Ct-Perfusion Absolute Ghost Infarct Core Is a Rare Phenomenon Associated with Poor Collateral Status in Acute Ischemic Stroke Patients

<b>Background:</b> 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 no evidence of infarct at 24 h follow-up imaging, compared to CTP core volume at admission. This phenomenon was named absolute GIC (aGIC), and we investigated its prevalence and predictors. <b>Methods:</b> 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 h 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. <b>Results:</b> 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 (<i>p</i> < 0.001), shorter (<3 h) onset-to-imaging time (<i>p</i> < 0.016), poorer collaterals (<i>p</i> < 0.001), and higher hypoperfusion intensity ratio (<i>p</i> < 0.001) compared to the non-aGIC group. In multivariate analysis, ASPECTS (odds ratio (OR), 2.37; <i>p</i> <0.001), onset-to-imaging time (OR, 0.99; <i>p</i> = 0.034), collateral score (OR, 0.24; <i>p</i> < 0.001), and hypoperfusion intensity ratio (OR, 23.2; <i>p</i> < 0.001) were independently associated with aGIC. <b>Conclusions:</b> 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.