Abstract WP49: Performance of CT, CTA, and MRI on Decision to Treat Emergent Large Vessel Occlusion (ELVO) in Patients who Present Greater Than 6 Hours After Stroke Onset

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Eleanor L DiBiasio ◽  
Ryan A McTaggart ◽  
Grayson L Baird ◽  
Shadi Yaghi ◽  
Eric L Tung ◽  
...  
Keyword(s):  
Mixed Model ◽  
Weighted Kappa ◽  
Stroke Onset ◽  
Lesion Volume ◽  
Diffusion Weighted Mri ◽  
Vessel Occlusion ◽  
Rater Reliability ◽  
Diffusion Weighted ◽  
Contrast Ct ◽  
The Impact

Background and purpose: We compared the value of Alberta Stroke Program Early Computed Tomographic scoring using CT (CT ASPECTS), collateral score on CT angiography (CTA), ASPECTS using diffusion-weighted MRI (DWI ASPECTS), DWI lesion volume, and DWI volume with National Institute of Health Stroke Scale (NIHSS) in determining candidacy of patients who presented >6 hours from stroke onset. Methods: Decision to treat was first determined for each test alone and then with knowledge from other tests. A dismantling design was used to determine the additive effects of each test. Any discrepancy between the first and subsequent decisions to treat, in terms of sensitivity and specificity, is the impact of gained knowledge and was assessed using a generalized mixed-model assuming a binary distribution with PROC GLIMMIX/SAS. Inter-rater reliability was examined using weighted-Kappa. Results: We identified 39 patients between December 1st, 2015 and June 30th 2016. Median time from last-known normal to non-contrast CT was 492 minutes. Median interval between non-contrast CT and CTA was 7 minutes, and between CTA and MRI, 75.5 minutes. For sensitivity, effect of knowledge gained from successive tests was not significant (Table 1; Fig. 1). However, significant gains in specificity were observed from successive tests (63% to 84%; p<.01). In particular, specificity increased by 14% (p=.09), 18% (p=.02), and 12% (p=.07), for DWI ASPECTS, DWI Volume, and DWI Volume+NIHSS, respectively. Inter-rater reliability was between .34-1.0 for each test. Conclusion: CT, CTA and MRI each have the ability to correctly determine ELVO patients who would be candidates for embolectomy. However, identification of poor candidates for endovascular therapy was significantly improved using diffusion-weighted MRI.

Abstract WP55: Through Thick and Thin: Improved Aspects Grading and Dense Vessel Detection Using Simple Ncct Post-processing

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
James W Evans ◽  
Sadanand Dey ◽  
Muneer Eesa ◽  
Prasanna Eswaradass ◽  
Ronda Lun ◽  
...  
Keyword(s):  
Maximum Intensity Projection ◽  
Improve Patient Care ◽  
Weighted Kappa ◽  
Slice Thickness ◽  
Post Processing ◽  
Rater Reliability ◽  
Thin Slice ◽  
Vessel Detection ◽  
Contrast Ct ◽  
Processing Techniques

Introduction: Assessing Alberta Stroke Program Early CT Score (ASPECTS) and identifying hyperdense arteries on non-contrast CT (NCCT) are important components of decision-making in acute stroke. Conventional practice uses 5mm averaged slice thickness NCCT for interpretation of these features. We have systematically evaluated several post processing techniques on NCCT to determine if there is improved reliability in identification of ASPECTS and hyperdense artery. Methodology: We assessed four post-processing techniques on NCCT namely (1) 5mm averaged thickness (2) Minimum Intensity Projection (mIP) - 5mm thickness (3) thin slices (0.625mm) and (4) Maximum Intensity Projection (MIP) - 5mm thickness (Figure 1). Three raters (student, fellow and expert) independently assessed 100 NCCT scans from the PRoveIT database. All scans were read at four different times 10-14 days apart. At each time-point the post processing modality was changed and the patient order randomized. Information on side of suspected infarction was provided. Raters were asked to score ASPECTS and identify presence of hyperdense artery at each reading. Inter-rater reliability was assessed using Intra-cluster correlation (ICC) for ASPECTS and weighted kappa (wKap) for hyperdense artery. Results: The highest inter-rater reliability was found with the MIP technique (ICC 0.42; p<0.001), followed by 5 mm average, mIP and thin slice respectively (ICC 0.33, 0.32, 0.20; all p<0.01). Highest agreement for hyperdense vessel detection was noted with thin slice (wKap 0.30; p<0.001) followed by Average, MIPs and mIPs respectively (wKap 0.25, 0.18, 0.13; all p <0.05). Conclusion: The use of MIP images for ASPECTS grading and thin images for hyperdense vessel detection improves reliability on NCCT. These simple processing steps are easily available on any modern scanner and may help improve patient care.

