目的:比较锥形束CT剂量指数(cone-beam CT dose index,CBDI)法、国际原子能机构(International Atomic Energy Agency,IAEA)5号报告建议的方法(以下简称“IAEA”)和美国医学物理学会(American Association of Physicists in Medicine,AA...目的:比较锥形束CT剂量指数(cone-beam CT dose index,CBDI)法、国际原子能机构(International Atomic Energy Agency,IAEA)5号报告建议的方法(以下简称“IAEA”)和美国医学物理学会(American Association of Physicists in Medicine,AAPM)111工作组建议的方法(TG111)3种锥形束CT辐射剂量测量方法的结果并分析差异,为锥形束CT质量控制中辐射剂量测量方法的选择提供依据。方法:按照CBDI、IAEA、TG1113种CBCT辐射剂量测量方法,使用圆柱形有机玻璃(poly methyl methacrylate,PMMA)模体、0.6cc指形电离室或100 mm笔形电离室,测量Varian CBCT系统各种扫描协议(标准剂量头、低剂量头、高质量头、低剂量胸、盆腔)下的辐射剂量,并计算加权辐射剂量和归一化辐射剂量,最终分析比较各扫描协议不同方法的辐射剂量差异。结果:加权辐射剂量在所有的扫描协议中均表现为TG111方法的值最高、CBDI方法次之、IAEA方法最低;归一化辐射剂量的结果在各协议中差异均较小,最大差异在低剂量头协议中(TG111和IAEA的差异为1.45 mGy),最小差异在低剂量胸协议中(CBDI和IAEA的差异为0.06 mGy)。结论:TG111方法是用于Varian CBCT系统辐射剂量测量的首选方法,不推荐IAEA的方法用于该类设备的测量。展开更多
AIM: To evaluate the relationship between hepatic fat infiltration and abdominal fat volume by using computed tomography (CT).METHODS: Three hundred and six patients who visited our obesity clinic between November 200...AIM: To evaluate the relationship between hepatic fat infiltration and abdominal fat volume by using computed tomography (CT).METHODS: Three hundred and six patients who visited our obesity clinic between November 2007 and April 2008 underwent fat protocol CT scans.The age range of the patients was 19 to 79 years and the mean age was 49 years.The male to female ratio was 116:190.Liver and spleen attenuation measurements were taken with three regions of interests (ROIs) from the liver and two ROIs from the spleen.Hepatic attenuation indices (HAIs) were measured as follows: (1) hepatic parenchymal attenuation (CTLP);(2) liver to spleen attenuation ratio (LS ratio);and (3) difference between hepatic and splenic attenuation (LSdif).Abdominal fat volume was measured using a 3 mm slice CT scan starting at the level of the umbilicus and was automatically calculated by a workstation.Abdominal fat was classified into total fat (TF),visceral fat (VF),and subcutaneous fat (SF).We used a bivariate correlation method to assess the relationship between the three HAIs and TF,VF,and SF.RESULTS: There were significant negative correlations between CTLP,LS ratio,and LSdif with TF,VF,and SF,respectively.The CTLP showed a strong negative correlation with TF and VF (r = -0.415 and -0.434,respectively,P < 0.001).The correlation between CTLP and SF was less significant (r = -0.313,P < 0.001).CONCLUSION: Fatty infiltration of the liver was correlated with amount of abdominal fat and VF was more strongly associated with fatty liver than SF.展开更多
Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC).By providing the functional tumor microvasculatu...Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC).By providing the functional tumor microvasculature,it also helps the assessment of therapeutic response of anti-angiogenic drugs as it may reflect tumor angiogenesis.Perfusion CT has been applied in clinical practice to delineate inflammatory or neoplastic lymph nodes irrespective of their size,identify micro-metastases and to predict metastases in advance of their development.It is of increasing significance for preoperative adjuvant therapies and avoidance of unnecessary interventions.Despite controversies regarding the techniques employed,its validity and reproducibility,it can be advantageous in the management of CRCs in which the prognosis is dependent on preoperative staging.With recent advances in the perfusion CT techniques,and incorporation to other modalities like positron emission tomography,perfusion CT will be a novel tool in the overall management of CRCs.This article aims at reviewing the existing clinical applications and recent advances of perfusion CT with a reference to future development in the management of CRCs.展开更多
