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Objective To evaluate the radiation dose of interventional procedure for children with congenital heart disease, and to analyze the differences in radiation dose and influencing factors. Methods A total of 94 children who underwent interventional procedure for congenital heart disease at a grade A tertiary hospital in Jinan, Shandong Province, China from June 2021 to September 2022 were included in this study. The patients were divided into three groups according to the type of procedure: ventricular septal defect occlusion group (VSD, 48 cases), patent ductus arteriosus occlusion group (PDA, 29 cases), and atrial septal defect occlusion group (ASD, 17 cases). The basic information of patients and postoperative dose reports were recorded. A statistical analysis was performed using SPSS software. Results The median cumulative air kerma (CAK) of VSD, PDA, and ASD was 100.5, 43.7, and 12.1 mGy, respectively. The median air kerma area product (KAP) of VSD, PDA, and ASD was 3.309, 1.313, and 0.540 Gy·cm2, respectively. The median KAP·kg−1 of VSD, PDA, and ASD was 0.179, 0.088, and 0.031 Gy·cm2·kg−1, respectively. There were significant differences in fluoroscopy time, number of cine images, CAK, KAP, and KAP·kg−1 among the three types of interventional procedures (P<0.05). Compared with PDA and ASD, VSD showed significantly higher fluoroscopy time, number of cine images, CAK, KAP, and KAP·kg−1 (P<0.05). Multiple linear regression analysis found that age (B=52.445, P<0.05), weight (B=13.077, P<0.05), fluoroscopy time (B=0.425, P<0.05), tube current (B=0.872, P<0.05), and number of cine images (B=0.660, P<0.05) were positively correlated with KAP, while there was no significant association between height and KAP (P>0.05). Conclusion There are differences in radiation dose among the three types of procedures. Reducing fluoroscopy time, tube current, and number of cine images while meeting the procedure requirements is of great significance for reducing the radiation dose received by children.
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@#<b>Objective</b> To apply a phantom for dose measurement in interventional therapy for pediatric vascular diseases, and calculate the effective dose (<i>E</i>) and conversion coefficient of dose area product (DAP) to <i>E</i>, and to provide a dose reference for studying radiation dose and radiation protection in children. <b>Methods</b> Thermoluminescent dosimeters were placed in the organs of the phantom. Low-, medium-, and high-dose groups were set for three types of vascular anomalies based on the duration of fluoroscopy. Digital subtraction angiography was used to simulate exposure conditions at different dose levels. The organ dose was measured, and the effective dose was calculated. <b>Results</b> For the three groups of vascular anomalies in the head and face, the red bone marrow doses were 8.15, 30.34, and 43.53 mGy, respectively, the effective doses were 12.88, 47.84, and 73.12 mSv, respectively; and the average conversion coefficient of DAP to <i>E</i> was 2.16. For the three groups of vascular anomalies in the trunk, the red bone marrow doses were 2.11, 15.62, and 31.21 mGy, respectively; the effective doses were 12.39, 70.56, and 134.60 mSv, respectively, and the average conversion coefficient of DAP to <i>E</i> was 3.03. For the three groups of vascular anomalies in the lower extremities, the red bone marrow doses were 3.58, 6.50, and 12.28 mGy, respectively, the effective doses were 3.64, 7.04, and 14.85 mSv, respectively, and the average conversion coefficient of DAP to <i>E</i> was 0.73. <b>Conclusion</b> Patient dose and DAP-to-<i>E</i> conversion coefficient are in the following order: vascular anomalies in the trunk > vascular anomalies in the head and face > vascular anomalies in the lower extremities. The dose data obtained can be used to estimate children’s radiation exposure.
