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Objective:To evaluate the value of radiomics based on contrast-enhanced spectral mammography (CESM) of internal and peripheral regions combined with clinical factors in predicting benign and malignant breast lesions of breast imaging reporting and data system category 4 (BI-RADS 4).Methods:A retrospective analysis was performed on the clinical and imaging data of patients with breast lesions who were treated in Yantai Yuhuangding Hospital (Center 1) Affiliated to Qingdao University from July 2017 to July 2020 and in Fudan University Cancer Hospital (Center 2) from June 2019 to July 2020. Center 1 included 835 patients, all female, aged 17-80 (49±12) years, divided into training set (667 cases) and test set (168 cases) according to the "train-test-split" function in Python software at a ratio of 8∶2; and 49 patients were included from Center 2 as external validation set, all female, aged 34-70 (51±8) years. The radiomics features were extracted from the intralesional region (ITR), the perilesional regions of 5, 10 mm (PTR 5 mm, PTR10 mm) and the intra-and perilesional regions of 5, 10 mm (IPTR 5 mm, IPTR 10 mm) and were selected by variance filtering, SelectKBest algorithm, and least absolute shrinkage and selection operator. Then five radiomics signatures were constructed including ITR signature, PTR 5 mm signature, PTR 10 mm signature, IPTR 5 mm signature, IPTR 10 mm signature. In the training set, univariable and multivariable logistic regressions were used to construct nomograms by selecting radiomics signatures and clinical factors with significant difference between benign and malignant BI-RADS type 4 breast lesions. The efficacy of nomogram in predicting benign and malignant BI-RADS 4 breast lesions was evaluated by the receiver operating characteristic curve and area under the curve (AUC). Decision curve and calibration curve were used to evaluate the net benefit and calibration capability of the nomogram.Results:The nomogram included ITR signature, PTR 5 mm signature, PTR 10 mm signature, IPTR 5 mm signature, age, and BI-RADS category 4 subclassification for differentiating malignant and benign BI-RADS category 4 breast lesions and obtained AUCs of 0.94, 0.92, and 0.95 in the training set, test set, and external validation set, respectively. The calibration curve showed good agreement between the predicted probabilities and actual results and the decision curve indicated a good net benefit of the nomogram for predicting malignant BI-RADS 4 lesions in the training set, test set, and external validation set.Conclusion:The nomogram constructed from the radiomics features of the internal and surrounding regions of CESM breast lesions combined with clinical factors is attributed to differentiate benign from malignant BI-RADS category 4 breast lesions.
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Objective:We propose a quality control plan which is suitable for the actual situation of our hospital and keep our CT equipment in a normal working condition, so that we can get the best image quality.Methods: According to “GB 17589-2011 Specification for quality assurance testing of X-ray computed tomography apparatus”, we can get quality testing data of GE Lightspeed VCT from different time.Results: The indicators in quarterly testing meet the requirements, and have little difference with ideal value. Meanwhile the testing indicators have no significant change after calibration. The indicators in half year testing meet the requirements, and have large difference with ideal value. Meanwhile the testing indicators have significant change after calibration. Conclusion: According to the test results, combined with the daily use of experience, we carry out the quality control program for the actual situation of our hospital. It reduces the failure rate of the equipment, and improves the picture quality of CT equipment.
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Objective:To do research on quality control and calibration period of medical monitor, to assure that the medical monitor is being its best performance and to provide a stable and consistency medical diagnostic images for doctors.Methods: Based on DICOM and AAPM-TG18 calibration standards and using luminance meter and monitor calibration software, our hospital implemented detection and correction quarterly to nine medical monitors. At the same time we tested the brightness response data of medical monitor continuously for 55 weeks and recorded the various brightness with the change of time, then we did some work in statistic analysis and curve fitting using MATLAB software.Results: The performance parameters of our hospital medical monitors are in AAPM-TG18 specified range and the display characteristics are also consistent with the DICOM standard; The change of brightness quarterly of medical monitor is 0~25cd/m2 which is accorded with the function of DICOM GSDF. Conclusion: In order to ensure the accuracy of the impact of image diagnosis system, it’s reasonable and effective to do medical monitors quarterly testing based on brightness response curve.
