Sarwani N, et al. - During this research, authors undertook a comparison of the variability in serum creatinine among inpatients receiving contrast imaging studies and among inpatients not receiving such studies. It was determined that among those who did not receive contrast, 18.3% had a creatinine increase of greater than 0.3 mg/dL, and before contrast, 14.2% had such increases. The similar increases among subjects who did not receive contrast vs patients who had not yet received contrast could be elucidated by the physiological variability. Findings exhibited that hydration therapy could explain the milder and fewer increases after contrast.