Computed Tomography Perfusion in Acute Ischemic Stroke

Mark N. Rubin, MD

David S. Liebeskind, MD; Mark W. Parsons, PhD; Max Wintermark, MD. Computed Tomography Perfusion Is Beyond Prime Time. Stroke. 2015

Magdy Selim, MD, PhD; Carlos A. Molina, MD. Computed Tomography Perfusion in Acute Ischemic Stroke: Is It Ready for Prime Time? Stroke. 2015
Michael H. Lev, MD. and Ramón G. González, MD, PhD.Computed Tomography Perfusion Is Not Ready for Prime Time. Stroke. 2015

In the East Coast vs West Coast (yes, Australia is honorarily part of our West Coast) stroke-neuroimaging-related battle of the year, these major players in the science of acute stroke treatment and imaging “discuss” whether or not computed tomography perfusion (CTP), clinically available for decades but recently in the treatment trial spotlight, should be broadly implemented in hyperacute stroke.

Team West Coast kicked things off with reminding us how simple and broadly available CTP is in the United States, extolled the virtues of its ability to give us mission-critical data for acute stroke therapy while easily integrated into already common CT-based stroke imaging protocols, then, for the knockout, also reminded us about how resounding positive the CTP-based selection trials were for therapy.

Team East Coast took the skeptical approach – perhaps with a bit of irony considering their contribution to CTP stroke science – citing that CTP is too imprecise on an individual patient level and diffusion magnetic resonance imaging (MRI) provides much more accurate “tissue data.”

For what it’s worth, in my experience I find the truth West-of-Center in this debate. Although I agree CTP is widely available, it is not always fast (performance or processing), does give a fair amount of radiation, can be obscured by patient motion and/or poor cardiac output, and is best for “gestalt” as the Partners suggest as CBV does not always cleanly match up with DWI changes. Dr. Liebeskind’s own colleague let us know every minute matters, and it is not clearly established that all patients should undergo this test – however many minutes it may take – if not of clear benefit.

That said, it has its uses, particularly in ischemic stroke of unknown time of onset but suspect within 6 hours and severe strokes (most typically associated with large-artery syndromes) for which an endovascular intervention is being considered. I also agree with the West Coast group that acute MRI is not feasible regionally, let alone nationally, let alone globally. If the mission is to reduce ischemic stroke morbidity and mortality broadly, then our diagnostics must be broadly applicable and MRI is cost-prohibitive in this sense.

Make sure you read this edition of Controversies in Stroke for yourself, as it’s rather crispy.