https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Optimal CT perfusion thresholds for core and penumbra in acute posterior circulation infarction https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53333 1 s and MTT>145%. Delay time (DT) best estimated the infarct core (AUC = 0.74). The optimal core threshold was a DT >1.5 s. The voxel-based analyses indicated CTP was most accurate in the calcarine (Penumbra-AUC = 0.75, Core-AUC = 0.79) and cerebellar regions (Penumbra-AUC = 0.65, Core-AUC = 0.79). For the volume-based analyses, MTT >160% demonstrated best correlation and smallest mean-volume difference between the penumbral estimate and follow-up MRI (R2 = 0.71). MTT >170% resulted in the smallest mean-volume difference between the core estimate and follow-up MRI, but with poor correlation (R2 = 0.11). Conclusion: CTP has promising diagnostic utility in POCI. Accuracy of CTP varies by brain region. Optimal thresholds to define penumbra were DT >1 s and MTT >145%. The optimal threshold for core was a DT >1.5 s. However, CTP core volume estimates should be interpreted with caution.]]> Wed 28 Feb 2024 16:20:57 AEDT ]]> Assessing the Relative Value of CT Perfusion Compared to Non-contrast CT and CT Angiography in Prognosticating Reperfusion-Eligible Acute Ischemic Stroke Patients https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43520 Wed 21 Sep 2022 11:25:48 AEST ]]> Cost-effectiveness of targeted thrombolytic therapy for stroke patients using multi-modal CT compared to usual practice https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35040 Wed 17 Nov 2021 16:32:15 AEDT ]]> Validating a predictive model of acute advanced imaging biomarkers in ischemic stroke https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33108 Wed 06 Apr 2022 14:05:06 AEST ]]> Ultra-Long Transfers for Endovascular Thrombectomy - Mission Impossible?: The Australia-New Zealand Experience https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50318 300 miles would benefit from EVT, achieving rates of functional independence (modified Rankin Scale [mRS] score of 0-2) at 3 months similar to those patients treated at the comprehensive stroke center in the randomized EVT extended window trials and that the selection of patients with computed tomography perfusion (CTP) at the referring site would be associated with ordinal shift toward better outcomes on the mRS. Methods: This is a retrospective analysis of patients transferred from 31 referring hospitals >300 miles (measured by the most direct road distance) to 9 comprehensive stroke centers in Australia and New Zealand for EVT consideration (April 2016 through May 2021). Results: There were 131 patients; the median age was 64 [53-74] years and the median baseline National Institutes of Health Stroke Scale score was 16 [12-22]. At baseline, 79 patients (60.3%) had noncontrast CT+CT angiography, 52 (39.7%) also had CTP. At the comprehensive stroke center, 114 (87%) patients underwent cerebral angiography, and 96 (73.3%) proceeded to EVT. At 3 months, 62 patients (48.4%) had an mRS score of 0 to 2 and 81 (63.3%) mRS score of 0 to 3. CTP selection at the referring site was not associated with better ordinal scores on the mRS at 3 months (mRS median of 2 [1-3] versus 3 [1-6] in the patients selected with noncontrast CT+CT angiography, P=0.1). Nevertheless, patients selected with CTP were less likely to have an mRS score of 5 to 6 (odds ratio 0.03 [0.01-0.19]; P<0.01). Conclusions: In selected patients transferred >300 miles, there was a benefit for EVT, with outcomes similar to those treated in the comprehensive stroke center in the EVT extended window trials. Remote hospital CTP selection was not associated with ordinal mRS improvement, but was associated with fewer very poor 3-month outcomes.]]