Clinical Application Of Multimodal CT In Predicting Hemorrhagic Transformation Treated With Intravenous Thrombolysis In Ischemic Stroke Patients

Aim: To determine the role of multimodal CT imaging on predicting hemorrhagic transformation in ischemic stroke patients treated with intravenous thrombolysis.clinical valueObjects and Methods: A total of 68 patients with ischemic stroke who underwent CT perfusion examination before intravenous thrombolysis in the Stroke Center of Drum Tower Hospital Affiliated to Medical College of Nanjing University from August2018 to July 2019 were screened out,and patients with posterior circulation ischemia and minor stroke were excluded.13 cases with hemorrhagic transformation within 7days were selected as the hemorrhagic group,and 25 cases without hemorrhage were selected as the non-hemorrhagic group.After correcting for clinical baseline data,patients with hemorrhagic transformation after thrombolysis were evaluated to identify the high-risk factors.The hemorrhagic transformation was graded according to Heidelberg classification,including hemorrhagic infarction,parenchymal hematoma,subarachnoid hemorrhage,and distant hemorrhage.Images were acquired using one-stop multimodal CT examination by Philip 256-slice CT machine.Routine CT scan,CT angiography and CT perfusion examination were performed immediately after excluding bleeding,and multimodal CT was processed twice using artificial intelligence F-stroke software.Clinical and radiologic data were collected and the associations between these imaging markers and hemorrhagic transformation rates were identified using logistic regression model.RESULTS: Thirty-eight patients with ischemic stroke in the time window of intravenous thrombolysis were enrolled in this study,including 8 patients with cardiogenic embolism(CE),21 patients with large artery Atheroscle(LAA),8patients with small-Artery occlusion(SAA),and 1 patient with unknown type.There were 13 patients in the bleeding group,including 3 cases of hemorrhagic infarction type 1,2 cases of hemorrhagic infarction type 2,4 cases of parenchymal hematoma type 1,2 cases of parenchymal hematoma type 2,1 case of subarachnoid hemorrhage and 1 case of distant hemorrhage.There were 25 patients in the non-bleeding group.The sensitivity and specificity for hemorrhagic transformation were 0.923 and 0.92(AUC=0.96,P<0.001)when the Alberta Stroke Program Early CT(ASPECT)score of one-stop multimodal CT was smaller than 6 and the ratio of neutrophils in serum was equal to 0.84 after thrombolysis.When the core infarct volume was larger than 15.6ml in patients undergoing bridging therapy,the sensitivity and specificity for hemorrhagic transformation were 84.6% and 84%(AUC=0.868,P<0.001).There was a moderate negative correlation between ASPECT score and core infarct volume(r=-0.407,p=0.011<0.05).Conclusion: Hemorrhagic transformation after acute ischemic stroke is a major complication of intravenous thrombolysis and intravascular therapy.In this study,when the ASPECT score was less than 7,neutrophil ratio > 0.84 in the serum was a risk factor for hemorrhagic transformation after thrombolysis.The core infarct larger than 15.6 ml was an important factor for hemorrhagic transformation in bridging therapy.In addition,higher National Institutes of Health Stroke Scale(NIHSS)and cardiogenic embolism were both high risk factors for hemorrhagic transformation.