T_max Volumes Predict Final Infarct Size and Functional Outcome in Ischemic Stroke Patients Receiving Endovascular Treatment

Abstract

The objective of this paper was to explore the utility of time to maximum concentration (T max )-based target mismatch on computed tomography perfusion (CTP) in predicting radiological and clinical outcomes in patients with acute ischemic stroke (AIS) with anterior circulation large vessel occlusion (LVO) selected for endovascular treatment (EVT). Methods: Patients with AIS underwent CTP within 24 hours from onset followed by EVT. Critically hypoperfused tissue and ischemic core volumes were automatically calculated using T max thresholds >9.5 seconds and >16 seconds, respectively. The difference between T max > 9.5 seconds and T max > 16 seconds volumes and the ratio between T max > 9.5 seconds and T max > 16 seconds volumes were considered ischemic penumbra and T max mismatch ratio, respectively. Final infarct volume (FIV) was measured on follow-up non-contrast computed tomography (CT) at 24 hours. Favorable clinical outcome was defined as 90-day modified Rankin Scale 0 to 2. Predictors of FIV and outcome were assessed with multivariable logistic regression. Optimal T max volumes for identification of good outcome was defined using receiver operating curves. Results: A total of 393 patients were included, of whom 298 (75.8%) achieved successful recanalization and 258 (65.5%) achieved good outcome. In multivariable analyses, all T max parameters were independent predictors of FIV and outcome. T max > 16 seconds volume had the strongest association with FIV (beta coefficient = 0.596 p <0.001) and good outcome (odds ratio [OR] = 0.96 per 1 ml increase, 95% confidence interval [CI] = 0.95-0.97, p < 0.001). T max > 16 seconds volume had the highest discriminative ability for good outcome (area under the curve [AUC] = 0.88,

Preserved Corticospinal Tract Revealed by Acute Perfusion Imaging Relates to Better Outcome After Thrombectomy in Stroke

“…Comparisons with postinterventional CT/ magnetic resonance imaging data are needed to validate the accuracy of the lesion delineation and the evaluation of alternative CTP-based core lesion definitions. 44 Third, mRS represents a parameter of global disability that lacks to detect domain-specific (eg, motor) deficits and alterations. 45 Using more complex outcome parameters reflecting deficits in motor, language, and attention, and their impact on functional independence most likely will help to identify the most relevant neuroanatomical structures for functional outcome after stroke.…”

Utilizing imaging parameters for functional outcome prediction in acute ischemic stroke: A machine learning study

“…7 Prognostic perfusion imaging parameters included relative cerebral blood flow (rCBF) <30%, time to maximum (Tmax) volumes, the hypoperfusion intensity ratio, the mismatch profile, and the cerebral blood volume (CBV) index. [8][9][10][11][12] In AIS patients with anterior circulation occlusions, it has been shown that the presence of collaterals is another important predictor of radiologic and clinical outcome. 13 These findings indicate that imaging parameters may be excellent prognostic indicators for patients with AIS.…”

Comparison of two automated CT perfusion software packages in patients with ischemic stroke presenting within 24 hours of onset

“…8 A threshold for the time to peak of the residue function (Tmax) exceeding 6 seconds has been identified as a reliable predictor for tissues at risk of infarction if there is no reperfusion. 9 However, the extent to which different software solutions can be used interchangeably, especially in terms of their clinical significance for planning treatment and estimating prognosis, remains uncertain. Previous research has indicated significant discrepancies in the calculated volumes of the ischemic core across different software, leading to inconsistent predictions of final infarct volume after mechanical thrombectomy.…”