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Background Using the hybrid electrocardiogram (ECG)-gated computed tomography (CT) technique, assessment of entire aorta, coronary arteries, and aortic valve can be possible using single-bolus contrast administration within a single acquisition. Purpose To compare the image quality of hybrid ECG-gated and non-gated CT angiography of the aorta and evaluate the effect of a motion correction algorithm (MCA) on coronary artery image quality in a hybrid ECG-gated aorta CT group. Material and Methods In total, 104 patients (76 men; mean age = 65.8 years) prospectively randomized into two groups (Group 1 = hybrid ECG-gated CT; Group 2 = non-gated CT) underwent wide-detector array aorta CT. Image quality, assessed using a four-point scale, was compared between the groups. Coronary artery image quality was compared between the conventional reconstruction and motion correction reconstruction subgroups in Group 1. Results Group 1 showed significant advantages over Group 2 in aortic wall, cardiac chamber, aortic valve, coronary ostia, and main coronary arteries image quality (all P < 0.001). All Group 1 patients had diagnostic image quality of the aortic wall and left ostium. The MCA significantly improved the image quality of the three main coronary arteries ( P < 0.05). Moreover, per-vessel interpretability improved from 92.3% to 97.1% with the MCA ( P = 0.013). Conclusion Hybrid ECG-gated CT significantly improved the heart and aortic wall image quality and the MCA can further improve the image quality and interpretability of coronary arteries. [ABSTRACT FROM AUTHOR]

Background Although fibrotic idiopathic interstitial pneumonias (IIPs) alone and those combined with pulmonary emphysema are naturally progressive diseases, the process of deterioration and outcomes are variable. Purpose To evaluate and compare serial changes of computed tomography (CT) abnormalities and prognostic predictive factors in fibrotic IIPs alone and those combined with pulmonary emphysema. Material and Methods A total of 148 patients with fibrotic IIPs alone (82 patients) and those combined with pulmonary emphysema (66 patients) were enrolled. Semi-quantitative CT analysis was used to assess the extents of CT characteristics which were evaluated on initial and follow-up CT images. Univariate and multivariate analyses were performed to assess the effects of clinical and CT variables on survival. Results Significant differences were noted between fibrotic scores, as determined using initial CT scans, in the fibrotic IIPs alone (21.22 ± 9.83) and those combined with pulmonary emphysema groups (14.70 ± 7.28) ( P < 0.001). At follow-up CT scans, changes in the extent of ground glass opacities (GGO) were greater ( P = 0.031) and lung cancer was more prevalent ( P = 0.001) in the fibrotic IIPs combined with pulmonary emphysema group. Multivariate Cox proportional hazards analysis showed changes in the extent of GGO (hazard ratio, 1.056) and the presence of lung cancer (hazard ratio, 4.631) were predictive factors of poor survivals. Conclusion Although patients with fibrotic IIPs alone and those combined with pulmonary emphysema have similar mortalities, lung cancer was more prevalent in patients with fibrotic IIPs combined with pulmonary emphysema. Furthermore, changes in the extent of GGO and the presence of lung cancer were independent prognostic factors of poor survivals. [ABSTRACT FROM AUTHOR]

Using an inductive framing analysis of news coverage, we examine how the most popular liberal and conservative news media in the United States and South Korea mobilize different nationalist narratives on China in responding to social, economic, and political upheavals during the early stages of the COVID-19 pandemic. We identify three major areas of political cleavage in both Korean and U.S. media discourse on nationalist identities vis-à-vis the construction of the national or racialized "Other." This includes (1) imagined solidarity against China as an adversary; (2) political disputes over boundary-making; (3) and the construction of ethnonational belonging and exclusion. Our research underscores how intrastate and interstate shifts during periods of crisis can heighten political cleavages along racial and ethnic fault lines and complicate dominant frameworks of civic and ethnic nationalism in both countries. [ABSTRACT FROM AUTHOR]

