Faces of Extrapleural Fat Sign CT Extra-Pleural Fat SignCT of a 72-year-old male shows a focal subsegmental area of atelectasis in the right lower lobe abutting the diaphragm associated with extra pleural fat proliferation secondary to the parenchymal infiltrate. This is an example of an extra-pleural fat signAshley Davidoff MD TheCommonVein.net 136036c