Microembolic Signals within 24 Hours of Stroke Onset and Diffusion-Weighted MRI Abnormalities

2006 ◽  
Vol 23 (4) ◽  
pp. 282-288 ◽  
Author(s):  
Makoto Nakajima ◽  
Kazumi Kimura ◽  
Atsuko Shimode ◽  
Fumio Miyashita ◽  
Makoto Uchino ◽  
...  
Keyword(s):  
Stroke Onset ◽  
Diffusion Weighted Mri ◽  
Diffusion Weighted ◽  
And Diffusion

Abstract TP40: Prediction of a Small DWI Lesion Using Single Phase Collateral Score and Noncontrast CT ASPECT Score

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Reza Hakimelahi ◽  
Karen A Buch ◽  
Thabele M Leslie-Mazwi ◽  
Joshua A Hirsch ◽  
James D Rabinov ◽  
...  
Keyword(s):  
Roc Curve ◽  
Strong Predictor ◽  
High Specificity ◽  
Weighted Kappa ◽  
Contralateral Side ◽  
Stroke Onset ◽  
Lesion Volume ◽  
Roc Curve Analysis ◽  
Kappa Test ◽  
Collateral Vessels

Introduction and Hypothesis: Small initial DWI lesion volume (≤70 mL) is a strong predictor of favorable outcome post i IA thrombectomy and has been used for patient selection in multiple clinical trials. We sought to investigate if collateral and/or CT ASPECT scores could predict a small DWI lesion volume. Methods: We included 130 consecutive patients with CTA showing ICA and/or proximal MCA occlusions who underwent DWI within 8 hours of stroke onset. DWI lesion volumes were dichotomized to small (≤70mL) and large (>70ml). Collateral vessels were categorized to 5 groups: 0=none, 1=minimal, 2=less than 50%, 3=more than 50%, 4=equal and 5=more than the contralateral side. Logistic regression, ROC curve analyses and weighted Kappa test were performed. Results: In 130 patients, 62 female (48%), the average values (mean±SD) were: age 70±17 years, NIHSS 16±6, DWI volume 59±65 mL, time after stroke onset 4.4±1.8 hours, CT ASPECT score 6±2 and collateral score 3±1. Time, age, gender, or occlusion site (ICA vs MCA) were not independent predictors of a small DWI volume with p values all >0.05. Collateral score (OR 6.32, P<0.0001), CT ASPECT score (OR 2.37, P<0.0001), and NIHSS (OR 0.87, P<0.0003) significantly contributed to prediction of a small DWI volume. ROC curve analysis with both ASPECT and collateral scores contributing to predicted probabilities showed an AUC of 0.93. The AUC was 0.88 and 0.85 for collateral and ASPECT scores alone respectively. Collateral score ≥3 with ASPECT ≥9 yields specificity of 97.4% and sensitivity of 48.9% while collateral score ≥4 alone provides specificity of 97.4% and sensitivity of 38.9%, missing approximately 16% and 43% of potential candidates for IA therapy based on a DWI lesion volume < 70 mL respectively. Inter-rater agreements between two neuroradiologists were k=0.53 (41.5% agreement) for collateral and k=0.53 (32.3% agreement) for ASPECT scores. Conclusion: Collateral score alone or combined with ASPECTS can predict a small DWI lesion volume with high specificity. However, sensitivity is relatively low and inter-rater agreement is fair. These findings should be considered when DWI is not available to select patients for IA therapy.

Diffusion-weighted MRI of the prostate at 3.0T: Comparison of endorectal coil (ERC) MRI and phased-array coil (PAC) MRI—The impact of SNR on ADC measurement

2013 ◽  
Vol 82 (10) ◽  
pp. e515-e520 ◽  
Author(s):  
Yousef Mazaheri ◽  
H. Alberto Vargas ◽  
Gregory Nyman ◽  
Amita Shukla-Dave ◽  
Oguz Akin ◽  
...  
Keyword(s):  
Phased Array ◽  
Diffusion Weighted Mri ◽  
Endorectal Coil ◽  
Diffusion Weighted ◽  
Phased Array Coil ◽  
The Impact ◽  
Array Coil

scholarly journals Admission Diffusion-Weighted Imaging Lesion Volume in Patients With Large Vessel Occlusion Stroke and Alberta Stroke Program Early CT Score of ≥6 Points

Stroke ◽  
2019 ◽  
Vol 50 (11) ◽  
pp. 3115-3120 ◽  
Author(s):  
Inwu Yu ◽  
Oh Young Bang ◽  
Jong-Won Chung ◽  
Yoon-Chul Kim ◽  
Eun-Hyeok Choi ◽  
...  
Keyword(s):  
Diffusion Weighted Imaging ◽  
Large Vessel ◽  
Lesion Volume ◽  
Large Vessel Occlusion ◽  
Vessel Occlusion ◽  
Diffusion Weighted

