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

Cluster Ages to Reconstruct the Milky Way Assembly (CARMA)

We present CARMA, the Cluster Ages to Reconstruct the Milky Way Assembly project, the aim of which is to determine precise and accurate age measurements for the entire system of known Galactic globular clusters (GCs) and to use them to trace the most significant merger events experienced by the Milky Way. The strength of CARMA relies on the use of homogeneous photometry, theoretical isochrones, and statistical methods, which will enable us to define a systematic uncertainty-free chronological scale for the complete sample of Milky Way GCs. In this paper, we describe the CARMA framework in detail, and present a first application on a sample of six metal-rich GCs, with the aim being to unequivocally elucidate the debated origin of NGC 6388 and NGC 6441. Our results demonstrate that this pair of clusters is coeval with another four systems that have a clear in situ origin. Moreover, their location in the age–metallicity plane matches that occupied by in situ field stars. The accurate age comparison enabled by the CARMA methodology rules out the possibility that NGC 6388 and NGC 6441 were accreted as part of a past merger event