Background: There have been few reports comparing image quality and radiation dose of aorta computed tomography angiography (CTA) between the high-pitch and the hybrid technique. Purpose: To compare the image quality and radiation dose among non-electrocardiogram (ECG)-gated high-pitch CTA and hybrid ECG-gated CTA of the aorta using 512-slice CT. Material and Methods: This retrospective study included 110 patients who underwent non-ECG-gated high-pitch CTA (group 1) or hybrid ECG-gated CTA (group 2) of the entire aorta. Interpretability, image noise, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and the mean effective radiation dose were compared. Results: The mean image noise of the whole aorta was significantly lower (15.7 ± 1.8 HU vs. 16.5 ± 1.2 HU, P = 0.008) in group 1 than in group 2. The CNR (22.3 ± 4.7 vs. 20.0 ± 3.9, P < 0.001) and SNR (26.5 ± 4.9 vs. 23.2 ± 4.0, P < 0.001) were higher in group 2 compared with group 1. Neither group showed a significant difference in interpretability of the ascending aorta, cardiac chamber, aortic valve, right ostium, and left ostium (all P = 1). The mean effective radiation dose was significantly lower in group 1 than in group 2 (3.5 ± 0.9 mSv vs. 4.3 ± 0.8 mSv, P < 0.001). Conclusion: The non-ECG-gated high-pitch technique shows significantly improved CNR and SNR due to reduced noise with lower radiation exposure. The interpretability of the cardiac structure, ascending aorta, aortic valve, and both ostia did not differ significantly between the two groups. [ABSTRACT FROM AUTHOR]

Background Reducing radiation dose inevitably increases image noise, and thus, it is important in low-dose computed tomography (CT) to maintain image quality and lesion detection performance. Purpose To assess image quality and lesion conspicuity of ultra-low-dose CT with model-based iterative reconstruction (MBIR) and to determine a suitable protocol for lung screening CT. Material and Methods A total of 120 heavy smokers underwent lung screening CT and were randomly and equally assigned to one of five groups: group 1 = 120 kVp, 25 mAs, with FBP reconstruction; group 2 = 120 kVp, 10 mAs, with MBIR; group 3 = 100 kVp, 15 mAs, with MBIR; group 4 = 100 kVp, 10 mAs, with MBIR; and group 5 = 100 kVp, 5 mAs, with MBIR. Two radiologists evaluated intergroup differences with respect to radiation dose, image noise, image quality, and lesion conspicuity using the Kruskal-Wallis test and the Chi-square test. Results Effective doses were 61-87% lower in groups 2-5 than in group 1. Image noises in groups 1 and 5 were significantly higher than in the other groups ( P < 0.001). Overall image quality was best in group 1, but diagnostic acceptability of overall image qualities in groups 1-3 was not significantly different (all P values > 0.05). Lesion conspicuities were similar in groups 1-4, but were significantly poorer in group 5. Conclusion Lung screening CT with MBIR obtained at 100 kVp and 15 mAs enables a ∼60% reduction in radiation dose versus low-dose CT, while maintaining image quality and lesion conspicuity. [ABSTRACT FROM AUTHOR]

Background: With regard to clinicopathological findings and disease prognosis, breast cancer in young women is different from that in older women. However, few studies have investigated magnetic resonance imaging (MRI) characteristics of young age-onset breast cancer.Purpose: To retrospectively evaluate and compare the MR images and clinicopathological characteristics of invasive breast cancer in young women (aged <35 years) with those of breast cancers in older premenopausal women (35-45 years).Material and Methods: A total of 270 invasive breast cancers in 266 premenopausal women aged 45 years and younger who underwent preoperative breast MRI and curative surgery were identified between 2009 and 2013. The subjects were divided into a young group (< 35 years, n = 56) and an older group (35-45 years, n = 214). MRI features and clinicopathological data were compared between the two groups.Results: The young group had more positive axillary lymph nodes, higher histologic grade, negative estrogen receptor (ER), negative progesterone receptor (PR), and higher p53 and Ki-67 expression compared to the older group. Using MRI, the young group was more likely to display a round/oval or lobular mass shape, a smooth mass margin, and a high signal intensity on T2-weighted images when compared to the older group. In multivariate analysis, positive axillary nodal status (adjusted odds ratio [OR], 4.070; P = 0.002), higher expression of p53 (adjusted OR, 2.902; P = 0.038), lobular mass shape (adjusted OR, 4.979; P = 0.028), and smooth mass margin (adjusted OR, 5.123; P = 0.048) were independently associated with the young group.Conclusion: MR morphologic features, including lobular mass shape and smooth mass margin, were independently associated with breast cancer in young women, in addition to positive axillary nodal status and higher p53 expression status. [ABSTRACT FROM AUTHOR]

