Diffuse MR pattern of abnormal marrow in a 29-year-old man with AML: T1-weighted sagittal (500/10, TR/TE) (A), T2-weighted, fat-suppressed fast spin echo sagittal (5000/96, TR/TE, ET 16) (B), and enhanced T1-weighted sagittal (500/10, TR/TE) (C) MR images of the thoracic spine. The abnormal vertebral bodies in (A) are dark and isointense to the intervertebral discs and in (B) they become bright. In (C), the abnormal marrow enhances and the vertebrae become brighter than the discs. Note extraosseous mass (arrowheads) in the posterior epidural space with preservation of the bony cortex.