Objective To investigate the value of prone-position MRI of lumbar spine for diagnosing pediatric occult tethered cord syndrome(OTCS).Methods A total of 67 children with suspected tethered cord syndrome(TCS)and confirmed OTCS by surgery were prospectively enrolled as OTCS group,while 73 healthy subjects were recruited as control group.Supine-and prone-position lumbar MR examinations were performed in both groups.The position of filum terminale on prone axial T2WI and the presence or absence of"sunset sign"(i.e.filum terminale located within the dorsal 1/2 of spinal canal on prone axial T2WI)were observed,spinal cord conus mobility was calculated.The efficacy of"sunset sign"for diagnosing OTCS in children was calculated through comparison between groups.Receiver operating characteristic curve was drawn,the area under the curve(AUC)was calculated to evaluate the diagnostic efficacy of spinal cord conus mobility.Results On prone-position axial T2WI,"sunset sign"was found in 58 cases(58/67,86.57％)but not in 9 cases(9/67,13.43％)in OTCS group,which was not even observed in control group.The sensitivity of"sunset sign"for diagnosing pediatric OTCS was 86.57％(58/67),with specificity of 100％(73/73),positive predictive value of 100％(58/58)and negative predictive value of 89.02％(73/82).The spinal cord conus mobility was(19.30±5.89)％in OTCS group and(31.71±6.58)％in control group,being statistically different between groups(t=-11.722,P＜0.001).The sensitivity,specificity and AUC of spinal cord conus mobility for diagnosing pediatric OTCS was 80.60％,90.41％and 0.920,respectively.Conclusion Prone-position MRI of lumbar spine could be used in diagnosing pediatric OTCS.

Objective To investigate the value of prone-position MRI of lumbar spine for diagnosing pediatric occult tethered cord syndrome(OTCS).Methods A total of 67 children with suspected tethered cord syndrome(TCS)and confirmed OTCS by surgery were prospectively enrolled as OTCS group,while 73 healthy subjects were recruited as control group.Supine-and prone-position lumbar MR examinations were performed in both groups.The position of filum terminale on prone axial T2WI and the presence or absence of"sunset sign"(i.e.filum terminale located within the dorsal 1/2 of spinal canal on prone axial T2WI)were observed,spinal cord conus mobility was calculated.The efficacy of"sunset sign"for diagnosing OTCS in children was calculated through comparison between groups.Receiver operating characteristic curve was drawn,the area under the curve(AUC)was calculated to evaluate the diagnostic efficacy of spinal cord conus mobility.Results On prone-position axial T2WI,"sunset sign"was found in 58 cases(58/67,86.57％)but not in 9 cases(9/67,13.43％)in OTCS group,which was not even observed in control group.The sensitivity of"sunset sign"for diagnosing pediatric OTCS was 86.57％(58/67),with specificity of 100％(73/73),positive predictive value of 100％(58/58)and negative predictive value of 89.02％(73/82).The spinal cord conus mobility was(19.30±5.89)％in OTCS group and(31.71±6.58)％in control group,being statistically different between groups(t=-11.722,P＜0.001).The sensitivity,specificity and AUC of spinal cord conus mobility for diagnosing pediatric OTCS was 80.60％,90.41％and 0.920,respectively.Conclusion Prone-position MRI of lumbar spine could be used in diagnosing pediatric OTCS.

To assure the clinical quality and requirement of CT shelter used in field environment, the factors related with the practical application were studied. The evaluation indicators of CT equipment were investigated. Based on the technical modification of vehicle shelter CT, the scanning conditions of shelter CT were analyzed. Moreover, the comparative study was done between shelter CT and common CT in hospitals. In result, in order to meet maneuverability application in the field, vehicle shelter CT was restrictive by the field conditions, traffic impacts and running requirement. The application of vehicle shelter CT was affected by the factors, such as mechanical stabilization, moving precision, power fluctuations and variations of temperature and humidity, etc. The results were helpful to improve the clinical quality of vehicle shelter CT and made a base for the quality control study in the future.
Humidity ; Temperature ; Tomography, X-Ray Computed ; instrumentation

To assure the clinical quality and requirement of CT shelter used in field environment, the factorsrelated with the practical application were studied. The evaluation indicators of CT equipment were investigated. Based on the technical modification of vehicle shelter CT, the scanning conditions of shelter CT were analyzed. Moreover, the comparative study was done between shelter CT and common CT in hospitals. In result, in order to meet maneuverability application in the field, vehicle shelterCT was restrictive by the field conditions, traffic impacts and running requirement. The application of vehicle shelter CT was affected by the factors, such as mechanical stabilization, moving precision, power fluctuations and variations of temperature and humidity, etc. The results were helpful to improve the clinical quality of vehicle shelter CT and made a base for the quality control study inthe future.

