To Compare Intravenous and Oral Hydration of the Prevention for CIN in Elderly Patients Undergoing Intravenous CECT (CINOECT)

Inclusion Criteria:

• Age>21
• informed consent
• Undergoing Intravenous Contrast-enhanced Computed Tomography

Exclusion Criteria:

• CT enhancement was not performed;
• Dialysis treatment of patients with end-stage renal failure or heart, kidney transplantation;
• Exposure to radioactive contrast medium within 48 hours prior to or within 72 hours of examination;
• Acute decompensated heart failure;
• Allergic to radioactive contrast agent;
• Be subjected to life - threatening trauma;
• Severe infection;
• Surgery was performed within 2 days of CT examination.
• Combined with multiple myeloma, urinary obstruction, aortic dissection
• Can cause acute kidney injury disease;
• Use of aminoglycosides and other nephrotoxic drugs 2 weeks before.