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Objective To discuss 7Be and a 77.2 keV full-energy peak with short half-life found in the water sample from the 3D water phantom of a proton therapy system. Methods We measured the water sample from the 3D water phantom of a proton therapy system according to Determination of Radionuclides in Water by Gamma Spectrometry (GB/T 16140—2018). Results The activity concentration of 7Be in the water sample was 1.30 × 101 Bq·L−1 on December 24, 2018; 4.3 × 101 Bq·L−1 on March 22, 2019; and 1.41 × 101 Bq·L−1 at the time of sampling on December 19, 2018. On December 24, 2018, the net peak area of the 77.2 keV full-energy peak in the sample was 683 ± 45, and the measurement time was 26123.02 s; on March 22, 2019, the net peak area decreased to the background level of 194 ± 49, and the measurement time was 86400.00 s. Conclusion In the 3D water phantom of the proton therapy system, 7Be can be generated from the spallation reaction between high-energy neutrons and oxygen in water. In addition, we find a full-energy peak at 77.2 keV with short half-life. The activity concentration of 7Be in the water sample is lower than the exemption level, but the activity concentration at sampling may not be the maximum activity concentration in the process of quality control. The inductive radionuclide 7Be produced in the 3D water phantom should be identified and properly evaluated in the assessment of occupational radiation hazards of proton therapy system.
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Objective:To explore the application value of artificial intelligence (AI) in image post-processing of reconstructed CTA based on CT cerebral perfusion (CTP).Methods:Clinical and radiological data of 100 patients suspected of cerebrovascular diseases in Hebei General Hospital from January to July 2020 were retrospectively selected. All patients were divided into A and B group on average according to the different examination schemes. Cerebral CTP examination was performed in group A (the temporal maximum intensity projective data set generated by the first 5 time phases in the maximum period of the difference between arteriovenous CT values selected as subgroup A1, and the corresponding original thin-layer images selected as subgroup A2), single phase CTA examination was performed in group B, manual and AI image post-processing were performed respectively. Subjective scoring of the image data was performed, and the objective bid evaluation indexes such as CT value, noise (SD), signal-to-noise ratio (SNR), contrast to noise ratio (CNR) were measured, the qualified rate of artificial and AI vascular segmentation was counted, and post-processing time were recorded. The objective evaluation indexes were compared between three groups using one-way ANOVA, and the Kruskal-Wallis H test was used to compare the difference of subjective scores.Results:Statistically significant differences were observed in subjective score and objective evaluation index of original images among group A1, group A2 and group B (all P<0.05). Among them, arterial enhancement, arteriolar detail display score, cerebral artery CT value, SNR and CNR in group A1 were higher than those in group A2 and group B (all P<0.05). In a total of 100 patients with 1 100 blood vessels, the qualified rates of AI vascular segmentation in group A1 [98.4% (541/550)] and group B [98.7% (543/550)] were higher than those of manual [82.9% (456/550), 87.1% (479/550), χ2=77.392, 56.521, P<0.001], but the qualified rate of AI vascular segmentation of group A2 [78.4% (431/550)] was lower than that of manual [85.6% (471/550), χ2=9.855, P=0.002]. The completion time of AI post-processing were reduced by 56.30%, 49.63%, 50.81%, respectively than those with manual. Conclusion:Compared with manual image post-processing, AI has certain advantages in image quality and work efficiency of reconstructed CTA post-processing based on CTP de-noising dataset, and it is worth popularizing and applying in the image post-processing of cerebrovascular disease, combined with artificial quality control.
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Pituitary metastasis is a rare tumor complication, and papillary thyroid carcinoma is a tumor with low hematogenous dissemination tendency. Here we report a rare case with pituitary metastasis from papillary thyroid cancer. This patient was 43 years old and was admitted to our hospital because of " blurred vision in the right eye" . She had partial thyroidectomy because of thyroid nodule 8 years ago, and was diagnosed as papillary thyroid carcinoma, but without any further treatment onwards. After admission, MRI revealed a pituitary mass protruding through the sella turcica into the right sphenoid sinus. Neuro-endoscopic transsphenoidal resection was performed to relieve visual impairment. Pathological result was papillary thyroid carcinoma pituitary metastasis. She underwent thyroidectomy 2 months later. Because tumor of the left lobe invaded the esophagus, it was resected palliatively, and adjuvant therapy with radioactive iodine was performed subsequently. This case suggests that long-term management of papillary thyroid carcinoma should be strengthened to reduce the risk of recurrence and metastasis, additionally radioiodine therapy is an important complementary treatment.
