Coronal images are shown from three patients with different degrees of marrow uptake on PET. FDG uptake within the marrow is seen on these sections in the thoracic spine (broken arrows) and within the liver (solid arrow). The intensity of uptake was graded as less than liver (A), equal to liver (B), or greater than liver (C), with the marrow deemed to be abnormal where uptake was equal to or greater than liver.