scholarly journals CT Perfusion in Acute Stroke Predicts Final Infarct Volume- Inter-observer Study

Author(s):  
Jai Jai Shiva Shankar ◽  
Gavin Langlands ◽  
Steve Doucette ◽  
Stephen Phillips

AbstractBackground: Computed tomography perfusion (CTP) is increasingly being used in the setting of acute ischemic stroke (AIS). The aim of the current study was to compare the prognostic utility of, and inter-observer variation between, baseline appearances on non-contrast CT (using Alberta Stroke Program Early CT score(ASPECTS)) and on CTP for predicting final infarct volume. We also assessed impact of training on interpretation of these images. Methods: Retrospectively, plain head computed tomography (CT) and CTP images at presentation and CT or diffusion imaging on follow up of patients with AIS were analyzed. The lesion volume on different CTP parameters was then correlated with the final infarct volume. This analysis was done by a Neuroradiologist, a stroke Neurologist and a medical student. Kappa statistics and Intra-class correlation coefficients were used for agreement between readers. Pearson correlation coefficients were used.Results: Thirty eight patients with AIS met all inclusion criteria. There was very good agreement among all readers for the CTP parameters. There was only fair agreement for ASPECT score. Correlation coefficient (r-square) between CTP parameters and final infarct volume showed that cerebral blood volume was the best parameter to predict the final infarct volume followed by cerebral blood flow and time to peak. The best reader to predict the final infarct volume on the initial CT perfusion study was the neuroradiologist followed by medical student and stroke neurologist. Conclusions: Cerebral blood volume defect correlated the best with the final infarct volume. There was a very good inter-observer agreement for all the CTP maps in predicting the final infarct volume despite the wide variation in the experience of the readers.

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Jelle Demeestere ◽  
Carlos Garcia-Esperon ◽  
Pablo Garcia-Bermejo ◽  
Fouke Ombelet ◽  
Patrick McElduff ◽  
...  

Objective: To compare the predictive capacity to detect established infarct in acute anterior circulation stroke between the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) on non-contrast computed tomography (CT) and CT perfusion. Methods: Fifty-nine acute anterior circulation ischemic stroke patients received brain non-contrast CT, CT perfusion and hyperacute magnetic resonance imaging (MRI) within 100 minutes from CT imaging. ASPECTS scores were calculated by 4 independent vascular neurologists, blinded from CT perfusion and MRI data. CT perfusion infarct core volumes were calculated by MIStar software. The accuracy of commonly used ASPECTS cut-off scores and a CT perfusion core volume of ≥ 70 mL to detect a hyperacute MRI diffusion lesion of ≥ 70 ml was evaluated. Results: Median ASPECTS score was 9 (IQR 7-10). Median CT perfusion core volume was 22 ml (IQR 10.4-71.9). Median MRI diffusion lesion volume was 24,5 ml (IQR 10-63.9). ASPECTS score of < 6 had a sensitivity of 0.37, specificity of 0.95 and c-statistic of 0.66 to predict an acute MRI lesion ≥ 70 ml. In comparison, a CT perfusion core lesion of ≥ 70 ml had a sensitivity of 0.76, specificity of 0.98 and c-statistic of 0.92. The CT perfusion core lesion covered a median of 100% of the acute MRI lesion volume (IQR 86-100%). Conclusions: CT perfusion is superior to ASPECTS to predict hyperacute MRI lesion volume in ischemic stroke.


Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Simon Morr ◽  
Maxim Mokin ◽  
Ashish Sonig ◽  
Kenneth Snyder ◽  
Adnan Siddiqui ◽  
...  

