Background CT-Perfusion (CTP) overestimation of core volume >10 mL compared to the final infarct volume (FIV) size is the current definition of the ghost infarct core (GIC) phenomenon. However, subsequent infarct growth might influence FIV. We aimed to report a more reliable assessment of GIC occurrence, defined as the lack of FIV at 24 hours follow-up imaging, compared to CTP core volume at admission. This phenomenon was named absolute GIC (aGIC) and we investigated its prevalence and predictors.

Methods A total of 652 consecutive stroke patients with large vessel occlusion who achieved successful recanalization (mTICI 2b-3) after Endovascular Treatment (EVT) and non-contrast CT (NCCT) follow-up imaging at 24 hours were retrospectively analyzed. Ischemic core volume was automatically generated from CTP, and FIV was manually determined on follow-up NCCT. Multivariable logistic regression was used to explore aGIC predictors.

Results We included 652 patients (53.3% female, median age 75 years), of whom 35 (5.3%) had an aGIC. The aGIC group showed higher ASPECTS (p<0.001), shorter (<3 hours) onset-to-imaging time (p<0.001), poorer collaterals (p<0.001), higher hypoperfusion intensity ratio (p=0.001) compared to the non-aGIC group. In multivariate analysis, ASPECTS (odds ratio [OR], 1.87; p<0.001), onset-to-imaging time (OR, 0.99; p=0.013), collateral score (OR, 0.45; p<0.004) and hypoperfusion intensity ratio (OR, 23.2; p<0.001) were independently associated with aGIC.

Conclusion aGIC is a more reliable evaluation of infarct core volume overestimation assessed on admission CTP and represents a rare phenomenon, associated with ultra-early presentation and poor collaterals.

Dr. Morotti declared consulting and expert meeting honoraria for EMG-REG International and AstraZeneca. Dr. Zini declared consulting and speaker fees from Boehringer-Ingelheim, Alexion-AstraZeneca and CSL Behring, Bayer, Angels Iniziative, Daiichi-Sankio. All the other Authors report no disclosures.

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