Search

Aims: Alterations in neuronal activity and cerebral hemodynamics have been reported in idiopathic generalized epilepsy (IGE) patients, possibly resulting in neurovascular decoupling; however, no neuroimaging evidence confirmed this disruption. This study aimed to investigate the possible presence of neurovascular decoupling and its clinical implications in childhood IGE using resting‐state fMRI and arterial spin labeling imaging. Methods: IGE patients and healthy participants underwent resting‐state fMRI and arterial spin labeling imaging to calculate degree centrality (DC) and cerebral blood flow (CBF), respectively. Across‐voxel CBF‐DC correlations were analyzed to evaluate the neurovascular coupling within the whole gray matter, and the regional coupling of brain region was assessed with the CBF/DC ratio. Results: The study included 26 children with IGE and 35 sex‐ and age‐matched healthy controls (HCs). Compared with the HCs, the IGE group presented lower across‐voxel CBF‐DC correlations, higher CBF/DC ratio in the right posterior cingulate cortex/precuneus, middle frontal gyrus, and medial frontal gyrus (MFG), and lower ratio in the left inferior frontal gyrus. The increased CBF/DC ratio in the right MFG was correlated with lower performance intelligence quotient scores in the IGE group. Conclusion: Children with IGE present altered neurovascular coupling, associated with lower performance intelligence quotient scores. The study shed a new insight into the pathophysiology of epilepsy and provided potential imaging biomarkers of cognitive performances in children with IGE. [ABSTRACT FROM AUTHOR]

Background: Successful generation of biomechanical‐model‐based deformable image registration (BM‐DIR) relies on user‐defined parameters that dictate surface mesh quality. The trial‐and‐error process to determine the optimal parameters can be labor‐intensive and hinder DIR efficiency and clinical workflow. Purpose: To identify optimal parameters in surface mesh generation as boundary conditions for a BM‐DIR in longitudinal liver and lung CT images to facilitate streamlined image registration processes. Methods: Contrast‐enhanced CT images of 29 colorectal liver cancer patients and end‐exhale four‐dimensional CT images of 26 locally advanced non‐small cell lung cancer patients were collected. Different combinations of parameters that determine the triangle mesh quality (voxel side length and triangle edge length) were investigated. The quality of DIRs generated using these parameters was evaluated with metrics for geometric accuracy, robustness, and efficiency. Metrics for geometric accuracy included target registration error (TRE) of internal vessel bifurcations, dice similar coefficient (DSC), mean distance to agreement (MDA), Hausdorff distance (HD) for organ contours, and number of vertices in the triangle mesh. American Association of Physicists in Medicine Task Group 132 was used to ensure parameters met TRE, DSC, MDA recommendations before the comparison among the parameters. Robustness was evaluated as the success rate of DIR generation, and efficiency was evaluated as the total time to generate boundary conditions and compute finite element analysis. Results: Voxel side length of 0.2 cm and triangle edge length of 3 were found to be the optimal parameters for both liver and lung, with success rate of 1.00 and 0.98 and average DIR computation time of 100 and 143 s, respectively. For this combination, the average TRE, DSC, MDA, and HD were 0.38–0.40, 0.96–0.97, 0.09–0.12, and 0.87–1.17 mm, respectively. Conclusion: The optimal parameters were found for the analyzed patients. The decision‐making process described in this study serves as a recommendation for BM‐DIR algorithms to be used for liver and lung. These parameters can facilitate consistence in the evaluation of published studies and more widespread utilization of BM‐DIR in clinical practice. [ABSTRACT FROM AUTHOR]

Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas (UCOGCP) is a rare pancreatic tumor that accounts for <1% of all primary pancreatic malignant tumors. Although the tumor is considered a variant of pancreatic ductal adenocarcinoma, there are substantial differences in the clinicopathological characteristics between UCOGCP and pancreatic ductal adenocarcinoma. Imaging examinations are useful in making a correct diagnosis, and providing a reasonable and effective surgical treatment regimen; however, the imaging characteristics of UCOGCP require further investigation. The present report describes a rare case of UCOGCP with rapid progression and poor prognosis. The patient could not undergo surgery and received chemotherapy drugs only. Chemotherapy did not markedly improve the outcome, and a follow-up 6 months after discharge showed that the patient had died. The present report describes this case and summarizes the available imaging findings to increase awareness, and to improve early diagnosis of this rare disease and therapeutic outcomes. [ABSTRACT FROM AUTHOR]

Fluid flow behavior is visualized through particle image velocimetry (PIV) for understanding and studying experimental fluid dynamics. However, traditional PIV methods require multiple cameras and conventional lens systems for image acquisition to resolve multi-dimensional velocity fields. In turn, it introduces complexity to the entire system. Meta-lenses are advanced flat optical devices composed of artificial nanoantenna arrays. It can manipulate the wavefront of light with the advantages of ultrathin, compact, and no spherical aberration. Meta-lenses offer novel functionalities and promise to replace traditional optical imaging systems. Here, a binocular meta-lens PIV technique is proposed, where a pair of GaN meta-lenses are fabricated on one substrate and integrated with a imaging sensor to form a compact binocular PIV system. The meta-lens weigh only 116 mg, much lighter than commercial lenses. The 3D velocity field can be obtained by the binocular disparity and particle image displacement information of fluid flow. The measurement error of vortex-ring diameter is ≈1.25% experimentally validates via a Reynolds-number (Re) 2000 vortex-ring. This work demonstrates a new development trend for the PIV technique for rejuvenating traditional flow diagnostic tools toward a more compact, easy-to-deploy technique. It enables further miniaturization and low-power systems for portable, field-use, and space-constrained PIV applications., (© 2023 Wiley‐VCH GmbH.)