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Objective@#To investigate the feasibility of one-step coronary and carotid-cerebrovascular computed tomography angiography (CTA) using high-pitch Double Turbo Flash mode and to analyze the image quality and radiation dose in patients with heart rate variability using multi-slice detector dual-source CT.@*Methods@#A total of 79 patients with heart rate variability higher than 3 beat/min (bpm) were retrospectively analyzed. They were grouped by the scanning methods. Group A (n=40) were performed double turbo flash mode for one-step coronary and carotid-cerebrovascular arteriesinjected with one injection of contrast agent.further divided into Single A (only the phase 1 image)and Double A(combined images of phases 1 and 2). Group B (n=39) were performed separately with twice injection of contrast agent. Subjective scoring was performed on the image quality of the group Single A, Double A and B using a 4-point. Then the objective parameters of image quality, CT attenuations, image noise, signal-to-noise (SNR), and contrast-to-noise (CNR), were evaluated. Then subjective scores, objective evaluation indicators, and radiation dose were compared with one-way ANOVA analysis among the three groups.Contrast agent were compared by using t test in group A and B.@*Results@#No significant difference was found (F=2.093, P=0.128) for the subjective scores of the head and neck CTA among the three groups with (3.47±0.51), (3.53±0.51), (3.69±0.47). Significant difference was found (F=50.955, P<0.01) for the subjective scores of coronary CTA among the three groups with (2.70±0.76), (3.35±0.66), (3.58±0.50), and there was no statistically significant difference between Double A and B groups (P=0.104), met the requirements for diagnosis. The objective evaluation of the three groups compared the head and neck CTA images were statistically significant (P<0.05), of which the difference between the Single A and the Double A was not statistically significant (P>0.05), met the requirements for diagnosis; the differences in SNR and CNR of coronary CTA images are statistically significant (F=12.991, 12.236, P<0.01), and there was no statistically significant difference between Double A and B (P>0.05), met the requirements for diagnosis. Radiation dose in the group Double A was lower than group B (decreased by 46.15%,P<0.01).The amount of the contrast agent in the group Double A was lower than group B (decreased by 44.13%, t=-45.455;P<0.01).@*Conclusion@#The double turbo flash mode is feasibility for one-step coronary and carotid-cerebrovascular CTA in patients with the heart rate variability using multi-slice dual-source CT.This scan mode can maintain the diagnostic image quality with low contrast agent and radiation dose.
