With the rapid development of society and the increasing improvement of living standard,people shows increasing demand for high quality of medical care so that more and more advanced medical instruments are applied to disease prevention,diagnosis and treatment.Thanks to the development of the professional medical technology,a new branch of medicine-clinical engineering has emerged.The history,current situation and future development of clinical engineering are mainly expounded.

With the rapid development of Picture Achieving and Communication System(PACS), the interpretation of medical images has been changing rapidly from a procedure based on films and light boxes to one based on computers and medical displays. The function parameters of Soft-Copy Reading carriers——medical grayscale display play an important part in radiodiagnosis because they can greatly influence the quality of medical image. It is very easy for quantitative assessment of this influence by using ROC curve theory, and it can direct hospital to select suitable medical display.

Objective To evaluate the influence of the resolution of medical grayscale LCD over the detective efficiency of pulmonary nodule.Methods By reviewing PACS, 93 on-line chest DR images were collected.These radiographs included 23 normal images that had no nodule confirmed by CT, 32 doubtful images that also had no nodule confirmed by CT,and 38 positive images that had nodules confirmed by CT.These nodules didn't show obvious calcification and their diameters were from 0.30 to 1.90 cm. Nine patients had multi-nodules.Three residents or postgraduates, three attending physicians, and three associate professors or professors interpreted the 93 chest images by using three types of displays: Barco Z-2261, Barco Z-3620 and Barco Z-5620.All observers evaluated their confidence of the presence of pulmonary nodule with five-point level rating scale : ( 1 ) definitely positive, ( 2 ) probably positive, ( 3 ) uncertain, (4) probably negative, (5)definitely negative.SPSS 11.5 software was used to analyze the results ,including to draw the ROC curves and to perform Z test.Results The areas under the ROC curves of 2 M display, 3 M display and 5 M display were 0.774,0.784,0.816 for experienced radiologists; for instructors were 0.754,0.764,0.768 ;for teaching assistants were 0.695,0.754,0.774.However, for the detection of pulmonary nodules,there was no significant difference between observers with different ranks using the same modality of display,and no significant difference was found between the different modalities of displays used by observers with the same rank.Conclusion It's equivalent for detection performance with 2,3 and 5 M medical grayscale LCD display in detecting pulmonary nodule; Experienced radiologists can get more information using 5 M display;By reasonably matching displays, we could improve the cost-efficacy.

Objective Evaluate the influence of medical monochrome liquid crystal display (LCD) with different resolutions on the detection of pulmonary nodules.Methods Ninety-three direct digital radiography (DR) chest images were selected on-line from picture archiving and communication system (PACS),including 38 positive,32 suspected and 23 normal cases.All of the images were confirmed by CT.These positive images were divided into group A and B according to the diameter of nodules.Three experienced radiologists blindly read the 93 images using three types of displays with different resolutions.Regarding the presence of nodule,five-point confidence system was used:definitely absent,probably absent,indefinite,probably present and definitely present.All observers marked their confidence levels of each image according to the presence of pulmonary nodule on different displays.Software SPSS 13.0 was employed for statistical analysis.Results In the group-A cases,the areas under ROC curves were 0.643,0.686 and 0.739,and in the group-B cases,those were 0.813,0.832 and 0.846 respectively.There was no difference in the detection efficacy among different radiodiagnostic systems.Conclusion Regardless of post-processing tools,it was equivalent to detect pulmonary nodules with different diameters of Group A or B among medical monochrome LCDs with different resolutions.

Perfofinance of the radio-diagnostic system can be evaluated quantitatively by the analysis method of the ROC curve.Areas under the ROC curves represent the diagnostic perfogrmance efficiency.A comparison of the perforrmance variance of the diagnostic system incurred by different diagnosticians,will find the diagnostic competence of individual diagnosticians.This can help hospital management in deploying personnel in the department of radiology reasonably.

