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  • Chen, Yasheng  (4)
  • Guilliams, Kristin  (4)
  • 2015-2019  (4)
  • Medicine  (4)
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  • 2015-2019  (4)
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  • Medicine  (4)
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  • 1
    Online Resource
    Online Resource
    Abstract W P32: CSF Volumetric Analysis Reliably Quantifies Cerebral Edema And Correlates With Clinical Deterioration In Large Hemispheric Infarcts
    Ovid Technologies (Wolters Kluwer Health) ; 2015
    In:  Stroke Vol. 46, No. suppl_1 ( 2015-02)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 46, No. suppl_1 ( 2015-02)
    Abstract: Background: Large hemispheric infarcts (LHI) may be complicated by cerebral edema. Midline shift (MLS), a standard radiographic measure, only crudely estimates extent of edema. Volumetric analysis of CSF compartments over time may provide a reliable and accurate means of quantifying severity and kinetics of edema after LHI. Methods: We retrospectively identified stroke patients with NIHSS≥8 and baseline CT within 6 hours who developed cerebral edema (without hemorrhage) on follow-up (FU) CTs. Two raters outlined the sulci and lateral ventricles ipsilateral (IL) and contralateral (CL) to the infarct on baseline and serial FU CTs (both within 48 hours and at peak edema, 2-5 days post-stroke) and quantified CSF and infarct volumes. Changes in compartment volumes from baseline to peak edema CT were correlated with MLS and edema-related neurologic worsening (need for hemicraniectomy, osmotic therapy, or decline in GCS, associated with MLS≥5mm). Results: Ten patients were analyzed (median NIHSS 14, time to early FU CT 30 hours, IQR 15-37 and to peak edema CT 75 hours, IQR 64-95). Inter-rater reliability for volume measures was excellent (intraclass correlation 〉 0.97). CSF volume diminished by 37±20% (49 ml) from baseline to peak edema, over half occurring within 48 hours; net decline in CSF volume correlated with infarct volume (r=-0.63,p=0.05). Greatest reductions in CSF were seen in IL sulci and IL ventricles (Figure, top), but it was % reduction in CL sulci that correlated best with MLS (Fig, bottom), even adjusting for infarct volume (p=0.02). Decline in volumes of IL and CL sulci were greater in the 5 subjects with neurological worsening (89% vs. 56% and 40% vs. 3%, p 〈 0.05), while infarct volume was not. Conclusions: CSF volumetrics is a reliable tool for quantifying cerebral edema after LHI and a novel method of studying edema kinetics. Loss of sulcal volume correlates with MLS and is more strongly associated with edema-related deterioration than infarct volume alone.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.46.suppl_1.wp32
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2015
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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    Online Resource
  • 2
    Online Resource
    Online Resource
    Abstract T P45: Automated CSF Segmentation to Quantify Cerebral Edema Following Large Hemispheric Ischemic Stroke
    Ovid Technologies (Wolters Kluwer Health) ; 2015
    In:  Stroke Vol. 46, No. suppl_1 ( 2015-02)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 46, No. suppl_1 ( 2015-02)
    Abstract: Introduction: Cerebral edema with resultant mass effect is a potentially fatal consequence of ischemic stroke, but early and sensitive biomarkers of brain tissue compression are lacking. To quantify brain mass effect, we developed a novel, automated segmentation method to delineate CSF spaces in CT images from ischemic stroke patients. Methods: CTs from sixteen acute ischemic stroke patients (median NIHSS 16.5, median age 61.5 yrs, 14-92 hrs after stroke onset) were included after informed consent was obtained. After infarction, conventional CSF segmentation using Hounsfield unit (HU) thresholding is suboptimal due to infarct hypodensity. Utilizing manually delineated infarct and CSF spaces as training samples, we augmented conventional HU threshold segmentation with level sets, sparse regression and random forest segmentation methods. Using leave-one-out cross-validation, the combined approach was compared to HU thresholding using Dice ratios (a measure of the overlap between the segmented and the ground-truth CSF spaces). Results: Shown is an example of a CT brain slice segmented by HU thresholding and the combined strategy: false negative (red), false positive (green), and true positive (yellow). The Dice ratios for HU thresholding and the combined approaches were 58.2±16.3% and 68.9±14.6%, respectively, demonstrating the significantly improved performance for the combined strategy (p=0.0014). Conclusions: We have developed an advanced image segmentation strategy to delineate CSF spaces which outperforms conventional HU thresholding. An automated CSF segmentation strategy will permit quantification of cerebral edema in a large population of stroke patients, as required for genetic studies, for example.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.46.suppl_1.tp45
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2015
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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    Online Resource
  • 3
