White Matter Hyperintensity is Associated with Malignant Cerebral Edema in Ischemic Stroke Treated with Thrombectomy.

BACKGROUND: White matter hyperintensity (WMH) burden may lead to poor clinical outcomes after endovascular thrombectomy (EVT). But the relationship between WMH burden and cerebral edema (CED) is unclear. PURPOSE: To examine the association between WMH burden and CED and functional outcome in patients treated with EVT. STUDY TYPE: Retrospective. SUBJECT: 344 patients with acute anterior circulation large-vessel occlusion stroke who received EVT at two comprehensive stroke centers. Mean age was 62.6 ± 11.6 years and 100 patients (29.1%) were female. FIELD STRENGTH/SEQUENCE: 3T, including diffusion-weighted imaging and fluid-attenuated inversion recovery (FLAIR) images. ASSESSMENT: The severity of WMH was evaluated using the Fazekas scale on a FLAIR sequence before EVT. The severity of CED was assessed using CED score (three for malignant cerebral edema [MCE]) and net water uptake (NWU)/time on post-EVT cranial CT. The impact of WMH burden on MCE, NWU/time, and 3-month poor outcome (modified Rankin scale >2) after EVT were assessed. STATISTICAL TESTS: Pearson's chi-squared test, Fisher exact test, 2-tailed t test, Mann-Whitney U test, multivariable logistic regression, multivariate regression analysis, Sobel test. A P value <0.05 was considered statistically significant. RESULTS: WMH burden was not significantly associated with MCE and parenchymal hemorrhage (PH) in the whole population (P = 0.072; P = 0.714). WMH burden was significantly associated with an increased risk of MCE (OR, 1.550; 95% CI, 1.128-2.129), higher NWU/time (Coefficient, 0.132; 95% CI, 0.012-0.240), and increased risk of 3-month poor outcome (OR, 1.434; 95% CI, 1.110-1.853) in the subset of patients without PH. Moreover, the connection between WMH burden and poor outcome was partly mediated by CED in patients without PH (regression coefficient changed by 29.8%). DATA CONCLUSION: WMH burden is associated with CED, especially MCE, and poor outcome in acute ischemic stroke patients treated with EVT. The association between WMH burden and poor outcome may partly be attributed to postoperative CED. TECHNICAL EFFICACY: Stage 5.

Efficient Beampattern Synthesis for Sparse Frequency Diverse Array via Matrix Pencil Method.

Due to the introduction of frequency offsets, the pattern synthesis problem of sparse Frequency diverse array (FDA) becomes more complicated than that of the phased array. A typical way to solve this problem is to use a global optimization algorithm, but this is usually time-consuming. In this paper, we propose an efficient non-iterative beampattern synthesis approach for sparse FDA. For a given reference pattern, which can be generated by other synthesis methods, we first sample it uniformly and construct the Hankel matrix with the sampled data. By low-rank processing, a low-rank approximation version of the Hankel matrix can then be obtained. Finally, the matrix enhancement and matrix pencil (MEMP) and matrix pencil (MP) methods are applied to estimate the antenna positions, frequency offsets, and excitations of the obtained array from the approximated matrix. Besides this, two typical FDA frameworks including multi-carrier FDA (MCFDA) and standard FDA (SFDA) are considered. Numerical simulation results prove that the proposed method outperforms the existing methods in terms of synthesis error, average runtime, and percentage of saving elements.

Multi-Target Tracking Using Windowed Fourier Single-Pixel Imaging.

The single-pixel imaging (SPI) technique enables the tracking of moving targets at a high frame rate. However, when extended to the problem of multi-target tracking, there is no effective solution using SPI yet. Thus, a multi-target tracking method using windowed Fourier single-pixel imaging (WFSI) is proposed in this paper. The WFSI technique uses a series of windowed Fourier basis patterns to illuminate the target. This method can estimate the displacements of K independently moving targets by implementing 6K measurements and calculating 2K windowed Fourier coefficients, which is a measurement method with low redundancy. To enhance the capability of the proposed method, we propose a joint estimation approach for multi-target displacement, which solves the problem where different targets in close proximity cannot be distinguished. Using the independent and joint estimation approaches, multi-target tracking can be implemented with WFSI. The accuracy of the proposed multi-target tracking method is verified by numerical simulation to be less than 2 pixels. The tracking effectiveness is analyzed by a video experiment. This method provides, for the first time, an effective idea of multi-target tracking using SPI.

High Systemic Inflammatory Protein Index Is Associated with Clinically Ineffective Reperfusion in Acute Anterior Circulation Ischemic Stroke Patients Undergoing Endovascular Treatment.

Nearly half of the patients undergoing endovascular treatment (EVT) do not have favorable outcomes despite successful recanalization of the occluded artery, which is also known as clinically ineffective reperfusion. We proposed a novel index-the systemic inflammatory protein index (SIPI), based on albumin, globulin, and C-reaction protein (CRP). We aimed to evaluate the relationship between inflammatory biomarkers at varying time points and the 90-day functional outcomes and investigate inflammatory biomarkers' dynamic changes during hospitalization in acute ischemic stroke (AIS) patients of anterior circulation undergoing EVT. We retrospectively recruited consecutive patients diagnosed with AIS of anterior circulation and treated with EVT from January 2018 to June 2022 in Nanfang Hospital. Albumin, globulin, and CRP were recorded on admission, 1 day, 3 days, and 7 days after EVT. An unfavorable functional outcome was defined as 90-day modified Rankin Scale (mRS) of 3-6. Albumin-to-globulin ratio (AGR), C-reactive protein-to-albumin ratio (CAR), and SIPI were calculated as follows: AGR = albumin/globulin; CAR = CRP/albumin; SIPI = CRP × globulin/albumin. A total of 238 consecutive anterior circulation AIS patients with EVT were included, among which 145 (60.9%) patients had unfavorable outcomes. After adjusting for confounding factors, admission globulin, admission AGR, 1-day AGR, 3-day albumin, 3-day CRP, 3-day CAR, 3-day SIPI, 7-day albumin, 7-day CRP, 7-day CAR, and 7-day SIPI showed an independent association with 90-day functional outcome. Of them, 3-day SIPI had the most robust discriminative ability with an area under the curve of 0.719 (CI 0.630-0.808, p < 0.001). There were differences in the dynamic change of inflammatory biomarkers between the subjects with favorable and unfavorable functional outcomes. Inflammatory biomarkers, including albumin, globulin, CRP, AGR, CAR, and SIPI, are independent predictors of 90-day unfavorable outcomes in anterior circulation AIS patients with EVT. SIPI of day 3 has the highest predictive value.

Predicting the storage time of green tea by myricetin based on surface-enhanced Raman spectroscopy.

The quality of green tea changes rapidly due to the oxidation and degradation of polyphenols during storage. Herein, a simple and fast Surface-enhanced Raman spectroscopy (SERS) strategy was established to predict changes in green tea during storage. Raman spectra of green tea with different storage times (2020-2015) were acquired by SERS with silver nanoparticles. The PCA-SVM model was established based on SERS to quickly predict the storage time of green tea, and the accuracy of the prediction set was 97.22%. The Raman peak at 730 cm-1 caused by myricetin was identified as a characteristic peak, which increased with prolonged storage time and exhibited a linear positive correlation with myricetin concentration. Therefore, SERS provides a convenient method for identifying the concentration of myricetin in green tea, and myricetin can function as an indicator to predict the storage time of green tea.