IMPORTANCEFor patients with large vessel occlusion strokes, it is unknown whether endovascular treatment alone compared with intravenous thrombolysis plus endovascular treatment (standard treatment) can achieve similar functional outcomes. OBJECTIVE To investigate whether endovascular thrombectomy alone is noninferior to intravenous alteplase followed by endovascular thrombectomy for achieving functional independence at 90 days among patients with large vessel occlusion stroke.DESIGN, SETTING, AND PARTICIPANTS Multicenter, randomized, noninferiority trial conducted at 33 stroke centers in China. Patients (n = 234) were 18 years or older with proximal anterior circulation intracranial occlusion strokes within 4.5 hours from symptoms onset and eligible for intravenous thrombolysis. Enrollment took place from May 20, 2018, to May 2, 2020. Patients were enrolled and followed up for 90 days (final follow-up was July 22, 2020).INTERVENTIONS A total of 116 patients were randomized to the endovascular thrombectomy alone group and 118 patients to combined intravenous thrombolysis and endovascular thrombectomy group. MAIN OUTCOMES AND MEASURESThe primary end point was the proportion of patients achieving functional independence at 90 days (defined as score 0-2 on the modified Rankin Scale; range, 0 [no symptoms] to 6 [death]). The noninferiority margin was −10%. Safety outcomes included the incidence of symptomatic intracerebral hemorrhage within 48 hours and 90-day mortality. RESULTSThe trial was stopped early because of efficacy when 234 of a planned 970 patients had undergone randomization. All 234 patients who were randomized (mean age, 68 years; 102 women [43.6%]) completed the trial. At the 90-day follow-up, 63 patients (54.3%) in the endovascular thrombectomy alone group vs 55 (46.6%) in the combined treatment group achieved functional independence at the 90-day follow-up (difference, 7.7%, 1-sided 97.5% CI, −5.1% to ϱ)P for noninferiority = .003). No significant between-group differences were detected in symptomatic intracerebral hemorrhage (6.1% vs 6.8%; difference, −0.8%; 95% CI, −7.1% to 5.6%) and 90-day mortality (17.2% vs 17.8%; difference, −0.5%; 95% CI, −10.3% to 9.2%).CONCLUSIONS AND RELEVANCE Among patients with ischemic stroke due to proximal anterior circulation occlusion within 4.5 hours from onset, endovascular treatment alone, compared with intravenous alteplase plus endovascular treatment, met the prespecified statistical threshold for noninferiority for the outcome of 90-day functional independence. These findings should be interpreted in the context of the clinical acceptability of the selected noninferiority threshold.

RESCUE BT Trial Investigators E ndovascular treatment has been shown to significantly increase the reperfusion rate and improve the functional outcomes of patients with acute ischemic stroke due to large vessel occlusion. [1][2][3][4] However, endovascular thrombectomy has historically failed to yield successful reperfusion in approximately 30% of patients. 5 Unsuccessful reperfusion likely arises in part from mechanical thrombectomy devices causing traumatic damage to the vascular endothelium with subendothelial matrix exposure, leading to platelet activation, adhesion, and aggregation and potentially resulting in reocclusion and thromboembolic complications. 6,7 Tirofiban, a highly selective nonpeptide platelet glycoprotein IIb/IIIa inhibitor with a relatively short half-life that can reversibly prevent platelet aggregation, has been proven to reduce the risk of thrombotic complications during percutaneous coronary intervention. [8][9][10] Given the benefit of treatment of acute coronary syndromes, a growing number of studies have evaluated tirofiban as an adjunctive treatment in patients with large vessel occlusion ischemic stroke IMPORTANCE Tirofiban is a highly selective nonpeptide antagonist of glycoprotein IIb/IIIa receptor, which reversibly inhibits platelet aggregation. It remains uncertain whether intravenous tirofiban is effective to improve functional outcomes for patients with large vessel occlusion ischemic stroke undergoing endovascular thrombectomy.OBJECTIVE To assess the efficacy and adverse events of intravenous tirofiban before endovascular thrombectomy for acute ischemic stroke secondary to large vessel occlusion.DESIGN, SETTING, AND PARTICIPANTS This investigator-initiated, randomized, double-blind, placebo-controlled trial was implemented at 55 hospitals in China, enrolling 948 patients with stroke and proximal intracranial large vessel occlusion presenting within 24 hours of time last known well.