Objective To assess the influence of medical monochrome liquid crystal displays (LCD) with different resolutions for the detection performance of micro-nodules (diameter <10 mm) on chest radiograms. Methods Eighty-seven DR chest images that were verified with CT were selected from PACS on-line, including 32 positive images, 32 suspected images and 23 normal images. The diameters of all nodules were lower than 10 mm. Three of high-, mid- and low-experienced radiologists who participated in the ROC study interpreted these 87 images using three types of LCDs with different resolutions, respectively. Regarding the presence of nodule, five-point confidence level rating scale was used, i.e. definitely absent, probably absent, possibly present, probably present and definitely present. All observers marked their confidence levels of every image according to the presence of pulmonary nodule on different displays. Software SPSS 13.0 was used for statistical analysis. Results AUC increased with the increasing resolutions and radiologists' experiences in 2MP, 3MP, 5MP displays. For the detection performance of pulmonary nodules (diameter <10 mm), there was no significant difference among different types of displays or different aptitudes of radiologists. Conclusion It's equivalent for the detection performance of pulmonary nodule (diameter <10 mm) on 2MP, 3MP and 5MP medical monochrome LCD when no restriction on the use of image post-processing tools. Highly-experienced radiologist can get the most information when using 5MP display. It is advisable to combine the diagnostic workstation system with high-, mid- and low-resolution monitors, and reasonable equipment scheme between different types of displays and different aptitudes of radiologists could result in better cost-efficacy.

Objective: Evaluate the influence of monochrome LCDs with different resolutions for the quality of detail imaging and detection performance of lesions. Methods: 93 DR chest images were selected from PACS on-line, including 38 positive cases, 32 suspected cases and 23 normal cases. The positive cases were divided into two groups A and B according the diameter of pulmonary nodules. Three of high-, mid-and low-experienced radiologists interpreted the 93 images on three types of displays independently. Each observer marked their confidence of the presence of pulmonary nodule with five-point rating scale : (1)definitely absent, (2)probably absent, (3)possibly present, (4)probably present and (5)definitely present, and the visual quality of lung markings with three-point rating scale:(1) excellent, (2)free, (3) inferior. Software SPSS 13.0 was used to analyze the results. Results: For the detection performance of lesion, while detecting nodules of Group A, the areas under ROC curves were 0.643、0.686、0.739 on 2MP、3MP and 3MP display for high-experienced radiologist. Those were 0.636、0.682、0.717 for mid-experienced radiologist and 0.623、0.656、0.721 for low-experienced radiologist; while detecting nodules of Group B, those were 0.813、0.832、0.846 for high-experienced d radiologist, 0.773、0.824、0.838 for mid-experienced radiologist and 0.763、 0.7.73、0.833 for low-experienced radiologist. There were no significant differences among detection performance ofradiodiagnostic systems. For the quality of detail imaging, while interpreting the visualization of lung markings, the difference between high-and mid-experienced radiologist or between high-and low-experienced radiologist on 5MP display was conspicuous (P<0.05). But the differences of other comparisons did not reach the significant level. Conclusions: For the detection performance ofpulmouary nodules, it is comparable among different radiodiagnostic systems; for the visualization of lung markings, high-experienced radiologist could get more information on 5MP display.

The medical imaging technology (MIT) specialty hasn't been set up for a long time in China, and the mode of educating students in other institutions vary greatly among different universities. There are several disadvantages in MIT specialty set up in the Affiliated hospitals of universities, such as unreasonable curriculum system, imperfections in teaching and research department, and inadequate guidance on students' innovation ability. Therefore, the solutions for alleviating the above problems that are unfavorable factors to education are proposed, so as to further improve the model of MIT specialty set up in the affiliated hospitals of universities and produce more competent graduates.

