Introduction:
Despite the described risk of contrast-induced nephropathy, defined as sudden (up-to 48–72 h) deterioration of renal function after the administration of contrast, guidelines for border level renal excretory function markers securing safe contrast CT have not been established. The aim of study was to assess the effect of CT with intravenous contrast on changes of renal excretory function markers.

Materials and methods:
In a prospective study, 60 patients who had CT with intravenous contrast were analyzed. Before CT and after 48 hours, the level of markers of renal function: creatinine, urea and potassium were marked in the patients’ serum and the eGFR value was calculated. The patients were divided into 2 groups, depending on the output value of creatinine and eGFR: group 1 – normal values and group 2 – slightly elevated ones by 20%.

Results:
The average concentration of creatinine before CT did not differ significantly from the values after contrast application (1.05 ± 0.23 vs. 1.03 ± 0.26 mg/dl). The average value of eGFR before contrast CT did not differ significantly from the value after contrast application (71.53 ± 18.86 vs. 74.25 ± 22.50 ml/min./1.73 m2). No significant changes in urea and potassium concentrations after radio-contrast application were observed. The values of the analyzed markers did not differ significantly compared to the baseline values in any group, nor did sex or type of CT have an effect on the marker levels.

Conclusions:
The intravenous administration of contrast during CT does not cause significant changes in renal excretory function markers, either in patients with normal renal function or in patients with baseline values elevated by 20%, irrespective of sex or type of CT.