首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
目的 采用单源光子CT较低管电压联合Care Dose 4D技术,评价主动脉成像图像质量和辐射剂量.方法 43例患者按照扫描管电压随机分为2组,即120 kV组(n=19)和100 kV组(n=24).平扫采用固定管电压(100、120 kV),增强扫描采用自动管电压调节技术(Care kV),参考管电压预设为100、120 kV,平扫和增强扫描均联合Care Dose 4D技术.比较不同扫描条件下2组患者主动脉图像质量、CT值和辐射剂量变化,包括平均容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)和有效剂量(ED).结果 平扫,2组主动脉上中下段CT值差异无统计学意义(P>0.05),100 kV组辐射剂量(CTDIvol、DLP、ED)明显低于120 kV组.平扫和增强扫描,100 kV组有效剂量ED较120 kV组分别降低41.36%和67.80%.Care 100 kV组主动脉各段的CT值均高于120 kV组(P<0.05),两组主动脉成像图像质量评分差异无统计学意义(P>0.05).结论 联合Care Dose 4D技术,Care kV低管电压能够明显降低主动脉CT血管成像辐射剂量,而图像质量不受影响.  相似文献   

2.
目的探讨80 kV管电压下迭代重建算法联合自动管电流调制技术在低剂量头颈部CT血管造影(CTA)中的应用价值。方法将100例行头颈部CTA检查患者分为对照组和观察组,每组50例。对照组进行CTA扫描时管电压120 kV,固定管电流250 mAs,采用滤波反投影法重建图像;观察组进行CTA扫描时管电压80 kV,自动管电流调制,采用iDose4 3级迭代算法重建图像。对比两组患者的图像质量主观评分、图像质量客观评价及辐射剂量。结果两组患者的图像质量主观评分差异无统计学意义(P>0.05);观察组左右颈总动脉、左右颈内动脉、基底动脉及左右大脑中动脉的CT值、基底动脉CT值的标准差、信噪比和对比噪声比均高于对照组(均P<0.05);观察组的容积CT剂量指数、剂量长度乘积及有效剂量均低于对照组(均P<0.05),观察组的有效剂量较对照组下降约55.7%。结论采用迭代重建算法联合自动管电流调制技术行低剂量头颈部CTA检查,可以在保证图像质量的前提下,有效地降低被检者的辐射剂量,实现辐射剂量个体化原则。  相似文献   

3.
目的:探讨螺旋CT管电流调控技术在肺部低剂量扫描的可行性和辐射防护价值。方法:随机抽取肺部CT检查患者60例。以固定管电压(120kV),在CT自动mA基础上,对照组分别选其1/2mA、1/4mA和1/8mA量进行扫描,以支气管或肺内结节病灶细节显示程度,对每一幅不同剂量图像信息显示结果进行比较。结果:60例4组不同管电流CT图像质量评分均数为:自动mA组为4.21,1/2mA组为3.68,1/4mA组为3.45,1/8mA组为2.42,方差分析差异有统计学意义。自动mA与1/4mAX线量为4:1,辐射剂量有明显差异。1/8mA扫描对肺内病灶可以观察,但图像质量较差。结论:CT管电流调控技术在肺部扫描的正确应用,可以在保证图像质量的同时,有效地降低受检者辐射剂量。CT自动mA调至1/4,可作为肺部低剂量扫描的优先选择条件。  相似文献   

4.
目的分析CT自动管电流智能调节技术(CARE Dose 4D)在不同管电压下正常人群胸部螺旋CT的图像质量和辐射剂量的关系。方法将63例体重指数(BMI=25–30)正常人群胸部CT影像学检查随机分为对照组A和研究组B、C三组(每组21例):管电压分别对应A组=120kV和B组=100kV组、C组=80kV,采用CT自动管电流智能调节技术,将3组图像的辐射剂量[CTDIvol]、剂量长度乘积(DLP)、有效剂量(ED)和图像质量信噪比(SNR)、对比噪声比(CNR)、3分法图像质量评分进行统计学对照分析。结果研究组与对照组两两比较,100kV、80kV组辐射剂量均明显低于对照组120kV,差异有明显统计学意义(P值均=0.000),有效辐射剂量(ED)分别降低为26%和68%;100kV组与120kV组图像质量SNR、CNR、3分法图像质量评分差异无统计学意义,80kV组SNR、CNR明显增大,与120kV对比组差异有明显统计学意义。结论体重指数(BMI=25–30)胸部螺旋CT扫描采用自动管电流智能调节技术下100kV能在不影响图像质量的前提下明显减少辐射剂量。  相似文献   

