AIM： To retrospectively evaluate the effectiveness of impedance monitoring for predicting popping during radiofrequency ablation （RFA） using internally cooled electrodes. METHODS： We reviewed 140 patients （94 mal...AIM： To retrospectively evaluate the effectiveness of impedance monitoring for predicting popping during radiofrequency ablation （RFA） using internally cooled electrodes. METHODS： We reviewed 140 patients （94 males, 46 females; age range 73.0 ＋ 11.1 year） who underwent RFA between February 2006 and November 2008 with a modified protocol using a limited power delivery rather than a conventional one to avoid popping. All the patients provided their written informed consent, and the study was approved by the institutional review board. Intraprocedural impedances were measured for the study subjects, and the tumors were classified into three types according to the characteristics of their impedance curves： increasing, flat, or decreasing. The tumors were further sorted into seven subtypes （A-G） depending on the curvature of the impedance curve＇ s increase or decrease. Relative popping rates were determined for the three types and seven subtypes. A chi-square test was performed to estimate statistical significance.RESULTS： A total of 148 nodules treated by RFA were analyzed. The study samples included 132 nodules of hepatocellular carcinoma, 14 nodules of metastatic liver cancer, and two nodules of intrahepatic cholangio- carcinoma. The numbers of nodules with each imped- ance curve type were as follows： 37 increasing-type nodules, 43 fiat-type nodules, and 68 decreasing-type nodules. Popping occurrence rates were 24.3%, 46.5% and 64.7%, respectively. Flat-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules （P = 0.039）. Decreasing-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules （P 〈 0.0001）. No- tably, nodules that showed a sharp decrease in imped- ance in the latter ablation period （subtype E） exhibited a significantly higher rate of popping compared to other subtypes. CONCLUSION： Intraprocedural impedance monitoring can be a useful tool to predict the occurrence of pop- ping during liver tumor RFA performed with internally cooled electrodes.展开更多
This study utilizes daily Asian Precipitation–Highly-Resolved Observational Data Integration Towards Evaluation（APHRODITE）gridded rainfall and the U.S.National Centers for Environmental PredictionDepartment of Ener...This study utilizes daily Asian Precipitation–Highly-Resolved Observational Data Integration Towards Evaluation（APHRODITE）gridded rainfall and the U.S.National Centers for Environmental PredictionDepartment of Energy reanalysis II products to examine the intraseasonal oscillations（ISOs）of rainfall over Eastern China during each summer of 1996,2002,and 2006.These three cases represent three typical spatial patterns of intraseasonal rainfall anomalies over Eastern China,with the strongest intraseasonal rainfall occurring over the middle and lower Yangtze Basin,southern Yangtze Basin,and Southeast China,respectively.The intraseasonal rainfall anomalies over Eastern China are dominated by both 30–60-and 10–20-day ISOs in each summer and are further modulated by the boreal summer ISOs（BSISOs）over the entire Asian summer monsoon region.The objective of this study is thus to apply the Bayesian wavelet-banding（WB）scheme to predicting intraseasonal rainfall over Eastern China.Several key factors associated with BSISOs are selected as predictors to experimentally develop a 15-day-lead statistical forecast.The forecast results show promise for the intraseasonal rainfall anomalies over Eastern China.Correlations generally greater than or equal to 0.6 are noted between the observed and predicted ISOs of rainfall over the major intraseasonal activity centers during each of the three summers.Such a high forecasting skill on intraseasonal timescales over various areas in Eastern China demonstrates the general usefulness of the WB scheme.展开更多
文摘AIM： To retrospectively evaluate the effectiveness of impedance monitoring for predicting popping during radiofrequency ablation （RFA） using internally cooled electrodes. METHODS： We reviewed 140 patients （94 males, 46 females; age range 73.0 ＋ 11.1 year） who underwent RFA between February 2006 and November 2008 with a modified protocol using a limited power delivery rather than a conventional one to avoid popping. All the patients provided their written informed consent, and the study was approved by the institutional review board. Intraprocedural impedances were measured for the study subjects, and the tumors were classified into three types according to the characteristics of their impedance curves： increasing, flat, or decreasing. The tumors were further sorted into seven subtypes （A-G） depending on the curvature of the impedance curve＇ s increase or decrease. Relative popping rates were determined for the three types and seven subtypes. A chi-square test was performed to estimate statistical significance.RESULTS： A total of 148 nodules treated by RFA were analyzed. The study samples included 132 nodules of hepatocellular carcinoma, 14 nodules of metastatic liver cancer, and two nodules of intrahepatic cholangio- carcinoma. The numbers of nodules with each imped- ance curve type were as follows： 37 increasing-type nodules, 43 fiat-type nodules, and 68 decreasing-type nodules. Popping occurrence rates were 24.3%, 46.5% and 64.7%, respectively. Flat-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules （P = 0.039）. Decreasing-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules （P 〈 0.0001）. No- tably, nodules that showed a sharp decrease in imped- ance in the latter ablation period （subtype E） exhibited a significantly higher rate of popping compared to other subtypes. CONCLUSION： Intraprocedural impedance monitoring can be a useful tool to predict the occurrence of pop- ping during liver tumor RFA performed with internally cooled electrodes.
基金jointly supported by the National Basic Research Program of China[grant numbers 2014CB953902,2012CB417203,and 2012CB955202]the Priority Research Program of the Chinese Academy of Sciences[grant number XDA11010402]+2 种基金the National Natural Science Foundation of China[grant numbers 4117505941375087and 91537103]
文摘This study utilizes daily Asian Precipitation–Highly-Resolved Observational Data Integration Towards Evaluation（APHRODITE）gridded rainfall and the U.S.National Centers for Environmental PredictionDepartment of Energy reanalysis II products to examine the intraseasonal oscillations（ISOs）of rainfall over Eastern China during each summer of 1996,2002,and 2006.These three cases represent three typical spatial patterns of intraseasonal rainfall anomalies over Eastern China,with the strongest intraseasonal rainfall occurring over the middle and lower Yangtze Basin,southern Yangtze Basin,and Southeast China,respectively.The intraseasonal rainfall anomalies over Eastern China are dominated by both 30–60-and 10–20-day ISOs in each summer and are further modulated by the boreal summer ISOs（BSISOs）over the entire Asian summer monsoon region.The objective of this study is thus to apply the Bayesian wavelet-banding（WB）scheme to predicting intraseasonal rainfall over Eastern China.Several key factors associated with BSISOs are selected as predictors to experimentally develop a 15-day-lead statistical forecast.The forecast results show promise for the intraseasonal rainfall anomalies over Eastern China.Correlations generally greater than or equal to 0.6 are noted between the observed and predicted ISOs of rainfall over the major intraseasonal activity centers during each of the three summers.Such a high forecasting skill on intraseasonal timescales over various areas in Eastern China demonstrates the general usefulness of the WB scheme.
