腹腔动脉CT血管成像固定毫安秒低剂量技术探讨

Objective To characterize the feasibility of low-dose CT angingraphy on 16-slice multislice computed tomography (16-MSCT), and its relationship to the noise in the pre-contrast image and enhancement value.Methods Forty-three consecutive patients (male 21, female 22, mean age 59 years, median age 56 years) underwent abdominal 16-MSCT (Toshiba Aquilion 16) with constant scanning parameters including 120 kVp, a 0.5-second gantry rotation time, a pitch of 0.938: 1, and 16×1-mm detector collimation.The mA was set at 200 in the pre-contrast scan and 160 in the contrast-enhanced scan.The arterial phase images were retrospectively reconstructed with 1-mm slice thickness, 0.8 mm interval.The pre-contrast noise was defined as the standard deviation (SD) of the aorta at the level of right posterior crura of diaphragm.The enhancement of aorta was also measured at level of celiac artery.The volume rendering of CT angiography was made and classified into three grades (excellent, good, bad).Receiver operating characteristic curve (ROC) was used to evaluate the relationship between the image quality of CT angiography and noise in the pre-contrast image and enhancement value.Results Twenty-five cases had the aorta enhancement between 300.0--400.0 HU.The sensitivity and specificity of excellent CTA image was 75% and 62%, respectively when the SD was 12.00.Eighteen cases had the aorta enhancement more than 400.0 HU.The sensitivity and specificity of excellent CTA image was all 100% when the SD was 12.25, and 100% and 75%, respectively when the SD was 13.35.The area under curve of CTA image quality and enhancement in receiver-operated characteristic analysis was O.907.The enhancement was more than 356.7 HU when the sensitivity and specificity of excellent CTA image was 100% and 60%, respectively, and 389.8 HU when 78% and 80%.When the enhancement was more than 442.4 HU, the specificity of excellent CTA image was 100%.Conclusions MSCT angiography with low radiation dose is feasible.Good CT angiography demands great enhancement, and then, the needed mAs is lower when the SD is smaller.     

应用彩色多普勒自动测量房间隔缺损分流量的临床评价

目的应用彩色多普勒自动测量心输出量功能(Automated Cardiac Flow Measurement,ACM)测量房间隔缺损分流量,并评价其临床应用价值.方法分别应用ACM直接法,ACM间接法与脉冲多普勒法测量40例经手术证实的房间隔缺损患者的分流量,并与手术中测量的缺损径对比.结果ACM直接法测量的分流量与ACM间接法及脉冲多普勒法测量结果之间有显著性差异,并与手术测量缺损径间呈直线相关(r＝0.83,P＜0.001).结论ACM为定量评价房间隔缺损分流量提供了一种简单、快速、精确的新的测量方法.     

基于320排螺旋CT大鼠全肝灌注模型制备的初步研究

目的探讨成功制造大鼠全肝灌注模型的成像参数及技术关键。材料与方法10只Wistar成年雄性大鼠,随机分5组。分别采用不同的对比剂注射剂量、浓度及流速。观察时间-密度曲线(TDC图)、CTA图及测量灌注值。结果采用11号留置针,对比剂浓度为150ml/mg,剂量为1ml,流速为1ml/s模式,可以得到良好的TDC曲线和灌注图。大鼠肝灌注主要参数:主动脉峰值1.5s,门脉峰值6.7s;肝组织峰值12s。结论成功制备大鼠全肝灌注模型将为进一步研究肝脏病变奠定基础。     

回生再造丸对帕金森病模型大鼠的影响

目的：探讨回生再造丸对帕金森病模型大鼠的影响。方法：通过向大鼠左侧黑质致密部（SNc）和中脑腹侧背盖区(VTA)纹状体两点注射6-羟基多巴胺（6-OHDA）的方法制作帕金森病大鼠模型,通过灌胃给药,连续3周,探讨回生再造丸高、中、低剂量（1.4,0.7,0.35 g?kg-1）对帕金森病大鼠的影响;旋转行为通过计数30 min内大鼠的旋转圈数测定;DA,HVA,MAO-B,AchE和GSH-px含量分别由其试剂盒测定。结果：回生再造丸可减少阿朴吗啡引起帕金森病大鼠30 min内的旋转圈数,降低损伤侧脑组织中的MAO-B活性,提高DA,HVA和AchE含量,但GSH-px含量无统计学差异。结论：回生再造丸对帕金森病模型大鼠具有一定的治疗作用。     

