目的探讨低管电压(80 k V)联合迭代重组技术在头颈部CT血管成像(CTA)扫描中对图像质量、辐射剂量的影响。方法将75例临床需要行头颈部CTA检查的患者随机编入A、B、C三组,每组25例。A组为常规剂量扫描,参数为120 k V、300 m As,经滤波反...目的探讨低管电压(80 k V)联合迭代重组技术在头颈部CT血管成像(CTA)扫描中对图像质量、辐射剂量的影响。方法将75例临床需要行头颈部CTA检查的患者随机编入A、B、C三组,每组25例。A组为常规剂量扫描,参数为120 k V、300 m As,经滤波反投影(FBP)重组;B、C组为低剂量扫描,管电流和管电压分别为120k V、180 m As,80 k V、180 m As,采用i Dose4迭代重组。对比分析CT图像质量,包括动脉强化值、对比噪声比(CNR)、图像质量评分及辐射剂量。计量资料采用配对t检验两两比较,图像质量评分采用非参数χ2检验进行统计分析。结果 (1)图像质量主观评分:A组3分1例,4分24例;B组3分2例,4分23例;C组3分5例,4分20例;统计学分析无差异(P﹥0.05)。(2)A、B两组主动脉弓、颈总动脉、颈内动脉及大脑中动脉的动脉强化CT值统计无明显差异(P﹥0.05);C组的CT动脉强化值高于A组(P<0.05)。(3)C组的背景噪声[(12.5±1.9)HU]高于A组[(9.0±1.6)HU](P<0.05);两组的CNR分别为(49.2±9.4)、(43.0±12.6),无统计学差异(P﹥0.05)。(4)A、B、C组的剂量长度乘积(DLP)分别为(925.1±48.5)、(571.4±24.2)、(164.1±7.0)m Gy·cm;辐射有效剂量(ED)分别为(2.87±0.15)、(1.77±0.08)、(0.51±0.02)m Sv,均有统计学意义(P<0.05),C组较A组辐射剂量明显降低,约82.3%。结论 256 CT头颈部CTA采用低管电压(80 k V)联合迭代重组技术能提供满足临床诊断要求的图像,同时明显降低辐射剂量。展开更多
On May 6, 2009, the X-ray imaging and biomedical application beamline(BL13W1) at Shanghai Synchrotron Radiation Facility(SSRF) officially opened to users, with 8–72.5 ke V X-rays. The experimental station is equipped...On May 6, 2009, the X-ray imaging and biomedical application beamline(BL13W1) at Shanghai Synchrotron Radiation Facility(SSRF) officially opened to users, with 8–72.5 ke V X-rays. The experimental station is equipped with four sets of X-ray CCD detectors of different pixel size(0.19–24 μm) for on-line phase-contrast imaging and micro-CT imaging with 0.8 μm spatial resolution and 1 ms temporal resolution. An in vivo microCT experiment for a living insect was realized in 4 s. An X-ray fluorescence detector is equipped for X-ray fluorescence mapping imaging and X-ray fluorescence micro-CT imaging with 50 μm spatial resolution. In order to meet different requirements from the users, several experimental methods, such as X-ray spiral micro-CT, Xray local micro-CT, X-ray fast micro-CT, X-ray grating-based differential micro-CT, X-ray fluorescence microCT and X-ray quantitative micro-CT have been developed, and nearly 60 papers related to those developments for this beamline have been published. Moreover, the beamline has realized the remote fast CT reconstruction,providing a great convenience for the users to process experimental data at their offices. As of August 2014,the beamline has offered the user beamtime of(23 145 h), from which 232 user papers have been published,including 151 SCI papers and 55 papers with SCI impact factor > 3. The quantity and quality of the user paper outcome keep a steady increase. Some typical user experimental results are introduced.展开更多
X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF ...X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline （BL13W1） are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.展开更多
文摘目的探讨低管电压(80 k V)联合迭代重组技术在头颈部CT血管成像(CTA)扫描中对图像质量、辐射剂量的影响。方法将75例临床需要行头颈部CTA检查的患者随机编入A、B、C三组,每组25例。A组为常规剂量扫描,参数为120 k V、300 m As,经滤波反投影(FBP)重组;B、C组为低剂量扫描,管电流和管电压分别为120k V、180 m As,80 k V、180 m As,采用i Dose4迭代重组。对比分析CT图像质量,包括动脉强化值、对比噪声比(CNR)、图像质量评分及辐射剂量。计量资料采用配对t检验两两比较,图像质量评分采用非参数χ2检验进行统计分析。结果 (1)图像质量主观评分:A组3分1例,4分24例;B组3分2例,4分23例;C组3分5例,4分20例;统计学分析无差异(P﹥0.05)。(2)A、B两组主动脉弓、颈总动脉、颈内动脉及大脑中动脉的动脉强化CT值统计无明显差异(P﹥0.05);C组的CT动脉强化值高于A组(P<0.05)。(3)C组的背景噪声[(12.5±1.9)HU]高于A组[(9.0±1.6)HU](P<0.05);两组的CNR分别为(49.2±9.4)、(43.0±12.6),无统计学差异(P﹥0.05)。(4)A、B、C组的剂量长度乘积(DLP)分别为(925.1±48.5)、(571.4±24.2)、(164.1±7.0)m Gy·cm;辐射有效剂量(ED)分别为(2.87±0.15)、(1.77±0.08)、(0.51±0.02)m Sv,均有统计学意义(P<0.05),C组较A组辐射剂量明显降低,约82.3%。结论 256 CT头颈部CTA采用低管电压(80 k V)联合迭代重组技术能提供满足临床诊断要求的图像,同时明显降低辐射剂量。
基金Supported by the National Natural Science Foundation of China(Nos.11475248 and 11105213)
文摘On May 6, 2009, the X-ray imaging and biomedical application beamline(BL13W1) at Shanghai Synchrotron Radiation Facility(SSRF) officially opened to users, with 8–72.5 ke V X-rays. The experimental station is equipped with four sets of X-ray CCD detectors of different pixel size(0.19–24 μm) for on-line phase-contrast imaging and micro-CT imaging with 0.8 μm spatial resolution and 1 ms temporal resolution. An in vivo microCT experiment for a living insect was realized in 4 s. An X-ray fluorescence detector is equipped for X-ray fluorescence mapping imaging and X-ray fluorescence micro-CT imaging with 50 μm spatial resolution. In order to meet different requirements from the users, several experimental methods, such as X-ray spiral micro-CT, Xray local micro-CT, X-ray fast micro-CT, X-ray grating-based differential micro-CT, X-ray fluorescence microCT and X-ray quantitative micro-CT have been developed, and nearly 60 papers related to those developments for this beamline have been published. Moreover, the beamline has realized the remote fast CT reconstruction,providing a great convenience for the users to process experimental data at their offices. As of August 2014,the beamline has offered the user beamtime of(23 145 h), from which 232 user papers have been published,including 151 SCI papers and 55 papers with SCI impact factor > 3. The quantity and quality of the user paper outcome keep a steady increase. Some typical user experimental results are introduced.
基金Supported by National Natural Science Foundation of China (10805071, 10705020)Major Research Plan of National Natural Science Foundation of China (2010CB834301)Chinese Academy of Sciences Key Project of International Co-operation(GJHZ09058)
文摘X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline （BL13W1） are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.
