Brain imaging inspired by outer space.

Medicine has many vividly named signs. We have compiled a list of radiological cerebral signs inspired by phenomena in outer space. These range from the well-known 'starry sky' appearance of neurocysticercosis or tuberculomas, to various lesser known signs including the 'starfield' pattern of fat embolism; 'sunburst' sign of meningiomas; 'eclipse' sign of neurosarcoidosis; 'comet tail' sign of cerebral metastases; 'Milky Way' sign of progressive multifocal leukoencephalopathy; 'satellite' and 'black hole' sign of intracranial haemorrhage; 'crescent' sign of arterial dissection and 'crescent moon' sign of Hirayama disease.