Introduction: Tools for evaluating risk of post-intervention risk hemorrhage in the setting of acute stroke include a noncontrast head CT based Alberta Stroke Program Early CT score (ASPECTS) and contrasted CT based perfusion plots. The correlation between these parameters is unknown. Methods: We performed a retrospective analysis of a prospectively collected endovascular stroke database of patients with M1 middle cerebral artery occlusion who underwent endovascular recanalization. We reviewed admission preintervention noncontrast CT for Alberta Stroke Program Early CT score (ASPECTS) and 320-detector row whole brain CT perfusion parameters (Cerebral blood volume and time to peak). Pearson correlation was determined between cerebral blood volume on the side of the stroke and ASPECTS. Results: ASPECTS and CT perfusion map were identified in 45 and 43 patients respectively. Statistically significant correlation was found between ASPECTS and cerebral blood volume data on CT perfusion MAP. (p=0.034, r=-0.28). The correlation coefficient is very weak. No correlation could be found between time to peak and ASPECTS. Conclusion: A statistically significant, but weak correlation exists between ASPECTS and CBV. Further research is needed to assess the physiological meaning of diverse imaging modalities utilized in the acute stroke setting.


2012 ◽  
Vol 18 (3) ◽  
pp. 303-308 ◽  
Author(s):  
M.U. Antonucci ◽  
J Mocco ◽  
J.A. Bennett

Transient contrast enhancement on computed tomography following endovascular treatment of stroke is a recognized entity that has been previously reported. Technological advances in brain imaging now have the potential to explore and refine its proposed etiology. We describe three patients in whom the location of contrast enhancement correlates with decreased cerebral blood volume on pre-therapeutic CT perfusion studies and with restricted diffusion on MRI. In this regard, contrast enhancement demarcated areas of completed cerebral infarction. The diagnostic and etiological implications are discussed.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Maxim Mokin ◽  
Elad Levy ◽  
Jeffrey L Saver ◽  
Mayank Goyal ◽  
Alain Bonafe ◽  
...  

Background and purpose: Advanced CT perfusion (CTP) imaging can estimate the size of the ischemic core, which can be used for selection of patients for endovascular therapy. The relative cerebral blood volume (rCBV) and cerebral blood flow (rCBF) thresholds chosen to identify ischemic core influence the accuracy of prediction. The purpose of this study was to analyze the accuracy of various rCBV and rCBF thresholds for predicting 27 hour infarct volume using RAPID automated analysis software. Methods: Patients from the SWIFT PRIME study with baseline and 27 hour follow-up CT perfusion scans were included if they had complete reperfusion based on Tmax>6s perfusion maps obtained at 27 hours. Patients from both the tPA and endovascular groups were included. Infarct volume was determined on MRI (FLAIR images) or CT scans obtained 27 hours after symptom onset. The predicted ischemic core volume on rCBV and rCBF maps using thresholds ranging between 0.2 and 0.8 was compared with the actual infarct volume to determine the most accurate thresholds. Results: Among the 47 subjects, the following baseline CTP thresholds most accurately predicted the actual 27 hour infarct volume: rCBV=0.34 (Median absolute error (MAE)=11.5 ml); rCBV=0.36, MAE=9.9 ml; rCBV=0.4, MAE=12.5 ml; rCBF=0.3, MAE=8.8 ml; rCBF=0.32, MAE=7.3; and rCBF=0.34, MAE=7.8. Conclusions: Brain regions with rCBF ≤ .32 or rCBV ≤ .36 provided the most accurate prediction of infarct volume in patients who achieved complete reperfusion with median absolute errors less than 10 ml. Our data support the value of automated image analysis software as a tool for accurate prediction of ischemic core lesion volume.


2020 ◽  
Vol 40 (10) ◽  
pp. 1966-1974 ◽  
Author(s):  
Vaishnavi L Rao ◽  
Michael Mlynash ◽  
Søren Christensen ◽  
Amarnath Yennu ◽  
Stephanie Kemp ◽  
...  

