In some oilfields with 3D seismic data, the deeper structure cannot be observed due to poor quality deep seismic data. Layer stripping using both seismic and gravity data is a solution for this problem but it cannot g...In some oilfields with 3D seismic data, the deeper structure cannot be observed due to poor quality deep seismic data. Layer stripping using both seismic and gravity data is a solution for this problem but it cannot get satisfactory results because the horizontal variations in formation density are ignored. We present a variable-density formation separation technique to address this problem. Based on 3D seismic depth data and laterallyvariable density derived from 3D seismic velocity data, the upper formation gravity effect is calculated by forward modeling and removed from the Bouguer gravity. The formation-separated gravity anomaly with variable density is obtained, which mainly reflects the deeper geological structure. In block XX of North Africa, the shallow formations seismic data is excellent but the data at the top of basement is poor. The formation-separated gravity anomaly processed under the control of 3D seismic data fits well with the known seismic interpretation and wells. It makes the geological interpretation more reliable.展开更多
Objective:To clarify anatomy-related factors in the cervical spine with subsidence of titanium mesh cage (TMC) after one-level cervical corpectomy and fusion. The effect of the cervical posture, segmental curvature an...Objective:To clarify anatomy-related factors in the cervical spine with subsidence of titanium mesh cage (TMC) after one-level cervical corpectomy and fusion. The effect of the cervical posture, segmental curvature and endplate gradient on this postoperative phenomenon was evaluated. Methods: Between August 2003 and March 2006, a total of the 236 patients underwent one-level corpectomy and TMC fusion. Their radiological examinations were reviewed and clinical outcomes evaluated. Results: In the patients who were followed up for 12 months, TMC subsidence occurred in 54 (28.6%) cases. C6 corpectomy had a significant higher risk (26/60, 43.3%) for TMC subsidence, which was correlated with the variation of the gradient of the vertebral endplates against cervical levels. Although the clinical outcome was comparable with those in the literature, the patients may have subsidence-related problems such as neck-shoulder pain, neurological deterioration and instrumental failure. Conclusion: To decrease the incidence of subsidence, TMC design should be optimized to be in line with anatomic characteristics of the cervical spine.展开更多
AIM： To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers （EI-CRCs）, and to determine whether malignancy grade depends on size. METHODS： A total of 583 consecutiv...AIM： To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers （EI-CRCs）, and to determine whether malignancy grade depends on size. METHODS： A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size： small （≤10 ram） and large （〉10 ram）. Clinicopathological features, incidence of lymph node metastasis （LNM） and risk factors for LNM, such as depth of invasion, lymphovascular invasion （LVI） and poorly differentiated adenocarcinoma （PDA） were analyzed in all resected specimens. RESULTS： There were 120 （21%） small and 463 （79%） large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer （sin： 1〉1000 μm） in 90 （75%） cases, LVI in 26 （22%） cases, and PDA in 12 （10%） cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 （82%） cases, LVI in 125 （27%） cases, and PDA in 79 （17%） cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.CONCLUSION： Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.展开更多
AIM:To investigate the clinical features and survival of patients treated for cholangiocarcinoma in our institution and to analyze the factors affecting their survival.METHODS:This retrospective cohort study assessed ...AIM:To investigate the clinical features and survival of patients treated for cholangiocarcinoma in our institution and to analyze the factors affecting their survival.METHODS:This retrospective cohort study assessed patients diagnosed with cholangiocarcinoma between January 1997 and December 2007 at the University Malaya Medical Centre in Malaysia.The clinical data and associated outcomes were collected using a structured proforma.RESULTS:Of the 69 patients diagnosed with cholangiocarcinoma,38 (55%) were male;mean patient age was 61 years.Twelve patients (17%) had intrahepatic,38 (55%) had perihilar and 19 (28%) had distal tumors.Only 12 patients underwent curative surgery,including seven R0 resections.Only one patient died within 30 d after surgery.The overall median survival was 4 mo,whereas the median survival of R0 resected patients was 16 mo.The overall 1-,2-and 3-year cumulative survival rates were 67%,17% and 17%,respectively.Survival rates were significantly associated with curative resection (P=0.002),intrahepatic tumor (P=0.003),negative margin status (P=0.013),early tumor stage (P=0.016),higher tumor differentiation (P=0.032) and absence of jaundice (P=0.038).Multivariate analysis showed that tumor location was a significant independent predictor of patient survival.CONCLUSION:Curative,margin-negative resection of early stage,well-differentiated intrahepatic tumors is associated with improved patient survival.展开更多
文摘In some oilfields with 3D seismic data, the deeper structure cannot be observed due to poor quality deep seismic data. Layer stripping using both seismic and gravity data is a solution for this problem but it cannot get satisfactory results because the horizontal variations in formation density are ignored. We present a variable-density formation separation technique to address this problem. Based on 3D seismic depth data and laterallyvariable density derived from 3D seismic velocity data, the upper formation gravity effect is calculated by forward modeling and removed from the Bouguer gravity. The formation-separated gravity anomaly with variable density is obtained, which mainly reflects the deeper geological structure. In block XX of North Africa, the shallow formations seismic data is excellent but the data at the top of basement is poor. The formation-separated gravity anomaly processed under the control of 3D seismic data fits well with the known seismic interpretation and wells. It makes the geological interpretation more reliable.
