Abstract WP55: Low Predictive Value of Multiphase CT Angiography for CT Perfusion Defined Ischemic Penumbra

Stroke ◽  
2018 ◽  
Vol 49 (Suppl_1) ◽  
Author(s):  
Robert Wannamaker ◽  
Harsha Jayaprakash ◽  
Jeremy Rempel ◽  
Brian Buck ◽  
Jayme Kosior ◽  
...  
Keyword(s):  
Ct Angiography ◽  
Predictive Value ◽  
Ct Perfusion ◽  
Ischemic Penumbra ◽  
Multiphase Ct

The Prognostic Value of CT Angiography and CT Perfusion in Acute Ischemic Stroke

2015 ◽  
Vol 40 (5-6) ◽  
pp. 258-269 ◽  
Author(s):  
Tom van Seeters ◽  
Geert Jan Biessels ◽  
L. Jaap Kappelle ◽  
Irene C. van der Schaaf ◽  
Jan Willem Dankbaar ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Clinical Outcome ◽  
Acute Ischemic Stroke ◽  
Ct Angiography ◽  
Predictive Value ◽  
Prognostic Value ◽  
Ct Perfusion ◽  
Patient Characteristics ◽  
Poor Clinical Outcome ◽  
Poor Outcome

Background: CT angiography (CTA) and CT perfusion (CTP) are important diagnostic tools in acute ischemic stroke. We investigated the prognostic value of CTA and CTP for clinical outcome and determined whether they have additional prognostic value over patient characteristics and non-contrast CT (NCCT). Methods: We included 1,374 patients with suspected acute ischemic stroke in the prospective multicenter Dutch acute stroke study. Sixty percent of the cohort was used for deriving the predictors and the remaining 40% for validating them. We calculated the predictive values of CTA and CTP predictors for poor clinical outcome (modified Rankin Scale score 3-6). Associations between CTA and CTP predictors and poor clinical outcome were assessed with odds ratios (OR). Multivariable logistic regression models were developed based on patient characteristics and NCCT predictors, and subsequently CTA and CTP predictors were added. The increase in area under the curve (AUC) value was determined to assess the additional prognostic value of CTA and CTP. Model validation was performed by assessing discrimination and calibration. Results: Poor outcome occurred in 501 patients (36.5%). Each of the evaluated CTA measures strongly predicted outcome in univariable analyses: the positive predictive value (PPV) was 59% for Alberta Stroke Program Early CT Score (ASPECTS) ≤7 on CTA source images (OR 3.3; 95% CI 2.3-4.8), 63% for presence of a proximal intracranial occlusion (OR 5.1; 95% CI 3.7-7.1), 66% for poor leptomeningeal collaterals (OR 4.3; 95% CI 2.8-6.6), and 58% for a >70% carotid or vertebrobasilar stenosis/occlusion (OR 3.2; 95% CI 2.2-4.6). The same applied to the CTP measures, as the PPVs were 65% for ASPECTS ≤7 on cerebral blood volume maps (OR 5.1; 95% CI 3.7-7.2) and 53% for ASPECTS ≤7 on mean transit time maps (OR 3.9; 95% CI 2.9-5.3). The prognostic model based on patient characteristics and NCCT measures was highly predictive for poor clinical outcome (AUC 0.84; 95% CI 0.81-0.86). Adding CTA and CTP predictors to this model did not improve the predictive value (AUC 0.85; 95% CI 0.83-0.88). In the validation cohort, the AUC values were 0.78 (95% CI 0.73-0.82) and 0.79 (95% CI 0.75-0.83), respectively. Calibration of the models was satisfactory. Conclusions: In patients with suspected acute ischemic stroke, admission CTA and CTP parameters are strong predictors of poor outcome and can be used to predict long-term clinical outcome. In multivariable prediction models, however, their additional prognostic value over patient characteristics and NCCT is limited in an unselected stroke population.

scholarly journals Imaging Triage of Patients with Late-Window (6–24 Hours) Acute Ischemic Stroke: A Comparative Study Using Multiphase CT Angiography versus CT Perfusion

2019 ◽  
Vol 41 (1) ◽  
pp. 129-133 ◽  
Author(s):  
M.A. Almekhlafi ◽  
W.G. Kunz ◽  
R.A. McTaggart ◽  
M.V. Jayaraman ◽  
M. Najm ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Comparative Study ◽  
Acute Ischemic Stroke ◽  
Ct Angiography ◽  
Ct Perfusion ◽  
Multiphase Ct

Embolization for acute gastrointestinal bleeding

2021 ◽  
Author(s):  
Aaron Teel
Keyword(s):  
Gastrointestinal Bleeding ◽  
Ct Angiography ◽  
Predictive Value ◽  
Clinical Success ◽  
Tertiary Care ◽  
Recurrent Bleeding ◽  
Complication Rates ◽  
Endoscopic Evaluation ◽  
Acute Gastrointestinal Bleeding ◽  
Multiphase Ct