AIM： To introduce the combination method of radio- chemoembolization for the treatment of selected he- patic metastases. METHODS： Twenty patients with biopsy proven hepat- ic metastases were selected from those who ...AIM： To introduce the combination method of radio- chemoembolization for the treatment of selected he- patic metastases. METHODS： Twenty patients with biopsy proven hepat- ic metastases were selected from those who underwent transarterial radiochemoembolization, a novel combina- tion protocol, between .lanuary 2009 and July 2010. Patients had different sources of liver metastasis. The treatment included transarterial administration of three chemotherapeutic drugs （mitomycin, doxorubicin and cisplatin）, followed by embolization with large （50-150 μm） radioisotope particles of chromic 32R Multiphasic computer tomography or computer tomography stud- ies, with and without contrast medium injections, were performed for all patients for a short-term period before and after the treatment sessions. The short-term effec- tiveness of this procedure was evaluated by modified response evaluation criteria in solid tumors （mRECIST）, which also takes necrosis into account. The subjective percentage of necrosis was also assessed. The re- sponse evaluation methods were based on the changes in size, number, and the enhancement patterns of the lesions between the pre- and post-treatment imaging studies. RESULTS： Patients had liver metastasis from colorectal carcinomas, breast cancer, lung cancer and carcinoid tumors. The response rate based on the mRECIST criteria was 5% for complete response, 60% for par- tial response, 10% for stable disease, and 25% for progressive disease. Regarding the subjective necrosis percentage, 5% of patients had complete response, 50% had partial response, 25% had stable disease, and 20% had progressive disease. Based on traditional RECIST criteria, 3 patients （15%） had partial response, 13 patients （65%） had stable disease, and 4 patients （20%） had disease progression. In most patients, colorectal carcinoma was the source of metastasis （13 patients）. Based on the mRECIST criteria, 8 out of these 13 patients had partial responses, while one remained stable, and 5 showed progressive disease. We also had 5 cases of breast cancer metastasis which mostly remained stable （4 cases）, with only one partial response after the procedure. Six patients had bilobar involvement; three of them received two courses of radiochemoembolization. The follow up imaging study of these patients was performed after the second ses- sion. In the studied patients there was no evidence of extrahepatic occurrence, including pulmonary radioac- tive deposition, which was proven by Bremsstrahlung scintigraphy performed after the treatment sessions. For the short-term follow-ups for the 2 mo after the therapy, no treatment related death was reported. The mostly common side effect was post-embolization syndrome, presented as vomiting, abdominal pain, and fever. Nineteen （95%） patients experienced this syndrome in different severities. Two patient had asci- tes （with pleural effusion in one patient） not related to hepatic failure. Moreover, no cases of acute liver failure, hepatic infarction, hepatic abscess, biliary necrosis, tu- mor rupture, surgical cholecystitis, or non-targeted gut embolization were reported. Systemic toxicities such as alopecia, marrow suppression, renal toxicity, or cardiac failure did not occur in our study group. CONCLUSION： Radiochemoembolization is safe and effective for selected hepatic metastases in a short- term follow-up. Further studies are required to show the long-term effects and possible complications of this approach.展开更多
