Computed tomography perfusion (CTP) is widely used in the evaluation of acute ischemic stroke patients for endovascular thrombectomy (EVT). The stability of CTP core estimation is suboptimal and ...varies between software packages. We aimed to quantify the volumetric and spatial agreement between the CTP ischemic core and follow-up infarct for four ischemic core estimation approaches using syngo.via.
We included successfully reperfused, EVT-treated patients with baseline CTP and 24h follow-up diffusion weighted magnetic resonance imaging (DWI) (November 2017-September 2020). Data were processed with syngo.via VB40 using four core estimation approaches based on: cerebral blood volume (CBV)<1.2mL/100mL with and without smoothing filter, relative cerebral blood flow (rCBF)<30%, and rCBF<20%. The follow-up infarct was segmented on DWI.
In 59 patients, median estimated CTP core volumes for four core estimation approaches ranged from 12-39 mL. Median 24h follow-up DWI infarct volume was 11 mL. The intraclass correlation coefficient (ICC) showed moderate-good volumetric agreement for all approaches (range 0.61-0.76). Median Dice was low for all approaches (range 0.16-0.21). CTP core overestimation >10mL occurred least frequent (14/59 24% patients) using the CBV-based core estimation approach with smoothing filter.
In successfully reperfused patients who underwent EVT, syngo.via CTP ischemic core estimation showed moderate volumetric and spatial agreement with the follow-up infarct on DWI. In patients with complete reperfusion after EVT, the volumetric agreement was excellent. A CTP core estimation approach based on CBV<1.2 mL/100mL with smoothing filter least often overestimated the follow-up infarct volume and is therefore preferred for clinical decision making using syngo.via.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
BACKGROUND AND PURPOSE—Thrombus imaging characteristics have been reported to be useful to predict functional outcome and reperfusion in acute ischemic stroke. However, conflicting data about this ...subject exist in patients undergoing endovascular treatment. Therefore, we aimed to evaluate whether thrombus imaging characteristics assessed on computed tomography are associated with outcomes in patients with acute ischemic stroke treated by endovascular treatment.
METHODS—The MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry is an ongoing, prospective, and observational study in all centers performing endovascular treatment in the Netherlands. We evaluated associations of thrombus imaging characteristics with the functional outcome (modified Rankin Scale at 90 days), mortality, reperfusion, duration of endovascular treatment, and symptomatic intracranial hemorrhage using univariable and multivariable regression models. Thrombus characteristics included location, clot burden score (CBS), length, relative and absolute attenuation, perviousness, and distance from the internal carotid artery terminus to the thrombus. All characteristics were assessed on thin-slice (≤2.5 mm) noncontrast computed tomography and computed tomography angiography, acquired within 30 minutes from each other.
RESULTS—In total, 408 patients were analyzed. Thrombus with distal location, higher CBS, and shorter length were associated with better functional outcome (adjusted common odds ratio, 3.3; 95% CI, 2.0–5.3 for distal M1 occlusion compared with internal carotid artery occlusion; adjusted common odds ratio, 1.15; 95% CI, 1.07–1.24 per CBS point; and adjusted common odds ratio, 0.96; 95% CI, 0.94–0.99 per mm, respectively) and reduced duration of endovascular procedure (adjusted coefficient B, −14.7; 95% CI, −24.2 to −5.1 for distal M1 occlusion compared with internal carotid artery occlusion; adjusted coefficient B, −8.5; 95% CI, −14.5 to −2.4 per CBS point; and adjusted coefficient B, 7.3; 95% CI, 2.9–11.8 per mm, respectively). Thrombus perviousness was associated with better functional outcome (adjusted common odds ratio, 1.01; 95% CI, 1.00–1.02 per Hounsfield units increase). Distal thrombi were associated with successful reperfusion (adjusted odds ratio, 2.6; 95% CI, 1.4–4.9 for proximal M1 occlusion compared with internal carotid artery occlusion).
CONCLUSIONS—Distal location, higher CBS, and shorter length are associated with better functional outcome and faster endovascular procedure. Distal thrombus is strongly associated with successful reperfusion, and a pervious thrombus is associated with better functional outcome.
