A national-scale high-resolution CCUS-shared pipeline layout for retrofitting multisectoral plants via onshore-offshore geological storage.

Carbon capture utilization and storage (CCUS) is an indispensable process to mitigate climate change. However, a precise and feasible CCUS layout with realistic geospatial connectivity is essential to support the prospective deployment of multisectoral plants on a national scale. This study proposed an onshore-offshore CCUS source-sink matching model, distinguished by CO2 source-sink dataset enhancement, realistic pipeline network optimization, and onshore-offshore geospatial connectivity to accurately map China's high-resolution CCUS layout. The findings showed that China's multisectoral CCUS supply potential of coal-fired power, steel, cement, and coal chemicals was approximately 1.75, 0.77, 0.56, and 0.23 Gt/a CO2, respectively. A complete geospatial connectivity pattern was established by connecting 1186 multisectoral CO2 sources with 307 onshore and 22 offshore storage sites via the shared pipeline network of 80,700 km, involving plant-level cost heterogeneity, industry competition, and CCUS cluster identification. This model can be applied to other countries or globally to enhance CCUS layout strategies.

Ecoclimate drivers shape virome diversity in a globally invasive tick species.

Spillovers of viruses from animals to humans occur more frequently under warmer conditions, particularly arboviruses. The invasive tick species Haemaphysalis longicornis, the Asian longhorned tick, poses a significant public health threat due to its global expansion and its potential to carry a wide range of pathogens. We analyzed meta-transcriptomic data from 3595 adult H. longicornis ticks collected between 2016 and 2019 in 22 provinces across China encompassing diverse ecological conditions. Generalized additive modeling revealed that climate factors exerted a stronger influence on the virome of H. longicornis than other ecological factors, such as ecotypes, distance to coastline, animal host, tick gender, and antiviral immunity. To understand how climate changes drive the tick virome, we performed a mechanistic investigation using causality inference with emphasis on the significance of this process for public health. Our findings demonstrated that higher temperatures and lower relative humidity/precipitation contribute to variations in animal host diversity, leading to increased diversity of the tick virome, particularly the evenness of vertebrate-associated viruses. These findings may explain the evolution of tick-borne viruses into generalists across multiple hosts, thereby increasing the probability of spillover events involving tick-borne pathogens. Deep learning projections have indicated that the diversity of the H. longicornis virome is expected to increase in 81.9% of regions under the SSP8.5 scenario from 2019 to 2030. Extension of surveillance should be implemented to avert the spread of tick-borne diseases.

Prevalence and risk factors of dental fluorosis among children aged 8-12 years in Shandong province of China.

This study was to investigate the prevalence and severity of children's dental fluorosis (DF) in Shandong and identified the potential risk factors for DF. A total of 87 villages in Shandong were investigated to calculate the prevalence of DF and Community Fluorosis Index (CFI) in 2018-2019. Six hundred and seventy children were enrolled to identify the potential risk factors using univariate and multivariate logistic regressions. Goodman-Kruskal Gamma was used to explore the factors related to the severity of DF. In 87 villages, 1249 of 8700 (14.36%) children still have DF. The prevalence of DF in most villages was below 40% in 2018-2019. Water fluorine concentration when selected for the study and urinary fluorine concentration were related to the risk of DF (P < 0.001). Some eating habits, like lower frequency of eating fresh vegetables, eggs, and beans, were associated with the risk of DF (P < 0.001). The high water fluorine concentration, and lower frequency of eating fresh vegetables, eggs, and beans were also related to the severity of DF (P < 0.001). DF in children in Shandong province is still a common endemic disease. This study tries to provide a useful guide for the prevention and control of DF.

A net-zero emissions strategy for China's power sector using carbon-capture utilization and storage.

Decarbonized power systems are critical to mitigate climate change, yet methods to achieve a reliable and resilient near-zero power system are still under exploration. This study develops an hourly power system simulation model considering high-resolution geological constraints for carbon-capture-utilization-and-storage to explore the optimal solution for a reliable and resilient near-zero power system. This is applied to 31 provinces in China by simulating 10,450 scenarios combining different electricity storage durations and interprovincial transmission capacities, with various shares of abated fossil power with carbon-capture-utilization-and-storage. Here, we show that allowing up to 20% abated fossil fuel power generation in the power system could reduce the national total power shortage rate by up to 9.0 percentages in 2050 compared with a zero fossil fuel system. A lowest-cost scenario with 16% abated fossil fuel power generation in the system even causes 2.5% lower investment costs in the network (or $16.8 billion), and also increases system resilience by reducing power shortage during extreme climatic events.