Background: Chest radiography value as a screening tool in those exposed to pulmonary tuberculosis (TB) is reduced by its lower sensitivity to detect small intrapulmonary lesions. Purpose: To evaluate the efficacy of digital tomosynthesis (DTS) screening of individuals that had contacted persons with active TB using low-dose computed tomography (CT) as the reference standard methods. Material and Methods: This retrospective, community-based screening study of 90 adults who had been in close contact with a TB case was undertaken at our institution. All individuals underwent clinical evaluation, digital radiography (DR), DTS, and low-dose chest CT. Observers assessed and classified DR and DTS images using CT as the reference-standard method. Based on clinical and imaging findings, TB status was classified as normal, latent, minimal, subclinical, and active. Diagnostic performances of DTS and DR for the interpretation of correct diagnosis were calculated. Results: The estimated effective doses for DR, DTS, and low-dose CT were 0.01 mSv, 0.1 mSv, and 0.33 mSv, respectively. TB statuses of the 90 individuals were as follows: 62 latent (68.9%); two subclinical (2.2%); and one minimal (1.1%). The sensitivities, specificities, and accuracies of DTS and DR in the interpretation of correct diagnosis were 75.8%, 100%, 91.1% and 48.5%, 96.5%, 78.9%, respectively. Conclusion: DTS appears to be superior to DR for the detection of lung lesions in individuals with TB contacts. DTS can offer a reasonable option for TB contact investigation. [ABSTRACT FROM AUTHOR]

Background: The coronary venous system is frequently used as an entry route to the heart and treatment modalities for many cardiac diseases and many procedures. Consequently, evaluation of the coronary venous system and understanding cardiac vein anatomy is crucial.Purpose: To determine the optimal image set in a comparison of noise-optimized linearly blended images (F_0.6) and noise-optimized virtual monoenergetic images (VMI+) evaluated by dual-energy computed tomography (DECT) for cardiac vein assessment.Material and Methods: Thirty-four patients (mean age 58.2 ± 14.2 years) who underwent DECT due to chest pain were enrolled. Images were post-processed with the F_0.6, and VMI+ algorithms at energy levels in the range of 40-100 keV in 10-keV increments. Enhancement (HU), noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively measured at two points in the great cardiac vein by consensus of two radiologists. Two blinded observers evaluated the subjective image quality of the great cardiac vein on a 4-point scale.Results: HU, noise, and SNR peaked at 40 keV VMI+ (P < 0.05) among 50-100 keV VMI+. CNR peaked at 100 keV VMI+; however, there were no significant differences compared to CNR images processed at 40-90 keV VMI+. HU and noise were significantly higher in 40 keV VMI+ than F_0.6 images; however, both SNR and CNR were significantly higher in F_0.6 images. An assessment of subjective vein delineation revealed that F_0.6 images had the highest scores.Conclusion: F_0.6 images were superior to VMI+ and provided the optimal image set for cardiac vein assessment. [ABSTRACT FROM AUTHOR]

Background Computed tomography venography (CTV) at low kVp using model-based iterative reconstruction (MBIR) can enhance vascular enhancement with noise reduction. Purpose To evaluate image qualities and radiation doses of CTV at 80 kVp using MBIR and a small iodine contrast media (CM) dose and to compare these with those of CTV performed using a conventional protocol. Material and Methods Sixty-five patients (mean age = 58.1 ± 7.2 years) that underwent CTV for the evaluation of deep vein thrombosis (DVT) and varicose veins were enrolled in this study. Patients were divided into two groups: Group A (35 patients, 80 kVp, MBIR, automatic tube current modulation, CM = 270 mg/mL, 100 mL) and Group B (30 patients, 100 kVp, filtered back projection [FBP], 120 fixed mA, CM = 370 mg/mL, 120 mL). Objective and subjective image qualities of inferior vena cava (IVC), femoral vein (FV), and popliteal vein (PV) were assessed and radiation doses were recorded. Results Mean vascular enhancement in group A was significantly lower than in group B ( P < 0.01). Noise in group A was significantly lower than in group B except for PV and contrast-to-noise ratio were not significantly different in the two groups ( P > 0.05). In addition, radiation dose in group A was significantly lower than in group B ( P < 0.001). Subjective image quality comparison revealed group A was statistically inferior to group B except for subjective image noise. Conclusion CTV at 80 kVp using MBIR with small iodine contrast dose provided acceptable image quality at a lower radiation dose than conventional CTV using FBP. [ABSTRACT FROM AUTHOR]