BACKGROUND AND PURPOSE—To assess the effect of inter-hospital transfer on time to treatment and functional outcome after endovascular treatment (EVT) for acute ischemic stroke, we compared patients ...transferred from a primary stroke center to patients directly admitted to an intervention center in a large nationwide registry.
METHODS—MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry is an ongoing, prospective, observational study in all centers that perform EVT in the Netherlands. We included adult patients with an acute anterior circulation stroke who received EVT between March 2014 to June 2016. Primary outcome was time from arrival at the first hospital to arterial groin puncture. Secondary outcomes included the 90-day modified Rankin Scale score and functional independence (modified Rankin Scale score of 0–2).
RESULTS—In total 821/1526 patients, (54%) were transferred from a primary stroke center. Transferred patients less often had prestroke disability (227/800 28% versus 255/699 36%; P=0.02) and more often received intravenous thrombolytics (659/819 81% versus 511/704 73%; P<0.01). Time from first presentation to groin puncture was longer for transferred patients (164 versus 104 minutes; P<0.01, adjusted delay 57 minutes 95% CI, 51–62). Transferred patients had worse functional outcome (adjusted common OR, 0.75 95% CI, 0.62–0.90) and less often achieved functional independence (244/720 34% versus 289/681 42%, absolute risk difference −8.5% 95% CI, −8.7 to −8.3).
CONCLUSIONS—Interhospital transfer of patients with acute ischemic stroke is associated with delay of EVT and worse outcomes in routine clinical practice, even in a country where between-center distances are short. Direct transportation of patients potentially eligible for EVT to an intervention center may improve functional outcome.
BACKGROUND—Randomized clinical trials in selected acute ischemic stroke patients reported that for every hour delay of endovascular treatment (EVT), chances of functional independence diminish with ...up to 3.4%. These findings may not be fully generalizable to clinical practice because of strict in- and exclusion criteria in these trials. Therefore, we aim to assess the association of time to EVT with functional outcome in current, everyday clinical practice.
METHODS—The MR CLEAN Registry is an ongoing, prospective, observational study in all centers that perform EVT in the Netherlands. Data were analyzed from patients treated between March 2014 and June 2016. In the primary analysis we assessed the association of time from stroke onset to start of EVT and time from stroke onset to successful reperfusion with functional outcome (measured with the modified Rankin Scale (mRS)), by means of ordinal logistic regression.
RESULTS—We analyzed 1488 acute ischemic stroke patients who underwent EVT. An increased time to start of EVT was associated with worse functional outcome (adjusted common odds ratio = 0.83 per hour, 95% Confidence Interval0.77-0.89) and a 2.2% increase in mortality. Every hour increase from stroke onset to EVT start resulted in a 5.3% decreased probability of functional independence (mRS 0-2). In the 742 patients with successful reperfusion, every hour increase from stroke onset to reperfusion was associated with a 7.7% decreased probability of functional independence.
CONCLUSIONS—Time to EVT for acute ischemic stroke in current clinical practice is strongly associated with functional outcome. Our data suggest that this association might be even stronger than previously suggested in reports on more selected patient populations from randomized controlled trials. These findings emphasize that functional outcome of EVT patients can be greatly improved by shortening onset to treatment times.
In a follow-up of a trial comparing endovascular thrombectomy with conventional therapy for acute ischemic stroke, the beneficial effect on functional recovery that was observed at 90 days was ...maintained at 2 years. Quality of life was better at 2 years with endovascular treatment.
We reported previously the 90-day outcomes of a trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands MR CLEAN) in which standard treatment was compared with endovascular treatment, administered within 6 hours after the onset of acute ischemic stroke caused by an intracranial arterial occlusion of the anterior circulation.
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Most patients in the intervention group were treated by mechanical thrombectomy with the use of retrievable stents. The trial showed that functional recovery at 90 days was better with the intervention than with standard treatment. Subsequently, the beneficial effect of mechanical thrombectomy on 90-day outcomes . . .
