Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acqu...Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv,P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.展开更多
The objective of this study was to provide the characteristics of hepatic computed tomography images and optimize their transition delay with a bolus-tracking technique for triple-phase hepatic computed tomography in ...The objective of this study was to provide the characteristics of hepatic computed tomography images and optimize their transition delay with a bolus-tracking technique for triple-phase hepatic computed tomography in cats.Dynamic triple-phase computed tomography was performed in nine healthy cats.The upper third of the liver was dynamically scanned every 0.5 s for 40 s.The time density curves of the aorta and hepatic parenchyma mean enhancement were analyzed.Triple-phase hepatic computed tomography was performed three times with a bolus trigger of 200 Hounsfield units of aortic enhancement.The transition delays of the arterial,portal,and hepatic parenchymal phases were respectively 0,5 and 60 s in the first scan;2,7 and 62 s in the second scan;and 4,9 and 64 s in the third scan.All computed tomography images were evaluated by a certificated radiologist.The arterial vessels and their main branches were well enhanced at a 2 s transition delay.The contrast of the portal vein to the liver parenchyma was most obvious at a 7 s transition delay.The mean enhancement of the hepatic parenchyma peaked at a 62 s transition delay,whereas the degree of enhancement of the hepatic vasculature decreased.In this study,the recommended transition delays for the arterial,portal,and hepatic parenchymal phases were 2 s,7 s and 62 s,respectively,after triggering at 200 Hounsfield units of aortic enhancement.This information may be helpful in diagnosing feline liver diseases and provides a key reference for the clinical implementation of CT.展开更多
基金Supported by the Ministry of Science and Technology of Inner Mongolia, China (20110504)
文摘Objective To investigate the feasibility of acquiring the similar homogeneous enhancement using bolus-tracking techniques with shortened respiratory time in prospectively electrocardiogram-gated high-pitch spiral acquisition mode (Flash mode) coronary computed tomography angiography (CCTA) compared with test bolus technique. Methods One hundred and eighty-four consecutive patients with mean heart rate ≤65 beats per minute undergoing CCTA were prospectively included in this study. The patients were randomly divided into two groups. Patients in the group A (n=92) instructed to shorten respiratory time received CCTA using bolus-tracking technique with high-pitch spiral acquisition mode (Flash mode), while those in the group B (n=92) underwent CCTA with test bolus technique. The attenuation in the ascending aorta, image noise, contrast-to-noise ratio and radiation doses of the two groups were assessed. Results There were no significant differences in the mean attenuation values in the ascending aorta (483.18±59.07 HU vs. 498.7±83.51 HU, P=0.183), image noise (21.4±4.5 HU vs. 20.9±4.3 HU, P=0.414), contrast-to-noise ratio (12.1±4.2 vs. 13.8±5.1, P=0.31) between the groups A and B. There were no significant differences in the radiation dose of dynamic monitoring scans (0.056±0.026 mSv vs. 0.062±0.018 mSv, P=0.068) and radiation dose of angiography (0.94±0.07 mSv vs. 0.96±0.15 mSv,P=0.926) between the two groups, while 15 mL less contrast material volume was administered in the group A than the group B. Conclusion Bolus-tracking technique with shortened time of respiratory in Flash mode of dual-source CT yields the similar homogeneous enhancement with less contrast material in comparison to the test bolus technique.
基金This study was supported by the National Natural Science Foundation of China(Nos:31802255,31972756 and 32072938).
文摘The objective of this study was to provide the characteristics of hepatic computed tomography images and optimize their transition delay with a bolus-tracking technique for triple-phase hepatic computed tomography in cats.Dynamic triple-phase computed tomography was performed in nine healthy cats.The upper third of the liver was dynamically scanned every 0.5 s for 40 s.The time density curves of the aorta and hepatic parenchyma mean enhancement were analyzed.Triple-phase hepatic computed tomography was performed three times with a bolus trigger of 200 Hounsfield units of aortic enhancement.The transition delays of the arterial,portal,and hepatic parenchymal phases were respectively 0,5 and 60 s in the first scan;2,7 and 62 s in the second scan;and 4,9 and 64 s in the third scan.All computed tomography images were evaluated by a certificated radiologist.The arterial vessels and their main branches were well enhanced at a 2 s transition delay.The contrast of the portal vein to the liver parenchyma was most obvious at a 7 s transition delay.The mean enhancement of the hepatic parenchyma peaked at a 62 s transition delay,whereas the degree of enhancement of the hepatic vasculature decreased.In this study,the recommended transition delays for the arterial,portal,and hepatic parenchymal phases were 2 s,7 s and 62 s,respectively,after triggering at 200 Hounsfield units of aortic enhancement.This information may be helpful in diagnosing feline liver diseases and provides a key reference for the clinical implementation of CT.