> Tue 18 Jul 2023 14:30:07 AEST ]]> Ischemic core thresholds change with time to reperfusion: a case control study https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:33103 0.05). Despite similar baseline CTP ischemic core volumes using the previously validated measure (relative cerebral blood flow [rCBF], <30%), thrombectomy patients had a smaller median 24-hour infarct core of 17.3ml (IQR, 11.3-32.8) versus 24.3ml (IQR, 16.7-42.2; p = 0.011) in alteplase-treated controls. As a result, the optimal threshold to define the ischemic core in thrombectomy patients was rCBF <20% (area under the curve [AUC], 0.89; 95% CI, 0.84, 0.94), whereas in alteplase controls the optimal ischemic core threshold remained rCBF <30% (AUC, 0.83; 95% CI, 0.77, 0.85). Interpretation: Thrombectomy salvaged tissue with lower CBF, likely attributed to earlier reperfusion. For patients who achieve rapid reperfusion, a stricter rCBF threshold to estimate the ischemic core should be considered.]]> Thu 27 Jan 2022 15:58:26 AEDT ]]> Exploring the relationship between ischemic core volume and clinical outcomes after thrombectomy or thrombolysis https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42116 p < 0.001). The group with a baseline core <30 mL contained mostly patients with distal M1 or M2 occlusions, and good collaterals ( p = 0.01). In patients with a baseline ischemic core volume >30 mL (internal carotid artery and mostly proximal M1 occlusions), EVT-R increased the odds of patients achieving an excellent clinical outcome (day 90 mRS 0–1 odds ratio 1.61, p < 0.001) and there was increased symptomatic intracranial hemorrhage in the IVT-R group with core >30 mL (20% vs 3% in EVT-R, p = 0.008). Conclusion: From this observational cohort, LVO patients with larger baseline ischemic cores and proximal LVO, with poorer collaterals, clearly benefited from EVT-R compared to IVT-R alone. However, for distal LVO patients, with smaller ischemic cores and better collaterals, EVT-R was associated with a lower odds of favorable outcome compared to IVT-R alone.]]> Thu 25 Aug 2022 11:08:38 AEST ]]> Machine learning segmentation of core and penumbra from acute stroke CT perfusion data https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52638 Thu 19 Oct 2023 15:12:05 AEDT ]]> Global white matter hypoperfusion on CT predicts larger infarcts and hemorrhagic transformation after acute ischemia https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30014 14 second R2 = 0.372, P = 0.011). Patients with WMHP also had larger acute infarcts and increased infarct growth compared to those without WMHP (mean 28 mL vs. 13 mL P < 0.001). Conclusion: White matter hypoperfusion remote to the acutely ischemic region on CTP is a marker of small vessel disease and was associated with increased HT, larger acute infarct cores, and greater infarct growth.]]> Thu 13 Jan 2022 10:29:30 AEDT ]]> STroke imAging pRevention and treatment (START): a longitudinal stroke cohort study: clinical trials protocol https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23444 Sat 24 Mar 2018 07:13:32 AEDT ]]> A multicentre, randomized, double-blinded, placebo-controlled phase III study to investigate EXtending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND) https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23824 1·2, and absolute mismatch >10 ml) will be randomized to either tissue plasminogen activator or placebo. Study outcome: The primary outcome measure will be modified Rankin Scale 0–1 at day 90. Clinical secondary outcomes include categorical shift in modified Rankin Scale at 90 days, reduction in the National Institutes of Health Stroke Score by 8 or more points or reaching 0–1 at day 90, recurrent stroke, or death. Imaging secondary outcomes will include symptomatic intracranial haemorrhage, reperfusion and or recanalization at 24 h and infarct growth at day 90.]]> Sat 24 Mar 2018 07:12:50 AEDT ]]> Too good to treat? Ischemic stroke patients with small computed tomography perfusion lesions may not benefit from thrombolysis https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30100 p = 0.022) and did not have different rates of mRS 0 to 2 (72% treated patients vs 77% untreated; RR, 0.93; 95% CI, 0.82-1.95; p = 0.23). Interpretation: This large observational cohort suggests that a portion of ischemic stroke patients clinically eligible for alteplase therapy with a small perfusion lesion have a good natural history and may not benefit from treatment.]]> Fri 01 Apr 2022 09:25:36 AEDT ]]>