BACKGROUND AND PURPOSE: Infarct core volume measurement using CTP (CT perfusion) is a mainstay paradigm for stroke treatment decision-making. Yet, there are several downfalls with cine CTP technology that can be overcome by adopting the simple perfusion reconstruction algorithm (SPIRAL) derived from multiphase CTA. We compare SPIRAL with CTP parameters for the prediction of 24-hour infarction.MATERIALS AND METHODS: Seventy-two patients had admission NCCT, multiphase CTA, CTP, and 24-hour DWI. All patients had successful/quality reperfusion. Patient-level and cohort-level receiver operator characteristic curves were generated to determine accuracy. A 10-fold cross-validation was performed on the cohort-level data. Infarct core volume was compared for SPIRAL, CTPtime-to-maximum, and final DWI by Bland-Altman analysis.RESULTS: When we compared the accuracy in patients with early and late reperfusion for cortical GM and WM, there was no significant difference at the patient level (0.83 versus 0.84, respectively), cohort level (0.82 versus 0.81, respectively), or the cross-validation (0.77 versus 0.74, respectively). In the patient-level receiver operating characteristic analysis, the SPIRAL map had a slightly higher, though nonsignificant (P , .05), average receiver operating characteristic area under the curve (cortical GM/WM, r ¼ 0.82; basal ganglia ¼ 0.79, respectively) than both the CTP-time-to-maximum (cortical GM/WM ¼ 0.82; basal ganglia ¼ 0.78, respectively) and CTP-CBF (cortical GM/WM ¼ 0.74; basal ganglia ¼ 0.78, respectively) parameter maps. The same relationship was observed at the cohort level. The Bland-Altman plot limits of agreement for SPIRAL and time-to-maximum infarct volume were similar compared with 24-hour DWI. CONCLUSIONS:We have shown that perfusion maps generated from a temporally sampled helical CTA are an accurate surrogate for infarct core. ABBREVIATIONS: AUC ¼ area under the curve; EVT ¼ endovascular therapy; mCTA ¼ multiphase CTA; ROC ¼ receiver operating characteristic; SPIRAL ¼ simple perfusion reconstruction algorithm; Tmax ¼ time-to-maximum E ndovascular therapy (EVT) for acute ischemic stroke can lead to remarkable results for improving stroke outcome. [1][2][3] The emphasis on fast treatment decisions for patients with acute ischemic stroke requires simple, quick, and accurate neuroimaging of patients for detection of early ischemic changes. Additionally, image-processing software that can provide this information should be preferably inexpensive and easily accessible to all stroke centers, both primary and comprehensive, around the world. CT is the most commonly used and practical imaging technique for assessing patients with acute stroke, but sensitivity and reliability are only modest, even in the hands of stroke specialists. Software systems, including perfusion analysis, to identify ischemic tissue using advanced imaging paradigms are now recommended by the American Stroke Association and have been used successfully in several clinical trials, including selection of patients fo...

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Polychromatic source X-ray fluorescence computed tomography (XFCT) is a novel imaging method, which is applied for the diagnosis and treatment studies of early stage cancer. In this paper, we propose a fast multi-pinhole L-shell XFCT imaging system to reduce the scan time and radiation dose, which has potential in detecting lower concentration of contrast agents (gold nanoparticles, GNPs). Two kinds of phantoms --the concentration-phantom 1 and the size-phantom 2 are designed to verify imaging performance for low-concentration and small-size ROI. The scanning processes are simulated by Geant4, and images are reconstructed by Optimized EM-TV algorithm. It is concluded that this imaging system is more sensitive in detecting low concentration GNPs than K-shell imaging system. Simulation experiments show the reconstructed images can achieve the highest CNR both for phantom 1 and phantom 2 with iterating 10 times. The detection limit can reach 0.16% when pinhole radius is 0.08mm.INDEX TERMS L-shell XFCT, multi-pinhole collimator, CNR, low-concentration, small-size ROI.