    Online Resource
    Online Resource
    Abstract W P317: Early CSF Volume Changes Predict Malignant Edema in Large Hemispheric Infarction
    Ovid Technologies (Wolters Kluwer Health) ; 2015
    In:  Stroke Vol. 46, No. suppl_1 ( 2015-02)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 46, No. suppl_1 ( 2015-02)
    Abstract: Background: Early clinical and radiographic measures (such as NIHSS or early CT hypodensity) incompletely predict which patients with hemispheric stroke will develop malignant cerebral edema. We evaluated whether quantitative changes in volume of CSF compartments on early follow-up (FU) CT predict peak radiographic edema and clinical worsening. Methods: We retrospectively identified patients with hemispheric infarcts, NIHSS≥8, baseline CT within 6 hours of stroke onset and FU CT within 48 hours (i.e. prior to development of maximal edema). Volumes of CSF in ipsilateral (IL) and contralateral (CL) sulci and lateral ventricles were manually outlined on both scans, as was infarct volume on FU CT. Midline shift (MLS) was measured on later CT at time of peak edema (if available). Reduction in CSF compartments from baseline and symmetry (IL:CL ratios) were correlated to peak MLS and edema-related clinical deterioration (need for hemicraniectomy, osmotic therapy, or GCS decline, with MLS 〉 5mm). Results: Ten patients were analyzed (median NIHSS 13, FU CT at median of 30 hours, IQR 15-37). Sulcal asymmetry (ratio of IL:CL volume) on FU CT was greater in the 4 subjects who deteriorated from malignant edema (median 0.26 vs. 0.79, see Figure), as was % reduction in IL sulcal volume from baseline (76% vs. 35%, p=0.06), while volume of early infarct was not. Hemispheric CSF asymmetry and % reduction in IL ventricular volume at early FU CT were strongly correlated with peak MLS (r=-0.95 and -0.96, both p=0.01). Linear regression found that both early infarct volume and % reduction in IL ventricle volume were strongly associated with MLS, adjusting for baseline CSF volume (Betas 0.55 and -0.48, both p=0.001). Conclusions: In this preliminary study, early CSF asymmetry and reduction in IL CSF volumes appear to predict development of MLS and malignant edema. Further validation is needed to test whether CSF volumetrics have utility in selection of patients for early aggressive interventions.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.46.suppl_1.wp317
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2015
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
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    Online Resource
  • 4
    Online Resource
    Online Resource
    Abstract TP210: Oxygen Extraction Fraction is Increased in the Borderzone Region of Healthy Young Adults
    Ovid Technologies (Wolters Kluwer Health) ; 2018
    In:  Stroke Vol. 49, No. Suppl_1 ( 2018-01-22)
    Details
    In: Stroke, Ovid Technologies (Wolters Kluwer Health), Vol. 49, No. Suppl_1 ( 2018-01-22)
    Abstract: Background: We have previously shown that the borderzone region demonstrates ischemic physiology, with low cerebral blood flow (CBF) and increased oxygen extraction fraction (OEF), in pediatric sickle cell anemia (SCA). This region is vulnerable in SCA as evidenced by increased infarct burden. Here we studied healthy adults to determine if borderzone physiology exists in the absence of apparent vascular disease. Methods: Healthy (N=17, 33 ± 9 yr) and SCA (N=13, 28 ± 7 yr) adults were recruited from a tertiary care SCA clinic. Individuals with vascular risk factors or chronic medical or neurological diseases were excluded. SCA subjects were excluded for stroke, vasculopathy, or transfusion therapy. Brain MRIs were prospectively obtained including: T1, FLAIR, dynamic susceptibility contrast (CBF), and asymmetric spin echo (OEF). Within each subject, 3 regions of low CBF were derived by normalizing CBF to its peak CBF. For gray matter (GM), regions were: 〈 25 th %, 25-50 th %, and 50-75 th % of mean thalamic CBF. For white matter (WM), regions were: 〈 25 th %, 25-35 th %, and 35-45 th % of mean GM CBF. Mean OEF across the 3 CBF regions were compared using Friedman test to account for repeated measures (Fig*). Results: Figure demonstrates the approximated borderzone with heatmaps (# of subjects with WM CBF 〈 25 th %) for healthy and SCA adults, alongside average OEF maps for each cohort. Both in healthy and SCA adults, GM and WM OEF were elevated in the region of lowest CBF. Furthermore, relative tissue volumes of CBF 〈 25 th % were higher in SCA than controls (GM: 16 vs 11%, p 〈 0.001; WM: 33 vs 23% p 〈 0.001), suggesting disease may redistribute CBF, effectively enlarging the borderzone. Conclusion: We found ischemic physiology (low CBF / high OEF) in the borderzone of healthy adults. Additional stressors limiting cerebral oxygen delivery such as chronic anemia in SCA or carotid occlusion may lead to enlargement of the borderzone, further elevation of OEF, and a heightened vulnerability to infarction.
    Type of Medium: Online Resource
    ISSN: 0039-2499 , 1524-4628
    URL: Article
    DOI: 10.1161/str.49.suppl_1.TP210
    RVK:
    XA 10000
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 2018
    detail.hit.zdb_id: 1467823-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
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