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Objective:Through getting acknowledge of the High-voltage of medical linear accelerator, it makes it possible for the relative medical workers to do a quick reaction to the repairmen and maintenance to the accelerator, and to maintain the machine to a good performance efficiently. While through understanding the application situation and development of accelerator, we could do a better choice at the terms of choosing an accelerator for hospital which meet the basic requirements and accuracy.Methods: Using the block diagram to introduce the main part of High-voltage of medical linear accelerator, and especially introduce the charging pinciple of charging transformer and the charge and discharge of PFN. The accelerator plays a vital fuction at radiation therapy, and we introduce the accelerator application in various fields and the development situation of technology application.Results: It’s significant to know the working principle of High- voltage as it’s helpful to ensure whether the machine works normal or not and to diagnose faults in it.Conclusion: In addition, through understanding the application situation and the development of accelerator, we could choose an appropriate accelerator for our hospital.
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Objective To explore the characteristics,application and significance of electrocardiogragh (ECG)in diagnosis and differential diagnosis of pulmonary embolism(PE)by contrasting the ECG of PE and several diseases with similiar clinical features.Methods A total of 364 cases were enrolled in this study,including 197 cases of PE,70 cares of coronary artery disease(CAD)with congestive heart failure(CHF),47 cases of essential hypertension(EH)with CHF,and 50 cases of acute lung injury/acute respiratory distress syndrome(ALI/ARDS).The ECG of these 364 PE cases were analyzed.Results The rates of axle right drift,lockward rotation,right bundle branch block and pulmonary P wave,V1 lead s-wave were higher than control groups,with significant difference.Bates of S1Q3T3,disposition of T wave in chest lead were the highest in PE group,with significant difference.Conclusion The main appearances of ECG in PE patients hint the heavy load of right ventricular and coronary ischemia.Perhaps S1Q3T3 is the appearance of axle right drift.The sensitivity and speciality of every feature is not good enough to diagnosis or differential diagnosis;dynamic observation of ECG is of great significance to the diagnosis of PE.
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Objective To quantify the expressions of collagen metabolic markers carboxy terminal propeptide of type I procollagen(PICP),nitrogen terminal propeptide of type I procollagen (PINP),nitrogen terminal propeptide of typeⅢprocollagen(PⅢNP),type I collagen carboxy terminal telopeptide (ICTP), matrix metalloproteinases(MMPs)and the tissue inhibitor of metalloproteinases(TIMPs)in the serum of atrial fibrillation patients by enzyme linked immunosorbent assay(ELISA),and to discuss the atrial structural remodeling during atrial fibrillation(AF).Methods 71 elderly patients were enrolled,24 patients had permanent AF,24 patients had paroxysmal AF,and 23 patients were in sinus rhythm.The serum levels of all markers were measured by ELISA. Results PICP was increased in permanent AF group versus the paroxysmal AF group and sinus rhythm group by 25.4%and 42.8%(all P<0.05),respectively.PⅢNP was increased in permanent AF group versus the paroxysmal AF group and sinus rhythm group by 17.9a% and 35.6%(all P<0.05),respectively,and was increased in the paroxysmal AF group versus the sinus rhythm group by 15.0%(P<0.05).PINP and ICTP did not differ significantly between the 3 groups(all P >0.05).MMP-1 was significantly increased by 25.6%(P<0.05)in the paroxysmal AF group versus the sinus rhythm group.MMP-2 was also significantly increased in permanent AF group versus the paroxysmal AF group and sinus rhythm group by 54.9%and 37.9%(all P<0.05),respectively.MMP-7,MMp-9 and TIMP-1 did not differ significantly between the 3 groups(P>0.05).TIMP-2was significantly decreased in the permanent AF group and paroxysmal AF group versus the sinus rhythm group by 21.8%and 11.8%(P<0.05),respectively. Conclusions Disturbance in the balance of MMP/TIMP system may perturb the balance of collagen synthesis and degradation during atrial fibrillation.This may be a contributing mechanism to atrial structural remodeling in atrial fibrillation,and may correlate with the initiation and maintenance of AF.
