Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate i...Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate image quality for PET/CT studies. Materials and Methods: Literature survey was initially based on the selection of keywords and years of publication to identify potentially relevant articles, then the further search was conducted on the authors and references from these articles. The abstract of each article was first appraised to decide whether the content was relevant to this research question. The articles were classified into five groups: studies on dosimetry, studies on radiation-induced diseases, studies on dose reduction methods for CT-based attenuation correction (CTAC), studies on dose reduction methods for CT localization, and studies on reducing the need for a full-dose diagnostic CT in PET/CT imaging. 58 peer-reviewed articles were selected and appraised and 29 articles were used to compose this literature review. Results: The published nuclear medicine and medical physics literature were reviewed. CT dose contributed 47% - 81% of the total effective dose of a standard PET/CT study and was associated with radiation-induced diseases. The dose reduction techniques were extracted and divided into three categories: reducing the CT dose for attenuation correction (AC) and localization, selectively localizing CT use, and reducing the need for a full-dose diagnostic CT. Conclusion: Three strategies have been demonstrated, with high potential for reducing patient dose while maintaining an adequate CT image quality, used for CTCA localization and diagnosis, respectively.展开更多
目的探讨256层螺旋CT高级迭代重组技术(iDose4)在低辐射剂量肺动脉成像应用中的价值。方法将需接受肺动脉CTA检查、身体质量指数(BMI)18.5~24.0的患者60例,随机分成常规组与低剂量组,每组各30例。常规组扫描管电压120 k V,管电流250 m ...目的探讨256层螺旋CT高级迭代重组技术(iDose4)在低辐射剂量肺动脉成像应用中的价值。方法将需接受肺动脉CTA检查、身体质量指数(BMI)18.5~24.0的患者60例,随机分成常规组与低剂量组,每组各30例。常规组扫描管电压120 k V,管电流250 m As,低剂量组扫描管电压80 k V,管电流100 m As,其余扫描参数两组一致。常规组用传统的滤波反投影重组算法(FBP),低剂量组采用迭代重组算法。由2名高级职称的放射科医师以统一标准对各组图像质量进行主观评价。测量、计算肺动脉CT值均数和对比噪声比(CNR)进行客观评价,并计算扫描的辐射剂量指标:平均容积CT辐射量指数(CTDIvol)、辐射量长度乘积(DLP)和有效辐射量(ED)。对两组图像质量主客观评价结果及辐射剂量进行统计学分析。结果两组图像质量主观评价比较无显著差异(P>0.05),常规组肺动脉CT值均数(388.43±35.27)HU,低剂量组肺动脉CT值均数(450.33±55.63)HU,差异具统计学意义(P<0.05);CNR分别是35.68±11.18、34.98±10.96,差异无统计学意义(P>0.05)。CTDIvol分别为16.90 m Gy、2.00 m Gy,DLP分别为(578.33±14.58)m Gy.cm、(93.77±5.92)m Gy.cm,ED分别为(8.10±0.20)m Sv、(1.31±0.08)m Sv,两组各辐射剂量指标的差异均有统计学意义(P<0.05)。结论 256层螺旋CT低剂量扫描结合迭代重建iDose4技术应用在肺动脉成像中,可保证图像质量同时大幅降低辐射剂量,值得临床推广应用。展开更多
目的探讨双源CT CARE Dose 4D(管电流调节技术)在儿童牙齿CT扫描中的运用价值。方法疑牙齿畸形行CT平扫及重建了解根尖情况的患儿70例,按时间先后分A、B两组,A组常规扫描(100kVp/150mAs),B组开启CARE Dose4D扫描(100kVp/参考电流150mAs)...目的探讨双源CT CARE Dose 4D(管电流调节技术)在儿童牙齿CT扫描中的运用价值。方法疑牙齿畸形行CT平扫及重建了解根尖情况的患儿70例,按时间先后分A、B两组,A组常规扫描(100kVp/150mAs),B组开启CARE Dose4D扫描(100kVp/参考电流150mAs),其余条件保持不变。比较A、B两组扫描方案的辐射剂量及所得图像的平均CT值、噪声、信号噪声比(SNR)、对比噪声比(CNR)、主观评分等。结果 A、B两组辐射剂量差异有统计学意义(t=-2.24,P=0.03)。与A组比较,B组有效剂量(ED)下降约23.15%;图像的平均CT值、噪声、SNR、CNR及主观评分比较差异无统计学意义(P>0.05)。结论应用双源CT CARE Dose 4D技术行儿童牙齿CT扫描,在降低辐射剂量的同时,不影响图像质量,值得临床推广。展开更多
文摘Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate image quality for PET/CT studies. Materials and Methods: Literature survey was initially based on the selection of keywords and years of publication to identify potentially relevant articles, then the further search was conducted on the authors and references from these articles. The abstract of each article was first appraised to decide whether the content was relevant to this research question. The articles were classified into five groups: studies on dosimetry, studies on radiation-induced diseases, studies on dose reduction methods for CT-based attenuation correction (CTAC), studies on dose reduction methods for CT localization, and studies on reducing the need for a full-dose diagnostic CT in PET/CT imaging. 58 peer-reviewed articles were selected and appraised and 29 articles were used to compose this literature review. Results: The published nuclear medicine and medical physics literature were reviewed. CT dose contributed 47% - 81% of the total effective dose of a standard PET/CT study and was associated with radiation-induced diseases. The dose reduction techniques were extracted and divided into three categories: reducing the CT dose for attenuation correction (AC) and localization, selectively localizing CT use, and reducing the need for a full-dose diagnostic CT. Conclusion: Three strategies have been demonstrated, with high potential for reducing patient dose while maintaining an adequate CT image quality, used for CTCA localization and diagnosis, respectively.