Distribution and bioaccumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans in the tissues of Yorkshire pig.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in various foods continuously concern the public. Pork and its byproducts, especially from Yorkshire pigs, are the largest meat food consumed by the general population in China. This study aims to investigate the distribution of PCDD/Fs in different tissues of Yorkshire pigs to understand their bioaccumulation. Yorkshire pigs were fed a known amount of PCDD/Fs through fly ash. PCDD/Fs were determined by isotope dilution method with a gas chromatography-high resolution mass spectrometer. The liver had the highest concentration levels (2041.33 pg/g lipid) and toxic equivalents values (69.14 pg/g lipid), followed by the spleen and lung, and the lowest ones in the brain. The liver also had the highest bioaccumulation of PCDD/Fs, and this level was considerably higher than that of other tissues. This study showed a strong accumulation capacity of the liver for polychlorinated dibenzo-p-dioxins and dibenzofurans under short-term exposure conditions, suggesting that the liver is a more sensitive tissue for monitoring PCDD/Fs in food safety risk monitoring. PRACTICAL APPLICATION: This paper may help the consumer in making food choices to minimize the exposure risk to Polychlorinated dibenzo-p-dioxins and dibenzofurans.

Assessment of potential, cost, and environmental benefits of CCS-EWR technology for coal-fired power plants in Yellow River Basin of China.

As an effective emission reduction approach, CO2 capture and storage (CCS) combined with enhanced water recovery (EWR) technology can not only reduce CO2 emissions, but can also recover deep saline water resources to relieve pressure on regional water resources, and can ensure the energy supply and both social and economic development. However, the environmental benefits and application costs of CCS-EWR are uncertain, and are determined by the technology level, geological conditions, and other physical factors. In this study, an optimal source-sink matching model and a techno-economic assessment model were developed to evaluate the contributions of CCS-EWR to carbon emission reduction and the increase of the water supply by considering various uncertain factors, as well as the corresponding costs. In addition, the Yellow River Basin (YRB) in China was selected as the research region because, while there are abundant coal-fired power plants (CFPPs) in the YRB, the water resources are scarce. The results revealed the following. (1) The maximum CO2 capture capacity of the 236 CFPPs in the YRB is about 738.77 Mt/a, and nearly 13.14 Gt of fresh water could be provided until the 236 CFPPs in the YRB retire, which can partially relieve the pressure on the supply of water resources. (2) With the consideration of the CCS-EWR benefits, the average cost of the 236 CFPPs in the YRB in their residual lifetime to reduce their CO2 emissions by 90% will be no more than 180 CNY/t. (3) The incentive effect of the increase of the industrial water price on the profits of CCS-EWR projects is not significant. CCS-EWR technology has better application prospects in China under the dual constraints of carbon-neutral targets and water shortages, and more policy support is required for its deployment.

How does "the Belt and Road" and the Sino-US trade conflict affect global and Chinese CO2 emissions?

In the context of the rapid development of the Belt and Road (B&R) Initiative, the continuous transfer of Sino-US trade to the B&R countries is an important means to mitigate the threat of Sino-US trade, and the environmental impact of this transfer should be considered, so as to provide a scientific basis for China's policy formulation about achieving this possible trade transfer with minimized environmental impacts. This study proposes a multiregional input-output model and analyzes the impact on carbon dioxide (CO2) emissions of transferring the Sino-US trade to the B&R countries for two types of scenarios. The results show the following: (1) A transfer of either the import trade or the export trade increases global and Chinese CO2 emissions by 81.76 Mt and 24.84 Mt, respectively. When both the import trade and export trade are transferred, the increases in CO2 emissions are only 0.22% and 0.26%, respectively. (2) Globally, the changes in international trade-embodied CO2 emissions are responsible for most of the global emission changes, especially the CO2 emissions exported from Russia, India, and many Southeast Asian countries to China. (3) Different from the impact on global emissions, the increases in Chinese domestic production-based CO2 emissions influence China's total CO2 emissions. Due to the imported CO2 emissions, the consumption-based CO2 emissions are affected to a greater degree and increase by 70.30 Mt, accounting for only 0.86% of the CO2 emissions in 2015. Finally, some policy implications are proposed.

