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沈杰  彭芸  曾骐  张祺丰  曾津津   《放射学实践》2011,26(1):82-85
目的:探讨螺旋CT在漏斗胸合并其它先天性畸形中的应用价值.方法:回顾性分析283例手术前行螺旋CT检查并采用螺旋CT重组技术的漏斗胸患儿临床及影像资料,分类记录漏斗胸患儿合并各种其它先天性畸形的种类及分布比例.结果:本组漏斗胸病例中合并其它先天性畸形47例,占16.61%.其中合并脊柱侧弯的比例最大(4.95%).按系...  相似文献   
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Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.  相似文献   
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应用模拟低剂量法行新生儿头颅CT扫描   总被引:1,自引:0,他引:1  
Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.  相似文献   
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目的 探讨儿童颞骨骨折的临床特点及治疗策略.方法 回顾性分析2014年7月~2021年7月首都医科大学附属北京儿童医院确诊的477例18岁以下颞骨骨折患儿的临床资料,包括患儿性别、年龄、受伤原因、影像学、面神经及听力学评估、并发症、治疗及预后.结果 477例颞骨骨折患儿中男358例、女119例,男女比例为3∶1,年龄范...  相似文献   
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目的 评价基于模型的迭代重建(MBIR)及自适应统计迭代重建(ASIR)优化100 kV儿童腹部CT血管造影(CTA)图像质量的价值。方法 对55例患儿行100 kV低剂量腹部CTA,分别采用MBIR、100% ASIR、80% ASIR、60% ASIR、40% ASIR及滤过反向投影(FBP)算法重建为6组图像,评价图像质量,包括图像噪声、大动脉(LA)及小动脉(SA)显示能力;对比各级动脉CT值及标准差(SD),计算信噪比(SNR)及对比噪声比(CNR)。结果 图像噪声主观评分及LA评分以MBIR图像最高,ASIR次之,FBP图像质量最差;SA评分以MBIR图像最佳,FBP次之;随权重提升,ASIR图像评分逐渐降低,100% ASIR最低(P均<0.05)。MBIR图像SD最低,其SNR及CNR明显高于其他图像(P均<0.05)。结论 MBIR可明显提高儿童低剂量CTA图像质量,100% ASIR仅可提高图像显示LA能力。  相似文献   
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Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.  相似文献   
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目的 探讨应用64层螺旋CT(MSCT),采用适宜噪声指数的Z轴自动管电流调节技术获得稳定的婴幼儿胸部CT扫描图像,并降低射线剂量的可行性研究.方法 选取100例根据临床需要行64层MSCT胸部扫描的3岁以下婴幼儿患儿,按年龄和体重用随机数字表法分为2组,每组各50例.对照组(中位年龄1.7岁)采用固定管电流扫描技术:1岁以下120 mA,≥1岁者150 mA;研究组(中位年龄1.4岁)采用z轴自动管电流调节扫描技术:1岁以下预设噪声指数为8,≥1岁为9,毫安设置范围为10~250 mA,其余扫描参数条件2组一致.记录2组CT剂最指数(CTDIvol)值.2名医师独立对图像质量采用5分制进行评估,>13分被认为符合临床诊断要求.采用Kappa方法评价不同观察者评定结果间的一致性.结果 对照组的平均客观噪声和CTDIvol分别为(4.78 4±0.58)和(6.68±0.62)mGy,研究组的平均客观噪声和CTDIvol分别是(7.84±0.66)和(2.34±0.71)mGy;研究组和对照组的平均管电流分为(41.6 4±11.6)和(99.2±7.7)mAs.研究组的平均CTDIvol较对照组下降了 65%.研究组和对照组平均图像质量评分分别为(3.46±0.40)和(4.65±0.46)分,所用图像均获得了满意的临床诊断要求,2名医师的评估结果获得了中等一致性(Kappa值分别为0.474和0.536).结论 64层MSCT自动管电流调节技术应用于婴幼儿胸部扫描时可以在降低射线剂量的基础卜获得稳定的图像质量,噪声指数设定在8或9较为适宜.  相似文献   
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Objective To determine the effects of dose reduction on multi-slice spiral CT(MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images.Methods Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans.Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool.A total of 855 image data sets were obtained for the 57 patients.Original and simulated dose-reduction scan images were analyzed.Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-peint scale and objective noise index.Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices.And the noise index and mean value was calculated.The degree of inter-observer concordance was determined by Kappa statistical analysis.The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed.Results On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively,the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20.2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively.The two radiologists had good intembserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoff ng (K=0.630, P=0.022).There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001).At 40% dose reduction to the standard protocol, the noise index was 2.44 and the image quality score was 3.21 which were considered clinically acceptable.Conclusion The study revealed that acceptable imagos could be obtained with mean noise index of 2.44 and 40% dose reduction.  相似文献   
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