ABSTRACT
Objective:To explore the value of the Wilcoxon-Mann-Whitney generalized dominance ratio (T max-weighted ratio) based on residual tissue time to peak (T max) delayed severity weighting in predicting the moderate to severe edema after acute anterior circulation ischemic stroke. Methods:The clinical and imaging features of patients with acute anterior circulation ischemic stroke from January 2019 to April 2022 in Yidu Central Hospital of Weifang were retrospectively analyzed. A total of 85 patients were enrolled, including 60 males and 25 females, with the age from 34 to 93 (67±11) years old. Patients underwent non-contrast CT, CT angiography of the head and neck, and CT perfusion imaging of the head, and ischemic core volume and the ratio of T max 4-6 s volume, T max 6-8 s volume, T max 8-10 s volume, and T max >10 s volume relative to the entire hypo-perfused area (T max>4 s volume) was measured, and the T max-weighted ratio was calculated, the collateral circulation were assessed. Patients were divided into mild edema group and moderate to severe edema group according to whether local swelling exceeded 1/3 of the unilateral cerebral hemisphere on non-contrast CT at 24-48 h. The indicators were compared between the two groups by independant t test, Mann-Whitney U and χ 2 test. The performance to predict moderate to severe edema was assessed using the receiver operating characteristic (ROC) curve. The univariate and multivariate logistic regression was used to analyze the risk factors for the moderate to severe edema. Differences in baseline National Institutes of Health Stroke Scale (NIHSS) score and infarct core volume were equalized by 1∶1 propensity score matching (PSM) and the differences of T max-weighted ratio between the two groups were further compared. Results:There were 52 cases in the mild edema group and 33 cases in the moderate to severe edema group. Baseline NIHSS score, T max>10 s volume, ischemic core volume, T max-weighted ratio and proportion of poor collateral circulation were higher in the moderate-severe edema group than those in the mild edema group ( P<0.001), T max 4-6 s volume was lower than in the mild edema group ( P<0.001). ROC analysis showed that the area under the curve (AUC) of T max-weighted ratio for predicting the incidence of moderate to severe edema was 0.885 (95%CI 0.798-0.944), with an optimal cut-off value of 1.17, sensitivity of 84.85% and specificity of 82.69% before PSM. The predictive ability based on T max-weighted ratio was similar to ischemic core volume( Z=0.64, P=0.520), T max 4-6 s volume ( Z=1.48, P=0.140) and superior to T max 6-8 s volume( Z=5.65, P<0.001), T max 8-10 s volume( Z=4.46, P<0.001), T max >10 s volume ( Z=2.91, P=0.004). Multivariate logistic regression analysis showed that T max-weighted ratio>1.17 was an independent predictor of the development of moderate to severe edema (OR=10.40,95%CI 2.65-40.83, P=0.001) through adjusted for baseline NIHSS score and ischemic core volume. After PSM, 14 patients in each group were included; the T max-weighted ratio was higher in the moderate-to-severe edema group than that in the mild edema group ( P<0.001), and the differences in other factors were not statistically significant (all P>0.05); ROC analysis showed that the AUC of T max-weighted ratio to predict the occurrence of moderate-to-severe edema was 0.852 (95%CI 0.667-0.957). Conclusion:The T max-weighted ratio can predict the occurrence of moderate-to-severe edema in brain tissue after acute anterior circulation ischemic stroke.
ABSTRACT
Objective To evaluate the feasibility of the lateralization of unilateral medial temporal lobe epilepsy(mTLE)by using arterial-spin-labeling(ASL)based perfusion MR imaging and investigate the changes of perfusion in the regions related to mTLE network and the relationship between the perfusion and the clinical status.Methods Twenty-five patients with left-sided and 23 with right-sided mTLE were enroiled,and 30 healthy volunteers were recruited.The cerebral blood flow(CBF)of related region was measured based on pulsed-ASL sequence on Siemens 3 T scanner.The CBF of the mTLE group were compared with that in the controls by using ANOVA analysis.The asymmetric indices of CBF in the medial temporal lobe were calculated as the lesion side compared with the normal side in matched region in mTLE group.Results Compared with the volunteers,the patients with mTLE showed the decrease of CBF in the bilateral medial and lateral temporal,the frontal and parietal regions relating to the default-mode network and more serious in lesion side.The CBF values of the medial temporal lobe were negatively correlated with the epilepsy duration(r =-0.51,P ＜0.01).The asymmetric index of CBF as-0.01 has a 76.0％(19/25)sensitivity and a 78.3％(18/23)specificity to distinguish the lesion side.Conclusions The decrease of CBF in the temporal and extra-temporal region by ASL-based MRI suggests the functional abnormalities in the network involved by mTLE.The ASL technique is a useful tool for lateralizing the unilateral mTLE.