Contrast-Induced Acute Kidney Injury(CIAKI) was defined as an absolute increase in serum creatinine of more than or equal to 0.3mg/dl (≥ 26.4 μmol/l), a percentage increase in serum creatinine of more than or equal to 50% (1.5-fold from baseline) within 48 hours of intravascular contrast administration in the absence of any alternative causes, or a reduction in urine output documented oliguria of less than 0.5 ml/kg per hour for more than six hours.