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Objective To investigate vagal effects on atrial fibrillation(AF)thresholds at different sites of pulmonary veins after autonomic denervation.Methods In 10 mongrel dogs,the cervical vagal trunks were isolated bilaterally and decentralized from Oct 2004 to May 2005.The ansae subclaviae were exposed bilaterally as they exited from the stellate ganglia,doubly ligated,and cut.Local rapid electrical stimulation(S1S1=80 ms,impulse duration 0.5 ms)was performed to right appendage(RAA)、left appendage(LAA)、left atrium(LA)and different sites of 4 pulmonary veins.AF threshold was determined at each site in the baseline state,during bilateral cervical vagal stimulation(VNS,12.5 Hz,impulse duration 0.5 ms,stimulation voltage 5～8 V)and during infusion of atropine.Results During VNS,a lower AF threshold was observed at all sites,especially at distal of 4 pulmonary veins(P0.05).Conclusion Vagal nerve not only contributes to the maintenance of AF originating from pulmonary veins,but also greatly promotes the initiation of AF.
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Objective To investigate the association between syncope and transient suppression of sinoatrial node in patients with preexcitation syndrome and paroxysmal supraventricular tachycardia (PSVT).Methods Twelve patients (male 8,female 4;age range:19-49 years) were enrolled due to WPW(Wolff-Parkinson-White) syndrome and syncope when the tachycardia terminated.The function of sinoatrial node was evaluated with clinical electrophysiologic study,and then radiofrequency catheter ablation (RFCA) or antitachycardia pacemaker were optimized for the patients with a follow-up of 2 to 5 years.Results Electrocardiographic features of the 12 patients were: ventricular preexcitation (type A in 7 and type B in 5) and long pause when tachycardias ended up.Electrophysiologic study revealed the function of sinoatrial node was normal.Four patients received antitachycardia pacing therapy,5 underwent RFCA,and 3 received both.The 2 to 5 years follow-up found no relapse of PSVT associated syncope.Conclusion Transient suppression of sinoatrial node might explain the mechanism of syncope with preexcitation and PSVT.However,the reason why such a small group of patients differ from the majority of preexcited cases in clinical course remains to be unsettled.The first choice of prevention and treatment for these patients should be eliminating PSVT.Conventional pacemaker implantation for preventing syncope seems to be unnecessary.
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Objective To inquire into T-type calcium channel effects on atrial electrical remodelling and its mechanisms during atrial fibrillation.Methods Animal experiment was performed in Peking University Pepole's Hospital from Feb.2002 to Oct.2006.Fifteen adult cross-bred dogs were used in the experiment.Ten dogs underwent continuous rapid atrial pacing(500 beats/min)for twenty-four weeks to create persistent atrial fibrillation.In five rapidly-paced dogs,50mg pure powder/day of mibefradil dihydrochloride was given from the second day after pacemaker implantation and continued until the twenty-fourth week.A group of size-matched dogs(n=5)without being given mibefradil was used as a pure atrial fibrillation group.Another group of size-matched dogs(n=5)without pacemaker implantation was used as a control group.Atrial fibrillation duration was determined by electrophysiological study.Canine atrial myocytes were isolated by enzymatic dissociation and intracellular Ca2+ cytosolic transient was studied with confocal imaging.Results (1)The preoperation atrial effective refractory period was 280/90~110 ms.In the twenty-fourth week after rapid atrial pacing,atrial effective refractory period was obviously extended(2000/1400~1700 ms)in the T-type Ca2+ channel blocker group compared with the preoperation one.In the twenty-fourth week,the induced rate of persistent atrial fibrillation was 75% in atrial fibrillation group,whereas the persistent atrial fibrillation occurred in only one case(20%)in the T-type Ca2+ channel blocker group.(2)Intracellular Ca2+ concentration of atrial myocytes was unremarkably changed in control group after blocking L-type Ca2+ channel(1.17?0.09 OD ratio),whereas the intracellular Ca2+ concentration was obviously enhanced(2.35?1.05 OD ratio)(P