Objective To investigate the value of the difference between peripheral arterial and venous blood gas analysis for the prognosis of patients with septic shock after resuscitation.Methods Patients with septic shock aged 18 to 80 years admitted to intensive care unit (ICU) of Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine from May 2016 to December 2017 were enrolled. The peripheral arterial blood and peripheral venous blood gas analysis were measured simultaneously after the early 6 hours resuscitation, including pH, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), base excess (BE), bicarbonate (HCO3-) and lactate (Lac) level, and the difference values between peripheral arterial and venous blood were calculated. According to the 28-day survival, the patients were divided into survival group and death group. Multiple Logistic regression analysis was used to analyze the risk factors of death, and the receiver operating characteristic curve (ROC) was used to analyze the prognostic value of blood gas analysis parameters for prognosis.Results A total of 65 patients with septic shock resuscitation were enrolled in the study, 35 survived while 30 died during the 28-day period. ① There was no significant difference in gender, age, and mean arterial pressure (MAP), central venous pressure (CVP), central venous oxygen saturation (ScvO2) and norepinephrine (NE) dose between the two groups.② The arterial and venous Lac, the difference of Lac (ΔLac) and PCO2 (ΔPCO2) between arterial and venous blood in death group were significantly higher than those in survival group [arterial Lac (mmol/L): 7.40±3.10 vs. 4.82±2.91, venous Lac (mmol/L): 9.17±3.27 vs. 5.81±3.29, ΔLac (mmol/L): 1.77±0.54 vs. 0.99±0.60, ΔPCO2 (mmHg, 1 mmHg =0.133 kPa): 9.64±5.08 vs. 6.70±3.71, allP < 0.01], and there was no significant difference in the other arterial and venous blood gas analysis index and its corresponding differential difference between two groups. ③ Multiple Logistic regression analysis showed that ΔPCO2 [β = 0.247, odd ratio (OR) = 1.280, 95％ confidential interval (95％CI) = 1.057-1.550,P = 0.011], and ΔLac (β = 2.696,OR = 14.820, 95％CI = 2.916-75.324,P = 0.001) were the independent risk factors for the prognosis of septic shock. ④ It was shown by ROC curve analysis that arterial blood Lac, ΔLac andΔPCO2 had predictive value on prognosis of septic shock, the area under ROC curve (AUC) was 0.792, 0.857, 0.680, respectively (allP < 0.05). When the best cut-off value of arterial Lac was 4.00 mmol/L, the sensitivity was 100％, and the specificity was 62.86％ for predictor of death in 28-day; when the best cut-off value of ΔLac was 1.25 mmol/L, the sensitivity was 93.33％, and the specificity was 68.57％ for predictor of death in 28-day; when the best cut-off value of ΔPCO2 was 4.35 mmHg, the sensitivity was 83.33％, and the specificity was 37.14％ for predictor of death in 28-day.Conclusions Compared to other parameters, the difference between peripheral arterial and venous blood gas analysis, ΔPCO2 and ΔLac had the best correlation with the prognosis of septic shock. The ΔPCO2 and ΔLac are the independent prognostic predictors for 28-day survival.

Objectives : To investigate the effect of sciatic nerve electrical stimulation ( SNES) on motor function recovery in rats with incomplete spinal cord injury (SCI) and its possible mechanism. Methods : The incomplete SCI model was constructed by modified Allen ′s method. Forty⁃five Sprague⁃Dawley (SD) rats were randomly divided into three groups : Sham , SCI , and SNES. Electrical stimulation parameters were 1 ms pulse width and 100 Hz , with 20 mins each time , once a day for 21 days. The motor function was assessed by Basso⁃Beattie⁃Bresnahan (BBB) locomotor function scale , and the action potential conduction was detected by electrophysiology. Hematoxy⁃lin⁃eosin (HE) staining was used to observe the pathological changes in the spinal cord and the average cross⁃sectional area (CSA) of biceps femoris muscle fibers. The number of brain⁃derived neurotrophic factor (BDNF) and tropomyosin⁃related kinase B (TrkB) positive cells , relative mRNA and protein expression were analyzed by immunohistochemistry , reverse transcription polymerase chain reaction (RT PCR) and Western blot separately. Results: On 21 d , the BBB score and average amplitude of action potential of SNES group were higher than those of SCI group , and the difference was statistically significant (P < 0. 05) . Compared with SCI group , the pathological injury of spinal cord tissue in SNES group was significantly improved , and the average CSA of biceps femoris muscles had a statistical difference (P < 0. 05) . The number of BDNF and TrkB positive cells in SNES group was higher than that in SCI group , and there were statistical differences (P < 0. 05) . The relative mRNA and protein expressions of BDNF and TrkB in SNES group were higher than those in SCI group , with statistical differences ( P <0. 05) . The relative mRNA and protein expressions of BDNF and TrkB in SNES group were higher than those in SCI group , with statistical differences ( P <0. 05) . Conclusion These results show that SNES contributes to alleviating spinal cord tissue injury , promoting the recovery of motor function and delaying the atrophy of muscles below the injury level. The possible mechanism is related to the increased expression of BDNF⁃TrkB proteins.