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Objective:To investigate the feasibility of one-step coronary and carotid-cerebrovascular computed tomography angiography (CTA) using high-pitch Double Turbo Flash mode and to analyze the image quality and radiation dose in patients with heart rate variability using multi-slice detector dual-source CT.Methods:A total of 79 patients with heart rate variability higher than 3 beat/min (bpm) were retrospectively analyzed. They were grouped by the scanning methods. Group A ( n=40) were performed double turbo flash mode for one-step coronary and carotid-cerebrovascular arteriesinjected with one injection of contrast agent.further divided into Single A (only the phase 1 image)and Double A(combined images of phases 1 and 2). Group B ( n=39) were performed separately with twice injection of contrast agent. Subjective scoring was performed on the image quality of the group Single A, Double A and B using a 4-point. Then the objective parameters of image quality, CT attenuations, image noise, signal-to-noise (SNR), and contrast-to-noise (CNR), were evaluated. Then subjective scores, objective evaluation indicators, and radiation dose were compared with one-way ANOVA analysis among the three groups.Contrast agent were compared by using t test in group A and B. Results:No significant difference was found ( F=2.093, P=0.128) for the subjective scores of the head and neck CTA among the three groups with (3.47±0.51), (3.53±0.51), (3.69±0.47). Significant difference was found ( F=50.955, P<0.01) for the subjective scores of coronary CTA among the three groups with (2.70±0.76), (3.35±0.66), (3.58±0.50), and there was no statistically significant difference between Double A and B groups ( P=0.104), met the requirements for diagnosis. The objective evaluation of the three groups compared the head and neck CTA images were statistically significant ( P<0.05), of which the difference between the Single A and the Double A was not statistically significant ( P>0.05), met the requirements for diagnosis; the differences in SNR and CNR of coronary CTA images are statistically significant ( F=12.991, 12.236, P<0.01), and there was no statistically significant difference between Double A and B ( P>0.05), met the requirements for diagnosis. Radiation dose in the group Double A was lower than group B (decreased by 46.15%, P<0.01).The amount of the contrast agent in the group Double A was lower than group B (decreased by 44.13%, t=-45.455; P<0.01). Conclusion:The double turbo flash mode is feasibility for one-step coronary and carotid-cerebrovascular CTA in patients with the heart rate variability using multi-slice dual-source CT.This scan mode can maintain the diagnostic image quality with low contrast agent and radiation dose.
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Objective To analyze the distribution characteristics and influencing factors of X-ray diagnostic imaging in Shandong province,and to estimate the application frequency of X-ray diagnostic imaging in the province,and provide data support for X-ray equipment.Methods A random sampliug method was used to extract 32 medical institutions as respondents from 10 prefecture-level cities in Shandong province.The basic information of medical institutions and the age,sex,examination and procedure of the subjects were analyzed.The distribution of the X-ray application was analyzed and estimated by using a multiple linear regression model.Results Totally 14 694 085 subjects were surveyed,and the proportion of male and female in the sample was not completely uniform.A total of 2 099 155 X-ray diagnostic information was collected in 2016,and the frequency of conventional radiography was the highest,accounting for 59.49％.The next was CT examination,accounting for 28.34％.The frequency of the two examinations showed an increasing trend with the age of subjects.For the total frequency of conventional diagnostic radiography and CT examination,the tertiary hospitals accounted for the highest proportion of the total,up to 52.13％,while the secondary hospitals accounted for the relatively low proportion of 30.09％,and the primary hospitals the lowest with 17.77％.The chest radiography had the highest proportion in conventional radiography accounting for 32.79％ of the total frequency of X-ray diagnostic imaging,and the head procedure had the highest proportion in CT examination,accounting for 10.07％ of the total frequency of X-ray diagnostic imaging.The fluoroscopy,mammography and dental radiography were mainly concentrated in the tertiary hospitals,and the primary hospitals had mainly radiography.Multiple linear regression models showed that the frequency of application of conventional X-ray diagnostic imaging (including radiography,fluoroscopy,dental radiography and mammography) was positively correlated with equipment quantity,number of outpatient and emergency patients,and tertiary hospitals (t=4.334,3.615,2.339,P＜ 0.05).CT examination was positively correlated with equipment quantity and the number of inpatient (t =2.167,2.595,P＜0.05).The frequency of conventional X-ray diagnostic imaging and CT examination in Shandong province were estimated about 491.17 examinations per 1 000 population and 258.17 examinations per 1 000 population respectively.Conclusions The frequency of X-ray exposure in Shandong province increased significantly compared with that during the " 9th Five-Year Plan" period.All relevant departments should take effective measures to strengthen medical radiation protection and reduce radiation risk.