Purpose: To retrospectively evaluate the clinical success and complication rates following interventional embolization for treatment of acute gastrointestinal bleeding (GIB) at a tertiary care centre. The secondary purpose was to evaluate results of practice change whereby multiphase CT angiography was requested prior to conventional angiograms. Methods: A retrospective chart review and analysis of 38 patients undergoing Interventional Radiology guided embolization for acute GIB was performed. Clinical success was defined as patient stability 30 days’ post embolization and complications included subsequent bleeding requiring endoscopy, surgery or additional embolization, or death. Results: Overall clinical success rate was 86.8% (33/38). Complications included 14 patients (36.8%) experiencing continued bleeding, 6 patients (15.8%) requiring repeat endoscopic evaluation, 8 patients (21.1%) requiring surgery, 3 patients (7.9%) requiring repeat embolization, and 4 deaths (10.5%). These results were not inferior to clinical success rates reported in the literature for GIB regardless of location. Positive predictive value for multiphase CT angiogram was 92.3% and the negative predictive value was 57.1%. Conclusions: Interventional angiography and embolization is an effective treatment for GIB with the most common complication being recurrent bleeding which may require additional endoscopic evaluation, surgical intervention or additional embolization. Clinical success and complication rates at this centre are similar to those reported in the literature. Continued evaluation of the utility of multiphase CT angiography prior to conducting embolization should be considered to determine its impact on rates of negative angiogram studies.

Abstract P334: Multiphase Computed Tomography Angiography-Perfusion for Quantitative Measurement of Ischemic Volumes

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Kevin J Chung ◽  
Donald H Lee ◽  
Sachin Pandey ◽  
Mayank Goyal ◽  
Bijoy K Menon ◽  
...  
Keyword(s):  
Ct Angiography ◽  
Ct Perfusion ◽  
Infarct Volume ◽  
Intraclass Correlation ◽  
Prototype Model ◽  
Limiting Factor ◽  
Quantitative Perfusion ◽  
Scan Time ◽  
Volume Measurements ◽  
Multiphase Ct

Introduction: Proficiency required to execute CT perfusion (CTP) protocols is a limiting factor in its use in acute stroke. We propose to calculate perfusion parametric maps and measure ischemic volumes using readily available non-contrast CT (NCCT) and multiphase CT angiography (mCTA) images. Materials and Methods: Twenty-five patients presenting with acute ischemic stroke were included in this study. Our proposed dynamic sequence (multiphase CT angiography-perfusion, mCTA-P) consisted of the NCCT as the pre-contrast baseline and three phases of mCTA, which corresponded to the peak arterial, peak venous, and late venous phases at 8 s intervals. CTP was acquired after mCTA and consisted of 22 dynamic images acquired over 60 s at 2.8 s intervals. A prototype model-based deconvolution algorithm (CT Perfusion 4D, GE Healthcare) was used to calculate cerebral blood flow (CBF) and Tmax maps for each series. Infarct was classified as voxels that satisfied both a time-dependent relative CBF threshold and Tmax > 8 s while penumbral voxels satisfied either threshold but not both. Results: Median (interquartile range) 24-hour follow-up infarct volume was 18.6 (4.7 to 34.3) ml and median stroke onset-to-CTP time was 124.0 (70.5 to 201.5) min. Bland-Altman analysis revealed good agreement between CTP and mCTA-P volume measurements as mean differences (limits of agreement) were -1.0 (-14.9 to 12.9) ml for infarct and 8.4 (-42.4 to 59.1) ml for penumbra. Intraclass correlation (95% confidence interval, p < 0.05) between CTP and mCTA-P volumes were 0.72 (0.46 to 0.87) for infarct and 0.68 (0.41 to 0.85) for penumbra, indicating good to moderate reliability. Conclusion: Quantitative perfusion can be estimated from NCCT and mCTA without introducing additional scan time, radiation dose, and contrast injections associated with CTP. Our technique allows assessments of early ischemic changes and collaterals to be augmented with quantitative perfusion measurements of ischemic volumes.

Ultra-low-dose multiphase CT angiography derived from CT perfusion data in patients with middle cerebral artery stenosis

2019 ◽  
Vol 62 (2) ◽  
pp. 167-174
Author(s):  
Xiaoling Wu ◽  
Yuelong Yang ◽  
Menghuang Wen ◽  
Lijuan Wang ◽  
Yunjun Yang ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Ct Angiography ◽  
Cerebral Artery ◽  
Low Dose ◽  
Ct Perfusion ◽  
Artery Stenosis ◽  
Multiphase Ct ◽  
Middle Cerebral Artery Stenosis

scholarly journals Dynamic CT but Not Optimized Multiphase CT Angiography Accurately Identifies CT Perfusion Target Mismatch Ischemic Stroke Patients

2019 ◽  
Vol 10 ◽  
Author(s):  
Huiqiao Tian ◽  
Chushuang Chen ◽  
Carlos Garcia-Esperon ◽  
Mark W. Parsons ◽  
Longting Lin ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Ct Angiography ◽  
Ct Perfusion ◽  
Dynamic Ct ◽  
Stroke Patients ◽  
Multiphase Ct
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