Altered functional brain networks in coronary heart disease: independent component analysis and graph theoretical analysis.

Coronary heart disease (CHD) confers a high risk of cognitive and mental impairments in patients. This study aimed to explore the association of CHD with functional connectivity and topological properties of brain networks. A total of 27 patients with CHD and 44 healthy controls (HCs) participated in this study and underwent a resting-state functional magnetic resonance imaging (rs-fMRI) scan. Intra- and internetwork functional connectivity alterations were explored using independent component analysis in CHD patients. Furthermore, graph theoretical analysis was adopted to assess abnormalities in small-world properties and network efficiency metrics of brain networks. Compared to HCs, CHD patients exhibited increased functional connectivity between the posterior default mode network and posterior visual network, as well as decreased functional connectivity between the left frontoparietal network and auditory network. In terms of graph theoretical analysis, small-world network topology was identified in both CHD patients and HCs. Furthermore, the nodal local efficiency of the left putamen was significantly decreased in CHD patients compared to HCs. This study revealed alterations in brain functional connectivity and topological properties in CHD patients, shedding light on the potential neurological mechanism underlying cognitive and mental impairments in these patients and suggesting unexplored connections between CHD and higher order cognitive processing.

Effect of Third-generation Dual-source CT Technology on Image Quality of Low-dose Chest CT.

Objective To evaluate the image quality and radiation dose of third-generation dual-source CT with tin filtration for spectral shaping and iterative reconstructions.Methods Thirty-five patients underwent low-dose CT (LDCT) for lung cancer screening on second-generation dual-source CT and follow-ups on third-generation dual-source CT. Image quality and radiation dose were compared between the two examinations.ResultsThe radiation dose of third-generation dual-source CT [dose-length product (DLP)(49.7±18.2)mGy·cm, effective dose (ED)(0.73±0.26)mSv] was lower than second-generation dual-source CT [DLP (86.37±13.44) mGy·cm, ED(1.20±0.42)mSv](t=6.01, P=0.000;t=6.57, P=0.000). The objective image noise of second-generation dual-source CT [(25.7±2.9)HU] was higher than that of third-generation dual-soure CT[(18.6±4.2)HU](t=5.24,P=0.000).The subjective image noise of second-generation dual-source CT [(4.60±0.49)scores] was significantly lower than that of third-generation dual-source CT [(4.80±0.40)scores] (t=4.15, P=0.000). Conclusion Chest CT for the detection of pulmonary nodules can be performed with third-generation dual-source CT that produces high image quality and low radiation dose when using a stellar infinity detector with spectral shaping.

Application of High-pitch CT Pulmonary Angiography at 70 kV Tube Voltage with 15 ml Contrast Medium Using Third-generation Dual-source CT.

Objective To assess the application of high-pitch CT pulmonary angiography (CTPA) at 70 kV tube voltage with 15 ml contrast medium using third-generation dual-source CT. Methods A total of 70 patients with clinically suspected pulmonary embolism were randomly divided into two groups: group A (n=35) underwent CTPA on conventional scanning mode (120 kV,80 ml contrast medium);and group B (n=35) underwent CTPA on high-pitch scanning mode at 70 kV tube voltage with 15 ml contrast medium. The CT values and standard deviations of the main pulmonary artery,apical segment of right upper pulmonary lobe (S1),and posterior basal segment of the right lower pulmonary lobe (S10),anterior thoracic air,and back muscles were measured. The signal to noise ratio (SNR),contrast to noise ratio (CNR),and effective dose (ED) were calculated. The overall image quality was evaluated by two blinded radiologists. The quality image was compared using non-parametric test on two independent samples. The potential differences in CT value,SNR,CNR,and ED were analyzed using the independent sample t-test. Results The CT values of main pulmonary artery [(300.62±77.54)HU vs.(332.80±102.80)HU;t=-1.53,P=0.13],S1 [(361.72±84.92)HU vs. (325.37±87.86)HU;t=1.81,P=0.08],and S10 [(359.54±89.61)HU vs. (318.26±87.19)HU;t=2.00,P=0.05] of right lung were not significantly different between group A and group B. The CNR of S1 (22.81±6.05 vs. 19.80±6.60;t=2.05,P=0.04) and S10 (22.65±6.37 vs. 19.28±6.63;t=2.23,P=0.03) of right lung in group A was significantly higher than in group B. The SNR of main pulmonary artery,S1,and S10 of right lung were not significantly different between group A and B. The subjective diagnostic quality values of group A and B were 1 (1,1) and 1 (1,1),respectively (Z=-0.08,P=0.93). The subjective diagnostic quality values evaluated by two radiologists showed excellent consistency(κ=0.87,P=0.01). The mean ED was 79% lower in group B [(0.92±0.23)mSv] than in group A [(4.33±1.80) mSv] (t=11.72,P=0.00).Conclusion Application of high-pitch mode in CTPA at 70 kV with 15 ml contrast medium using third-generation dual-source CT can remarkably reduce radiation dose without affecting image quality.

Quantitative assessment of Pulmonary Alveolar Proteinosis (PAP) with ultra-dose CT and correlation with Pulmonary Function Tests (PFTs).

BACKGROUND: The purpose of this study was to investigate whether ultra-low-dose chest computed tomography (CT) can be used for visual assessment of CT features in patients with pulmonary alveolar proteinosis (PAP) and to evaluate the relationship between the quantitative analysis of the ultra-low-dose CT scans and the pulmonary function tests (PFTs). METHODS: Thirty-eight patients (mean [SD] age, 44.47 [12.28] years; 29 males, 9 females) with PAP were enrolled and subjected to two scans each with low-dose CT (reference parameters: 120 kV and 50 mAs) and ultra-low-dose CT (reference parameters, 80 kV, 25 mAs). Images were reconstructed via filtered back projection (FBP) for low-dose CT and iterative reconstruction (IR) for ultra-low-dose CT. All patients underwent PFT. The Visual analysis for ground glass opacity (GGO) is performed. The quantitative CT and PFT results were analyzed by canonical correlations. RESULTS: The mean body mass index (BMI) was 25.37±3.26 kg/m2. The effective radiation doses were 2.30±0.46 and 0.24±0.05 mSv for low-dose and ultra-low-dose CT, respectively. The size-specific dose estimates were 5.81±0.81 and 0.62±0.09 mSv for low-dose and ultra-low-dose CT. GGOs and interlobular septal thickening were observed bilaterally in all patients. The average visual GGO score was lower in the upper field (2.67±1.24) but higher in the middle and lower fields (3.08±1.32 and 3.08±0.97, respectively). The average score for the whole lung was 2.94±1.19. There is a significant correlation between PFTs and quantitative of ultra-low-dose CT (canonical loading = 0.78). CONCLUSIONS: Ultra-low-dose CT has the potential to quantify the lung parenchyma changes of PAP. This technique could provide a sensitive and objective assessment of PAP and has good relation with PFTs. In addition, the radiation dose of ultra-low-dose CT was very low.

Radiological and Clinical Features of Eosinophilic Granulomatosis with Polyangiitis.

Eosinophilic granulomatosis with polyangiitis(EGPA),also known as Churg-Strauss syndrome,is a clinically rare small-vessel vasculitis associated with antineutrophil cytoplasmic antibodies (ANCAs) and the hypereosinophilic syndromes (HESs),characterized by asthma,disseminated necrotizing vasculitis,extravascular granulomas,peripheral eosinophilia,and tissue eosinophilia. This article reviews the pathology,imaging,and clinical features of EGPA.