The radiographic appearance of an acute on chronic subdural hemorrhage may vary depending on the type of re-bleed and the organization of chronic bleed. 

It may appear isodense to the brain tissue, as a small acute bleed will mix with the lucent fluid of the chronic hemorrhage. Repeated trauma with active bleeding will cause a clot to form and would appear as a hyperdense lump within hypodense hemorrhage. It may also have a layered or ‘sedimentation appearance’. This is caused by the separation of extra-axial fluids of varying densities by internal membranes within the chronic clot. 

As illustrated in the case study, the layered appearance of various blood components are separated by the internal membranes and gravity on the left. Contralaterally, a gradation from the chronic bleed anteriorly to the acute bleed posteriorly in the parietal parts of the skull is seen. This is due to the higher density of the acute bleed and supine position.