BACKGROUND:Short-segment pedicle screw technology has been extensively used in the treatment and repair of thoracolumbar burst fractures in the clinic. However, it requires further investigations whether bone graft through unilateral pedicle channel has superiority. ＜br> OBJECTIVE:To observe the perioperative effects on thoracolumbar burst fractures posterior by bone graft through unilateral pedicle channel with short pedicle screw segment fixation. ＜br> METHODS:Clinical data of 57 cases of thoracolumbar burst fractures without neurological symptoms treated by short segment pedicle screw internal fixation therapeutic method at the Department of Orthopedics, The First People’s Hospital of Yinchuan City from January 2009 to December 2013 were retrospectively analyzed. According to therapeutic methods, they were divided into three groups:pedicle screw fixation through injured vertebrae (n=21), unilateral pedicle screw fixation with vertebrae pedicle screw (n=19), and the short segment pedicle screw fixation with unilateral pedicle screw fixation and bone graft through pedicle channel (n=17). We observed the changes in operation time, the blood loss volume in operation, postoperative drainage blood (at the period of removing the drainage tube), injured vertebrae height’s ratio, the Cobb’s angel of injured vertebrae sagittal plane, vertebral canal encroachment rate and visual analog scale. ＜br> RESULTS AND CONCLUSION:(1) The unilateral pedicle screw fixation and bone graft by pedicle channel could prolong operation time and increase postoperative drainage blood volume (P＜0.05). (2) Three operation methods improved vertebral body height. (3)There were no significant differences in Cobb’s angle postoperation among the three groups (P>0.05). These data suggested that the bone graft through pedicle channel was not the factors to improve the spine kyphosis. (4) Bone graft by pedical channel improved vertebrae channel value. (5) Bone graft through pedicle channel combined with screw implantation could improve pain after treatment. These findings indicated that the therapeutic technology of short pedicle screw fixation on thoracolumbar vertebral burst fracture with unilateral pedicle fixation and bone graft through pedicle channel is a safe reliable operation method.

This research work was aimed to improve the performance of magnetic induction tomography (MIT) system by designing a high-performance excitation source and the optimal excitation coil. A new type excitation source with adjustable output was designed, and then the power circuit was simulated by the software ICPA. Focused and solenoid coils were designed in accordance with the design principle of coil, then the optimal excitation coil was proved by measuring the magnetic field distribution and the experimentation of phase detection using neuron cell models. At the stated excitation frequency, the parameters of the excitation source are output power 0.035 W-31.4 W, steady output peak current over 1 A, frequency stability 10(-9), and THD amplitude less than -51dB. When compared with other coils, the focused discal excitation coil is most effective for phase detection with the use of neuron cell models. The excitation source can produce the stated frequency sine wave with higher frequency stability, lower THD and wider adjustable output power. The phase difference between normal cell model and edema cell model was more significant by measurement using focused discal coil.
Brain ; physiology ; Electronics, Medical ; instrumentation ; Equipment Design ; Humans ; Image Processing, Computer-Assisted ; Magnetics ; instrumentation ; Tomography ; methods

OBJECTIVE: To explore the high-risk fault risk of CT simulator and the main causes of the risk, and to put forward effective risk management strategies. METHODS: The failure mode and effect analysis method was used to identify and control the operational fault risk of CT simulator. RESULTS: 5 major fault components, 8 fault failure models and 17 failure causes were analyzed. The top 5 failure causes are:anode target surface burn caused by direct scanning without warming up the tube (590.4), tube failure (518.2), burnout of joints caused by aging of high voltage cables (424.2), motor carbon brush wear (304.8) and belt break (296.4). CONCLUSIONS The failure mode and effect analysis method can effectively identify the risk of equipment failure, and thus specifically formulate risk management and control measures to ensure the normal operation of equipment and the safety of doctors and patients.
Equipment Failure ; statistics & numerical data ; Humans ; Risk Management ; methods ; Tomography, X-Ray Computed ; standards

OBJECTIVE: To establish a set of evaluation system of digital radiography clinical value and provide foundation for the maturity assessment of digital radiography. METHODS: The evaluation system of clinical value of digital radiography was established by literature survey,expert consultation,and percentage weight method. RESULTS: The expert authority coefficients were 0.81 and 0.88,respectively.After two rounds of consultation,variation coefficients of each item ranged from 0 to 0.207,and the coefficient coordination were 0.599.The index system consisted of 5 first-level indexes and 12 second-level indexes.The weights of first-level indexes such as image quality,safety,usability,economic and social indicators share of the weight are 0.298,0.294,0.199,0.121 and 0.088 respectively. CONCLUSIONS A completed and scientific evaluation system was established,which provides a scientific assessment tool for clinical value of digital radiography.
Delphi Technique ; Radiographic Image Enhancement ; standards

OBJECTIVE: To explore the application value of MAR algorithm in metal artifact removal of CT simulator. METHODS: CT phantom with titanium plate was scanned using conventional algorithms and MAR algorithms, respectively. Artifact index(AI), contrast-to-noise ratio(CNR) and AI values at different slices were used to analyze the artifact images. RESULTS: In artifact index, MAR algorithm (10.28±2.60) is significantly lower than conventional algorithm (20.65±5.04); In contrast-to-noise ratio index, MAR algorithm (7.81±1.12) is better than conventional algorithm (5.61±1.36). The above indicators were statistically significant in both algorithms (P<0.01). In the slices affected by metal artifacts, the artifact index decreased by 21.72%~88.40% after the MAR algorithm. CONCLUSIONS MAR algorithm can significantly reduce the metal artifacts and improve the clinical value of CT data.
Algorithms ; Artifacts ; Metals ; Phantoms, Imaging ; Titanium ; Tomography, X-Ray Computed