Increased brain iron in patients with thyroid-associated ophthalmopathy: a whole-brain analysis.

Background: To investigate the whole-brain iron deposition alternations in patients with thyroid-associated ophthalmopathy (TAO) using quantitative susceptibility mapping (QSM). Methods: Forty-eight patients with TAO and 33 healthy controls (HCs) were enrolled. All participants underwent brain magnetic resonance imaging scans and clinical scale assessments. QSM values were calculated and compared between TAO and HCs groups using a voxel-based analysis. A support vector machine (SVM) analysis was performed to evaluate the performance of QSM values in differentiating patients with TAO from HCs. Results: Compared with HCs, patients with TAO showed significantly increased QSM values in the bilateral caudate nucleus (CN), left thalamus (TH), left cuneus, left precuneus, right insula and right middle frontal gyrus. In TAO group, QSM values in left TH were positively correlated with Hamilton Depression Rating Scale (HDRS) scores (r = 0.414, p = 0.005). The QSM values in right CN were negatively correlated with Montreal Cognitive Assessment (MoCA) scores (r = -0.342, p = 0.021). Besides that, a nearly negative correlation was found between QSM values in left CN and MoCA scores (r = -0.286, p = 0.057). The SVM model showed a good performance in distinguishing patients with TAO from the HCs (area under the curve, 0.958; average accuracy, 90.1%). Conclusion: Patients with TAO had significantly increased iron deposition in brain regions corresponding to known visual, emotional and cognitive deficits. QSM values could serve as potential neuroimaging markers of TAO.

The feasibility of 1-stop examination of coronary CT angiography and abdominal enhanced CT.

This study aims to evaluate the feasibility of performing coronary computed tomography angiography (CCTA) and abdominal enhanced computed tomography (CT) with 1-time injection of the agent.CCTA images (right coronary artery, left anterior descending coronary artery, and left circumflex coronary artery) were collected from 20 patients who completed a 1-stop combined examination of CCTA and abdominal enhanced CT (group A), 20 patients who only underwent abdominal enhanced CT (group B1), and 20 patients who only underwent CCTA (group B2). These images were interpreted using the 5-point Likert scale system by 2 experienced radiologists, and abdominal images were observed for breathing artifact. CT value, signal-to-noise ratio (SNR), and CTDI were recorded and compare among the 3 groups.The difference in image quality of the coronary and total volume of the contrast agent between group A and group B1 was not statistical significant (P > .05). The CT value and SNR in group B1 (CCTA) (CT: 394.65 ±â€Š59.23, SNR: 17.38 ±â€Š4.13) increased, compare with Group A (CT: 360.35 ±â€Š34.16, SNR: 13.76 ±â€Š1.84, P = .03, .01), while CTDI was undifferentiated between group A (17.14 ±â€Š6.20) and group B1 (18.38 ±â€Š9.79) (P = .64). The difference in CT value and SNR at the arterial phase and CT value at the venous phase between group A (abdomen) and group B2 were statistically significant, the CTDI in group A (9.09 ±â€Š1.05) increased, compared with group B2 (8.23 ±â€Š1.33) (P = .03), and SNR at the venous phase in group B2 (12.50 ±â€Š2.43) increased, compared with group A (10.89 ±â€Š2.03) (P = .03).Revolution CT can capture full images and very rapidly switch to the scan mode, enabling a 1-stop axial CCTA and enhanced helical abdominal scan. The 1-stop combined scan resulted in a satisfactory image quality, which reduced the contrast agent dose and simplified the workflow.The 1-stop combined scan allows for the high success rate of the examination, reduces the number of examinations, and decreases the dose and risk of injection of the contrast agent. This would be helpful for patients to obtain diagnostic images in time.

State conversion based on terahertz plasmonics with vanadium dioxide coating controlled by optical pumping.

The state conversion and terahertz (THz) wave modulation based on a plasmonic device composed of silicon column arrays with vanadium dioxide (VO2) coating were experimentally demonstrated. For double 45° tilted optical pumping, a state conversion from dielectric photonic crystal (PC) to metallic PC was demonstrated due to the insulator-metal transition (IMT) of VO2 with the pump power increasing. In this process, a broadband intensity modulation with 70% modulation depth was achieved. Furthermore, for normally incident optical pumping, another state conversion from dielectric PC to plasmonic device was also demonstrated due to the partial IMT of VO2, and the out of plane PC resonance gradually changed to be plasmonic resonances. This device and its modulation scheme will be of great significance for potential THz applications.