Objective: To investigate the diagnostic value of multidetector spiral CT (MSCT) in acute thoracolumbar spinal fracture and fracture-dislocation. Methods: CT imaging files of 152 consecutive traumatic patients with th...Objective: To investigate the diagnostic value of multidetector spiral CT (MSCT) in acute thoracolumbar spinal fracture and fracture-dislocation. Methods: CT imaging files of 152 consecutive traumatic patients with thoracolumbar fractures were retrospectively reviewed. MSCT scannings were performed with a collimation of 3-5 mm and a pitch of (5.5). The postprocessing included sagittal and coronal multiplannar reconstruction, and 3-D reconstruction.Results: There were 88 cases of compression fracture, 54 cases of burst fracture and 10 cases of fracture-dislocation. Transverse images of MSCT could visualize all fractures directly and determine whether spinal canal was intact. Postprocessing image was helpful in depicting the displacement of fragment and orientation of dislocation.Conclusions: MSCT plays an important role in diagnosis and management of acute thoracolumbar spinal fracture and fracture-dislocation.展开更多
Rare event data is encountered when the events of interest occur with low frequency, and the estimators based on the cohort data only may be inefficient. However, when external information is available for the estimat...Rare event data is encountered when the events of interest occur with low frequency, and the estimators based on the cohort data only may be inefficient. However, when external information is available for the estimation, the estimators utilizing external information can be more efficient. In this paper, we propose a method to incorporate external information into the estimation of the baseline hazard function and improve efficiency for estimating the absolute risk under the additive hazards model. The resulting estimators are shown to be uniformly consistent and converge weakly to Gaussian processes. Simulation studies demonstrate that the proposed method is much more efficient. An application to a bone marrow transplant data set is provided.展开更多
Objective To assess the value of E/(e’×s)in estimating left ventricular diastolic dysfunction in patients with coronary heart disease by dual Doppler echocardiograph.Methods Seventy-seven consecutive coronary he...Objective To assess the value of E/(e’×s)in estimating left ventricular diastolic dysfunction in patients with coronary heart disease by dual Doppler echocardiograph.Methods Seventy-seven consecutive coronary heart disease patients with preserved systolic function underwent echocardiographic study were included.The E,e’and s were obtained by the dual Doppler echocardio-展开更多
文摘Objective: To investigate the diagnostic value of multidetector spiral CT (MSCT) in acute thoracolumbar spinal fracture and fracture-dislocation. Methods: CT imaging files of 152 consecutive traumatic patients with thoracolumbar fractures were retrospectively reviewed. MSCT scannings were performed with a collimation of 3-5 mm and a pitch of (5.5). The postprocessing included sagittal and coronal multiplannar reconstruction, and 3-D reconstruction.Results: There were 88 cases of compression fracture, 54 cases of burst fracture and 10 cases of fracture-dislocation. Transverse images of MSCT could visualize all fractures directly and determine whether spinal canal was intact. Postprocessing image was helpful in depicting the displacement of fragment and orientation of dislocation.Conclusions: MSCT plays an important role in diagnosis and management of acute thoracolumbar spinal fracture and fracture-dislocation.
基金partly supported by the National Natural Science Foundation of China(No.11690015,11301355,11671275,11771431 and 71501016)Key Laboratory of RCSDS,CAS(No.2008DP173182)+1 种基金Qin Xin Talents Cultivation Program(QXTCP B201705)Beijing Information Science&Technology University
文摘Rare event data is encountered when the events of interest occur with low frequency, and the estimators based on the cohort data only may be inefficient. However, when external information is available for the estimation, the estimators utilizing external information can be more efficient. In this paper, we propose a method to incorporate external information into the estimation of the baseline hazard function and improve efficiency for estimating the absolute risk under the additive hazards model. The resulting estimators are shown to be uniformly consistent and converge weakly to Gaussian processes. Simulation studies demonstrate that the proposed method is much more efficient. An application to a bone marrow transplant data set is provided.
文摘Objective To assess the value of E/(e’×s)in estimating left ventricular diastolic dysfunction in patients with coronary heart disease by dual Doppler echocardiograph.Methods Seventy-seven consecutive coronary heart disease patients with preserved systolic function underwent echocardiographic study were included.The E,e’and s were obtained by the dual Doppler echocardio-