Prior to the implementation of arterial spin labeling (ASL) in clinical multi-center studies, it is important to establish its status quo inter-vendor reproducibility. This study evaluates and ...compares the intra- and inter-vendor reproducibility of pseudo-continuous ASL (pCASL) as clinically implemented by GE and Philips.
22 healthy volunteers were scanned twice on both a 3T GE and a 3T Philips scanner. The main difference in implementation between the vendors was the readout module: spiral 3D fast spin echo vs. 2D gradient-echo echo-planar imaging respectively. Mean and variation of cerebral blood flow (CBF) were compared for the total gray matter (GM) and white matter (WM), and on a voxel-level.
Whereas the mean GM CBF of both vendors was almost equal (p = 1.0), the mean WM CBF was significantly different (p<0.01). The inter-vendor GM variation did not differ from the intra-vendor GM variation (p = 0.3 and p = 0.5 for GE and Philips respectively). Spatial inter-vendor CBF and variation differences were observed in several GM regions and in the WM.
These results show that total GM CBF-values can be exchanged between vendors. For the inter-vendor comparison of GM regions or WM, these results encourage further standardization of ASL implementation among vendors.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Prediction of the final infarct volume in acute ischemic stroke patients.•Takes into account the baseline CTP images and the time and treatment parameters.•Convolutional neural network trained and ...validated on a multicenter dataset.•Operates on the native CTP measurements without explicit deconvolution.•Improved performance over classical approach.
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CT Perfusion (CTP) imaging has gained importance in the diagnosis of acute stroke. Conventional perfusion analysis performs a deconvolution of the measurements and thresholds the perfusion parameters to determine the tissue status. We pursue a data-driven and deconvolution-free approach, where a deep neural network learns to predict the final infarct volume directly from the native CTP images and metadata such as the time parameters and treatment. This would allow clinicians to simulate various treatments and gain insight into predicted tissue status over time. We demonstrate on a multicenter dataset that our approach is able to predict the final infarct and effectively uses the metadata. An ablation study shows that using the native CTP measurements instead of the deconvolved measurements improves the prediction.
In a multicenter Chinese trial involving 656 patients with large-vessel occlusion, endovascular thrombectomy was noninferior, within a 20% margin of confidence, to endovascular thrombectomy with ...intravenous alteplase given within 4.5 hours after stroke. The incidence of intracerebral hemorrhage was similar in the two groups.
BACKGROUND AND PURPOSE—A score of ≥2B on the modified Thrombolysis in Cerebral Infarction scale is generally regarded as successful reperfusion after endovascular treatment for ischemic stroke. The ...extended Thrombolysis in Cerebral Infarction (eTICI) includes a 2C grade, which indicates near-perfect reperfusion. We investigated how well the respective eTICI scores of 2B, 2C, and 3 correlate with clinical outcome after endovascular treatment.
METHODS—We used data from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands Registry, a prospective, nationwide registry of endovascular treatment in the Netherlands. We included patients with a proximal intracranial occlusion of the anterior circulation for whom final antero-posterior and lateral digital subtraction angiography imaging was available. Our primary outcome was the distribution on the modified Rankin Scale at 90 days per eTICI grade. We performed (ordinal) logistic regression analyses, using eTICI 2B as reference group, and adjusted for potential confounders.
RESULTS—In total, 2807/3637 (77%) patients met the inclusion criteria. Of these, 17% achieved reperfusion grade eTICI 0 to 1, 14% eTICI 2A, 25% eTICI 2B, 12% eTICI 2C, and 32% eTICI 3. Groups differed in terms of age (P<0.001) and occlusion location (P<0.01). Procedure times decreased with increasing reperfusion grades. We found a positive association between reperfusion grade and functional outcome, which continued to increase after eTICI 2B (adjusted common odds ratio, 1.22 95% CI, 0.96–1.57 for eTICI 2C versus 2B; adjusted common odds ratio, 1.33 95% CI, 1.09–1.62 for eTICI 3 versus 2B).
CONCLUSIONS—Our results indicate a continuous relationship between reperfusion grade and functional outcome, with eTICI 3 leading to the best outcomes. Although this implies that interventionists should aim for the highest possible reperfusion grade, further research on the optimal strategy is necessary.
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