Imaging of intracranial haemorrhage.

Intracranial haemorrhage can be a devastating disorder that requires rapid diagnosis and management. Neuroimaging studies are not only required for diagnosis but also provide important insights into the type of haemorrhage, the underlying aetiology, and the accompanying pathophysiology. Historically, CT has been the diagnostic imaging study of choice; however, there is a growing body of data that suggest that MRI is at least as sensitive as CT to detect haemorrhage in the hyperacute setting, and superior to CT in the subacute and chronic settings. Blood has characteristic appearances on both imaging modalities at each stage (acute, subacute, and chronic) and it is important that physicians are familiar with the appearance of various types of intracranial haemorrhage on CT and MRI and their clinical implications. In addition, new imaging applications, such as magnetic resonance spectroscopy and diffusion tensor imaging, are promising research techniques that have the potential to enhance our understanding of the tissue injury and recovery that result from intracranial haemorrhage.