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find Author "YUAN Yuan" 8 results
  • Assessment of Low-Dose Radiation in Coronary Artery Imaging by 64-Slices Multi-detector CT

    【摘要】 目的 评价64层螺旋CT低剂量冠状动脉血管成像的价值。 方法 2009年1-6月157例患者随机分为3组,常规剂量组(A组)管电流量采用1 000 mAs,两个低剂量组(B、C组)分别采用800、600 mAs。对3组的图像质量、噪声、CT剂量指数(CTDI)、剂量长度乘积(DLP)和有效剂量(ED)进行评估。 结果 A、B、C组图像噪声分别为20.50±3.23、23.02±3.05和26.28±2.58,组间差异均无统计学意义(Pgt;0.05);A、B、C组的CTDI分别为(58.7±0.23)、(46.98±2.27)、(35.28±3.56) mGy,DLP分别为(1 050.88±89.63)、(846.21±57.86)、(641.13±32.15) mGy?cm,ED分别为(14.78±2.56)、(11.85±1.87)、(8.98±1.15) mSv,B、C组的CTDI、DLP、ED均明显低于常规剂量A组(Plt;0.05),C组的CTDI、DLP、ED均为3组中最低值。 结论 64层螺旋CT冠状动脉血管检查,采用600 mAs管电流量获得的冠脉图像既可满足诊断需要,又可使患者接受的辐射剂量降低。【Abstract】 Objective To evaluate the best tube current for low-dose radiation CT in coronary artery imaging by 64-slices multi-detector CT. Methods From January to June 2009, a total of 157 consecutive patients were randomly divided into 3 groups: group A (conventional group): 1 000 mAs; group B: 800 mAs; group C: 600 mAs. The image quality, noise, CT dose index (CTDI), dose length product (DLP) and effective dose (ED) in each group were measured and compared respectively. Results The image noise scores in group A, B, and C were (20.50±3.23), (23.02±3.05) and (26.28±2.58), respectively. There was no statistically significant difference among the three groups in the two indexes (Pgt;0.05). The CTDI in group A, B and C were (58.7±0.23), (46.98±2.27), and (35.28±3.56) mGy, respectively; the DLP in each were (1 050.88±89.63), (846.21±57.86), and (641.13±32.15) mGy?cm, respectively; the Ed were (14.78±2.56), (11.85±1.87), and (8.98±1.15) mSv, respectively. All of the differences among the three groups in CTDI, DLP and ED were statistically significant (Plt;0.05). Conclusion The image with 600 mAs as tube current in the coronary artery imaging of 64-slices multi-detector CT could fulfill the need of the diagnosis, and the radiation dose is apparently lower than the conventional scan.

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  • Application progress of dual-energy CT in pancreatic imaging

    Objective To summarize the recent application progress of dual-energy CT in pancreatic imaging. Methods The domestic and international published literatures related to the application of dual-energy CT in pancreatic imaging in recent years were collected and reviewed. Results Dual-energy CT could provide the morphological image and function information of tissues and organs simultaneously. At present, the clinical application of dual-energy CT in pancreatic imaging included low tube voltage technology, iodine overlay, virtual non-enhanced imaging, and monoenergetic imaging. Conclusion Dual-energy CT could contribute to detecting pancreatic lesions, reducing radiation dose, and improving image quality in pancreatic imaging.

    Release date:2017-06-19 11:08 Export PDF Favorites Scan
  • Low-dose Multislice Spiral CT for Upper Urinary Tract Obstruction in Children

    【摘要】 目的 探讨多层螺旋CT低剂量扫描在小儿上尿路梗阻性疾病中的应用价值。 方法 2008年1月-2009年6月经临床手术证实尿路梗阻的患儿52例,按梗阻的原因分为结石组13例与非结石组39例。将非结石组患儿,按照年龄分为0~1岁(8例)、1~5岁(16例)和5~10岁(15例)3个组,均采用个性化的低剂量扫描方式。 结果 结石组与非结石组阳性诊断率均为100%。低剂量扫描患儿所接受的辐射剂量明显降低,CT扫描管电流不变,管电压降低1/3,CT检查的辐射剂量可降低约70%,且均可达到临床诊断要求。 结论 多层螺旋CT低剂量个性化扫描在小儿上尿路梗阻性疾病中诊断中具有明显优势。【Abstract】 Objective To evaluate low-dose multislice spiral CT for upper urinary tract obstruction in children. Methods From January 2008 to June 2009, 52 children with upper urinary tract obstruction were diagnosed via clinical surgeries. The patients were divided into two groups according to whether having renal calculus (13 patients) or not (39 patients). The patients in non-calculus group were divided into three sub-groups: aged 0-1 (eight patients), 1-5 (16 patients), and 5-10 (15 patients). Low dose multislice spiral CT with different doses was performed. Results The rate of positive predictive diagnosis was 100% in both calculus and non-calculus group. Low dose scan reduced the radiation dose of children. The fixed tube current and the decreased tube voltage (decreased 1/3) led to the decrease of the radiation dose (decreased 70%), which were feasible for diagnosis. Conclusion Low-dose multislice spiral CT was available for upper urinary tract obstruction in children.