Background: The classic magnetic resonance imaging (MRI) feature of endometriomas is the shading sign, which is characterized by T2-shortening in ovarian cystic lesions that are hyperintense on T1-weighted images. The shading sign is infrequently observed in hemorrhagic ovarian cysts. Purpose: To investigate the value of MRI with diffusion-weighted imaging (DWI) for distinguishing endometriomas from hemorrhagic cysts in the ovary. Material and Methods: This retrospective study included 91 patients with 98 ovarian endometriomas and 21 hemorrhagic ovarian cysts that were confirmed pathologically, who had undergone MRI with DWI. Two radiologists compared MRI features, including size, bilaterality, multilocularity, the shading sign, the ovarian lesion/muscle signal intensity ratio at T2-weighted images, and T2 dark spots, between endometriomas and hemorrhagic cysts. We also compared the mean ADC value between endometriomas and hemorrhagic cysts, and determined the optimal cutoff ADC value for differentiating endometriomas from hemorrhagic cysts. Results: The size and mean ADC values were significantly different between endometriomas and hemorrhagic cysts. The mean ADC values of endometriomas and hemorrhagic cysts were 1.06 ± 0.38 × 10 (-3) mm(2)/s and 0.73 ± 0.29 × 10(-3) mm(2)/s, respectively (P < 0.002). The optimal cutoff ADC value for differentiating endometriomas from hemorrhagic cysts was 0.849 × 10(-3) mm(2)/s (sensitivity, 77.6%; specificity, 76.2%). Conclusion: The addition of DWI could help in differentiating endometriomas from hemorrhagic cysts in the ovary, when conventional MRI is challenging. [ABSTRACT FROM AUTHOR]

Background: Preoperative localization with lipiodol for identifying small or deeply seated pulmonary nodules is simple and useful for thoracoscopic surgery. Although several studies about performance and complication rates of lipiodol localization have been reported, there has been no report about the performance and complication rates of lipiodol localization with regard to the CT appearance of pulmonary nodules. Purpose: To evaluate the performance and complication rates of localization of pulmonary nodules with lipiodol prior to video-assisted thoracoscopic surgery with regard to the CT appearance of nodules. Material and Methods: After institutional review board approval and informed consent were obtained, lipiodol marking was performed in 67 patients (33 men and 34 women; mean age 58 years) with 68 nodules. All nodules were marked with 0.4-0.5 mL lipiodol under CT guidance on the day of surgery. The size of the targeted nodule and the shortest distance to the accessible pleural surface were measured. Lipiodol accumulation of a targeted nodule was scored by use of a four-point scale (0: none, 1: within 1 cm around a nodule, 2: partial accumulation within a nodule, 3: total accumulation within a nodule). Any complications after localization of nodules were noted. We analyzed the score of lipiodol accumulation and the presence of complications for the CT appearance of pulmonary nodules using the Mann Whitney U test, Fisher's exact test and the Kruskall Walis test. Results: The average nodule size was 11.4 mm (range 3.0-28.3 mm) and the average distance to the pleural surface was 13.7 mm (range 0-51.4 mm). Lipiodol accumulation scores of nodules were as follows: score 3 (n=19, 28%), score 2 (n=37, 54%), score 1 (n=11, 16%), and score 0 (n=1, 2%). Lipiodol accumulation scores of nodules were different according to the size of nodules (Kruskal Wallis test, p=0.023). Pneumothorax after localization occurred in 20 (29%) patients and the incidence was higher in nodules located in the subpleural area (Mann Whitney U test, p=0.048). Pulmonary hemorrhage along the needle tract occurred in five (7%) patients and was more frequent in patients with deep nodules as compared to shallow nodules (Mann Whitney U test, p < 0.001). Conclusion: Lipiodol marking under CT guidance is a useful and safe procedure for the intraoperative localization of pulmonary nodules. Of variable CT findings, lesion size is important to determine the degree of lipiodol accumulation and the lesion depth is the most important feature for the development of postprocedural complications. [ABSTRACT FROM AUTHOR]