To improve the usage rate and quality of emergency equipment in the hospital, the emergency equipment management was studied. The specialized management and common use of emergency equipment in a hospital was analysed with statistical methods. The usage rate, economic effectiveness and management quality of the equipment were evaluated. Based on the practical experience, the superiorities of the specialized management and common use of emergency equipment in hospitals were summarized, and the inferior positions and their improvement approaches were proposed. As a result, the hospital resource allocation was optimized and the equipment management level was improved by using the specialized management and common use of emergency equipment in the hospital.
Emergency Service, Hospital ; organization & administration ; Materials Management, Hospital ; organization & administration

To improve the usage rate and quality of emergency equipments in the hospital, the emergency equipment management was studied. The specialized management and common use of emergency equipments in a hospital was analysed with statistical methods. The usage rate, economic effectiveness and management quality of the equipments were evaluated. Based on the practical experience, the superiorities of the specialized management and common use of emergency equipments in hospitals were summarized, and the inferior positions and their improvement approaches were proposed. As a result, the hospital resource al ocation was optimized and the equipments management level was improved by using the specialized management and common use of emergency equipments in the hospital.

Three algorithms of electrical impedance tomography (EIT) are studied in this paper. The image resolution, anti-noise property and computation rapidity of the reconstruction algorithms are compared. As a result, it shows that back-projection algorithm has good anti-noise property, that NOSER algorithm generates images with good resolution, and that sensitivity matrix algorithm has moderate property.
Algorithms ; Electric Impedance ; Image Processing, Computer-Assisted ; methods

Clinical experiments are always used to evaluate the safety and validity of medical devices. The experiments have two types of clinical trying and testing. Ethic review must be done by the ethics committee of the medical department with the qualification of clinical research, and the approval must be made before the experiments. In order to ensure the safety and validity of clinical experiments of medical devices in medical institutions, the contents, process and approval criterions of the ethic review were analyzed and discussed.
Biomedical Research ; ethics ; Equipment and Supplies ; ethics ; Ethical Review ; Humans

Objective To apply electrical impedance tnmography that is a new evaluation ap-proach to monitor the development of retroperitoneal injury. We used retroperitoneal inject blood model in pigs to study the feasibility on monitoring retroperitoneal bleeding and to provide premise in theory and practice for clinical application. Methods Five pigs were used on the experiment. We insert a vessel into the retroperitoneal and inject blood to simulate retroperitoneal bleeding. Sixteen electrodes were atta-ched on the abdominal region circumference of pigs and used for electrical current injection and surface voltage measurement. Then the monitoring images were performed by electrical impedance tomography. Results The images of electrical impedance tomography retroperitoneal inject blood model of five pigs were clear, the minimal impedance scale was decreasing significantly as the bleeding volume increasing and the images were changed significantly too. The computerized tomography and the dissecting results confirmed the blood was limited in retroperitoneal. Conclusions The establishments of pigs retroper-itoneal inject blood model was successful. The images of electrical impedance tomography retroperitoneal inject blood model were clear with significant contrast. It's feasible to use electrical impedance tomography system to monitor the retroperitoneal bleeding. This technique may become a useful tool for monitoring ret-roperitoneal injury in intensive care patients.

Piglets having each a body weight of 20-30 kg and an abdominal perimeter like human's were used in the experiment. Being guided by ultrasound, we stabbed the piglet's abdomen, placed a catheter on the liver's lower margin, then injected the anticoagulated blood through the catheter by electrical infusion pump with constant speed respectively, and monitored the whole process by EIT. We observed the image change, using Ultrasound and CT to examine the area of blood injection after the end of monitoring,and we dissected to check the result of observations. The results reveal: (1) Ultrasound, CT and dissection are all able to find out a large amount of blood in piglet's abdominal cavity; (2) The pixel value of EIT target area decreases with the increase of blood, and the change in impedance image can be obviously observed. Therefore, this animal model is suitable for simulating intraperitoneal bleeding, and the speed of bleeding therein can be controlled. We can get a limpid image when EIT is used for monitoring the intraperitoneal bleeding simulated by this animal model.
Animals ; Electric Impedance ; Female ; Hemorrhage ; diagnosis ; etiology ; physiopathology ; Image Interpretation, Computer-Assisted ; methods ; Male ; Monitoring, Physiologic ; methods ; Peritoneal Diseases ; diagnosis ; etiology ; physiopathology ; Plethysmography, Impedance ; methods ; Swine ; Tomography ; methods