Is There a Clinically Relevant Ischemic Penumbra?
Perfusion MR imaging is superior. Both methods provide information of similar quality. However, MR imaging systems can evaluate a larger proportion of the brain.86 The answer to each question is based on review of the literature and the practical everyday clinical experience of dealing with stroke patients who come to our hospital.2 So what do we use at the Massachusetts General Hospital? The answer is both techniques whenever possible. We perform both in most acute stroke cases because we are fortunate to have in our emergency department state-of-the-art CT and MR imaging that are located close to each other. The studies are also rapid, with CT/CTA/CT perfusion requiring 10 minutes or less and the MR imaging being restricted to diffusion, perfusion, and perhaps 1 additional sequence taking no more than 10 minutes of imaging time. An example of our approach is shown in Fig 6. Many institutions will have CT and MR imaging in different locations, raising logistic issues. The optimal solu