Researchers at Colombia University Medical Center in New York say levels of creatine -- previously linked to nephropathy or kidney damage in the contrast material studies -- may go up even if the contrast material is not used.

"Because serum creatinine levels change frequently in the absence of iodinated contrast media material, prior studies of the relationship between iodinated contrast material and renal function must be interpreted with caution, and future experiments should have appropriate controls," lead author Dr. Jeffrey Newhouse says in a statement. "We don't claim that IV contrast material never induces nephropathy, but it may do so less frequently and severely than previously thought. If subsequent experimentation proves its safety, it could be used more frequently in patients with renal failure."

Newhouse and colleagues reviewed the creatinine levels of patients' records at Colombia who had not received iodinated contrast material.

"We then compared that to previously published articles which found a relationship between contrast media, serum creatinine levels and nephropathy," Newhouse says. "We found that the creatinine level increases just as often in those who do not receive contrast material as in those who do."