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Objective To compare the image quality produced by MR high resolution vessel wall imaging (HR?VWI) and ultrasound (US) in evaluating carotid plaque load. Methods This prospective study enrolled 21 patients with carotid plaques undergoing HR?VWI and subsequent 2D US between August 2016 to January 2017 in Hebei General Hospitial. The plaque thickness (PT), lumen area (LA), wall area (WA) and total vessel area (TVA) of the plaques were measured and normalized wall index (NWI) was calculated on both HR?VWI images and US for those plaques with image quality score≥3 and matching between the two methods. The plaque load index was compared by using the independent sample t test or the non?parametric Wilcoxon test, and the correlation between the indexes was based on the Pearson test. Results Forty?five carotid plaques were matched with HR?VWI and US. There was no significant difference in PT, LA, WA, TVA and NWI detected by HR?VWI and ultrasound (P>0.05). The parameters measured by two methods were correlated (r values were 0.83, 0.85, 0.32, 0.83 and 0.59, P<0.05). Conclusion There is a good consistency between HR?VWI and conventional ultrasound in the measurement of carotid plaque load.
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A"3+2"standardized training program of assistant general practitioner was launched in Shanghai Jiading District in 2012 in order to train new medical talent in suburb area.The program was developed through the jointed efforts among the government,medical school and train bases.The model was designed as training assistant general practitioners with distinctive sequential education process in different levels and stages.After five years of practice,the"3+2"standardized training program of assistant general practitioner has accomplished its goal,which provides a reference for training assistant general practitioners in Shanghai Municipality.
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OBJECTIVE:To investigate the effects of loading-dose rosuvastain before early percutaneous coronary intervention (PCI) on reperfusion arrhythmias in patients with acute non-ST-segment elevation myocardial infarction (NSTEMI).METHODS:A total of 136 patients with NSTEMI were randomly divided into loading-dose group (68 cases) and control group (68 cases).Both groups who were not given anti-platelet drugs were given loading-dose of Aspirin enteric-coated tablets 300 mg+Clopidogrel sulfate tablets 600 mg immediately after admission.The patients who were given aspirin regularly were given loading-dose of Clopidogrel sulfate tablets 600 mg only once after admission.The patients who were given clopidogrel regularly were given loading-dose of Aspirin enteric-coated tablets 300 mg only once.Those received PCI 12-24 h after medication.After PCI,they took Aspirin enteric-coated tablets 100 mg for life+Clopidogrel bisulfate tablets 75 mg at least 12 months.Loading-dose group was given loading-dose of Rosuvastatin calcium tablets 20 mg orally,12 h before surgery.All patients began to take Rosuvastatin calcium tablets 10 mg,once a day,since the night after the operation.Coronary angiography and the occurrence of reperfusion arrhythmia were observed in 2 groups.The levels of CK-MB and cTnT,major adverse cardiovascular events (MACE) were observed before and after surgery.RESULTS:There was no statistical significance in the number of diseased vessels,culprit vessels,the degree of culprit vessels stenosis or the incidence of MACE between 2 groups (P＞ 0.05).The incidence of reperfusion arrhythmia in loading-dose group was significantly lower than control group,with statistical significance (P＜0.01).There was no statistical significance in the degree of culprit vessels stenosis between 2 groups (P＞0.05).Before surgery,there was no statistical significance in the levels of CK-MB or cTnT between 2 groups (P＞0.05).After surgery,the levels of CK-MB and cTnT in 2 groups were significantly higher than before surgery,but the loading-dose group was significantly lower than the control group,with statistical significance (P＜0.01).CONCLUSIONS:Preoperative loading-dose of rosuvastatin before PCI can reduce the incidence of reperfusion arrhythmias in NSTEMI patients.
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The application of continuous quality improvement program in standardized residency training examination in the central Hospital of Shanghai Jiading was introduced to inquire into the way to improve the quality of standardized training of resident doctors. Through the steps of FOCUS-PDCA, we continuously improved the examination content and quality compliance training personnel, and developed the examination process including test, training, supervision, learning and using. After the implementation of the project, the percentage of the departments that meet the residency training examination requirements has been increased from 33.3%to 100%in our hospital. The percentage of the students that passed the licensed medical skills examination was 96.6%in that year. 100%of the students passed the graduation comprehen-sive examination. Year-end evaluation showed that the students' satisfaction degree to the teachers increased from 94.5%to 98.2%. Thus, through the implementation of CQI project, we achieved the goal of promoting teaching and promoting learning.
