Abstract T P53: Regional Vascular Status On Multi-phase CTA Correlates Well With Regional CT Perfusion Estimates And Final Tissue Fate
Introduction: Multi-phase CTA (mCTA) is a new imaging tool that generates time resolved images of contrast filling-in and washout within pial vessels in ischemic brain regions. In this study, we seek to demonstrate criterion and predictive validity of this imaging tool regionally by comparing vascular status as assessed using mCTA with CT perfusion estimates and with final tissue fate.
Methods: Data is from PRove-IT, an ongoing multi-national prospective study that seeks to understand the utility of multi-modal imaging in the triage of acute ischemic stroke patients. Only patients with M1-MCA occlusions were included for the analysis. “Delay” in maximal pial vessel enhancement, “Extent” of maximal pial vessel enhancement and degree of “Washout” of contrast within these pial vessels was each graded on a 3-point scale in each of the 5 ASPECTS regions (M2-6)(Fig 1). CBF, CBV, MTT, T Max and T0 values were calculated within these same ASPECTS regions on CTP. Reperfusion status was assessed regionally using the Kim’s template. Final tissue fate per region was determined on 24 hr MR/CT.
Results: We included 45 patients (225 ASPECTS regions) in the study. Specific parameters on mCTA correlated with specific perfusion estimates on CTP [Delay and T0 time (Kruskal-Wallis p=0.001), Washout and MTT (p<0.001), Extent and CBV (p<0.001)] regionally. On multivariable linear regression, Washout (p=0.04) and Extent grade (p<0.001) in each region were independently associated with ipsi-regional CBF. Classification and regression tree analysis (CART) discriminated between regional CBF thresholds ranging from <7ml/100gm/min to >15ml/100gm/min using a combined “Washout+Extent” grade on mCTA. In the early reperfusers, this combined “Washout+Extent” grade was related significantly with tissue fate regionally (Fisher’s p=0.04).
Conclusion: Regional vascular status on mCTA provides similar information to CTP estimates and is capable of predicting final tissue fate regionally.
Author Disclosures: A. Trivedi: None. S. Ahn: None. C. d’Esterre: None. S. Patil: None. E. Qazi: None. E. Fainardi: None. M. Rubiera: None. A. Khaw: None. T. Lee: None. A.M. Demchuk: Honoraria; Modest; Covidien honoraria for CME. Research Grant; Significant; Unrestricted grant for ESCAPE trial: Covidien. M. Goyal: Other; Significant; Patent pending. B. Menon: None.
- © 2015 by American Heart Association, Inc.