A 19-year-old Chinese man presented to the emergency department with pain in the lower back, which started soon after he had carried some heavy boxes. He denied any fall or trauma preceding the pain. There was no sciatica or neurological deficit on examination. He maintained a normal gait and anal tone. The lumbar spine radiographs were normal. Magnetic resonance (MR) imaging was requested in order to evaluate his persistent back pain. What do the MR images show? What is the diagnosis? Clinics in diagnostic imaging (150)Nor DIAGNOSISAcute spontaneous spinal epidural haematoma. CLIN ICA L COU RS EThe patient was admitted under the care of a spinal surgeon. Those older than 40 years of age show two peak locations, namely the cervicothoracic and thoracolumbar junctions. M e d ic a l E d u c atio n 668 668The presence of the posterior epidural venous plexus supports the commonly accepted theory of a venous cause to the haematoma, where the valveless venous plexus permits a reversal in blood flow when pressure is increased during injury or activity. On sagittal MR images, SSEH is seen as a biconvex-shaped mass separated from the underlying neural structures by a curvilinear low-signal-intensity structure -the dura mater