MINIMIZING RADIATION-DOSE TO PATIENT AND STAFF DURING FLUOROSCOPIC, NASOENTERAL TUBE INSERTIONS

It is possible to reduce greatly fluoroscopic radiation dose if some image degradation is acceptable. Since the fluoroscopic image during nasoenteral tube placements is used for guidance and not for diagnosis, a lower contrast image with increased quantum mottle can be easily tolerated. The three methods to reduce the radiation dose rate that were investigated consisted of removing the antiscatter grid, increasing the diameter of the optical aperture controlling the percentage of light reaching the television camera from the image intensifier output phosphor, and setting the fluoroscopic mA to the minimum value so that the kVp could be maximized. Fluoroscopic frozen video frames of a clinical tube insertion comparing the images with and without the dose-saving techniques are presented. Measurements of the radiation dose rates using a Plexiglas phantom show that the dose for patient and staff during fluoroscopic-guided nasoenteral tube placements can be reduced by over a factor of 10 without significantly adversely affecting the actual placement procedure.