Vena Cava Filter (IMAGE) Michigan State University Caption A new study out of MSU reveals when vena cava filters should -- and should not -- be used in patients with a pulmonary embolism. Credit Courtesy photo Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.