Inequality of household energy and water consumption in China: An input-output analysis.

Household consumption activities affect energy and water consumption directly and indirectly. Based on input-output modeling, this paper divided Chinese urban and rural residents into 12 groups, and investigated the impact of the consumption activities of residents with different levels of income on China's energy and water consumption from the perspective of consumers. Two main results were found. 1) In 2012, the energy consumption caused by the consumption activities of the highest-income urban residents accounted for 17.3% of the total energy consumption. For water resources, the per capita water withdrawal and consumption of the highest-income urban residents reached 481.21 m3 and 284.45 thousand m3, 6 times more than that of the low-income rural residents. 2) We identified medium and medium-high income urban residents as the key groups of residents. From the perspective of the industrial sectors, the key sectors for high energy consumption and water usage included the Electricity and Agricultural sectors, and we identified the Electricity sector as the key sector for the water and energy nexus of the residential sectors. The conclusions of this paper have pertinence for policymaking, and they provide an appropriate policy basis for guiding residents' energy and water consumption.

The impact of climate change on residential energy consumption in urban and rural divided southern and northern China.

In different regions of China, climate change has various influences on urban and rural residential energy consumption, which also shows that the research on it could be profoundly vital in order to formulate the energy-saving and emission-reducing policies. Based the provincial panel data from 2000-2016, the extended stochastic impacts by regression on population, affluence, and technology (extended STIRPAT) model was utilized to evaluate the impacts of climate change on residential energy consumption in different Chinese regions. The results show that: (1) during 2000 to 2016, the urban and rural energy consumption enlarged by 878.83 billion kWh and 488.98 billion kWh, respectively. In addition, electricity and oil have occupied more proportion in urban energy consumption, while coal still plays an important role in rural residential energy consumption (28.2%). (2) Heating degree day (HDD) and cooling degree day (CDD) have positive influences on urban and rural residential energy consumption in different areas, and the elastic coefficients are 0.028-0.371 and 0.066-0.158, respectively. (3) The elastic coefficient of CDD in urban areas of southern regions (0.158) is much larger than that in northern regions (0.068).

Decomposition analysis of energy-related CO2 emission in the industrial sector of China: Evidence from the LMDI approach.

Energy consumption and increasing CO2 emissions in China are mainly indorsed to the industrial sector. The objective of this study was to explore the main factors driving CO2 emissions in China's industry throughout 1991-2016. Based on the log-mean Divisia index (LMDI) method, this study decomposes the change of industry-related CO2 emissions into energy structure effect, income effect, energy intensity effect, carbon emission, and labor effect. The core results indicate that CO2 emissions in China's industry experienced a significant increase from 738.5 to 7271.8 Mt during 1991-2013, while it decreased to 6844.0 Mt in 2016. The income effect and labor effect are the top two emitters, which accounted for increases of 351.8 Mt and 57.8 Mt in CO2 emissions respectively. Additionally, the energy structure effect also played a role in increasing CO2 emissions. Energy intensity and carbon emission effects are the most important factors in reducing CO2 emissions. The policy suggestions about the different period-wise analyses in terms of economic growth, energy structure, and energy intensity are provided.

Comparative study on the influence of final use structure on carbon emissions in the Beijing-Tianjin-Hebei region.

The Beijing-Tianjin-Hebei region's rapid economic development has led to a dramatic increase in its CO2 emissions, which is closely related to various regions' consumption habits and structures. In this paper, the decomposition analysis method based on input and output (IO-SDA) was applied to decompose the CO2 emissions change of the Beijing-Tianjin-Hebei region from 1997 to 2012 into five driving factors: population, carbon emission efficiency, production structure, final use structure and per capita regional GDP, and then the final use structure factor was further analyzed. The results show that: (1) the population and per capita regional GDP promote the CO2 emissions of all regions; Carbon emission efficiency is the biggest offsetting factor; The effect of final use structure changes on the growth of CO2 emissions in Beijing and Hebei remains unchanged. The effect on Tianjin was from 0.7Mt offset to 0.8Mt promotion. (2) Urban household consumption is the most important factor offsetting CO2 emissions in Beijing. Investment and export are the most important final use types for promoting the growth of CO2 emissions in Tianjin and Hebei, with the contribution of 95.78% and 88.09%, respectively. (3) From the sectoral perspective: The construction sector has the greatest impact on the total capital formation of the three regions. In terms of exports, Beijing's tertiary industry has the largest offsetting effect, while Tianjin and Hebei mainly rely on the promotion of metal smelting and other manufacturing industries. Finally, some policy implications for low carbonization are proposed in the Beijing-Tianjin-Hebei region.

