BACKGROUND: The prospective study assessed infarct growth rate (IGR) in acute ischemic stroke (AIS) with large vessel occlusion (LVO) after recanalization in early time window. Early IGR (EIGR) and late IGR (LIGR) were correlated with imaging and clinical data; we searched for outcome predictors. METHODS: We included 71 consecutive patients. Subjects underwent computed tomography perfusion (CTP) for ischemic core volume assessment at 99.0 minutes (median) from stroke onset, recanalization was performed at 78.0 minutes (median) from CTP. Final infarct volume (FIV) was measured on 24±2 hours imaging follow-up. EIGR was calculated as the core volume/time between stroke onset and CTP; LIGR was calculated as FIV/time between CTP and imaging follow-up. Twenty-two subjects were assessed as poor outcome, 49 as good outcome. Group differences were tested by Mann-Whitney test and χ2 test. Bayesian logistic regression models were used to predict clinical outcome, Pearson correlations for the log-transformed predictors. RESULTS: Subjects with poor outcome were older, median age 78.0 [interquartile range (IQR): 71.8, 83.8] versus 68.0 (IQR: 57.0, 73.0) years; 95% confidence interval (CI): 6.00 to 16.00; P<0.001. Their stroke severity scale was higher, median 19.0 (IQR: 16.0, 20.0) versus 15.5 (IQR: 10.8, 18.0); 95% CI: 1.00 to 6.00; P<0.001. They had higher EIGR, median 23.9 (IQR: 6.4, 104.0) versus 6.7 (IQR: 1.7, 13.0) mL/h; 95% CI: 3.26 to 53.68; P=0.002; and larger core, median 52.5 (IQR: 13.1, 148.5) versus 10.0 (IQR: 1.4, 20.0) mL; 95% CI: 11.00 to 81.00; P<0.001. In subjects with poor outcome, infarct growth continued after thrombectomy with LIGR 2.0 (IQR: 1.2, 9.7) versus 0.3 (IQR: 0.0, 0.7) mL/h; 95% CI: 1.10 to 6.10; P<0.001; resulting in larger FIV, median 186.5 (IQR: 49.3, 280.8) versus 18.5 (IQR: 8.0, 34.0) mL; 95% CI: 55.30 to 214.00; P<0.001. Strong correlations among predictors were found e.g., core and EIGR (r=0.942), LIGR and FIV (r=0.779), core and FIV (r=0.761). Clinical outcome was best predicted using data from later measurements as FIV and LIGR. CONCLUSIONS: Data from later measurements were more predictive, there was no major benefit to use growth over volume data.

• Klíčová slova
• Computed tomography perfusion (CTP), core, infarction, progressors,
• Publikační typ
• časopisecké články MeSH

CT perfusion (CTP) is used for the evaluation of brain tissue viability in patients with acute ischemic stroke (AIS). We studied the accuracy of three different syngo.via software (SW) settings for acute ischemic core estimation in predicting the final infarct volume (FIV). The ischemic core was defined as follows: Setting A: an area with cerebral blood flow (CBF) < 30% compared to the contralateral healthy hemisphere. Setting B: CBF < 20% compared to contralateral hemisphere. Setting C: area of cerebral blood volume (CBV) < 1.2 mL/100 mL. We studied 47 AIS patients (aged 68 ± 11.2 years) with large vessel occlusion in the anterior circulation, treated in the early time window (up to 6 h), who underwent technically successful endovascular thrombectomy (EVT). FIV was measured on MRI performed 24 ± 2 h after EVT. In general, all three settings correlated with each other; however, the absolute agreement between acute ischemic core volume on CTP and FIV on MRI was poor; intraclass correlation for all three settings was between 0.64 and 0.69, root mean square error of the individual observations was between 58.9 and 66.0. Our results suggest that using CTP syngo.via SW for prediction of FIV in AIS patients in the early time window is not appropriate.

• Klíčová slova
• endovascular thrombectomy, magnetic resonance imaging, penumbra, stroke imaging, syngo.via,
• Publikační typ
• časopisecké články MeSH

The absolute majority of strokes in high-income countries, roughly 91%, are of ischemic origin. This review is focused on acute ischemic stroke (AIS) with large vessel occlusion (LVO) in the anterior circulation, which is considered the most devastating subtype of AIS. Moreover, stroke survivors impose substantial direct and indirect costs of care as well as costs due to productivity loss. We review of diagnostic possibilities of individual imaging methods such as computed tomography and magnetic resonance imaging, and discuss their pros and cons in the imaging of AIS. The goals of non-invasive imaging in AIS are as follows: (a) to rule out intracranial hemorrhage and to quickly exclude hemorrhagic stroke and contraindications for intravenous thrombolysis; (b) to identify potential LVO and its localization and to quickly provide guidance for endovascular treatment; (c) to assess/estimate the volume or size of the ischemic core. We suggest fast diagnostic management, which is able to quickly satisfy the above-mentioned diagnostic goals in AIS with LVO.

• Klíčová slova
• CT, MRI, large vessel occlusion, thrombectomy,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: The initial core infarct volume predicts treatment outcome in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). According to the literature, CT perfusion (CTP) is able to evaluate cerebral parenchymal viability and assess the initial core in AIS. We prospectively studied whether limited-coverage CTP with automated core calculation correlates with the final infarct volume on follow-up non-enhanced CT (NECT) in patients successfully treated by mechanical thrombectomy. METHODS: We enrolled 31 stroke patients (20 women aged 74.4±12.9 years and 11 men aged 66±15.4 years; median initial NIHSS score 15.5) with occlusion of the medial cerebral artery and/or the internal carotid artery that were treated by successful mechanical thrombectomy. CTP performed in a 38.6 mm slab at the level of basal ganglia was included in the CT stroke protocol, but was not used to determine indication for mechanical thrombectomy. The infarction core volume based on CTP was automatically calculated using dedicated software with a threshold defined as cerebral blood flow <30% of the value in the contralateral healthy hemisphere. The final infarction volume was measured on 24-hour follow-up NECT in the same slab with respect to CTP. Pearson and Spearman correlation coefficients and robust linear regression were used for comparison of both volumes, P values <0.05 were considered as statistically significant. RESULTS: The median time from stroke onset to CT was 77 minutes (range, 31-284 minutes), and the median time from CT to vessel recanalization was 95 minutes (range, 55-215 minutes). The mean CTP-calculated core infarct volume was 24.3±19.2 mL (median 19 mL, range 1-79 mL), while the mean final infarct volume was 21.5±39.5 mL (median 8 mL; range 0-210 mL). Only a weak relationship was found between the CTP-calculated core and final infarct volume [Pr(29) =0.32, P=0.078; rho =0.40, P=0.028]. Regression analysis showed CTP significantly overestimated lower volumes. CONCLUSIONS: In our prospective study, the infarction core calculated using limited-coverage CTP only weakly correlated with the final infarction volume measured on 24-hour follow-up NECT; moreover, CTP significantly overestimated lower volumes. Our results do not support the use of limited-coverage CTP for guiding treatment recommendations in patients with AIS.

• Klíčová slova
• Stroke imaging, core, mechanical thrombectomy, middle cerebral artery, perfusion imaging,
• Publikační typ
• časopisecké články MeSH