Diagnostic Value Of Whole Brain CT Perfusion Source Image For Evaluation Of Ischemic Penumbra And Infarct Core

Objective:The Alberta Stroke Program Early CT Score(ASPECTS)was analyzed on non-contrast-enhanced CT(NCCT)scan of the head,cerebral blood flow(CBF),cerebral blood volume(CBV),arterial phase whole brain CT perfusion source image(CTPA-SI),venous phase whole brain CT perfusion source image(CTPV-SI),and non-contrast-enhanced CT scan of the brain after 2-7 days(NCCT~1).The purpose of this study was to evaluate the correlation between CTP-SI methodology and CT perfusion parameters methodology in predicting infarct core and penumbra.Methods:1.Case material:(1)We collect and analysis the patients with acute ischemic stroke who were admitted to the Second Affiliated Hospital of Dalian Medical University from August2016 to January 2019;(2)Inclusion criteria:The National Institutes of Health Stroke Scale(NIHSS)score?4 points;no history of stroke;pre-onset modified Rankin score(mRs)?2 points;anterior circulation ischemia(anterior cerebral artery and middle cerebral artery supply area).(3)Exclusion criteria:intracranial hemorrhage and tumor;blood glucose<2.7mmol/L or>22.2 mmol/L(the coma due to hyperglycemia or hypoglycemia is difficult to identify ischemic stroke);the history of contrast agent allergy;the history of renal insufficiency;imaging data incomplete;NIHSS score?25 points;poor image quality can not be analyzed.2.Examination methods and image processing:All patients underwent NCCT scan of the head,whole brain CT perfusion(CTP),head and neck CTA angiography and NCCT~1.The ASPECTS score was used to evaluate the extent of CTPA-SI and CTPV-SI images in patients with acute ischemic stroke.The infarct area in the NCCT~1 was used as the"gold standard"for the final infarction to further confirm the value of the CTPA-SI/CTPV-SI mismatch model in the diagnosis of infarct core and ischemic penumbra.The ischemic penumbra model(CBV/CBF mismatch model)was compared to determine the diagnostic performance.3.Statistical analysis:(1)The consistency of the results of the two physicians was analyzed by Kappa test.(2)The difference between ASPECTS score of CTPA-SI and ASPECTS score of CTPV-SI was analyzed by Wilcoxon rank sum test.(3)The relationship between each Imaging parameters(ASPECTS score of CTPV-SI,ASPECTS score of CBV,ASPECTS score of final infarction in NCCT~1)was compared by multiple linear regression analysis.(4)The Spearman correlation analysis was used to test the correlation between the ASPECTS score of CTPV-SI and the ASPECTS score of the final infarction in the NCCT~1 scan of the brain,the ASPECTS score of CBV and the ASPECTS score of the final infarction in the NCCT~1 scan of the brain.The correlation between the ASPECTS score of CTPV-SI,the ASPECTS score of CBV and the ASPECTS score of the final infarction in NCCT~1 was compared.Result:1.All 40 patients were enrolled in the study.According to the results of CTP and CTA,11 cases of infarction were located on the right side and 10 cases on the left side.Among them,there were 6 cases of left middle cerebral artery and 7 cases of right middle cerebral artery.There were 4 cases of internal carotid artery and 4 cases of right internal carotid artery.2.The median ASPECTS score of CTPA-SI is 5 points(1-10 points),and the median ASPECTS score of CTPV-SI is 8 points(2-10 points).Statistical analysis confirmed that there was a difference between the ASPECTS score of CTPA-SI and the ASPECTS score of CTPV-SI.3.There is a clear linear relationship between the ASPECTS score of CBV and the ASPECTS score of CTPV-SI,the ASPECTS score of CBF and the ASPECTS score of CTPA-SI.The statistical analysis shows that the slopes in the regression equation are1.042 and 0.948,respectively.That is,the ASPECTS score of CBV was almost equal to the ASPECTS score of CTPV-SI;The ASPECTS score of CBF is also substantially equal to the ASPECTS score of CTPA-SI.Therefore,it can be inferred that the CTPA-SI image can replace the CBF to determine the infarct and ischemic penumbra,and the CTPV-SI image can replace the CBV to evaluate the infarct core.4.There is a positive correlation between the ASPECTS score of CTPV-SI and the ASPECTS score of the NCCT~1,the ASPECTS score of CBV and the ASPECTS score of the NCCT~1.The correlation coefficients were 0.971 and 0.934,respectively.The ASPECTS scores of CTPV-SI were more correlated in the ASPECTS score of the NCCT~1.Conclusion:1.CTPA-SI and CTPV-SI have different ischemic ranges in patients with acute stroke,and the CTPV-SI/CTPA-SI mismatch model has certain diagnostic value for the diagnosis of ischemic penumbra.2.CTPV-SI/CTPA-SI mismatched model and CBV/CBF mismatched model have a good correlation in the diagnosis of ischemic penumbra.CTPV-SI/CTPA-SI mismatch model is closer to the real state,and the diagnostic accuracy is higher.It is beneficial to the clinical rapid discrimination of the ischemic penumbra.