https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Dissecting proactive control processes in task-switching: a model-based neuroscience approach https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:13645 Wed 11 Apr 2018 11:43:52 AEST ]]> Perfusion computer tomography: imaging and clinical validation in acute ischaemic stroke https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17430 2 s was the most accurate computed tomography perfusion threshold in predicting the extent of critically hypoperfused tissue with both receiver operating curve analysis (area under curve 0.86), and the volumetric validation (mean difference between computed tomography perfusion and 24-h diffusion-weighted imaging lesions = 2 cm2, 95% confidence interval 0.5–3.2 cm2). Cerebral blood flow <40% (of contralateral) within the relative delay time >2 s perfusion lesion was the most accurate computed tomography perfusion threshold at defining infarct core with both receiver operating characteristic analysis (area under curve = 0.85) and the volumetric validation. Using these thresholds, the extent of computed tomography perfusion mismatch tissue (the volume of ‘at-risk’ tissue between the critically hypoperfused and core thresholds) salvaged from infarction correlated with clinical improvement at 24 h (R2 = 0.59, P = 0.04) and 90 days (R2 = 0.42, P = 0.02). Patients with larger baseline computed tomography perfusion infarct core volume (>25 ml) also had poorer recovery at Day 90 (P = 0.039). Computed tomography perfusion can accurately identify critically hypoperfused tissue that progresses to infarction without early reperfusion, and the computed tomography perfusion cerebral blood flow infarct core closely predicts the final volume of infarcted tissue in patients who do reperfuse. The computed tomography perfusion infarct core and at-risk measures identified are also strong predictors of clinical outcome.]]> Sat 24 Mar 2018 08:01:40 AEDT ]]> Influence of occlusion site and baseline ischemic core on outcome in patients with ischemic stroke https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:48518 p < 0.001). Vessel occlusion location was not a strong predictor of outcomes compared to baseline ischemic core (area under the curve, mRS 0-1, 0.64 vs 0.83; mRS 0-2, 0.70 vs 0.86, p < 0.001). There was no interaction between occlusion location and ischemic core (interaction coefficient 1.00, p = 0.798). Conclusions: Ischemic stroke patients with a distal occlusion have higher rate of excellent and favorable outcome than patients with an M1 occlusion. The baseline ischemic core was shown to be a more powerful predictor of functional outcome than the occlusion location, but the relationship between ischemic core and outcome does not different by occlusion locations.]]> Mon 20 Mar 2023 17:06:46 AEDT ]]> Cerebral arterial pulsatility and global white matter microstructure impact spatial working memory in older adults with and without cardiovascular risk factors https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38215 50 years, n = 92). The latter were further subdivided into two subgroups with (CV+, n = 25) and without (CV−, n = 67) cardiovascular risk factors. Arterial pulsatility was measured using cardiac-gated phase-contrast flow quantification sequence and three indexes of whole-brain white matter microstructural organization [i.e., fractional anisotropy (FA), radial diffusivity (RaD), mean diffusivity (MD)] were derived from diffusion-weighted imaging (DWI). Cognitive ability was assessed using global cognitive functioning (MoCA) and a measure of working memory [sensitivity (d′) from a 2-back task]. Neither the whole group analysis nor the younger adult group showed an association between measures of arterial pulsatility, global white matter microstructural organization, and cognition. In older adults, higher MD and RaD were associated with increased arterial pulsatility and poorer working memory performance. The indirect pathway from arterial pulsatility to working memory performance via both MD and RaD measures was significant in this group. Interestingly, a comparison of CV+ and CV− subgroups showed that this mediating relationship was only evident in older adults with at least one CV risk factor. These findings are consistent with cardiovascular risk factors as underlying arterial, white matter, and cognitive decline in cognitively normal older adults.]]> Fri 13 Aug 2021 14:31:48 AEST ]]> Large-Scale Evidence for an Association between Peripheral Inflammation and White Matter Free Water in Schizophrenia and Healthy Individuals https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46105 Fri 11 Nov 2022 11:44:05 AEDT ]]>