原花青素体外清除自由基活性的研究

从葡萄籽中提取高纯度的原花青素 ,测得其对稳定自由基 1 ,1 -联苯 -β-苦基偕腙肼( DPPH)的半数抑制浓度 ( EC50 )为 44mg/L ;又利用 2 -脱氧 - D-核糖法产生· OH,在原花青素浓度为 1 0 g/L时可清除该体系中 80 %的· OH,表明原花青素是一种天然有效的自由基清除剂     

东芝TCT-600HQ型CT机故障检修一例

故障现象扫描时旋转过冲,不能得到图像。机械位置必须复位后,才能重新启动。分析检修我们从检查机械起始,限位传感器及过冲保护器均正常。怀疑旋转速度控制出了问题,本机机架旋转的控制信号见维修手册２Ｄ２７０－０２３Ｅ图４２－６５。测量伺服系统的控制电压,在...     

CT灌注新技术及临床应用探讨

灌注成像是指应用一定的影像学手段检测活体灌注过程,并行定量或半定量分析,以反映所研究的器官组织在生理和病理情况下的血流动力学改变,获取微循环信息。灌注成像技术的出现和发     

腹腔动脉CT血管成像固定毫安秒低剂量技术探讨

Objective To characterize the feasibility of low-dose CT angingraphy on 16-slice multislice computed tomography (16-MSCT), and its relationship to the noise in the pre-contrast image and enhancement value.Methods Forty-three consecutive patients (male 21, female 22, mean age 59 years, median age 56 years) underwent abdominal 16-MSCT (Toshiba Aquilion 16) with constant scanning parameters including 120 kVp, a 0.5-second gantry rotation time, a pitch of 0.938: 1, and 16×1-mm detector collimation.The mA was set at 200 in the pre-contrast scan and 160 in the contrast-enhanced scan.The arterial phase images were retrospectively reconstructed with 1-mm slice thickness, 0.8 mm interval.The pre-contrast noise was defined as the standard deviation (SD) of the aorta at the level of right posterior crura of diaphragm.The enhancement of aorta was also measured at level of celiac artery.The volume rendering of CT angiography was made and classified into three grades (excellent, good, bad).Receiver operating characteristic curve (ROC) was used to evaluate the relationship between the image quality of CT angiography and noise in the pre-contrast image and enhancement value.Results Twenty-five cases had the aorta enhancement between 300.0--400.0 HU.The sensitivity and specificity of excellent CTA image was 75% and 62%, respectively when the SD was 12.00.Eighteen cases had the aorta enhancement more than 400.0 HU.The sensitivity and specificity of excellent CTA image was all 100% when the SD was 12.25, and 100% and 75%, respectively when the SD was 13.35.The area under curve of CTA image quality and enhancement in receiver-operated characteristic analysis was O.907.The enhancement was more than 356.7 HU when the sensitivity and specificity of excellent CTA image was 100% and 60%, respectively, and 389.8 HU when 78% and 80%.When the enhancement was more than 442.4 HU, the specificity of excellent CTA image was 100%.Conclusions MSCT angiography with low radiation dose is feasible.Good CT angiography demands great enhancement, and then, the needed mAs is lower when the SD is smaller.     

MR“一站”式心脏解决方案

MR心脏检查的临床应用受到越来越多的关注.MRI不仅可就形态学作出精确诊断,还可进行多参数的心脏功能分析.     

动态容积CT在急性脑卒中成像中的应用

在美国,脑卒中居严重长期致残病因的首位,是第3位的致死病因^[1-2]。据估计,在2008年,脑卒中导致的直接和间接损失高达650亿美元^[3]。脑卒中病人的愈后很大程度取决于缺血脑组织血流重建的速度。脑卒中发生时，每分钟因缺血而死亡的神经元大约是190万个^[4]。血流重建越快，病人愈后越好。