Bracco Diagnostics has sent its customers an update regarding its voluntary recall of the CardioGen-82 rubidium generator. The company indicated that user error, a higher than expected strontium breakthrough, or a combination of both factors likely accounted for the triggering of gamma ray emission sensors by two patients crossing the U.S. border in July.

In the letter dated Oct. 17, the Princeton, N.J.-based company explained that all recalled generators capable of being evaluated were within operating specifications. “Our investigation findings, to date, continue to support that the unexpected radiation levels may have been due to user error or strontium breakthrough higher than what is expected with normal generator use or a combination of both.”

The company stressed its commitment to "expeditiously" returning CardioGen-82 to the market and anticipates a limited and progressive reintroduction of the product in the first or second quarter of 2012.

Bracco also urged sites and professional societies to communicate their experiences with CardioGen-82 and PET myocardial perfusion imaging to the FDA.