Abstract 59: Extending the Time for Thombolysis in Emergency Neurological Deficits (EXTEND) - High Prevalence of Intracranial Vessel Occlusion in Wake-up-stroke Patients

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Henry Ma ◽  
Bruce C Campbell ◽  
Mark W Parsons ◽  
Christopher Levi ◽  
Atte Meretoja ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Artery ◽  
Stroke Onset ◽  
Phase Iii ◽  
Neurological Deficits ◽  
Lesion Volume ◽  
Stroke Patients ◽  
Vessel Occlusion ◽  
Intracranial Vessel ◽  
Ct Angiogram

Background: EXTEND is an investigator-initiated, randomised, double-blind and placebo-controlled Phase III trial of intravenous alteplase vs placebo in patients with ischemic stroke 4.5-9 hours from stroke onset or wake-up-stroke (WUS). The prevalence of intra-cranial vessel occlusion in WUS patients remains to be determined and can guide the development of optimal therapy for this unique group of stroke patients. Objective: To study the prevalence and characteristics of intra-cranial vessel occlusion in this WUS cohort. Methods: Ischemic stroke patients within 4.5-9 hours from stroke onset or with WUS (time of WUS onset defined as the midpoint between time to sleep and awakening with the stroke symptoms) are eligible for enrollment. Criteria for entry into the trial include perfusion-diffusion mismatch using a perfusion threshold of Tmax>6sec and a perfusion:diffusion lesion volume ratio of >1.2. Diffusion lesion volume must be <70mL based on assessment by automated RAPID software. Intra-cranial vessel occlusion was assessed on MR or CT angiogram performed at randomisation and 24 later. Two expert readers assessed these images independently. Results: 97 patients had images with adequate quality, including 63 (65%) in the WUS group with median age of 77.0 yrs (IQR 67.0, 81.0) and NIHSS of 14.0 (9.0, 19.0). 62 of 63 patients (98%) had vessel occlusion with 44.4% involving M1 of the middle cerebral artery, 17.5% M2, 4.8% M3, 25.4% both internal carotid artery (ICA) and M1, 4.8% ICA alone and 3.1% the posterior cerebral artery. The median ischemic core volume was 15.0 ml (6.5, 31.5), Tmax>6 volume 88.5ml (58.0, 122.0), mismatch volume 65.5ml (42.8, 92.0), and ratio of 4.8 (2.5, 8.7). 19 patients (30%) demonstrated recanalization on follow-up imaging. Conclusion: In WUS patients there is a very high rate of intracranial vessel occlusion with relatively large volumes of salvageable penumbral tissue. Intravenous thrombolytic therapy followed by thrombectomy in selected cases may be an appropriate therapeutic option with safety and efficacy remaining to be established in randomized controlled trials.

scholarly journals Non-invasive monitoring of longitudinal changes in cerebral hemodynamics in acute ischemic stroke using BOLD signal delay

2018 ◽  
Vol 40 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Ahmed A Khalil ◽  
Kersten Villringer ◽  
Vivien Filleböck ◽  
Jiun-Yiing Hu ◽  
Andrea Rocco ◽  
...  
Keyword(s):  
Cerebral Perfusion ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Time Shift ◽  
Lesion Volume ◽  
Bold Signal ◽  
Stroke Patients ◽  
Vessel Occlusion ◽  
Non Invasive ◽  
Over Time

Relative delays in blood-oxygen-level-dependent (BOLD) signal oscillations can be used to assess cerebral perfusion without using contrast agents. However, little is currently known about the utility of this method in detecting clinically relevant perfusion changes over time. We investigated the relationship between longitudinal BOLD delay changes, vessel recanalization, and reperfusion in 15 acute stroke patients with vessel occlusion examined within 24 h of symptom onset (D0) and one day later (D1). We created BOLD delay maps using time shift analysis of resting-state functional MRI data and quantified perfusion lesion volume changes (using the D1/D0 volume ratio) and severity changes (using a linear mixed model) over time. Between baseline and follow-up, BOLD delay lesions shrank (median D1/D0 ratio = 0.2, IQR = 0.03–0.7) and BOLD delay severity decreased (b = −4.4 s) in patients with recanalization, whereas they grew (median D1/D0 ratio = 1.47, IQR = 1.1–1.7) and became more severe (b = 4.3 s) in patients with persistent vessel occlusion. Clinically relevant changes in cerebral perfusion in early stroke can be detected using BOLD delay, making this non-invasive method a promising option for detecting tissue at risk of infarction and monitoring stroke patients following recanalization therapy.

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