tokens: The 80 patients in the study consecutively received either iopromide ( group A , n = 40 ) or iohexol ( group B , n = 40 ). Serum sodium ( Na ), potassium ( K ), and creatinine ( Cr ) were measured 24 h before angiography as baseline values , then measured again at 12 -, 24 -, and 48 - h intervals after CM use .