目的探讨个体化大剂量高速率生理盐水在头颈部CTA降低入路静脉伪影的可行性研究。方法选取2021年3月至2021年8月我院头颈部CTA检查80例,前瞻性分成两组,每组40例。两组受检者均以0.06倍体重kg值作对比剂速率,实验组采用1.4倍对比剂速率...目的探讨个体化大剂量高速率生理盐水在头颈部CTA降低入路静脉伪影的可行性研究。方法选取2021年3月至2021年8月我院头颈部CTA检查80例,前瞻性分成两组,每组40例。两组受检者均以0.06倍体重kg值作对比剂速率,实验组采用1.4倍对比剂速率作高速率生理盐水;对照组生理盐水与对比剂等速率,对比剂与生理盐水分别注射9秒和14秒。记录各受检者生理盐水速率及总量;比较入路静脉伪影采用主观评分;测量主动脉弓、头臂干、颈总动脉、锁骨下动脉、大脑基底动脉、上腔静脉、头臂静脉、锁骨下静脉CT值,比较评分及CT值差异。结果实验组生理盐水速率3.6~6.7mL/s(平均5.4±0.7 m L/s),总量50.4~93.8 m L(平均74.7±9.5mL);对照组速率2.4~4.8mL/s(平均3.6±0.7mL/s),总量33.6~67.2mL(平均49.8±9.9mL),两组速率及总量差异具有统计学意义(P<0.01)。主观评分实验组1分25例,2分15例;对照组1分7例,2分22例,3分11例,评分差异具有统计学意义(P<0.01)。实验组各目标动脉CT值高于对照组,实验组上腔静脉、头臂静脉、锁骨下静脉CT值低于对照组,各目标血管CT值差异具有统计学意义(P<0.01)。结论采用1.4倍对比剂速率的个体化大剂量高速率生理盐水在头颈CTA检查可明显降低入路静脉伪影,提高动脉血管CT值。展开更多
We investigate the dopant site selectivity of CaCu_(3)Ti_(4)O_(12)(CCTO)using the first principles calculations.Our results show that,for four cases of possible occupancy by La atom,lattice expansions and formation en...We investigate the dopant site selectivity of CaCu_(3)Ti_(4)O_(12)(CCTO)using the first principles calculations.Our results show that,for four cases of possible occupancy by La atom,lattice expansions and formation enthalpies with different dopant quantities indicate that doped La cations are preferentially substituted for Ca sites in CaCu_(3)Ti_(4)O_(12),which is excellent in agreement with the experimental observation(Choi et al.Adv.Mater.21(2009)885).Furthermore,more interesting information of doping is also explored by the analysis of density of states and it is found that La substituting for Cu may advance the electron conduction in CCTO.It supplies a potential solution for limitations of CCTO devices by exploring the effect when La substitutes for Cu sites in the CCTO crystal.展开更多
文摘目的探讨个体化大剂量高速率生理盐水在头颈部CTA降低入路静脉伪影的可行性研究。方法选取2021年3月至2021年8月我院头颈部CTA检查80例,前瞻性分成两组,每组40例。两组受检者均以0.06倍体重kg值作对比剂速率,实验组采用1.4倍对比剂速率作高速率生理盐水;对照组生理盐水与对比剂等速率,对比剂与生理盐水分别注射9秒和14秒。记录各受检者生理盐水速率及总量;比较入路静脉伪影采用主观评分;测量主动脉弓、头臂干、颈总动脉、锁骨下动脉、大脑基底动脉、上腔静脉、头臂静脉、锁骨下静脉CT值,比较评分及CT值差异。结果实验组生理盐水速率3.6~6.7mL/s(平均5.4±0.7 m L/s),总量50.4~93.8 m L(平均74.7±9.5mL);对照组速率2.4~4.8mL/s(平均3.6±0.7mL/s),总量33.6~67.2mL(平均49.8±9.9mL),两组速率及总量差异具有统计学意义(P<0.01)。主观评分实验组1分25例,2分15例;对照组1分7例,2分22例,3分11例,评分差异具有统计学意义(P<0.01)。实验组各目标动脉CT值高于对照组,实验组上腔静脉、头臂静脉、锁骨下静脉CT值低于对照组,各目标血管CT值差异具有统计学意义(P<0.01)。结论采用1.4倍对比剂速率的个体化大剂量高速率生理盐水在头颈CTA检查可明显降低入路静脉伪影,提高动脉血管CT值。
基金Supported by the National Natural Science Foundation of China under Grant Nos 11074017 and 51032002the IHLB(No PHR201007101),the Beijing Nova Program(No 2008B10)+1 种基金the Beijing Natural Science Foundation(No 1102006)the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the Ministry of Education.
文摘We investigate the dopant site selectivity of CaCu_(3)Ti_(4)O_(12)(CCTO)using the first principles calculations.Our results show that,for four cases of possible occupancy by La atom,lattice expansions and formation enthalpies with different dopant quantities indicate that doped La cations are preferentially substituted for Ca sites in CaCu_(3)Ti_(4)O_(12),which is excellent in agreement with the experimental observation(Choi et al.Adv.Mater.21(2009)885).Furthermore,more interesting information of doping is also explored by the analysis of density of states and it is found that La substituting for Cu may advance the electron conduction in CCTO.It supplies a potential solution for limitations of CCTO devices by exploring the effect when La substitutes for Cu sites in the CCTO crystal.
