目的分析智能最佳管电压(CARE k V)技术在胸部CT平扫中降低辐射剂量和减少图像伪影的应用价值。方法将210例胸部CT平扫患者按扫描时间分为A、B、C组,每组70例。所有患者均开启智能毫安技术(CARE Dose 4D)模式,A组采用120 k V、B组采用10...目的分析智能最佳管电压(CARE k V)技术在胸部CT平扫中降低辐射剂量和减少图像伪影的应用价值。方法将210例胸部CT平扫患者按扫描时间分为A、B、C组,每组70例。所有患者均开启智能毫安技术(CARE Dose 4D)模式,A组采用120 k V、B组采用100 k V、C组采用CARE k V技术。使用PACS工作站进行图像质量主观评价,测量胸廓入口层面脊柱旁肌肉、肺动脉干层面及右下肺静脉层面的降主动脉CT值、噪声等,记录扫描参数等。对组间图像质量、辐射剂量等进行统计学分析。结果 C组扫描时自动选择管电压及管电流,其中包括13例100 k V、47例120 k V、10例140 k V。B组与A组比较,有效毫安秒(the effective m As)、CT容积剂量指数(CTDIvol)、有效吸收剂量(ED)分别降低10.35%、46.69%、46.26%;C组与A组比较,分别降低35.08%、35.34%、33.48%,组间的差异均有统计学意义(P<0.05)。胸廓入口层面组间两两比较,C组和A组间的噪声(SD)、信噪比(SNR)、图像质量评分差异无统计学意义;C组和B组比较,C组的SD显著低于B组,而SNR和图像质量评分显著高于B组,差异均有统计学意义(P<0.05)。C组的条状伪影及伪影严重程度明显少于(轻于)A组和B组,图像质量显著优于低剂量B组。中下肺层面图像质量评分组间差异无统计学意义(P>0.05)。结论 CARE k V技术能够根据患者体型和解剖部位自动地选择管电压和调整管电流,提高工作效率,在显著降低胸部CT平扫辐射剂量的同时,可以有效地降低胸廓入口层面的噪声,减少图像伪影,改善图像质量。展开更多
目的评价智能最佳管电压（CARE k V）技术在幼儿胸部CT扫描中的应用价值。方法选取80例1~3岁胸部CT扫描患儿,随机分成两组：A组40例采用CARE k V技术扫描;B组40例采用固定k V技术扫描,两组均采用自动管电流调节（CARE Dose 4D）技术,比...目的评价智能最佳管电压（CARE k V）技术在幼儿胸部CT扫描中的应用价值。方法选取80例1~3岁胸部CT扫描患儿,随机分成两组：A组40例采用CARE k V技术扫描;B组40例采用固定k V技术扫描,两组均采用自动管电流调节（CARE Dose 4D）技术,比较两组的图像质量和辐射剂量。结果两组的图像质量均能满足诊断要求,两组间图像质量评分差异无统计学意义（P〉0.05）,A组平均有效辐射剂量（ED）平均（0.40±0.07）m Sv,B组平均（0.52±0.06）m Sv,差异性有统计学意义（P〈0.05）。结论在幼儿胸部CT扫描中,使用CARE k V技术,与单独应用CARE Dose 4D技术相比,在保证图像质量的同时更能降低幼儿辐射剂量,值得推广应用。展开更多
目的:探讨智能最佳管电压(CARE k V)技术在降低胸部CT辐射剂量中的应用价值。材料与方法:回顾性选择2014年11月至2016年11月我院收治的具有胸痛、咳嗽、咳血等症状并行胸部CT检查的患者180例,根据管电压类型分为A组(60例)、B组(70例)和C...目的:探讨智能最佳管电压(CARE k V)技术在降低胸部CT辐射剂量中的应用价值。材料与方法:回顾性选择2014年11月至2016年11月我院收治的具有胸痛、咳嗽、咳血等症状并行胸部CT检查的患者180例,根据管电压类型分为A组(60例)、B组(70例)和C组(50例),A组管电压选用传统常规数值,B组选取低管电压,C组为CARE k V组。记录对比三组的辐射剂量、图像质量可观评价和图像质量主观评价。结果:B、C两组均比A组明显降低,B组有效吸收剂量比A组降低43.31%,C组比A组降低27.29%,差异均有统计学意义(P<0.05);A组和C组的图像质量客观评分和主观评分均明显高于B组,差异有统计学意义(P<0.05);A组和C组相比差异无统计学意义(P>0.05)。结论:CARE k V技术比常规管电压组可降低约27%的胸部CT辐射剂量,同时可提供优质的检查图像,具有很高的应用价值,值得推广应用。展开更多
In this paper, we extend a novel unconstrained multiobjective optimization algorithm, so-called multiobjective extremal optimization （MOEO）, to solve the constrained multiobjective optimization problems （MOPs）. Th...In this paper, we extend a novel unconstrained multiobjective optimization algorithm, so-called multiobjective extremal optimization （MOEO）, to solve the constrained multiobjective optimization problems （MOPs）. The proposed approach is validated by three constrained benchmark problems and successfully applied to handling three multiobjective engineering design problems reported in literature. Simulation results indicate that the proposed approach is highly competitive with three state-of-the-art multiobjective evolutionary algorithms, i.e., NSGA-11, SPEA2 and PAES. Thus MOEO can be considered a good alternative to solve constrained multiobjective optimization problems.展开更多
With the growing deployment of smart distribution grid,it has become urgent to investigate the smart distribution grid behavior during transient faults and improve the system stability.The feasibility of segmenting la...With the growing deployment of smart distribution grid,it has become urgent to investigate the smart distribution grid behavior during transient faults and improve the system stability.The feasibility of segmenting large power grids and multiple smart distribution grids interconnections using energy storage technology for improving the system dynamic stability was studied.The segmentation validity of the large power grids and smart distribution grid inverter output interconnections power system using energy storage technology was proved in terms of theoretical analysis.Then,the influences of the energy storage device location and capacity on the proposed method were discussed in detail.The conclusion is obtained that the ESD optimal locations are allocated at the tie line terminal buses in the interconnected grid,respectively.The effectiveness of the proposed method was verified by simulations in an actual power system.展开更多
