对于数码相机想必大家早有耳闻了吧?今天我有幸试用了EPSON公司的Photo PC 700。 打开包装,其庐山真面目尽收眼底。它的外形十分小巧,外形尺寸仅为144.2mm(长)×69.8mm(宽)×49.3mm(高),重量为280克,携带极为方便,特象家用的傻...对于数码相机想必大家早有耳闻了吧?今天我有幸试用了EPSON公司的Photo PC 700。 打开包装,其庐山真面目尽收眼底。它的外形十分小巧,外形尺寸仅为144.2mm(长)×69.8mm(宽)×49.3mm(高),重量为280克,携带极为方便,特象家用的傻瓜照相机。该“傻瓜”着一袭黑装,“皮肤”细腻,其正前方展现给我的是镜头和闪光灯,平时不用时它隐藏在镜头盖后面,拍照时逆时针拧动镜头盖即可睁开“眼镜”展开更多
A discriminant method for optimizing activity in nuclear medicine studies is validated by comparison with ROC （received operating characteristic）-curves. The method is tested in 21 single photon emission computerize...A discriminant method for optimizing activity in nuclear medicine studies is validated by comparison with ROC （received operating characteristic）-curves. The method is tested in 21 single photon emission computerized tomography （SPECT）, performed with a cardiac phantom. Three different lesions （Lb L2 and L3） were placed in the myocardium-wall by pairs fbr each SPECT. Three activities （84, 37 or 18.5 MBq） of 99mTc were used as background. Linear discriminant analysis was used to select the parameters that characterize image quality among the measured variables in the images [（Background-to-Lesion （B/Li） and Signal-to-Noise （S/N） ratios）]. Two clusters with different image quality （P=0.021 ） were obtained. The ratios B/Lj, B/L2 and B/L3 are the parameters used to construct the function with 100% of cases correctly classified into the clusters. The value of 37 MBq was the lowest tested activity for which good results for the B/Li ratios were obtained. The result coincides with the applied ROC-analysis （r=0.89）.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
文摘对于数码相机想必大家早有耳闻了吧?今天我有幸试用了EPSON公司的Photo PC 700。 打开包装,其庐山真面目尽收眼底。它的外形十分小巧,外形尺寸仅为144.2mm(长)×69.8mm(宽)×49.3mm(高),重量为280克,携带极为方便,特象家用的傻瓜照相机。该“傻瓜”着一袭黑装,“皮肤”细腻,其正前方展现给我的是镜头和闪光灯,平时不用时它隐藏在镜头盖后面,拍照时逆时针拧动镜头盖即可睁开“眼镜”
基金Project supported by the Third World Academy of Sciences (TWAS), Cuba
文摘A discriminant method for optimizing activity in nuclear medicine studies is validated by comparison with ROC （received operating characteristic）-curves. The method is tested in 21 single photon emission computerized tomography （SPECT）, performed with a cardiac phantom. Three different lesions （Lb L2 and L3） were placed in the myocardium-wall by pairs fbr each SPECT. Three activities （84, 37 or 18.5 MBq） of 99mTc were used as background. Linear discriminant analysis was used to select the parameters that characterize image quality among the measured variables in the images [（Background-to-Lesion （B/Li） and Signal-to-Noise （S/N） ratios）]. Two clusters with different image quality （P=0.021 ） were obtained. The ratios B/Lj, B/L2 and B/L3 are the parameters used to construct the function with 100% of cases correctly classified into the clusters. The value of 37 MBq was the lowest tested activity for which good results for the B/Li ratios were obtained. The result coincides with the applied ROC-analysis （r=0.89）.
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。
