Abstract
Recent advances are allowing computed tomography (CT) and magnetic resonance imaging
(MRI) to add diagnostic information derived from microscopic-scale brain structure,
pathology, and physiology to the gross pathologic information that has been the core
of brain imaging diagnosis since the 1980s. Physiologic imaging with MR perfusion
weighted imaging has joined MR diffusion imaging as an essential components of stroke
and brain tumor MRI. At the same time, the volume scanning revolution in CT technology
has dramatically decreased the radiation doses required for CT perfusion imaging by
allowing routine simultaneous CT perfusion and noninvasive dynamic bone subtracted
CT angiography (CTA) without a significant increase in radiation dose over conventional
head CT–CTA alone. Although ongoing research and clinical trials is needed to define
more precisely how these techniques can best be exploited to improve clinical care
and patient outcomes, in the acute stroke and subarachnoid hemorrhage populations
the radiation risk associated with CT perfusion imaging is negligible and the physiologic
information promises significant patient safety benefits.
Keywords
perfusion - stroke - brain tumor
