Covidien's subsidiary Mallinckrodt has filed suit against two U.S. units of Italy's Bracco for patent infringement on a contrast power injector for patients undergoing MRI.

The St. Louis-based Mallinckrodt is asking for a jury trial, unspecified damages and an injunction to prevent infringement by Bracco's E-Z-EM of Lake Success, N.Y., and Acist Medical Systems of Eden Prairie, Minn., reported the Boston Globe.

"Mallinckrodt is the implied exclusive licensee of the patent" and the defendants wrongly "sell a power injector under the name EmpowerMR" that violates the patent, according to a complaint filed April 4 in federal court in Wilmington, Del., the Globe reported.

"We recently filed a patent infringement lawsuit against Acist Medical Systems and E-Z-EM, in the U.S. District Court of the Federal District of Delaware. The lawsuit relates to infringement of a patent involving an MR injector system. We have no further comment on this matter," according to an email response from Covidien.