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Objective To compare the single-shot fields irradiated by three focusing modes of γ-knife and explore the approaches for improving the quality of stereotactic radiosurgery.Methods GAFCHROMIC(R) EBT3 mode flushing-free film was used to measure the single-shot fields irradiated by multi-source static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode of γ-knife.Also the uniformity and penumbra of the single-shot fields were compared.Results The 2D dose distribution of the single-shot fields irradiated by three focusing modes of γ-knife was different.In the axis (x,y,z),the rang of penumbra axial length ratios of multisource static focusing modes,multi-source single-axis rotating focusing mode and single-source double-axis rotating focusing mode were 0.13-0.48,0.17-0.33 and 0.28-0.54,in the diagonal direction of the wings plane (NSD,PSD),were 0.31-0.39,0.38-0.43 and 0.54-0.72,respectively;the penumbra axial length ratio of single-source double-axis rotating focusing mode was bigger than in multi-source static focusing modes and multi-source single-axis rotating focusing mode.On the no-wings plane,the area ratios of 80％ dose curve enveloped and 50％ dose curve enveloped(A80％/A50％)were 0.40,0.47 and 0.19,on the wings plane,were 0.61,0.53 and 0.35,respectively.The field uniformity of multi-source static focusing modes and multi-source single-axis rotating focusing mode were superior to single-source doubleaxis rotating focusing mode.Conclusions Considering dose distribution of the single-shot fields,the multi-source static focusing modes devices and the multi-source single-axis rotating focusing mode devices should be preferred,when important tissues and organs are adjacent to the target areas.Compared with single-source double-axis rotating focusing mode,both multi-source static focusing modes and multi-source single-axis rotating focusing mode could make more target areas to be surrounded by high dose region.
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Purpose Protein is the main influencing factors for diffusion weighted imaging (DWI) signals and apparent diffusion coefficient (ADC), it results in hyperintensity on DWI and low ADC, but not fully matched in clinic. This paper aims to investigate the effect of protein type and concentration on the signal intensity (SI) and ADC of DWI. Materials and Methods Different concentrations of albumin, globulin solution and the mixed solution were created in vitro. DWI was performed on GE 1.5T superconducting nuclear MRI system. Results ① There was a linear negative correlation between the ADC value and the concentrations of protein solution (at 37℃, ra= - 0.849, Pa0.05; at 40℃ , r= - 0.270, P>0.05). ② SI of the albumin solution was significantly higher than the globulin solution at the same concentration and temperature (t=3.96, P0.05). Conclusion The nature of the cystic fluid can be understood preliminarily through quantitative analysis of the cystic fluid DWI and ADC values, so as to provide theoretical basis for the qualitative diagnosis of cystic lesions in vivo.
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Objective To study the method of measuring the position accuracy and the step distance accuracy of afterloading system with192Ir source by using flushing-free film.Methods The position accuracy and the step distance accuracy of a China-made afterloading system with192Ir source was measured by using GAFCHROMIC (R) EBT3 flushing-free film.The film was scanned to proper image format,required by dose analysis software,by EPSON PREFACTION V700 PHOTO scanner.Then images are analyzed by using film dose analysis software in SNC Patient 5.2.Results With focus on the center of active section of source,the position accuracy of this afterloading system with192Ir source was-0.75 mm.Using film analysis could make the step point to tell apart if the step distance was 5 mm away by the method of film analysis,but couldnot make it to tell apart if the step distance was 2.5 mm away.The 2.5 mm step distance accuracy could be judged if the distance between the 1 st point and the 3rd point was 5 mm,then the 2.5 mm step distance could be deemed to no deviation.The 5 mm step distance of this afterloading system had no deviation in continuous 9 step points measured by flushing-free film.The indirect measuring results of the 2.5 mm step distance had no deviation as well.The position accuracy of this afterloading system measured with the flushing-free film accorded with the national standards.Conclusions The method of measuring the position accuracy and the step distance accuracy of the afterloading system with192Ir source by using flushing-free film is technically feasible.
