AIM:To identify the clinicopathological risk factors correlated with residual tumor in hepatocellular carcinoma (HCC) patients after resection. METHODS:From January 2001 to April 2007,766 HCC patients who had undergon...AIM:To identify the clinicopathological risk factors correlated with residual tumor in hepatocellular carcinoma (HCC) patients after resection. METHODS:From January 2001 to April 2007,766 HCC patients who had undergone resection were included in this research. Lipiodol angiography was performed within 2 mo after surgery and followed by post-Lipiodol computed tomography (CT) 4 wk later for all 766 patients to monitor tumor in the remnant liver. Tumor detected within the first 3-mo postoperative period was defined as residual tumor. Patients were divided into 2 groups:disease or disease-free within the first 3 mo after surgery. Risk factors for residual tumor were investigated among various clinicopathological variables. RESULTS:A total of 63 (8.22%) patients were found to have residual tumor after surgery. Three independent factors associated with residual tumor were identified by multivariate analysis:preoperative serum α-fetoprotein (AFP) level [odds ratio (OR) = 1.68 (95% confidence interval (CI):1.20-2.36)],tumor size [OR = 1.73 (95% CI:1.29-2.31)] and microvascular invasion [OR = 1.91 (95% CI:1.12-3.24)]. CONCLUSION:Residual tumor is related to AFP level,tumor size and microvascular invasion. Patients at high risk should undergo closer follow-up and could be candidates for multimodality therapy.展开更多
A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavati...A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavation.The testing conditions are similar to those to be experienced by host rocks around disposal galleries for radioactive waste.X-ray computed tomography is performed at different steps for each test with the samples remaining inside the loading cell.Initial analysis of the tomography images allows of the observation of the deformation of the central hole.In addition,particles manual tracking and 3D volumetric digital image correlation processing methods are considered being used to analyze the particles displacements and the boundary deformation of the sample quantitatively.An unsymmetrical damaged zone is induced around the hole,with a reverse deformation trend being found at the boundary after unloading,which indicates that the significant anisotropic deformation of boom clay can be induced by mechanical unloading.展开更多
We compared DVHs （dose volume histograms） of two tangential irradiation techniques for whole breast RT （radiotherapy） CT （computed tomography） based 2D （two dimensional） technique with wedge filters and 3D CRT...We compared DVHs （dose volume histograms） of two tangential irradiation techniques for whole breast RT （radiotherapy） CT （computed tomography） based 2D （two dimensional） technique with wedge filters and 3D CRT （three dimensional conformal radiotherapy） with segmented fields. These two modalities are commonly used in external beam radiotherapy of breast cancer in Clinical Center Nis, Clinic of Oncology, Serbia. Therapy plans that employed two techniques were generated for eighteen patients. Dosimetric outcomes of each technique were investigated. The maximum dose of breast CTV was significantly reduced from 55.83 Gy for 2D to 54.1 Gy for 3D CRT. Also, the maximum dose of lung tissue decreased from 51.81 Gy for 2D to 49.61 Gy for 3D. The dose conformity and uniformity were much better with 3D CRT segmented field technique.展开更多
Objective： To investigate the biomechanical effect of different volume, distribution and leakage to adjacent disc of bone cement on the adjacent vertebral body by threedimensional osteoporosis finite element model of...Objective： To investigate the biomechanical effect of different volume, distribution and leakage to adjacent disc of bone cement on the adjacent vertebral body by threedimensional osteoporosis finite element model of lumbar. Methods ： L4-L5 motion segment data of the cadaver of an old man who had no abnormal findings on roentgenogrmns were obtained from computed tomography （CT） scans. Three-dimensional model of L4-L5 established with Mimics software, and finite element model of L4-L5 functional spinal unit （FSU） was established by Ansys 7. 0 software. The effect of different loading conditions and distribution of bone cement after vertebroplasty on the adjacent vertebral body was investigated. Results： This study presented a validated finite element model of L4-L5 FSU with a simulated vertebroplasty augmentation to predict stresses and strains of adjacent untreated vertebral bodies. The findings from this FSU study suggested the endplate and disc stress of the adjacent vertebral body was not influenced by filling volume of bone cement but unipedicle injection and leakage to the disc of bone cement could concentrate the stress of adjacent endplate. Conclusions： Asymmetric distributions and leakage of cement into intervertebral disc can improve the stress of endplate in adjacent vertebral body. These results suggest that optimal biomechaulcal configuration should have symmetric placement and avoid leakage of cement in operation.展开更多