    Release date:2016-08-26 02:21 Export PDF Favorites Scan
  • Application of scalp electroencephalogram in treatment of refractory epilepsy with vagus nerve stimulation

    Electroencephalogram (EEG) has been an important tool for scientists to study epilepsy and evaluate the treatment of epilepsy for half a century, since epilepsy seizures are caused by the diffusion of excessive discharge of brain neurons. This paper reviews the clinical application of scalp EEG in the treatment of intractable epilepsy with vagus nerve stimulation (VNS) in the past 30 years. It mainly introduces the prediction of the therapeutic effect of VNS on intractable epilepsy based on EEG characteristics and the effect of VNS on EEG of patients with intractable epilepsy, and expounds some therapeutic mechanisms of VNS. For predicting the efficacy of VNS based on EEG characteristics, EEG characteristics such as epileptiform discharge, polarity of slow cortical potential changes, changes of EEG symmetry level and changes of EEG power spectrum are described. In view of the influence of VNS treatment on patients’ EEG characteristics, the change of epileptiform discharge, power spectrum, synchrony, brain network and amplitude of event-related potential P300 are described. Although no representative EEG markers have been identified for clinical promotion, this review paves the way for prospective studies of larger patient populations in the future to better apply EEG to the clinical treatment of VNS, and provides ideas for predicting VNS efficacy, assessing VNS efficacy, and understanding VNS treatment mechanisms, with broad medical and scientific implications.

    Release date:2020-10-20 05:56 Export PDF Favorites Scan
  • Analysis of the SARS-CoV-2 specific antibodies and immune function of COVID-19 patients one year after discharge

    ObjectiveTo summarize the results of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibody, total antibody and cellular immune function of COVID-19 convalescent patients one year after discharge, and to analyze the correlation between the SARS-CoV-2 antibody and the indexes of immune function. MethodsA total of 41 confirmed COVID-19 patients discharged from Chengdu Public Health Clinical Medical Center from January to April 2020 and followed up one year after discharge were included in the study as the research group, including 18 males and 23 females with an average age of 47.83±12.95 years. The results of SARS-CoV-2 IgG, total antibody and immune function indexes one year after discharge were collected in order to discuss the correlation of SARS-CoV-2 and cellular immune function. A total of 40 healthy employees of the hospital vaccinated against COVID-19 were randomly selected as the vaccine group, including 10 males and 30 females with an average age of 43.90±6.86 years. The SARS-CoV-2 antibodies between the two groups were compared. ResultsCD8+T cell count was higher and CD4+T/CD8+T was lower in male patients than those in female patients (all P<0.05). The IgG and total antibodies in patients with re-detectable positive RNA test were both higher than those in patients without re-detectable positive RNA test, but the differences were not statistically significant (P=0.158, 0.060). The positive rate of SARS-CoV-2 IgG in the research group was 80.5% (33/41). SARS-CoV-2 IgG was positively correlated with total antibody (P<0.001). There was a positive correlation between CD4+T cell count and SARS-CoV-2 IgG (r=0.455, P=0.003). The positive rate of SARS-CoV-2 IgG, SARS-CoV-2 IgG amount and total antibody amount in the research group were significantly higher than those in the vaccine group (all P<0.001). ConclusionSARS-CoV-2 IgG of most COVID-19 patients one year after discharge is positive, and their SARS-CoV-2 total antibody is significantly higher than people vaccinated against COVID-19, which suggests that patients infected with SARS-CoV-2 can obtain lasting protection, but the protection may be gradually weaken over time. The degree of antibody attenuation in patients with re-detectable positive RNA test may be weaker. In the convalescence stage, the dynamics of SARS-CoV-2 IgG may be closely related to cellular immune function.

