Color-coded multiphase computed tomography angiography may predict outcome in anterior circulation acute ischemic stroke.

PURPOSE: To evaluate whether arterial and venous color-coded mCTA score may predict clinical outcome in anterior circulation acute ischemic stroke. METHODS: Consecutive patients referred to the emergency department with anterior circulation acute ischemic stroke (AIS) were retrospectively reviewed at our center. All patients underwent multimodal brain computed tomography (CT) imaging, including non-contrast CT (NCCT) and multiphase computed tomography angiography (mCTA). Baseline collateral scores of color-coded mCTA, also known as ColorViz, and conventional mCTA were recorded. mCTA was assessed by a 6-point scale whereas color-coded mCTA was assessed by a 3-point scale. In the Color-coded maps, a different color is assigned to intracranial vessels based on the arrival time of the contrast medium and on a per-person adaptive threshold technique. We compared the radiological and clinical features of a group of patients who reached independency (defined as modified Rankin Scale score ≤ 2) with those of patients who did not. A multivariate logistic regression model was then used to assess the potential of color-coded mCTA scores to predict patients' outcome after AIS. RESULTS: A total of 86 patients (36 M, 50 F) were enrolled in the study. Multivariate logistic regression showed that score 3 at Color-coded mCTA was a good predictor of favorable outcome (p = 0.003). Moreover, NIHSS at onset (p = 0.004) and discharge (p < 0.001) along with ischemic core area (p = 0.011) were significant predictors of favorable prognosis. CONCLUSION: our data confirm that ColorViz is a useful and easily understandable neuroimaging tool that might have a predictive role in assessing the outcome of anterior circulation acute ischemic stroke patients regardless of revascularization therapy.

ColorViz, a New and Rapid Tool for Assessing Collateral Circulation during Stroke.

Prognosis of patients with acute ischemic stroke is strictly related to the patency and prominence of the collateral leptomeningeal pathways distal to the arterial occlusion. The gold standard for assessment of collateral circulation is conventional angiography, but it is invasive and used in selected cases. To date, the most reliable technique is multiphase CTA; currently, the available classifications of collateral circles are often complex, time-consuming, and require a trained observer. The purpose of our work is to establish the effectiveness of a new semi-automatic post-processing software (ColorViz FastStroke, GE Healthcare, Milwaukee, Wisconsin) in evaluation of collateral circulation compared to the six-point classifications of multiphase CTA already validated in literature. We selected 86 patients with anterior ischemic stroke symptoms who underwent multiphasic CTA in our emergency department. Two radiologists separately evaluated the collateral leptomeningeal vessels, analyzing respectively, the multiphase CTA (using the six-point scale and its trichotomized form) and ColorViz (using a three-point scale). Then the results were matched. We found a good correlation between the two different analyses; the main advantage of ColorViz is that, while maintaining fast diagnostic times, it allows a simpler and more immediate evaluation of collateral circulation, especially for less experienced radiologists.