5.
目的 探讨100kV管电压结合自动毫安调节技术行低剂量CT肺静脉成像的可行性.方法 将患者分为100 kV组(26例)和120 kV组(43例),分别采用100 kV和120 kV管电压结合自动毫安调节技术肺静脉CT扫描,定量和定性评价两组图像的质量和辐射剂量.结果 100 kV组的有效剂量较120 kV组降低24%,差异具有统计学意义(P<0.01).图像质量量化评价显示100 kV组与120 kV组两组信噪比、对比噪声比差异无统计学意义(P>0.05);目测评分为100 kV组5分13例、4分11例、3分2例;120 kV组为5分31例、4分8例、3分4例,差异无统计学意义(P>0.05).100 kV组右下肺静脉平均CT值较120 kV组升高48.56 HU(P<0.05).结论 100 kV与120 kV结合自动毫安调节技术,肺静脉成像在能够保证图像质量的同时,降低辐射剂量.  相似文献   

6.
目的:探讨新生儿头颅低剂量CT扫描最佳参数在新生儿缺氧缺血性脑病(HIE)诊断中的应用价值.方法:前瞻性选取临床拟诊HIE 120例,随机等分为4组.扫描参数:管电压120 kV,层厚、层间距7 mm,管电流常规剂量组200 mAs、低剂量组分别为100,75,50 mAs行颅脑扫描.对比4种剂量扫描产生的CT剂量加权...  相似文献   

7.
目的:探讨多层螺旋CT低辐射和低对比剂浓度(双低技术)扫描在肺动脉血管成像中应用的可行性。方法:(1)体模实验:分别用生理盐水将碘海醇稀释成16.0、11.1、7.7和5.4 g/L的碘溶液5 mL置于4个塑料软管中,管外包裹新鲜猪肉,制备成肺部血管模型;模型定位后采用西门子双源256排CT扫描仪进行扫描,管电压分别设置为80、120 kV,管电流分别设置为100、150、200、300 mA,采用iDose4技术进行图像重建;计算重建图像的对比信噪比(CNR)、信号噪声比(SNR)。(2)人体试验:将60例临床高度疑似肺动脉栓塞患者分为对照组和观察组各30例,对照组采用常规扫描(管电压120 kV、管电流300 mA、碘海醇350 g/L),观察组采用双低技术扫描(管电压80 kV、管电流300 mA、碘海醇270 g/L),均采用iDose4进行图像重建。比较两组重建图像的质量。结果:相同管电流不同管电压、不同碘浓度扫描图像CNR、SNR的差异均无统计学意义(P>0.05)。观察组与对照组比较,图像质量评分,肺动脉主干、左右肺动脉和...  相似文献   

8.
目的 探讨多参数设置在优化低剂量胸腹部CT扫描图像质量及辐射剂量中的应用效果。方法 选取2020年5月至2022年5月于本院行低剂量胸腹部CT扫描的140例患者作为研究对象,按随机数字表法分为4组,各35例。所有患者均选用GE 64排CT扫描仪开展检测,4组iCT管电流均设置为17 mAs,其中A、B两组均以Dose Right扫描,C、D两组固定管电流扫描,其中A组管电压120 kv、B组管电压100 kv、C组管电压120 kv, D组管电压100 kv,其余扫描参数4组均保持一致。比较4组图像质量、信噪比(SNR)变化及辐射剂量。结果 A组、B组肺窗、纵隔窗、腰大肌iDose4、IMR图像质量评分高于C组、D组,差异有统计学意义(P<0.05);A组、B组肺窗、纵隔窗、腰大肌iDose4、IMR图像质量评分相比,差异无统计学意义(P>0.05);A组、B组iDose4图像SNR、IMR图像SNR高于C组、D组,A组iDose4图像SNR高于B组,A组DLP、ED高于B组、C组、D组,B组mGy、mSv低于C组、高于D组,差异有统计学意义(P<0.05)。结论 当...  相似文献   