目的通过阶梯式扫描协议探寻头颈部CTA的优化扫描剂量。方法连续选择临床怀疑头颈部血管病变并行256层CTA检查的269例患者,从200 mA s原始条件开始,按检查时间顺序分别采用10 mA s阶梯式降低管电流量扫描至130 mA s共8组,分别测量并评...目的通过阶梯式扫描协议探寻头颈部CTA的优化扫描剂量。方法连续选择临床怀疑头颈部血管病变并行256层CTA检查的269例患者,从200 mA s原始条件开始,按检查时间顺序分别采用10 mA s阶梯式降低管电流量扫描至130 mA s共8组,分别测量并评估各组患者图像的背景软组织噪声(CT值的标准差)、目标血管的信噪比(SNR)、对比噪声比(CNR)、图像质量评分以及射线剂量指标[CT剂量指数(CTDI)、剂量长度乘积(DLP)、有效剂量(ED)]。采用统计学检验评价各组间的差异。结果实验总共历时8周,于130 mA s触发实验终止条件,并返回至140 mA s。随管电流阶梯式调整,辐射剂量线性下降,按周次顺序CTDI分别为13.50、12.84、12.18、11.49、10.80、10.12、9.44 mG y,有效剂量ED平均值分别为4.39、4.21、3.97、3.75、3.49、3.29、3.09 mS v。其中第7周140 mA s管电流量组的CTDI、DLP、ED平均值最低,分别为:CTDIVol 9.44 mG y,DLP 423.42 mG y/cm,ED 3.09mS v,较基础条件200 mA s相比,剂量降低比例达30%,各组患者射线剂量指标CTDI、DLP、ED之间的差异均有统计学意义(P<0.05);各组患者的目标血管SNR、血管-背景CNR之间的差异无统计学意义(P>0.05)。结论阶梯式参数优化方法可以科学、有效的摸索出扫描剂量与图像质量的最佳平衡点,优化现有设备的合理低剂量扫描;以本单位为例,256层CT头颈部血管成像检查,采用9.44 mG y扫描剂量(140 mA s管电流)既可满足临床诊断要求,又能降低受检群体接受的辐射剂量。展开更多
文摘目的:比较锥形束CT剂量指数(cone-beam CT dose index,CBDI)法、国际原子能机构(International Atomic Energy Agency,IAEA)5号报告建议的方法(以下简称“IAEA”)和美国医学物理学会(American Association of Physicists in Medicine,AAPM)111工作组建议的方法(TG111)3种锥形束CT辐射剂量测量方法的结果并分析差异,为锥形束CT质量控制中辐射剂量测量方法的选择提供依据。方法:按照CBDI、IAEA、TG1113种CBCT辐射剂量测量方法,使用圆柱形有机玻璃(poly methyl methacrylate,PMMA)模体、0.6cc指形电离室或100 mm笔形电离室,测量Varian CBCT系统各种扫描协议(标准剂量头、低剂量头、高质量头、低剂量胸、盆腔)下的辐射剂量,并计算加权辐射剂量和归一化辐射剂量,最终分析比较各扫描协议不同方法的辐射剂量差异。结果:加权辐射剂量在所有的扫描协议中均表现为TG111方法的值最高、CBDI方法次之、IAEA方法最低;归一化辐射剂量的结果在各协议中差异均较小,最大差异在低剂量头协议中(TG111和IAEA的差异为1.45 mGy),最小差异在低剂量胸协议中(CBDI和IAEA的差异为0.06 mGy)。结论:TG111方法是用于Varian CBCT系统辐射剂量测量的首选方法,不推荐IAEA的方法用于该类设备的测量。
文摘AIM: To evaluate the relationship between hepatic fat infiltration and abdominal fat volume by using computed tomography (CT).METHODS: Three hundred and six patients who visited our obesity clinic between November 2007 and April 2008 underwent fat protocol CT scans.The age range of the patients was 19 to 79 years and the mean age was 49 years.The male to female ratio was 116:190.Liver and spleen attenuation measurements were taken with three regions of interests (ROIs) from the liver and two ROIs from the spleen.Hepatic attenuation indices (HAIs) were measured as follows: (1) hepatic parenchymal attenuation (CTLP);(2) liver to spleen attenuation ratio (LS ratio);and (3) difference between hepatic and splenic attenuation (LSdif).Abdominal fat volume was measured using a 3 mm slice CT scan starting at the level of the umbilicus and was automatically calculated by a workstation.Abdominal fat was classified into total fat (TF),visceral fat (VF),and subcutaneous fat (SF).We used a bivariate correlation method to assess the relationship between the three HAIs and TF,VF,and SF.RESULTS: There were significant negative correlations between CTLP,LS ratio,and LSdif with TF,VF,and SF,respectively.The CTLP showed a strong negative correlation with TF and VF (r = -0.415 and -0.434,respectively,P < 0.001).The correlation between CTLP and SF was less significant (r = -0.313,P < 0.001).CONCLUSION: Fatty infiltration of the liver was correlated with amount of abdominal fat and VF was more strongly associated with fatty liver than SF.
文摘Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC).By providing the functional tumor microvasculature,it also helps the assessment of therapeutic response of anti-angiogenic drugs as it may reflect tumor angiogenesis.Perfusion CT has been applied in clinical practice to delineate inflammatory or neoplastic lymph nodes irrespective of their size,identify micro-metastases and to predict metastases in advance of their development.It is of increasing significance for preoperative adjuvant therapies and avoidance of unnecessary interventions.Despite controversies regarding the techniques employed,its validity and reproducibility,it can be advantageous in the management of CRCs in which the prognosis is dependent on preoperative staging.With recent advances in the perfusion CT techniques,and incorporation to other modalities like positron emission tomography,perfusion CT will be a novel tool in the overall management of CRCs.This article aims at reviewing the existing clinical applications and recent advances of perfusion CT with a reference to future development in the management of CRCs.
