Lum C, Ahmed ME, Patro S, Thornhill R, Hogan M, Iancu D, et al. Computed Tomgraphic Angiography and Cerebral Blood Volume Can Predict Final Infarct Volume and Outcome After Recanalization. Stroke. 2014
As was recently discussed, acute stroke evaluations start out fairly structured but can quickly get complicated. This is especially true if a provider is considering endovascular reperfusion therapies, which currently exist in a sort of evidence-based-therapeutic purgatory. We have amazing “physiology” neuroimaging studies, namely perfusion-based CT and MRI, that make all the sense in the world to be helpful in selecting for patients at risk but treatable and those for whom the proverbial ship has sailed, but, to oversimplify, no dice.
While experts work on better trial design with better devices and better imaging modalities, we have to take care of these patients now.
That being the case, the Ottawa Stroke Research Group has made an interesting contribution to the field of advanced neuroimaging for acute stroke decision making. They put together a cohort of prospectively enrolled patients with acute ischemic stroke and “a clean CT” who ended up triaged to the endovascular suite for intervention. The group routinely screens for large vessel occlusion and perfusion abnormalities prior to endovascular treatment, and thus embarked on a study to compare a non-contrast CT to CTA source images to CT-perfusion based cerebral blood volume (CBV) findings to 24-hour infarct on a repeat CT head and 30-day outcome. The details are interesting, but overall, the CTA source images and CBV were better able to predict size of infarct on CT at 24h, which was fairly well tied to 30-day outcome in their cohort.
To suggest we should start routinely triaging patients to the endovascular suite based on their methodology and findings alone would be a perilous jump in logic. However, at least in this particular subset of patients, these findings can inform future trials and at least gives us a sense that, while still in the Wild West of complex acute stroke care, these fairly readily available and rapidly obtained radiographic signs may be of some clinical utility.