文摘目的:探讨在新生儿胸部CT检查中,结合使用低管电压、固定管电流以及不同权重的iDose4重建技术对图像质量的影响,并评估其可行性。方法:搜集80例行CT检查的新生儿,随机分到A、B两组,A组采用自动曝光控制技术,B组采用固定管电流扫描(33 mA),采用iDose^(4)重建法重建出1~7级不同权重的肺窗和纵隔窗图像,并对比分析图像质量。记录患儿的CTDIVOL,后依据回归模型计算出体型特异性剂量估算值(size specific dose estimate,SSDE),并对比分析。结果:A、B两组患儿iDose^(4)重建算法的最佳权重肺窗为3级,纵隔窗为4级;A、B组患儿CTDIVOL分别为(1.04±0.21)mGy和(0.91±0.18)mGy,A组较B组高12.5%(t=2.17,P=0.04);A、B组患儿的SSDE分别为(2.41±0.36)mGy和(2.07±0.32)mGy,A组较B组高15.4%(t=3.19,P<0.05);A、B组患儿CTDIVOL离散度分别为20.2%(0.21/1.04)和19.8%(0.18/0.91),A、B组患儿SSDE离散度分别为14.5%(0.36/2.41)和15.5%(0.32/2.07)。结论:在新生儿CT检查时推荐使用低管电压、低固定管电流及适当的重建算法权重相结合的方法进行扫描,同时,推荐采用SSDE评估新生儿的辐射剂量。
文摘目的探讨256层螺旋CT高级迭代重组技术(iDose4)在低辐射剂量肺动脉成像应用中的价值。方法将需接受肺动脉CTA检查、身体质量指数(BMI)18.5~24.0的患者60例,随机分成常规组与低剂量组,每组各30例。常规组扫描管电压120 k V,管电流250 m As,低剂量组扫描管电压80 k V,管电流100 m As,其余扫描参数两组一致。常规组用传统的滤波反投影重组算法(FBP),低剂量组采用迭代重组算法。由2名高级职称的放射科医师以统一标准对各组图像质量进行主观评价。测量、计算肺动脉CT值均数和对比噪声比(CNR)进行客观评价,并计算扫描的辐射剂量指标:平均容积CT辐射量指数(CTDIvol)、辐射量长度乘积(DLP)和有效辐射量(ED)。对两组图像质量主客观评价结果及辐射剂量进行统计学分析。结果两组图像质量主观评价比较无显著差异(P>0.05),常规组肺动脉CT值均数(388.43±35.27)HU,低剂量组肺动脉CT值均数(450.33±55.63)HU,差异具统计学意义(P<0.05);CNR分别是35.68±11.18、34.98±10.96,差异无统计学意义(P>0.05)。CTDIvol分别为16.90 m Gy、2.00 m Gy,DLP分别为(578.33±14.58)m Gy.cm、(93.77±5.92)m Gy.cm,ED分别为(8.10±0.20)m Sv、(1.31±0.08)m Sv,两组各辐射剂量指标的差异均有统计学意义(P<0.05)。结论 256层螺旋CT低剂量扫描结合迭代重建iDose4技术应用在肺动脉成像中,可保证图像质量同时大幅降低辐射剂量,值得临床推广应用。
文摘目的探讨双源CT CARE Dose 4D(管电流调节技术)在儿童牙齿CT扫描中的运用价值。方法疑牙齿畸形行CT平扫及重建了解根尖情况的患儿70例,按时间先后分A、B两组,A组常规扫描(100kVp/150mAs),B组开启CARE Dose4D扫描(100kVp/参考电流150mAs),其余条件保持不变。比较A、B两组扫描方案的辐射剂量及所得图像的平均CT值、噪声、信号噪声比(SNR)、对比噪声比(CNR)、主观评分等。结果 A、B两组辐射剂量差异有统计学意义(t=-2.24,P=0.03)。与A组比较,B组有效剂量(ED)下降约23.15%;图像的平均CT值、噪声、SNR、CNR及主观评分比较差异无统计学意义(P>0.05)。结论应用双源CT CARE Dose 4D技术行儿童牙齿CT扫描,在降低辐射剂量的同时,不影响图像质量,值得临床推广。
