In fluoroscopy with an image intensifier: When utilising a brightness control curve optimised for an iodine contrast study, as image brightness reduces automatic brightness control should increase only the kV until the max kV that can be sustained by the tube before increasing mA.
The description is a curve that is optimised for reduced dose at the expense of image quality. For iodine studies the kV should be maintained around 60 kV which is optimum for imaging iodine with a K-absorption edge of 33 keV.
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