Exploring the changes and driving forces of water footprints in China from 2002 to 2012: A perspective of final demand.

Due to economic development and population growth, the water shortage in China has gradually become increasingly severe. In this paper, by developing an environmentally expanded input-output (IO) model, water footprint in China during 2002-2012 is calculated from the perspective of final demand. Furthermore, a structural decomposition analysis (SDA) model is used to study the driving factors of the water footprint of rural and urban household consumption, gross fixed capital formation and exports. The findings indicate that: 1) the water footprint driven by final demand in China increased by 18.3% during 2002-2012, reaching 617.68 billion m3 in 2012, of which urban household consumption accounts for the highest proportion. 2) Of the different sectors, agricultural commodities have the highest water footprint, accounting for 35% of national water footprint in 2012. 3) In terms of the driving factors, water efficiency inhibits the increase of water footprint regardless of final demand types, while GDP per capita makes a great contribution to its rise. 4) As for rural household consumption, the most important driving factor is the inhibition effects of consumption pattern in water footprint. For urban household consumption, the water footprint is inhibited by consumption pattern but promoted by production structure during 2002-2010. However, it is no longer the case during 2010-2012 that consumption pattern becomes a promoting factor, with production structure being inhibiting one. 5) Regarding gross fixed capital formation, its water footprint increase driven by consumption pattern is only 12.4 billion m3 during 2007-2010. As for exports, consumption pattern causes the decline of water footprint after 2005 and the overall water footprint of exports declines during 2007-2012. Finally, this paper provides policy implications with respect to the promotion of China's water footprint conservation.

Computed tomography portography of patients with cirrhosis with normal body mass index: Comparison between low-tube-voltage CT with low contrast agent dose and conventional CT.

This study is to investigate the computed tomography (CT) image quality of the low- tube-voltage protocol with low contrast agent dose.CT portography was performed in 118 cirrhosis patients with body mass index (BMI) less than 25 kg/m under 2 protocols: Protocol A, tube voltage of 90 kVp/395 mAs and contrast agent dosage of 1.2 mL/kg, and, Protocol B, tube voltage of 120 kVp/200 mAs and contrast agent dosage of 1.5 mL/kg.The number of patients in each protocol was 59. The CT value noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in portal veins was comparatively analyzed between the 2 protocols. The subjective image quality was further assessed on 5-point scales. Radiation dose was also recorded and statistical analysis was performed.The CT value, CNR, and SNR of the images were higher at 90 kVp than those at 120 kVp (P < .05). There was no significant difference in image noise between the 2 protocols (P > .05). The CT dose index volume, dose-length product, and effective dose at 90 kVp were 18.2%, 16.0%, and 16.0% less than that at 120 kVp, respectively. There was no difference in image quality score between the 2 protocols (P > .05). The average amount of contrast agent was decreased by 17.8% when the 90 kVp protocol was used.CT portography at 90 kVp combined with low-dosage contrast agent leads to a significant reduction in radiation dose and improved SNR and CNR, without deterioration of image quality.

Is APC hypermethylation a diagnostic biomarker for bladder cancer? A meta-analysis.

