目的通过比较非对称回波的最小二乘估算法迭代水脂分离(iterative decomposition of water and fat withecho asymmetric and least-squares estimation,IDEAL)技术中T_2加权成像(T_2weighted imaging,T_2WI)和短时间反转恢复(short tim...目的通过比较非对称回波的最小二乘估算法迭代水脂分离(iterative decomposition of water and fat withecho asymmetric and least-squares estimation,IDEAL)技术中T_2加权成像(T_2weighted imaging,T_2WI)和短时间反转恢复(short time inversion recovery,STIR)序列的图像质量,探讨两种脂肪抑制技术在颈椎前路术后患者核磁共振成像(magnetic resonance imaging,MRI)中的应用价值。方法回顾性分析20例颈椎前路术后患者的矢状面IDEAL-T_2WI和STIR序列的MRI。比较两组间金属伪影面积的大小、总体图像质量、脊髓的可见性以及脂肪抑制的均匀性。结果 IDEAL-T_2WI和STIR序列图像的平均金属伪影面积分别为(786±398)mm2和(774±394)mm^2,二者的差异无统计学意义(P=0.329)。在脊髓的可见性方面,二者的差异无统计学意义(P=0.317)。而在总体图像质量和脂肪抑制的均匀性方面,IDEAL-T_2WI序列的图像均优于STIR序列(P<0.05)。结论在颈椎前路术后患者的3.0T MRI中,I-DEAL-T_2WI序列可以替代STIR序列作为最佳的脂肪抑制技术。展开更多
In this paper, the results characterize the convergence of Ishikawa type iterative sequences (with errors) for constructing the solutions of strongly accretive operator equations, the solutions of rn-accretive operato...In this paper, the results characterize the convergence of Ishikawa type iterative sequences (with errors) for constructing the solutions of strongly accretive operator equations, the solutions of rn-accretive operator equations, and the fixed points of strong pseudocontractions. These results extend and improve Theorems 1-3 of Chidume and Osilike (Nonlinear Anal. TMA, 1999, 36(7): 863-872).展开更多
Let E be a real Banach space and K be a nonempty closed convex and bounded subset of E. Let Ti ： K→ K, i=1, 2,... ,N, be N uniformly L-Lipschitzian, uniformly asymptotically regular with sequences {ε^（i）n} and as...Let E be a real Banach space and K be a nonempty closed convex and bounded subset of E. Let Ti ： K→ K, i=1, 2,... ,N, be N uniformly L-Lipschitzian, uniformly asymptotically regular with sequences {ε^（i）n} and asymptotically pseudocontractive mappings with sequences {κ^（i）n}, where {κ^（i）n} and {ε^（i）n}, i = 1, 2,... ,N, satisfy certain mild conditions. Let a sequence {xn} be generated from x1 ∈ K by zn：= （1-μn）xn＋μnT^nnxn, xn＋1 ：= λnθnx1＋ [1 - λn（1 ＋ θn）]xn ＋ λnT^nnzn for all integer n ≥ 1, where Tn = Tn（mod N）, and {λn}, {θn} and {μn} are three real sequences in [0, 1] satisfying appropriate conditions. Then ｜｜xn- Tixn｜｜→ 0 as n→∞ for each l ∈ {1, 2,..., N}. The results presented in this paper generalize and improve the corresponding results of Chidume and Zegeye, Reinermann, Rhoades and Schu.展开更多
文摘目的通过比较非对称回波的最小二乘估算法迭代水脂分离(iterative decomposition of water and fat withecho asymmetric and least-squares estimation,IDEAL)技术中T_2加权成像(T_2weighted imaging,T_2WI)和短时间反转恢复(short time inversion recovery,STIR)序列的图像质量,探讨两种脂肪抑制技术在颈椎前路术后患者核磁共振成像(magnetic resonance imaging,MRI)中的应用价值。方法回顾性分析20例颈椎前路术后患者的矢状面IDEAL-T_2WI和STIR序列的MRI。比较两组间金属伪影面积的大小、总体图像质量、脊髓的可见性以及脂肪抑制的均匀性。结果 IDEAL-T_2WI和STIR序列图像的平均金属伪影面积分别为(786±398)mm2和(774±394)mm^2,二者的差异无统计学意义(P=0.329)。在脊髓的可见性方面,二者的差异无统计学意义(P=0.317)。而在总体图像质量和脂肪抑制的均匀性方面,IDEAL-T_2WI序列的图像均优于STIR序列(P<0.05)。结论在颈椎前路术后患者的3.0T MRI中,I-DEAL-T_2WI序列可以替代STIR序列作为最佳的脂肪抑制技术。
基金NNSF of China(19801023)Teachiug and Research A ward Fund for Outstanding Young Teachers in Higher Edncation Institutions of MOE.Chinal.
文摘In this paper, the results characterize the convergence of Ishikawa type iterative sequences (with errors) for constructing the solutions of strongly accretive operator equations, the solutions of rn-accretive operator equations, and the fixed points of strong pseudocontractions. These results extend and improve Theorems 1-3 of Chidume and Osilike (Nonlinear Anal. TMA, 1999, 36(7): 863-872).
基金Foundation item： the National Natural Science Foundation of China （No. 10771141） the Natural Science Foundation of Zhejiang Province （Y605191） the Natural Science Foundation of Heilongjiang Province （No. A0211） and the Scientific Research Foundation from Zhejiang Province Education Committee （No. 20051897）.
文摘Let E be a real Banach space and K be a nonempty closed convex and bounded subset of E. Let Ti ： K→ K, i=1, 2,... ,N, be N uniformly L-Lipschitzian, uniformly asymptotically regular with sequences {ε^（i）n} and asymptotically pseudocontractive mappings with sequences {κ^（i）n}, where {κ^（i）n} and {ε^（i）n}, i = 1, 2,... ,N, satisfy certain mild conditions. Let a sequence {xn} be generated from x1 ∈ K by zn：= （1-μn）xn＋μnT^nnxn, xn＋1 ：= λnθnx1＋ [1 - λn（1 ＋ θn）]xn ＋ λnT^nnzn for all integer n ≥ 1, where Tn = Tn（mod N）, and {λn}, {θn} and {μn} are three real sequences in [0, 1] satisfying appropriate conditions. Then ｜｜xn- Tixn｜｜→ 0 as n→∞ for each l ∈ {1, 2,..., N}. The results presented in this paper generalize and improve the corresponding results of Chidume and Zegeye, Reinermann, Rhoades and Schu.