Objective： To demonstrate the validity and reliability of volumetric quantitative computed tomography （vQCT） with multi-slice computed tomography （MSCT） and dual energy X-ray absorptiometry （DXA） for hip bone m...Objective： To demonstrate the validity and reliability of volumetric quantitative computed tomography （vQCT） with multi-slice computed tomography （MSCT） and dual energy X-ray absorptiometry （DXA） for hip bone mineral density （BMD） measurements, and to compare the differences between the two techniques in discriminating postmenopausal women with osteoporosis-related vertebral fractures from those without. Methods： Ninety subjects were enrolled and divided into three groups based on the BMD values of the lumbar spine and/or the femoral neck by DXA. Groups 1 and 2 consisted of postmenopausal women with BMD changes 〈-2SD, with and without radiographically confirmed vertebral fracture （n= 11 and 33, respectively）. Group 3 comprised normal controls with BMD changes 〉-ISD （n-46）. Post-MSCT （GE, LightSpeed16） scan reconstructed images of the abdominal-pelvic region, 1.25 mm thick per slice, were processed by OsteoCAD software to calculate the following parameters： volumetric BMD values of trabecular bone （TRAB）, cortical bone （CORT）, and integral bone （INTGL） of the left femoral neck, femoral neck axis length （NAL）, and minimum cross-section area （mCSA）. DXA BMD measurements of the lumbar spine （AP-SPINE） and the left femoral neck （NECK） also were performed for each subject. Results： The values of all seven parameters were significantly lower in subjects of Groups 1 and 2 than in normal postmenopausal women （P〈0.05, respectively）. Comparing Groups 1 and 2, 3D-TRAB and 3D-INTGL were significantly lower in postmenopausal women with vertebral fracture（s） [（109.8±9.61） and （243.3±33.0） mg/cm^3, respectively] than in those without [（148.9±7.47） and （285.4±17.8） mg/cm^3, respectively] （P〈0.05, respectively）, but no significant differences were evident in AP-SPINE or NECK BMD. Conclusion： the femoral neck-derived volumetric BMD parameters using vQCT appeared better than the DXA-derived ones in discriminating osteoporotic postmenopausal women with vertebral fractures from those without, vQCT might be useful to evaluate the effect of osteoporotic vertebral fracture status on changes in bone mass in the femoral neck.展开更多
文摘AIM:To identify the clinicopathological risk factors correlated with residual tumor in hepatocellular carcinoma (HCC) patients after resection. METHODS:From January 2001 to April 2007,766 HCC patients who had undergone resection were included in this research. Lipiodol angiography was performed within 2 mo after surgery and followed by post-Lipiodol computed tomography (CT) 4 wk later for all 766 patients to monitor tumor in the remnant liver. Tumor detected within the first 3-mo postoperative period was defined as residual tumor. Patients were divided into 2 groups:disease or disease-free within the first 3 mo after surgery. Risk factors for residual tumor were investigated among various clinicopathological variables. RESULTS:A total of 63 (8.22%) patients were found to have residual tumor after surgery. Three independent factors associated with residual tumor were identified by multivariate analysis:preoperative serum α-fetoprotein (AFP) level [odds ratio (OR) = 1.68 (95% confidence interval (CI):1.20-2.36)],tumor size [OR = 1.73 (95% CI:1.29-2.31)] and microvascular invasion [OR = 1.91 (95% CI:1.12-3.24)]. CONCLUSION:Residual tumor is related to AFP level,tumor size and microvascular invasion. Patients at high risk should undergo closer follow-up and could be candidates for multimodality therapy.
基金supported by Fundamental Research Funds for the Central Universities (No.FRF-TP-14-033A1)TIMODAZ project as part of the sixth EURATOM framework programme for nuclear research and training activities (2002–2006)The Department of Diagnostic and Interventional Radiology of the CHUV and the collaboration with Laboratoire 3S-R,Grenoble are gratefully acknowledged
文摘A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavation.The testing conditions are similar to those to be experienced by host rocks around disposal galleries for radioactive waste.X-ray computed tomography is performed at different steps for each test with the samples remaining inside the loading cell.Initial analysis of the tomography images allows of the observation of the deformation of the central hole.In addition,particles manual tracking and 3D volumetric digital image correlation processing methods are considered being used to analyze the particles displacements and the boundary deformation of the sample quantitatively.An unsymmetrical damaged zone is induced around the hole,with a reverse deformation trend being found at the boundary after unloading,which indicates that the significant anisotropic deformation of boom clay can be induced by mechanical unloading.