We previously demonstrated that in the DEFUSE 3 trial, the union of the baseline core and the 24-h Tmax > 6 s perfusion lesion predicts the infarct volume at 24 h. Presently, we assessed if collateral robustness measured by the hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index accounts for the variance in these predictions. DEFUSE 3 patients underwent MRI/CT perfusion imaging at baseline and 24 h post-randomization. We compared baseline and follow-up HIR and CBV index across subgroups stratified by differences between predicted and observed 24-h infarct volumes. Of 123 eligible patients, 34 with 24-h infarcts larger than predicted had less favorable collaterals at baseline (HIR 0.43 vs. 0.32, p = 0.006; CBV Index 0.78 vs. 0.85, p = 0.001) and 24 h (HIR 0.56 vs. 0.07, p = 0.004; CBV Index 0.47 vs. 0.73, p = 0.006) compared to 71 patients with more accurate infarct volume prediction. Eighteen patients with 24-h infarcts smaller than predicted had similar baseline collateral scores but more favorable 24-h CBV indices (0.81 vs. 0.73, p = 0.040). Overall, patients with 24-h infarcts larger than predicted had evidence of less favorable baseline collaterals that fail within 24 h, while patients with 24-h infarcts smaller than predicted typically had favorable collaterals that persisted for 24 h.


Stroke ◽  
2019 ◽  
Vol 50 (11) ◽  
pp. 3274-3276 ◽  
Author(s):  
Aneka Mueller ◽  
Marlies Wagner ◽  
Elke Hattingen ◽  
Alexander Seiler ◽  
Se-Jong You ◽  
...  

Background and Purpose— Patients with large-vessel stroke frequently need to be transferred to comprehensive stroke centers for endovascular treatment. An update of physiological perfusion parameters and stroke progression on arrival is desirable. We examined the reliability of preinterventional pooled blood volume (PBV)-maps acquired by flat-panel detector computed tomography (CT) in the interventional angiography suite. Methods— The volumes of preinterventional perfusion deficit in flat-panel detector CT-PBV source images were compared with final infarct volume on follow-up multislice-CT after endovascular treatment of 29 consecutive patients with occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA). Results— Endovascular treatment was successful in 26 patients (Thrombolysis in Cerebral Infarction, 2b-3). Overall, the median preinterventional PBV-deficit was 9×larger than median final infarct volume on multislice-CT (86.4 mL [10.3; 111.6] versus 9.6 mL [3.6; 36.8]). This was especially evident in the subgroup of successful recanalization (PBV-deficit: 87.5 mL [10.6; 115.1], final infarct: 8.7 mL [3.6; 29]). In futile recanalization, the final infarct tended to be underestimated (PBV-deficit: 86.4 mL [5.9; –] and final infarct: 116.4 mL [3.5; –]). Conclusions— Flat panel detector CT-PBV is not reliable in predicting the final infarct volume and should not be used in clinical decision making for endovascular treatment of acute cerebral artery occlusions.


2010 ◽  
Vol 80 (1) ◽  
pp. 160-166 ◽  
Author(s):  
Yi Liu ◽  
Raphael Olszewski ◽  
Emanuel Stefan Alexandroni ◽  
Reyes Enciso ◽  
Tianmin Xu ◽  
...  

Abstract Objective: To determine the accuracy of volumetric analysis of teeth in vivo using cone-beam computed tomography (CBCT). Materials and Methods: The physical volume (Vw) of 24 bicuspids extracted for orthodontic purposes (16 were imaged with the I-CAT and 8 with the CB MercuRay) were determined using the water displacement technique. Corresponding pretreatment CBCT image data were uploaded into Amira 4.0 for segmentation and radiographic volume (Va). All measurements were performed twice by two observers. The statistical difference between Vw and Va was assessed using a paired t-test. The intraobserver and interobserver reliability were determined by calculating Pearson correlation coefficients and intraclass correlation coefficients. Results: The overall mean Vw of teeth specimens was 0.553 ± 0.082 cm3, while the overall mean Va was 0.548 ± 0.079 cm3 (0.529 ± 0.078 cm3 for observer 1 and 0.567 ± 0.085 cm3 for observer 2). There were statistically significant differences between Va and Vw (P &lt; .05). Between observer 1 and observer 2, Va measurements were statistically significantly different (P &lt; .05). The interobserver and intraobserver correlation coefficient for Vw was high. Lastly, surface smoothing reduced the volume by 3% to 12%. Conclusions: In vivo determination of tooth volumes from CBCT data is feasible. The measurements slightly deviate from the physical volumes within −4% to 7%. Smoothing operations reduce volume measurements. Currently, no requirements for accuracy of volumetric determinations of tooth volume have been established.


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