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Objective To explore the establishment of a rabbit model of atrial fibrillation by wireless telemetering and stimulation technology.Method An implantable telemetering stimulator which was independently designed and devel-oped was hypodermically implanted in New Zealand rabbits.The implantable telemetering stimulator was made with the core development and design of MSP single-chip microcomputer of TI Corporation ( Texas Instruments) and RF wireless trans-ceiver chip CC2250 of TI Corporation.The design of the implantation system was optimized to cater to the exploratory ex-periment to establish atrial fibrillation model of New Zealand rabbits.The implanter was implanted into the abdominal sub-cutaneous tissue of the New Zealand rabbits, the collecting electrodes were placed in the oxter subcutaneous tissues of the left and the right upper extremities, and the two stimulating electrodes were sutured at the left auricle and the left atrium. The signals were collected and stimulated by the wireless transceiver.The I-lead ECG electrical signals were continuously monitored on the body surface by a Powerlab physiological recorder.High frequency ( >20 Hz) suprathreshold stimulus ( intensity 2 mA, pulse width 1 ms) was emitted by specialized stimulation software of a computer program by the interval ( stimulating for 2 s and pausing for 2 s) .In case of atrial fibrillation during intervals, the stimulation could be stopped by hand.In case of sinus rhythm, the stimulation could be continued.Results The implantable telemetering stimulator can work stably in vivo ( including collecting stimulated electrocardio signal and emitting stimulations) for 30 days.Atrial fibril-lation can be induced after stimulating in vivo of the New Zealand rabbits for 3 weeks, with a duration of >48 h.Conclu-sions Applying implantable telemetering stimulator can build a New Zealand istead of beagles model of atrial fibrillation which is more consistent with welfare optimization and substitution principle for laboratory animals.
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Objective To analyze the psychological condition of postgraduates in clinical hos-pitals of colleges and universities before and after the implementation of psychological mentor scheme so as to evaluate the effect. Methods Quantitative questionnaire (SCL-90 scale) and qualitative fo-cus interview were used to compare psychological condition of postgraduates. Totally 182 copies of questionnaires were sent to two hospitals (A and B) respectively. Then, psychological mentor scheme was carried out in A hospital. Afterwards, 206 and 140 copies of questionnaires were sent again to the hospitals respectively to compare the results. Eight student psychological consultants, 12 postgraduates and 5 postgraduate management staff were enrolled in qualitative focus interview. Excell2003 software was adopted to establish the database and SPSS 11.0 software was used for statistical analysis. Descrip-tive analysis, frequency analysis, t test, chi-square test and variance analysis were adopted for data analysis. P<0.05 signifies for statistically significant difference. Results Mental health status of both groups was better than the national level before the implementation (total SCL score: A hospital=118 . 08 ±36.20; B hospital =100.33 ±22.90). However, SCL-90 score of A hospital was decreased (total SCL score: 102.58 ±25.23) and that of B hospital (total SCL score:134.01 ±38.92) was in-creased (part of items higher than the adult national norm) at one year after conducting psychological mentor scheme. Conclusions Psychological mentor scheme can effectively relieve stress and interper-sonal stress so as to reduce the general psychological problems and can help to improve mental health of the students.
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Objective To study the calculational method for the radiotherapy facilities of the medical linear accelerator' s useful beam towars its maze.Methods The shielding calculation was made under the relevant national standards for a radiotherapy treatment room and compared with the test results.Results The dose rates at the maze entrance as calculated and measured were 89 and 86 μSv/h inside the maze door,as well as 5.7 and 6.2 μSv/h outside the maze door,respectively.The calculated results were consistent with measured results.Conclusions By comparison of calculated results with measured results,the accuracy of the theoretical calculation method could be verified.
