantly improved by the use of the grid, to a degree dependent on various factors, the relevance of this improvement in clinical radiology will depend on exactly what information is being sought. It is recommended that radiologists should use the grid with discretion when performing fluoroscopic examinations on children and that the apparatus for such examinations should have the capability for easy removal and reintroduction of the grid.