Baseline imaging for determining infarct core in patients with acute ischemic stroke: noncontrast computed tomography...

To compare the value of noncontrast computed tomography (NCCT) and computed tomography perfusion (CTP) in determining the infarct core in patients with acute ischemic stroke (AIS).

Four hundred and forty-nine AIS patients who underwent baseline NCCT and CTP assessment, endovascular thrombectomy (EVT) and follow-up imaging evaluation from October 2019 to August 2023 were retrospectively enrolled. Alberta Stroke Program Early Computed Tomography Score (ASPECTS) were assessed on baseline NCCT, cerebral blood flow (CBF) colored map and follow-up imaging. Baseline infarct core volume was calculated as regions with reduction in the relative CBF < 30% of that in contralateral normal tissue. "NCCT-CTP mismatch" was defined as low ASPECTS (< 6) with small infarct core (< 70 ml) (LASC), or high ASPECTS (≥ 6) with large infarct core (≥ 70 ml) (HALC).

"NCCT-CTP mismatch" was found in 145 (32.3%) patients, and 35.9% of them achieved good outcomes after EVT. IVT using before CTP imaging (OR, 1.833; P = 0.005) and higher admission NIHSS (OR, 1.055; P < 0.001) were independently associated with "NCCT-CTP mismatch". LASC patients exhibited longer stroke onset time [median, 306 min vs. 125 min; P = 0.004] and higher rate of hemorrhagic infarction (33.1% vs. 8.3%, P = 0.077) after EVT than HALC patients. Compared with CBF map, stronger correlations of deep basal ganglia regional infarct were found between baseline NCCT and follow-up imaging for both early and late presenters (all P < 0.05).

About 30% patients showed "NCCT-CTP mismatch", and 35.9% of them achieved good outcome. Despite NCCT showing stronger correlations, CTP could provide complementary information to NCCT, therefore both were suggested in future practice.