9.
目的 探讨低剂量联合全模型迭代重建应用于心房颤动患者左房肺静脉及心功能一站式检查的可行性。方法 将行射频消融术的60例心房颤动患者随机分为试验组(30例)和对照组(30例),所有患者术前均行左房肺静脉CT血管造影检查。试验组扫描条件为管电压80 kV,管电流350 mA,采用全模型迭代算法重建;对照组扫描条件为管电压100 kV,管电流500 mA,采用迭代重建算法(iDose4)重建。比较两组的图像质量主观和客观评分、辐射剂量相关指标。分析试验组基于CT和超声测量的心功能指标的一致性。结果 试验组的图像质量主观评分高于对照组(P<0.05)。试验组左心房、降主动脉、右上肺静脉、右下肺静脉、左上肺静脉、左下肺静脉的噪声值低于对照组,对比度噪声比和信噪比高于对照组(P<0.05)。试验组的容积CT剂量指数、剂量长度乘积、有效剂量低于对照组(P<0.05),且上述指标的降低率分别为56.6%、 59.5%及59.6%。试验组基于CT和超声测量的左心室最大容积及左室射血分数的组内相关系数分别为0.896、0.912(P<0.05),一致性较好。结论 对于心房颤动患者,...  相似文献   

10.
目的 探讨自动管电压联合自动管电流在冠状动脉CT血管成像(Coronary Computed Tomography Angiography,CCTA)中的应用价值。方法 回顾性收集90例于我院行CCTA的受检者,按照扫描参数分为A组(n=43)和B组(n=47)。A组、B组分别采用固定管电压联合自动管电流(固定管电压100kV,参考管电流370mAs)、自动管电压联合自动管电流(参考管电压100 kV,参考管电流370 mAs)。对比两组的图像质量主观评分、冠状动脉CT值、噪声值、对比噪声比(Contrast to Noise Ratio,CNR)、管电压、管电流、容积CT剂量指数(Volume CT Dose Index,CTDIvol)、剂量长度乘积(Dose Length Product,DLP)和有效剂量(Effective Dose,ED)。结果 在图像质量方面,两组图像质量主观评分均≤3分,能满足临床诊断要求;两组图像主观评分、CNR差异无统计学意义(P>0.05);B组冠状动脉CT值、噪声值高于A组,差异均有统计学意义(P<0.05)。在...  相似文献   

11.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.  相似文献   

12.
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.  相似文献   

13.
Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P< 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P< 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.  相似文献   

14.
目的:评价使用安心颗粒对急诊经皮冠状动脉介入术(PPCI)术后生活质量的影响.方法:将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组(术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次)和对照组(仅接受基础药物治疗).所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表(MIDAS)、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果:入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异(P>0.05);出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低(P<0.05);组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低(P<0.05).两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血(P>0.05).两组发生轻度血小板减少症的患者数比较无差异(P>0.05).结论:PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.  相似文献   

15.
Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P<0.01);the MAP decreased(P<0.01)and the HR increased drastically(P<0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.  相似文献   

16.
Objective:To investigate the gene expression of osteoprotegerin(OPG) and osteoclast differentiation factor(ODF) in the bone tissue of patients with hip fracture due to osteoporosis. Methods:OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers(over 50 years old) with hip fracture(Observer Group) and 30 cases of hip facture sufferers with no osteoporosis(Control group) were analyzed with the Semi-Quantitative RT-PCR method. Results:The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion:Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.  相似文献   

17.
Objective:To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas(SPTP). Methods:Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin(HE) staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results:Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin(9/9 cases), AAT(9/9 cases), NSE(9/9 cases), ACT(7/9 cases), CK20(2/9 cases), CgA(1/9 cases), S-100(3/gcases), PR(4/gcases), Syn(3/9 cases) and CD56(5/9cases), negative in CEA and ER. Conclusion:SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.  相似文献   

18.
Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.  相似文献   

19.
Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.  相似文献   

20.
Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号