Combination of DWI and 3D-PCASL to study acute ischemic stroke

YANG Min; LI Haige; WU Yahong; ZHU Jianguo

Abstract：Objective The aim of this study is to assess the combination of diffusion weighted imaging (DWI) and three-dimensional pseudo-continuous arterial spin labeling (3D-PCASL) in patients with acute ischemic stroke (AIS).Methods Patients with suspected AIS were examined by magnetic resonance imaging within 48 h of symptom onset.Forty-five patients (mean age was 66.27 ± 13.27 years) who underwent magnetic resonance angiography (MRA) and DWI was identified as having AIS with ischemic core was enrolled,where ischemic core referred to the area of high DWI signal and decreased apparent diffusion coefficient (ADC) value.ADC and ASL cerebral blood flow (CBF) were measured.The paired t-test was applied to compare ASLCBF and DWI-ADC measurements between ischemic core and contralateral normal brain regions.Pearson's correlation was used to evaluate the correlations among quantitative results.Linear regression and receiver operating characteristic (ROC) curve were applied to assess the difference of diagnostic efficacy anong different quantitative parameters.Results The ADC and CBF values of ischemic penumbras were significantly lower than those of the contralateral norinal brain regions (0.50 ± 0.15 VS.0.80 ± 0.13 um2/ms,P ＜ 0.001;17.04 ± 6.97 VS.34.14 ± 13.53 ml · 100 g-1 · min-1,P ＜ 0.001,respectively).A significant correlation was detected between ADC and CBF (r =0.583,P ＜0.001).The combination of ADC and CBF performed best in diagnosis of AIS with the area of under ROC curve (AUC) 0.955.Conclusion The decrease in cerebral blood perfusion primarily results in the decrease ADC in ischemic core.The combination of DWI and 3D-PCASL has important clinical significance for diagnosis of AIS.