Application of Image Segmentation on Evaluating Infarct Core in Acute Ischemic Stroke Using CT Perfusion

Abstract

Purpose:Investigate the threshold setting and accuracy of CTP in predicting the infarct core volume of acute ischemic stroke. Material and method:43 acute ischemic stroke patients admitted to the Department of Neurology of the First Hospital of Jilin university underwent Intra-arterial therapy from 2017.1 to 2017.12, and were retrospectively analyzed. Multimodal CT perfusion were examined prior to therapy, and non-contrast CT(NCCT) or MRI were reexamined 2-14 days after onset. Based on the mTICI following DSA intervention, the subjects were further categorized into recanalization positive group(mTICI 2b-3) and recanalization negative group(mTICI<2b). The infarct core volume was predicted via the MTT/CBV dual-threshold by CTP(Threshold setting: MTT>145%; 7 thresholds for CBV with an interval of 0.5, ranging between 2.0-5.0). The final infarct volume(FIV) was determined by follow up NCCT or MRI, and the difference of FIV was analyzed between the recanalization positive group and the recanalization negative group. Results:The FIV and the predicted infarct core volumes were compared among all patients. The predicted volumes by threshold 3 (Z=1.717, p=0.086), threshold 4(Z=0.110, p=0.912) and threshold 5(Z=1.678, p= 0.093 ) were close to the FIV. However, the difference compared to FIV did not differ significantly among threshold 3, 4and5.The predicted volumes by threshold 2 (Z=1.882, p=0.060), threshold 3(Z=0.154, p=0.877) and threshold 4(Z=1.471, p=0.141) were close to the FIV in the recanalization-positive group. The difference analysis of threshold 2, 3 and 4 revealed closest prediction of threshold 2, with a median volume of 32.61(19.20~61.74).However, the difference compared to FIV did not differ significantly among threshold 2, 3 and 4.The predicted volumes by threshold threshold 5(Z=1.156, p=0.248), threshold 6(Z=0.800, p=0.424) and threshold 7(Z= 0.267, p=0.790) were close to the FIV in the recanalization-negative group.The difference analysis of threshold 5, 6 and 7 revealed closest prediction of threshold 7, with a median volume of 20.92(11.88~110.63). However, the difference compared to FIV did not differ significantly among threshold 5, 6 and 7. Conclusions: CTP predicted infarct core volume in AIS is highly correlated to FIV. More precise predictions might be achieved via adopting dynamic parameter thresholds based on the state of recanalization.