OBJECTIVE: Numerous studies have been performed to investigate the association between APC promoter hypermethylation and bladder cancer risk. Nevertheless, the conclusion was uncertain due to small sample size, different ethnicities, and tumor subtype. Hence, to accurately assess the effect of APC promoter hypermethylation on the risk of bladder cancer, we performed the meta-analysis. MATERIALS AND METHODS: We retrieved the relevant literatures from electronic databases such as PubMed, Web of Science, Wanfang, Vapp, and CNKI (Chinese National Knowledge Infrastructure). 95% CI and OR were calculated to evaluate the associations of APC promoter hypermethylation with risk and clinical features of bladder cancer. Heterogeneity among studies was assessed with Q test and I 2 statistic. In addition, the diagnostic sensitivity, specificity, and area under the curve (AUC) value of APC hypermethylation for bladder cancer were calculated. RESULTS: In total, 14 articles with 531 controls and 1,293 cases were included to assess the associations of APC promoter hypermethylation with the risk and clinical characteristics of bladder cancer. The significant association between APC promoter hypermethylation and bladder cancer risk was detected (OR =17.01, CI =7.40-39.07). Furthermore, the results revealed that APC promoter hypermethylation was significantly correlated with the grade of bladder tumor (pTNM stage: OR =1.84, CI =0.87-3.93; grade: OR =4.11, CI =1.62-10.43). According to the results of diagnostic evaluation, the diagnostic sensitivity, specificity, and AUC value of APC hypermethylation for bladder cancer risk were 0.52 (95% CI =0.41-0.63), 0.98 (95% CI =0.90-1.00), and 0.80 (95% CI =0.76-0.83), respectively. CONCLUSION: This meta-analysis revealed that APC promoter hypermethylation was a risk factor for bladder cancer risk. In addition, APC promoter hypermethylation was significantly associated with the grade of bladder cancer. APC hypermethylation might be a useful biomarker for the clinical diagnosis of bladder cancer.

Distant Metastasis and Survival Outcomes after Computed Tomography-Guided Needle Biopsy in Resected Stage I-III Non-Small Cell Lung Cancer.

Background and objective Several reports describe the needle-tract implantation after percutaneous needle lung biopsy. The present study evaluated whether preoperative computed tomography-guided needle biopsy (CTNB) affected the distant metastasis and overall survival in patients with early non-small cell lung cancer (NSCLC). Methods A total of 1667 patients with pathological stage I-III NSCLC were assimilated. Of these, 168 patients received preoperative CTNB, whereas 1499 patients were not subjected to any biopsy before surgical resection. Propensity score matching method was adopted to balance the observed covariates between the two groups. Cox regression analysis and Kaplan-Meier estimations were used for survival analysis. Subset analysis was performed in the p-stage ≤ II cases. Results The distant metastasis and mortality were not significantly increased for all patients with preoperative CTNB (P = 0.142 and P = 0.125, respectively). The subset analysis of p-stage ≤ II cases showed that CTNB increased the risk of distant metastasis (P = 0.032) while not increasing the risk of mortality (P = 0.086). Conclusion CTNB can increase the risk of distant metastasis in the p-stage ≤ II patients.

Low-Dose Scanning Technology Combined with Low-Concentration Contrast Material in Renal Computed Tomography Angiography (CTA): A Preliminary Study.

BACKGROUND This study is to investigate the feasibility of low iodine concentration contrast material (CM) combined with low tube voltage and adaptive statistical iterative reconstruction (ASIR) in renal computed tomography angiography (CTA). MATERIAL AND METHODS A total of 136 patients were enrolled in this prospective trial, and randomly divided into two groups: group A (n=68) and group B (n=68). Group A received 120-kVp and iopromide (370 mg/mL) with filtered back projection (FBP) reconstruction, and group B received 100-kVp and iodixanol (270 mg/mL) with ASIR 40% (ASIR40). An equal iodine dose (300 mg/kg body weight) and the same iodine delivery rate (1,500 mg I/s) were given to all patients. Density, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured, and the image quality and visualization of renal arteries were scored. Dose-length product (DLP) and CT dose index volume (CTDIvol) were recorded, and effective doses (ED) were calculated. RESULTS There was no significant difference in image noise between groups A and B (p>0.05). The vessel attenuation, SNR, and CNR were significantly higher in group B than group A (all p<0.05). The subjective image quality and visualization of renal artery branches were similar in these two groups (p>0.05). Compared with group A, the CTDIvol, DLP, and ED in group B were decreased by 38.58%, 37.24%, and 37.24%, respectively (p=0.000). CONCLUSIONS Compared with 120-kVp with FBP reconstruction, the protocol of 100-kVp with ASIRP40 reconstruction provided high-quality renal CTA results, which allowed for reduced iodine concentration and decreased radiation dose.

[Distant Metastasis and Survival Outcomes after Computed Tomography-guided Needle Biopsy in Stage I-II Non-small Cell Lung Cancer].