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  • Application of interatrial shunt device in patients with severe pulmonary hypertension

    Pulmonary arterial hypertension (PAH) is a severe, progressive disease leading to right ventricular failure and finally death. Lung transplantation is recommended for PAH patients who do not respond to targeted drug combination therapy or World Health Organization functional class (WHO FC) Ⅲ or Ⅳ. However, only 3% of PAH patients can recieve the lung transplantation. A novel implantable interatrial shunt device (ISD) can create a relatively fixed right-to-left shunt established by balloon atrial septostomy (BAS). The device may decompress the right sided chambers, facilitate left heart filling, improve organ perfusion and reduce the likelihood of syncope, acute pulmonary hypertensive crisis and death. The systemic oxygen transport improves despite hypoxemia. Implantation is simple, feasible and safe, and the X-ray time and operation time are short. There is no severe complication or thrombosis during the mid-term follow-up of the clinical studies and the device remained patent. The syncope symptoms, six-minute walk distance, cardiac index and systemic oxygen transport improve significantly in the patients. ISD may be currently the last alternative treatment to improve symptoms and prolong survival in currently drug-resistant patients with severe PAH.

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  • Stiff left atrial syndrome after Mei mini maze procedure for atrial fibrillation: A retrospective study

    ObjectiveTo analyze the clinical characteristics of stiff left atrial syndrome (SLAS) after Mei mini maze procedure for atrial fibrillation (AF), and to explore its risk factors and treatments. Methods We retrospectively analyzed the clinical data of the patients who underwent Mei mini maze procedure in Xinhua Hospital between 2010 and 2020. According to whether SLAS occurred in the early postoperative period, patients were divided into a SLAS group and a non-SLAS group. The basic data, perioperative echocardiogram and laboratory test indexes of the two groups were compared. Results A total of 1 056 patients were collected. There were 672 (63.6%) males with an average age of 63.6±9.3 years, including 489 patients with persistent AF and 567 patients with paroxysmal AF. Fourteen (14/1 056, 1.3%) patients developed SLAS, with an average occurrence time of 2.1±1.1 days after the surgery. The average follow-up time of the whole group was 21.4±7.8 months. Two patients in the SLAS group developed SLAS again after discharge, and the occurrence time was 3 weeks and 4 weeks after the operation, respectively; while no SLAS occurred after discharge in the non-SLAS group. Diabetes and small preoperative left atrial diameter were risk factors for SLAS after surgery. Patients with SLAS had a good prognosis after adequate diuretic therapy. Conclusion The incidence of SLAS after Mei mini maze procedure for AF is low, and it mostly occurs in the early postoperative period. After adequate diuretic treatment, the prognosis is good.

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  • Application of Dual-Source Computed Tomography Low Dose Technology in Upper Abdomen Enhanced Inspection

    Objective To discuss the application of dual-source computed tomography (CT) low dose technology in the upper abdomen enhanced inspection. Methods Six hundred consecutive patients from July 2011 to February 2012 in this hospital were orderly divided into ordinal tube current (210 mAs) group and low dose tube current group (200 mAs,190 mAs,180 mAs,170 mAs,and 165 mAs). The standard deviation (SD) of subcutaneous fat,signal to noise ratio (SNR) of liver and pancreas, contrast to noise ratio (CNR) of liver-erector spinae and pancreas-erector spinae,score of subjective diagnosis and the indexes of radiation dose,including CT dose index (CTDI),dose length product (DLP),effective dose (ED) were measured,calculated,and assessed respectively on CT images of arterial phase and portal phase from each group. Results The SD of subcutaneous fat, SNRs of liver and pancreas,score of subjective diagnosis,and the CTDI,DLP,ED of CT images in arterial phase and portal phase were significantly different from each other (P<0.05),while CNRs of liver-erector spinae and pancreas-erector spinae were not statistically significant (P>0.05). The SNR,radiation dose,and score of subjective diagnosis of the 165 mAs tube current group were the lowest among all the groups,but the images of the 165 mAs tube current group could not fulfill the need of diagnosis. Conclusions It is really feasible that the method of decreasing tube current gradually in the upper abdomen enhanced CT inspection could ensure that the radiologists could adapt the low dose image bit by bit,and this methods could be popularized to all kinds of CT facilities we own currently. The images with 170 mAs as tube current in the upper abdomen enhanced inspection of dual-source CT could fulfill the need of diagnosis,and the radiation dose of patients is apparently lower than that the conventional scan.

    Release date:2016-09-08 10:37 Export PDF Favorites Scan
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