文摘Objective:To clarify anatomy-related factors in the cervical spine with subsidence of titanium mesh cage (TMC) after one-level cervical corpectomy and fusion. The effect of the cervical posture, segmental curvature and endplate gradient on this postoperative phenomenon was evaluated. Methods: Between August 2003 and March 2006, a total of the 236 patients underwent one-level corpectomy and TMC fusion. Their radiological examinations were reviewed and clinical outcomes evaluated. Results: In the patients who were followed up for 12 months, TMC subsidence occurred in 54 (28.6%) cases. C6 corpectomy had a significant higher risk (26/60, 43.3%) for TMC subsidence, which was correlated with the variation of the gradient of the vertebral endplates against cervical levels. Although the clinical outcome was comparable with those in the literature, the patients may have subsidence-related problems such as neck-shoulder pain, neurological deterioration and instrumental failure. Conclusion: To decrease the incidence of subsidence, TMC design should be optimized to be in line with anatomic characteristics of the cervical spine.
文摘AIM： To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers （EI-CRCs）, and to determine whether malignancy grade depends on size. METHODS： A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size： small （≤10 ram） and large （〉10 ram）. Clinicopathological features, incidence of lymph node metastasis （LNM） and risk factors for LNM, such as depth of invasion, lymphovascular invasion （LVI） and poorly differentiated adenocarcinoma （PDA） were analyzed in all resected specimens. RESULTS： There were 120 （21%） small and 463 （79%） large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer （sin： 1〉1000 μm） in 90 （75%） cases, LVI in 26 （22%） cases, and PDA in 12 （10%） cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 （82%） cases, LVI in 125 （27%） cases, and PDA in 79 （17%） cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.CONCLUSION： Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.
文摘AIM:To investigate the clinical features and survival of patients treated for cholangiocarcinoma in our institution and to analyze the factors affecting their survival.METHODS:This retrospective cohort study assessed patients diagnosed with cholangiocarcinoma between January 1997 and December 2007 at the University Malaya Medical Centre in Malaysia.The clinical data and associated outcomes were collected using a structured proforma.RESULTS:Of the 69 patients diagnosed with cholangiocarcinoma,38 (55%) were male;mean patient age was 61 years.Twelve patients (17%) had intrahepatic,38 (55%) had perihilar and 19 (28%) had distal tumors.Only 12 patients underwent curative surgery,including seven R0 resections.Only one patient died within 30 d after surgery.The overall median survival was 4 mo,whereas the median survival of R0 resected patients was 16 mo.The overall 1-,2-and 3-year cumulative survival rates were 67%,17% and 17%,respectively.Survival rates were significantly associated with curative resection (P=0.002),intrahepatic tumor (P=0.003),negative margin status (P=0.013),early tumor stage (P=0.016),higher tumor differentiation (P=0.032) and absence of jaundice (P=0.038).Multivariate analysis showed that tumor location was a significant independent predictor of patient survival.CONCLUSION:Curative,margin-negative resection of early stage,well-differentiated intrahepatic tumors is associated with improved patient survival.
