AIM:To investigate the value of C-arm Lipiodol computed tomography(CT) for intra-procedural hepatocellular carcinoma(HCC) lesion detection during transcatheter arterial chemoembolization(TACE).METHODS:Forty patients(3...AIM:To investigate the value of C-arm Lipiodol computed tomography(CT) for intra-procedural hepatocellular carcinoma(HCC) lesion detection during transcatheter arterial chemoembolization(TACE).METHODS:Forty patients(37 male,3 female;mean age,52.6 ± 12.5 years,age range:25-82 years) diagnosed with HCC were enrolled in this study.All patients underwent 64-slice CT 1-2 wk before TACE.During the procedure,hepatic angiography was performed first.Following diagnostic embolization with Lipiodol injected into the hepatic artery,a C-arm CT scan was immediately conducted(C-arm Lipiodol CT).If new HCC lesions were confirmed,gelfoam particles were super-selectively injected into the tumor-nourishing blood vessel.A Lipiodol CT scan was performed 7-14 d after TACE.All images acquired from 64-slice CT,digital subtraction angiography(DSA),C-arm Lipiodol CT and Lipiodol CT were retrospectively reviewed by four radiologists and the number of detected lesions in each examination was counted,respectively.The results of Lipiodol CT were taken as the diagnostic reference.Alpha-fetoprotein values were examined both before and after TACE.This study only takes into account the lesions that were not found or were considered suspicious on 64-slice CT before TACE.RESULTS:Preprocedural 64-slice CT detected a total of 13 suspicious lesions in the 40 patients.DSA detected ten definite and four suspicious lesions.C-arm Lipiodol CT detected 71 lesions in total and Lipiodol CT confirmed 67 lesions with a diameter range of 3-12 mm.Four false-positive lesions,which were detected by C-arm Lipiodol CT,were considered to be hepatic artery-portal vein fistulas.The average alpha-fetoprotein values before and after TACE were significantly different(452.3 ± 192.6 ng/m L vs 223.8 ± 93.2 ng/m L;P = 0.039).CONCLUSION:C-arm Lipiodol CT has a higher diagnostic sensitivity for small HCC lesions.This technique may help physicians make intraproceduraldecisions to provide patients with earlier treatment.展开更多
Modern medicine is unthinkable without X-rays. Accurate diagnosis, leading to effective treatment, is largely based on precise X-ray examinations. The creation of new, modern equipment and various medical procedures t...Modern medicine is unthinkable without X-rays. Accurate diagnosis, leading to effective treatment, is largely based on precise X-ray examinations. The creation of new, modern equipment and various medical procedures that meet the increased requirements are a priority in our time. X-ray examinations are of particular importance for the orthopedic and traumatological clinics, where they provide information about presence of a fracture in the patient’s body, about the concrete operation performed or about the effect of a suitable treatment. Along with their benefits X-rays have also a harmful effect. This requires special care to protect from this radiation. In this direction, research is constantly being done to improve the quality of radiation protection. Park MR, Lee KM and co-authors, compare the dose load obtained using C-arm and O-arm X-ray systems (which have the capability of combined 2D fluoroscopy and 3D computed tomography imaging). In their study, an orthopedic surgical procedure using C-arm and O-arm systems in 2D fluoroscopy modes was simulated. The radiation doses to susceptible organs of the operators were investigated. He results obtained show that the O-arm system delivered higher doses to the sensitive organs of the operator in all configurations [1]. The article of Stephen Balte briefly reviews the available technologies for measuring or estimation of patient skin dose in the interventional fluoroscopic environment, created by various X-ray equipment including C-arm systems. Given that many patients require multiple procedures, this documentation also aids in the planning of follow up visits [2]. Chong Hing Wong, Yoshihisa Kotani and co-authors evaluate the radiation exposures (RE) to the patient and surgeon during minimally invasive lumbar spine surgery with instrumentation using C-arm image intensifier or O-arm intraoperative CT. The results they get are in favor of the O-arm system [3]. The article “Virtual fluoroscopy for intraoperative C-arm positioning and radiation dose reduction” discusses positioning of an intraoperative C-arm system to achieve clear visualization of a particular anatomical feature by a system for virtual fluoroscopy (called FluoroSim) that could dramatically reduce time and received dose during the procedures. FluoroSim was found to reduce the radiation exposure required for C-arm positioning without reducing positioning time or accuracy, providing a potentially valuable tool to assist surgeons [4]. In our study, we performed practical measurements to show how the patient can be treated by applying most effective radiation protection when using a mobile C-arm X-ray system. For the study, we used exposure upon a phantom placed on the patient’s table. For an X-ray shielding, we used a protective apron with a lead equivalent of 1 mm, placed in two layers on the phantom. In each subsequent series of exposures, the protective apron was placed on the phantom, in a different position relative to the X-ray beam. The general conclusion of our study is that in order to obtain maximum protection from scattered radiation when using C-arm X-ray systems, the patient must be protected by a shielding with a suitable lead equivalent for the procedure performed which must be placed between patient’s body and X-ray tube, perpendicular to the X-ray beam pointed toward the region of interest.展开更多
For a 3D C-arm computed tomography(CT) system, actual path of the scanner may deviate from the idea circle geometry because of mechanicalinstability,leading to perturbation artifacts in reconstructed images. In this p...For a 3D C-arm computed tomography(CT) system, actual path of the scanner may deviate from the idea circle geometry because of mechanicalinstability,leading to perturbation artifacts in reconstructed images. In this paper, we proposed a modified FBP method for the perturbed trajectories taking into account 6 perturbation parameters without tassuming any condition to be ideal. The preliminary studies demonstrated that this algorithm can acquire promising reconstruction image quality even when the perturbations are relatively large. The comparison of performances among different perturbation parameters is useful for constructing a C-arm CT system.展开更多
