ABSTRACT
Objective: To explore the value of three-dimensional arterial spin labeling (ASL) combined with diffusion weighted imaging (DWI) in evaluation on ischemic penumbra (IP) and prognosis of patients with acute cerebral infarction (ACI). Methods: Data of 45 ACI patients were retrospectively analyzed. Brain ASL images and DWI of all patients were collected. According to the improved Rankin scale (mRS) score at the end of the third month of follow-up, the patients were divided into good prognosis group, medium prognosis group and poor prognosis group. The presence of IP was assessed according to the measured maximum DWI high signal area (SDWI) and ASL abnormal perfusion area (SASL). The values of cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) of the infarct lesion (IL), brain tissue near the edge of the lesions (BNL) and the corresponding contra area were recorded, and the relative values (rCBF and rADC) of lesion side/contra were calculated. CBF and ADC values of IL of BNL and contra area in different prognostic groups were compared, as well as of rCBF and rADC in different prognostic groups. The diagnostic efficacy of rCBF of IL and BNL for evaluating poor prognosis of ACI patients were analyzed, respectively, so as the combined diagnostic efficacy. The correlation between rCBF or rADC and mRS score were analyzed. Results: Totally 40 ACI patients showed hypoperfusion in the IL areas, and IP was present in 23 of them. The difference of prognosis between patients with IP and those without IP was statistically significant (χ2=6.742, P=0.034). CBF and ADC values of IL of 3 groups, the CBF values of BNL in good and medium prognosis groups were lower than those in contra area (all P<0.05). There were statistical differences of rCBF of IL between poor prognosis group and good or medium prognosis group (both P<0.05), while no statistical difference of rCBF of BNL in 3 groups was found (F=3.20, P=0.05). AUC of rCBF of IL or BNL assessing poor prognosis of ACI was 0.92 and 0.79, the optimal cutoff values was 0.41 and 0.93, and the Youden indexs was 0.72 and 0.57, respectively. AUC of combined diagnosis was 0.94, and Youden index was 0.79. The rCBF of IL was negatively correlated with mRS score (r=-0.642, P<0.001). Conclusion: Three-dimensional ASL combined with DWI could be used to evaluate IP and prognosis of ACI patients, providing references for the formulation of ACI treatment plan.