High-field magnetic resonance image of a huge calcified chronic subdural haematoma, so-called "armoured brain".

Calcification of chronic subdural haematoma is called "armoured brain" when it covers most of the cortical surface. We report high-field magnetic resonance images of the armoured brain, and discuss the relationship between operative findings, computer assisted tomographic (CT) findings and the change in relaxation time on magnetic resonance images. In our case, low, iso, and high density layers were detected on computer assisted tomography. The change in relaxation time of a liquefied haematoma showed good agreement with chronological change in intracerebral haematoma, and the material was easily detected on magnetic resonance images. But with a grainy and mud-like haematoma, the change in relaxation time did not coincide with the state of the intracerebral haematoma. It is generally said that in the detection of a calcified mass, computer assisted tomography is superior to magnetic resonance images and this was also true in the present case. While there are a few reports on computer assisted tomographic findings for the armoured brain, this is probably the first report on high-field (1.5T) magnetic resonance imaging of the armoured brain.