Grid selection for oral cholecystography.
A radiographic and fluoroscopic unit was modified to image without a grid, with one 6:1 grid, and with two crossed 6:1 grids, placed with the strips at right angles (equivalent to a 12:1 grid). Fifty patients were studied in all three modes in both horizontal and upright positions. The crossed 6:1 grids were superior in 80% of cases. In those cases where no grid or one grid was superior, there was a shorter exposure time or no movement by the patient. High-ratio grids should be used for routine cholecystography combined with shorter exposure times for the initial procedure.
D002765:Cholecystography / Q000379:methods*; D006801:Humans; D013679:Technology, Radiologic