文摘We compared DVHs （dose volume histograms） of two tangential irradiation techniques for whole breast RT （radiotherapy） CT （computed tomography） based 2D （two dimensional） technique with wedge filters and 3D CRT （three dimensional conformal radiotherapy） with segmented fields. These two modalities are commonly used in external beam radiotherapy of breast cancer in Clinical Center Nis, Clinic of Oncology, Serbia. Therapy plans that employed two techniques were generated for eighteen patients. Dosimetric outcomes of each technique were investigated. The maximum dose of breast CTV was significantly reduced from 55.83 Gy for 2D to 54.1 Gy for 3D CRT. Also, the maximum dose of lung tissue decreased from 51.81 Gy for 2D to 49.61 Gy for 3D. The dose conformity and uniformity were much better with 3D CRT segmented field technique.
文摘Objective： To investigate the biomechanical effect of different volume, distribution and leakage to adjacent disc of bone cement on the adjacent vertebral body by threedimensional osteoporosis finite element model of lumbar. Methods ： L4-L5 motion segment data of the cadaver of an old man who had no abnormal findings on roentgenogrmns were obtained from computed tomography （CT） scans. Three-dimensional model of L4-L5 established with Mimics software, and finite element model of L4-L5 functional spinal unit （FSU） was established by Ansys 7. 0 software. The effect of different loading conditions and distribution of bone cement after vertebroplasty on the adjacent vertebral body was investigated. Results： This study presented a validated finite element model of L4-L5 FSU with a simulated vertebroplasty augmentation to predict stresses and strains of adjacent untreated vertebral bodies. The findings from this FSU study suggested the endplate and disc stress of the adjacent vertebral body was not influenced by filling volume of bone cement but unipedicle injection and leakage to the disc of bone cement could concentrate the stress of adjacent endplate. Conclusions： Asymmetric distributions and leakage of cement into intervertebral disc can improve the stress of endplate in adjacent vertebral body. These results suggest that optimal biomechaulcal configuration should have symmetric placement and avoid leakage of cement in operation.
文摘Objective： To demonstrate the validity and reliability of volumetric quantitative computed tomography （vQCT） with multi-slice computed tomography （MSCT） and dual energy X-ray absorptiometry （DXA） for hip bone mineral density （BMD） measurements, and to compare the differences between the two techniques in discriminating postmenopausal women with osteoporosis-related vertebral fractures from those without. Methods： Ninety subjects were enrolled and divided into three groups based on the BMD values of the lumbar spine and/or the femoral neck by DXA. Groups 1 and 2 consisted of postmenopausal women with BMD changes 〈-2SD, with and without radiographically confirmed vertebral fracture （n= 11 and 33, respectively）. Group 3 comprised normal controls with BMD changes 〉-ISD （n-46）. Post-MSCT （GE, LightSpeed16） scan reconstructed images of the abdominal-pelvic region, 1.25 mm thick per slice, were processed by OsteoCAD software to calculate the following parameters： volumetric BMD values of trabecular bone （TRAB）, cortical bone （CORT）, and integral bone （INTGL） of the left femoral neck, femoral neck axis length （NAL）, and minimum cross-section area （mCSA）. DXA BMD measurements of the lumbar spine （AP-SPINE） and the left femoral neck （NECK） also were performed for each subject. Results： The values of all seven parameters were significantly lower in subjects of Groups 1 and 2 than in normal postmenopausal women （P〈0.05, respectively）. Comparing Groups 1 and 2, 3D-TRAB and 3D-INTGL were significantly lower in postmenopausal women with vertebral fracture（s） [（109.8±9.61） and （243.3±33.0） mg/cm^3, respectively] than in those without [（148.9±7.47） and （285.4±17.8） mg/cm^3, respectively] （P〈0.05, respectively）, but no significant differences were evident in AP-SPINE or NECK BMD. Conclusion： the femoral neck-derived volumetric BMD parameters using vQCT appeared better than the DXA-derived ones in discriminating osteoporotic postmenopausal women with vertebral fractures from those without, vQCT might be useful to evaluate the effect of osteoporotic vertebral fracture status on changes in bone mass in the femoral neck.