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In this paper, we described an ultra-low power, wearable ECG system capable of long term monitoring and mass storage. This system is based on micro-chip PIC18F27J13 with consideration of its high level of integration and low power consumption. The communication with the micro-SD card is achieved through SPI bus. Through the USB, it can be connected to the computer for replay and disease diagnosis. Given its low power cost, lithium cells are used to support continuous ECG acquiring and storage for up to 15 days. Meanwhile, the wearable electrodes avoid the pains and possible risks in implanting. Besides, the mini size of the system makes long wearing possible for patients and meets the needs of long-term dynamic monitoring and mass storage requirements.
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Electrocardiografía Ambulatoria , Procesamiento de Señales Asistido por ComputadorRESUMEN
Objective To investigate the value of blood oxygenation level dependent (BOLD) MRI in detecting monkey cerebral ischemic penumbra (IP). Methods Six monkeys were used to make reversible middle cerebral artery occlusion (MCAO) model by an interventional microcatheter method. MR DWI, PWI mean transit time (MTT), T_2WI and quantitative T_2 map, T_2~* map were performed at MCAO (0 h) and 1,3,6,12,24,48 h after reperfusion. Reversible transverse relaxation rate (R_2') BOLD imaging was calculated using quantitative T_2 and T_2~* maps. Lesion volume percentage (lesion volume/bilateral hemispheres volume) were measured on 0 h DWI,48 h T_2WI and TTC staining. Ischemic area was subdivided into infracted core (high signal area on both 0 h DWI and 48 h T_2 WI), IP (high signal on 0 h DWI, iso on 48 h T_2 WI) and oligemia (0 h delayed MTT, iso signal on both 0 h DWI and 48 h T_2 WI). Relative R_2' (rR_2') was calculated to get ratio between the lesion and mirror area in contralateral healthyhemisphere. Paired t test and correlation analysis were used for comparison of lesion volume percentage. rR_2' values at each time point were compared by ANOVA. Results Reversible MCAO models were made successfully in 4 of 6 monkeys. Lesion volume porcentage on 48 h T_2 WI was reduced compared to that on Oh DWI [ (8.16±0.55)% vs (11.37±1.41)% ,t=6.472,P<0.05]. There was no significant difference in lesion volume percentage between TTC staining and 48 h T_2 WI[ (8.15±0.62)% vs (8.16±0.55)%, t= 0.150,P>0.05], which showed significant positive correlation (r=0.98, P<0.05). rR_2' values were significant different at each time point, with highest in ohgemia followed by IP and infarcted core (P< 0.05). rR_2' values in infracted core, IP and oligemia were: 0 h(1.129±0.108,1.329±0.081,1.584± 0.103,F=36.19,P<0.05),1 h(0.668±0.082,1.237±0.072,1.435±0.066,F=134.09,P<0.05), 3 h (0.536±0.075,1.453±0.081,1.770±0.141, F=256.30, P<0.05), 6 h (0.259±0.050,2.435± 0.131,2.957±0.177,F=803.25,P<0.05), 12 h(0.385±0.054,2.447±0.148,3.254±0.184,F= 743.74,P<0.05),24 h(0.083±0.026,1.968±0.127,3.101±0.144,F=1236.26,P<0.05),48 h (0.246±0.058,3.694±0.218,4.297±0.322, F=557.02, P<0.05). After reperfusion, rR_2' values in IP and oligemia showed increased trend with time evolution and reflected positive BOLD effect, while the infracted core showed decreased trend, reflecting negative BOLD effect. Conclusion R_2' BOLD can delineate IP from infracted core according to the difference of oxygen metabolic status in ischemic brain tissue.