As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - INFLIGHT JUST AFTER ROTATION A STRANGE RUBBING NOISE WAS HEARD FROM THE COCKPIT FOLLOWED BY A THUMP. A STRONG VIBRATION WAS FELT IN THE REAR OF THE AIRCRAFT. RETURNED TO BOS AND LANDED WITHOUT INCIDENT. FOUND METAL IN OIL FILTER. REPLACED RIGHT ENGINE. FLIGHT DATA RECORDER DOWNLOAD REQUESTED FROM ENGINEERING.