Intraosseous lipoma: 61-year-old female with chronic left knee pain. Frontal (a) and lateral (b) radiographs of the asymptomatic right knee obtained for comparison. Radiographs demonstrate a lucent lesion in the right tibial metaphysis with sclerotic margins and a narrow zone of transition. There is no periosteal reaction or associated soft tissue mass. Coronal T1W (c) and PD FS (d) images show the tibial metadiaphyseal lesion as isointense to fat on T1W with signal loss on the proton density fat saturated image.