Several studies in 2014 suggested that intravenous iodinated contrast use in computed tomography (CT) scanning was not associated with acute kidney injury. Now, the Mayo Clinic has performed a retrospective study of data investigating 5758 adults with chronic kidney disease stages 1−5 who underwent either noncontrast CT or iodixanol-enhanced contrast CT and who had pre- and post-CT serum creatinine measurements. The researchers chose to confine this cohort to recipients of iodixanol, an iso-osmolar contrast agent.
The contrast-exposed and noncontrast groups (≈1500 patients in each group) were statistically very similar on a broad range of variables, including baseline renal function. Contrast exposure was not associated with excess AKI incidence, need for dialysis, or mortality for all degrees of renal function. No contrast-associated worsening of renal function was apparent even in these patients with advanced renal disease.
The new iso-osmolar contrast agents have several advantages over the previously used hyperosmolar contrast agents. First, there is little risk of acute kidney injury compared with the older contrast agents. Second, there is less risk of fluid overload with the newer iso-osmolar contrast agents compared with the older hyperosmolar contrast solutions.