基金Supported by Funding from the Chinese Ministry of Science and Technology,No.2012BAI15B08International Cooperation Projects of the Ministry of Science and Technology,No.2012DFA30850
文摘AIM:To investigate the value of C-arm Lipiodol computed tomography(CT) for intra-procedural hepatocellular carcinoma(HCC) lesion detection during transcatheter arterial chemoembolization(TACE).METHODS:Forty patients(37 male,3 female;mean age,52.6 ± 12.5 years,age range:25-82 years) diagnosed with HCC were enrolled in this study.All patients underwent 64-slice CT 1-2 wk before TACE.During the procedure,hepatic angiography was performed first.Following diagnostic embolization with Lipiodol injected into the hepatic artery,a C-arm CT scan was immediately conducted(C-arm Lipiodol CT).If new HCC lesions were confirmed,gelfoam particles were super-selectively injected into the tumor-nourishing blood vessel.A Lipiodol CT scan was performed 7-14 d after TACE.All images acquired from 64-slice CT,digital subtraction angiography(DSA),C-arm Lipiodol CT and Lipiodol CT were retrospectively reviewed by four radiologists and the number of detected lesions in each examination was counted,respectively.The results of Lipiodol CT were taken as the diagnostic reference.Alpha-fetoprotein values were examined both before and after TACE.This study only takes into account the lesions that were not found or were considered suspicious on 64-slice CT before TACE.RESULTS:Preprocedural 64-slice CT detected a total of 13 suspicious lesions in the 40 patients.DSA detected ten definite and four suspicious lesions.C-arm Lipiodol CT detected 71 lesions in total and Lipiodol CT confirmed 67 lesions with a diameter range of 3-12 mm.Four false-positive lesions,which were detected by C-arm Lipiodol CT,were considered to be hepatic artery-portal vein fistulas.The average alpha-fetoprotein values before and after TACE were significantly different(452.3 ± 192.6 ng/m L vs 223.8 ± 93.2 ng/m L;P = 0.039).CONCLUSION:C-arm Lipiodol CT has a higher diagnostic sensitivity for small HCC lesions.This technique may help physicians make intraproceduraldecisions to provide patients with earlier treatment.
文摘Modern medicine is unthinkable without X-rays. Accurate diagnosis, leading to effective treatment, is largely based on precise X-ray examinations. The creation of new, modern equipment and various medical procedures that meet the increased requirements are a priority in our time. X-ray examinations are of particular importance for the orthopedic and traumatological clinics, where they provide information about presence of a fracture in the patient’s body, about the concrete operation performed or about the effect of a suitable treatment. Along with their benefits X-rays have also a harmful effect. This requires special care to protect from this radiation. In this direction, research is constantly being done to improve the quality of radiation protection. Park MR, Lee KM and co-authors, compare the dose load obtained using C-arm and O-arm X-ray systems (which have the capability of combined 2D fluoroscopy and 3D computed tomography imaging). In their study, an orthopedic surgical procedure using C-arm and O-arm systems in 2D fluoroscopy modes was simulated. The radiation doses to susceptible organs of the operators were investigated. He results obtained show that the O-arm system delivered higher doses to the sensitive organs of the operator in all configurations [1]. The article of Stephen Balte briefly reviews the available technologies for measuring or estimation of patient skin dose in the interventional fluoroscopic environment, created by various X-ray equipment including C-arm systems. Given that many patients require multiple procedures, this documentation also aids in the planning of follow up visits [2]. Chong Hing Wong, Yoshihisa Kotani and co-authors evaluate the radiation exposures (RE) to the patient and surgeon during minimally invasive lumbar spine surgery with instrumentation using C-arm image intensifier or O-arm intraoperative CT. The results they get are in favor of the O-arm system [3]. The article “Virtual fluoroscopy for intraoperative C-arm positioning and radiation dose reduction” discusses positioning of an intraoperative C-arm system to achieve clear visualization of a particular anatomical feature by a system for virtual fluoroscopy (called FluoroSim) that could dramatically reduce time and received dose during the procedures. FluoroSim was found to reduce the radiation exposure required for C-arm positioning without reducing positioning time or accuracy, providing a potentially valuable tool to assist surgeons [4]. In our study, we performed practical measurements to show how the patient can be treated by applying most effective radiation protection when using a mobile C-arm X-ray system. For the study, we used exposure upon a phantom placed on the patient’s table. For an X-ray shielding, we used a protective apron with a lead equivalent of 1 mm, placed in two layers on the phantom. In each subsequent series of exposures, the protective apron was placed on the phantom, in a different position relative to the X-ray beam. The general conclusion of our study is that in order to obtain maximum protection from scattered radiation when using C-arm X-ray systems, the patient must be protected by a shielding with a suitable lead equivalent for the procedure performed which must be placed between patient’s body and X-ray tube, perpendicular to the X-ray beam pointed toward the region of interest.
基金Doctoral Program of Higher Education of Chinagrant number:20093218110024+1 种基金International Science and Technology Cooperation Grantgrant number:BZ2008060
文摘For a 3D C-arm computed tomography(CT) system, actual path of the scanner may deviate from the idea circle geometry because of mechanicalinstability,leading to perturbation artifacts in reconstructed images. In this paper, we proposed a modified FBP method for the perturbed trajectories taking into account 6 perturbation parameters without tassuming any condition to be ideal. The preliminary studies demonstrated that this algorithm can acquire promising reconstruction image quality even when the perturbations are relatively large. The comparison of performances among different perturbation parameters is useful for constructing a C-arm CT system.