BACKGROUND: Computed tomography-guided needle biopsy (CTNB) is a well-established and commonly used technique for diagnosing pulmonary nodules with high accuracy and safety. Needle-tract implantation after CTNB has been reported in various reports. The aim of this study is to evaluate whether preoperative CTNB affected the distant metastasis and overall survival in pathological stage I-II lung cancer patients. METHODS: A total of 1,234 patients with pathological stage I-II non-small cell lung cancer were collected. 113 patients received preoperative CTNB, and 1,121 patients did not receive any biopsy before surgical resection. Propensity score-matching method was adopted to balance observed covariates between two groups, 113 pairs were matched. Cox regression analysis and Kaplan-Meier estimates were used to process survival analysis. RESULTS: Distant metastasis free survival (DMFS) was significantly poorer in the preoperative CTNB group than in the non-biopsy group (P=0.032). But there was no difference in the overall survival between the two groups (P=0.086). CONCLUSIONS: CTNB increased the risk of distant metastasis, not increasing the risk of mortality.

MicroRNA-146a Ameliorates Inflammation via TRAF6/NF-κB Pathway in Intervertebral Disc Cells.

BACKGROUND Intervertebral disc degeneration (IDD) has been widely recognized as a major contributor to low back pain. Accumulating evidence suggests that IDD is linked to various pro-inflammatory cytokines and metabolites. Recently, numerous studies have demonstrated that microRNAs (miRNAs) play a pivotal role in the development of most disorders, including degenerative disc diseases. Previous reports have revealed that miRNA-146a (miR-146a) could attenuate neuropathic pain in the spinal cord. The aim of this study was to investigate the role of miR-146a in the inflammatory response of IDD. MATERIAL AND METHODS Quantitative real-time (RT)-PCR was performed to investigate the levels of miR-146a in the PBMCs (peripheral blood mononuclear cells) of patients with IDD. Human nucleus pulposus (NP) cells were transiently transfected with miR-146a mimic; control NP cell transfections lacked miR-146a. Then all NP cells were treated with LPS (10 µM) to induce inflammation. The mRNA levels of miR-146a in NP cells were determined by RT-PCR. In addition, the mRNA and protein expression levels of tumor necrosis factor (TNF), receptor-associated factor 6 (TRAF6), and nuclear factor (NF)-κB in NP cells were evaluated by quantitative RT-PCR and Western blot analysis, respectively. RESULTS We found that miR-146a was significantly downregulated in the PBMCs of patients. Moreover, overexpression of miR-146a significantly decreased the levels of pro-inflammatory cytokines in LPS-stimulated NP cells. The mRNA and protein levels of TRAF6 and NF-κB were downregulated by miR-146a overexpression. CONCLUSIONS These results suggest that overexpression of miR-146a could promote IDD through the TRAF/NF-κB pathway. Our findings also highlight miR-146a as a novel possible therapeutic target for IDD.

Spectral CT demonstration of the superior mesenteric artery: comparison of monochromatic and polychromatic imaging.

RATIONALE AND OBJECTIVES: To investigate the performance of spectral computed tomography (CT) in depiction of the superior mesenteric artery (SMA) compared to conventional polychromatic CT. MATERIALS AND METHODS: This prospective study had institutional review board approval, and written informed consent was obtained. Fifty patients underwent spectral CT examination using gemstone spectral imaging with a single-tube, fast dual-tube voltage-switching technique. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for SMA angiography. The CNR for SMA at the selected monochromatic level was compared with that from the conventional polychromatic images. Image quality and visibility of the branch order of SMA were also assessed and compared. RESULTS: The monochromatic images at 50 keV (mean 50.09 ± 1.98) provided the optimal CNR for SMA angiography. At this energy level, the monochromatic images had higher (20.8 vs 9.2) CNR than the polychromatic images, and the image quality was superior to conventional polychromatic images (P < .05). Fourth to fifth (mean 4.3) and third to fourth (mean 3.5) order branches of SMA were demonstrated at monochromatic and polychromatic images, respectively. CONCLUSIONS: Gemstone spectral imaging with monochromatic images at 50 keV by spectral CT could improve the CTA image quality and demonstrate more branch order in depiction of normal SMA compared to conventional polychromatic imaging.