文摘AIM： To introduce the combination method of radio- chemoembolization for the treatment of selected he- patic metastases. METHODS： Twenty patients with biopsy proven hepat- ic metastases were selected from those who underwent transarterial radiochemoembolization, a novel combina- tion protocol, between .lanuary 2009 and July 2010. Patients had different sources of liver metastasis. The treatment included transarterial administration of three chemotherapeutic drugs （mitomycin, doxorubicin and cisplatin）, followed by embolization with large （50-150 μm） radioisotope particles of chromic 32R Multiphasic computer tomography or computer tomography stud- ies, with and without contrast medium injections, were performed for all patients for a short-term period before and after the treatment sessions. The short-term effec- tiveness of this procedure was evaluated by modified response evaluation criteria in solid tumors （mRECIST）, which also takes necrosis into account. The subjective percentage of necrosis was also assessed. The re- sponse evaluation methods were based on the changes in size, number, and the enhancement patterns of the lesions between the pre- and post-treatment imaging studies. RESULTS： Patients had liver metastasis from colorectal carcinomas, breast cancer, lung cancer and carcinoid tumors. The response rate based on the mRECIST criteria was 5% for complete response, 60% for par- tial response, 10% for stable disease, and 25% for progressive disease. Regarding the subjective necrosis percentage, 5% of patients had complete response, 50% had partial response, 25% had stable disease, and 20% had progressive disease. Based on traditional RECIST criteria, 3 patients （15%） had partial response, 13 patients （65%） had stable disease, and 4 patients （20%） had disease progression. In most patients, colorectal carcinoma was the source of metastasis （13 patients）. Based on the mRECIST criteria, 8 out of these 13 patients had partial responses, while one remained stable, and 5 showed progressive disease. We also had 5 cases of breast cancer metastasis which mostly remained stable （4 cases）, with only one partial response after the procedure. Six patients had bilobar involvement; three of them received two courses of radiochemoembolization. The follow up imaging study of these patients was performed after the second ses- sion. In the studied patients there was no evidence of extrahepatic occurrence, including pulmonary radioac- tive deposition, which was proven by Bremsstrahlung scintigraphy performed after the treatment sessions. For the short-term follow-ups for the 2 mo after the therapy, no treatment related death was reported. The mostly common side effect was post-embolization syndrome, presented as vomiting, abdominal pain, and fever. Nineteen （95%） patients experienced this syndrome in different severities. Two patient had asci- tes （with pleural effusion in one patient） not related to hepatic failure. Moreover, no cases of acute liver failure, hepatic infarction, hepatic abscess, biliary necrosis, tu- mor rupture, surgical cholecystitis, or non-targeted gut embolization were reported. Systemic toxicities such as alopecia, marrow suppression, renal toxicity, or cardiac failure did not occur in our study group. CONCLUSION： Radiochemoembolization is safe and effective for selected hepatic metastases in a short- term follow-up. Further studies are required to show the long-term effects and possible complications of this approach.
文摘目的通过阶梯式扫描协议探寻头颈部CTA的优化扫描剂量。方法连续选择临床怀疑头颈部血管病变并行256层CTA检查的269例患者,从200 mA s原始条件开始,按检查时间顺序分别采用10 mA s阶梯式降低管电流量扫描至130 mA s共8组,分别测量并评估各组患者图像的背景软组织噪声(CT值的标准差)、目标血管的信噪比(SNR)、对比噪声比(CNR)、图像质量评分以及射线剂量指标[CT剂量指数(CTDI)、剂量长度乘积(DLP)、有效剂量(ED)]。采用统计学检验评价各组间的差异。结果实验总共历时8周,于130 mA s触发实验终止条件,并返回至140 mA s。随管电流阶梯式调整,辐射剂量线性下降,按周次顺序CTDI分别为13.50、12.84、12.18、11.49、10.80、10.12、9.44 mG y,有效剂量ED平均值分别为4.39、4.21、3.97、3.75、3.49、3.29、3.09 mS v。其中第7周140 mA s管电流量组的CTDI、DLP、ED平均值最低,分别为:CTDIVol 9.44 mG y,DLP 423.42 mG y/cm,ED 3.09mS v,较基础条件200 mA s相比,剂量降低比例达30%,各组患者射线剂量指标CTDI、DLP、ED之间的差异均有统计学意义(P<0.05);各组患者的目标血管SNR、血管-背景CNR之间的差异无统计学意义(P>0.05)。结论阶梯式参数优化方法可以科学、有效的摸索出扫描剂量与图像质量的最佳平衡点,优化现有设备的合理低剂量扫描;以本单位为例,256层CT头颈部血管成像检查,采用9.44 mG y扫描剂量(140 mA s管电流)既可满足临床诊断要求,又能降低受检群体接受的辐射剂量。