文摘目的分析智能最佳管电压(CARE k V)技术在胸部CT平扫中降低辐射剂量和减少图像伪影的应用价值。方法将210例胸部CT平扫患者按扫描时间分为A、B、C组,每组70例。所有患者均开启智能毫安技术(CARE Dose 4D)模式,A组采用120 k V、B组采用100 k V、C组采用CARE k V技术。使用PACS工作站进行图像质量主观评价,测量胸廓入口层面脊柱旁肌肉、肺动脉干层面及右下肺静脉层面的降主动脉CT值、噪声等,记录扫描参数等。对组间图像质量、辐射剂量等进行统计学分析。结果 C组扫描时自动选择管电压及管电流,其中包括13例100 k V、47例120 k V、10例140 k V。B组与A组比较,有效毫安秒(the effective m As)、CT容积剂量指数(CTDIvol)、有效吸收剂量(ED)分别降低10.35%、46.69%、46.26%;C组与A组比较,分别降低35.08%、35.34%、33.48%,组间的差异均有统计学意义(P<0.05)。胸廓入口层面组间两两比较,C组和A组间的噪声(SD)、信噪比(SNR)、图像质量评分差异无统计学意义;C组和B组比较,C组的SD显著低于B组,而SNR和图像质量评分显著高于B组,差异均有统计学意义(P<0.05)。C组的条状伪影及伪影严重程度明显少于(轻于)A组和B组,图像质量显著优于低剂量B组。中下肺层面图像质量评分组间差异无统计学意义(P>0.05)。结论 CARE k V技术能够根据患者体型和解剖部位自动地选择管电压和调整管电流,提高工作效率,在显著降低胸部CT平扫辐射剂量的同时,可以有效地降低胸廓入口层面的噪声,减少图像伪影,改善图像质量。
文摘目的评价智能最佳管电压（CARE k V）技术在幼儿胸部CT扫描中的应用价值。方法选取80例1~3岁胸部CT扫描患儿,随机分成两组：A组40例采用CARE k V技术扫描;B组40例采用固定k V技术扫描,两组均采用自动管电流调节（CARE Dose 4D）技术,比较两组的图像质量和辐射剂量。结果两组的图像质量均能满足诊断要求,两组间图像质量评分差异无统计学意义（P〉0.05）,A组平均有效辐射剂量（ED）平均（0.40±0.07）m Sv,B组平均（0.52±0.06）m Sv,差异性有统计学意义（P〈0.05）。结论在幼儿胸部CT扫描中,使用CARE k V技术,与单独应用CARE Dose 4D技术相比,在保证图像质量的同时更能降低幼儿辐射剂量,值得推广应用。
文摘目的:探讨智能最佳管电压(CARE k V)技术在降低胸部CT辐射剂量中的应用价值。材料与方法:回顾性选择2014年11月至2016年11月我院收治的具有胸痛、咳嗽、咳血等症状并行胸部CT检查的患者180例,根据管电压类型分为A组(60例)、B组(70例)和C组(50例),A组管电压选用传统常规数值,B组选取低管电压,C组为CARE k V组。记录对比三组的辐射剂量、图像质量可观评价和图像质量主观评价。结果:B、C两组均比A组明显降低,B组有效吸收剂量比A组降低43.31%,C组比A组降低27.29%,差异均有统计学意义(P<0.05);A组和C组的图像质量客观评分和主观评分均明显高于B组,差异有统计学意义(P<0.05);A组和C组相比差异无统计学意义(P>0.05)。结论:CARE k V技术比常规管电压组可降低约27%的胸部CT辐射剂量,同时可提供优质的检查图像,具有很高的应用价值,值得推广应用。
基金Project (No.60574063) the National Natural Science Foundation of China
文摘In this paper, we extend a novel unconstrained multiobjective optimization algorithm, so-called multiobjective extremal optimization （MOEO）, to solve the constrained multiobjective optimization problems （MOPs）. The proposed approach is validated by three constrained benchmark problems and successfully applied to handling three multiobjective engineering design problems reported in literature. Simulation results indicate that the proposed approach is highly competitive with three state-of-the-art multiobjective evolutionary algorithms, i.e., NSGA-11, SPEA2 and PAES. Thus MOEO can be considered a good alternative to solve constrained multiobjective optimization problems.
基金Project(N110404031)supported by the Fundamental Research Funds for the Central Universities,China
文摘With the growing deployment of smart distribution grid,it has become urgent to investigate the smart distribution grid behavior during transient faults and improve the system stability.The feasibility of segmenting large power grids and multiple smart distribution grids interconnections using energy storage technology for improving the system dynamic stability was studied.The segmentation validity of the large power grids and smart distribution grid inverter output interconnections power system using energy storage technology was proved in terms of theoretical analysis.Then,the influences of the energy storage device location and capacity on the proposed method were discussed in detail.The conclusion is obtained that the ESD optimal locations are allocated at the tie line terminal buses in the interconnected grid,respectively.The effectiveness of the proposed method was verified by simulations in an actual power system.
