64层CT下肢动脉成像技术研究

目的探讨64层CT下肢动脉成像强化质量的对比剂注射方式。方法前瞻性地选择60例疑诊下肢动脉病变的病人,利用64层螺旋CT行下肢动脉CT血管成像。采用不同的扫描和重建参数,应用370mgI/100ml浓度的对比剂100ml团注或采用先70ml的对比剂后50ml的0.9%生理盐水用双筒高压注射器分别以4.0ml/s的注射速度团注入肘静脉,应用对比剂追踪触发扫描方式待腹主动脉CT阈值达120HU时延迟7s开始扫描;利用MIP和VR方式重建CTA图像;对比不同参数和不同对比剂应用方式的CT血管成像图像质量。结果最佳的扫描与重建参数为准直64×0.6mm,螺距1.5,层厚1.0,重建间隔50%;最佳的对比剂应用方式为(浓度为370mgI/100ml)对比剂70ml、生理盐水50ml以4.0ml/s注射速度按先后顺序团注。结论选择合适的准直、螺距以保证适当的扫描速度,选择合适的对比剂浓度、用量和注射速度以保证血管内足够的对比剂峰值浓度及峰值持续时间,此二者是64层CT下肢动脉成像成功的关键。     

CT多层面重建和三维重建用于术前评价胸主动脉病变

作者评价了胸主动脉增强CT多平面和三维重建对术前制定治疗方案的价值。53例胸主动脉病变患者采用螺旋扫描方式采集数据,用19号针经肘静脉注入对比剂Iopramide(300mg/ml)100ml。扫描方式或采用5ml/s的快速手推注射,在注入40ml后即开始扫描,或是在100ml团注后立即扫描。扫描层厚5～10mm,螺旋CT的螺距为1,扫描间隔15～20s。图像用Advantage Windows1.2重建。对     

屏气状态下正常肺实质多层螺旋CT首过期灌注成像初探

目的 探讨屏气状态下肺实质多层螺旋CT首过期的灌注值.方法 共收集健康国人志愿者60例,按注射对比剂速度不同平均分为3组,首先行肺部常规平扫,之后选择Perfusion序列对肺门层面进行同层动态增强扫描.对比剂采用优维显300(Ultravist 300,碘含量300 mg/ml),注射速度3 ml/s、4 ml/s和5 ml/s,总注入量为40 ml.通过高压注射器经肘前静脉团注,单次扫描时间为0.5 s,扫描间隔时间亦为0.5 s,即扫描周期为1.0 s,曝光同时注入对比剂(即延迟时间为0 s),共扫描30个周期,每个病例共获得30幅选定层面首过期的动态增强图像.应用DynEva软件通过感兴趣区域分析法获得双侧肺实质及肺动脉的时间密度曲线,根据公式计算正常肺实质首过期的灌注值及强化率.结果 注射速度为3 ml/s、4 ml/s和5 ml/s时健康国人肺实质的灌注值分别为(1.41±0.26)(均值±标准差)ml·min-1·ml-1,(1.01±0.14)ml·min-1·ml-1,(1.08±0.12)ml·min-1·ml-1;肺实质灌注值在注射速度为3 ml/s时与在注射速度为4 ml/s和5 ml/s时差异有统计学意义,后两者差异无统计学意义.结论 多层螺旋CT测量屏气状态下肺实质灌注值是可行的,当对比剂注射速率为4ml/s或以上时结果可靠,考虑到病人的外周静脉耐受压力,宜选择4 ml/s的注射速率.     

影响16层螺旋CT冠状动脉成像质量技术因素的探讨

目的:探讨16层螺旋CT冠状动脉血管成像技术。方法:272例受检者行16层螺旋CT冠状动脉血管成像检查,采用电影扫描序列,层厚为1.25mm或0.625mm,螺距为0.275:1,对比剂1.5~2ml/kg,注射速率3~4ml/s,采用容积再现(VR)、多平面重建(MPR)、曲面重建(CPR)和仿真内窥镜(VE)进行图像后处理重建,显示冠状动脉主干及其主要分支。结果:心率对图像质量的影响较大(χ2=23.936,P<0.01),心率平稳,心率在55~75次/min,MSCT对冠状动脉主干及主要分支显示率80.3%达到诊断要求,心率大于90次/分时,冠状动脉的主要分支显示不清;重建相位窗在55%、65%和75%之间显示一、二级高质量冠状动脉图像的例数无显著性差异(χ2=1.980,P>0.05),选择重建相位窗为75%可提高工作效率;采用扫描层厚为0.625mm或1.25mm(重建间隔为0.625)所得到的图像质量可满足影像及临床诊断需要(χ2=0.833,P>0.05),选择扫描层厚1.25mm所获得图像的信噪比及移动伪影明显减少;采用3.5ml/s或4ml/s注射速率图像重建后达到一、二级水平的图像质量基本接近(χ2=0.268,P>0.05),使用注射速率为3.5ml/s,显示冠状动脉清晰且受腔静脉伪影少。结论:心率平稳且小于75次/min,使用合适的重建相位窗、对比剂及扫描参数,MSCT可满意显示冠状动脉主干及主要分支,可作为冠状动脉粥样硬化疾患的筛选,对血管搭桥和内支架放置术后复查的评价有较高临床价值。     

低剂量与常规剂量对比剂双能量肺灌注图像质量对比分析

目的:探讨对比剂剂量对双源CT双能量肺灌注成像质量的影响.方法:疑肺动脉栓塞患者行双源CT双能量肺灌注扫描,30例使用低剂量(0.7ml/kg)对比剂,30例使用常规剂量对比剂(1.5ml/kg),注射速率均为4.5ml/s.扫描后同时获得肺动脉CTA及肺灌注图像.测量左、右叶肺动脉干及各肺叶动脉增强后的CT值,对比分析两组间增强后的CT值.判断肺灌注图像质量并分级,比较两组的肺灌注图像质量差异.结果:低剂量组与常规剂量组左、右叶肺动脉干及各肺叶动脉增强后的CT值无明显差异(P＞0.05).肺段及亚段肺动脉图像清晰显示.低剂量组肺灌注图像大部分信号均匀(26/30),常规剂量组肺灌注图像大部分信号均匀(24/30).常规剂量组上腔静脉、右心房高密度对比剂所致灌注伪影明显多于低剂量组(48:10).结论:低剂量与常规剂量双能量肺灌注成像的肺动脉图像质量无明显差异,降低对比剂剂量可以减少双能量肺灌注图像的伪影.     

扫描频率和层厚选择对肾皮质CT灌注参数值的影响

目的 研究选择不同扫描频率和层厚对肾皮质CT灌注参数值的影响.方法 15例志愿者行肾脏CT灌注扫描,扫描时间为32 s.扫描层厚为5 mm,重建层厚2.5 mm.采用cine扫描模式完成扫描.然后依据间隔1 s、2 s、3 s分别选取一系列图像进行灌注分析,观察不同时间间隔灌注参数血流量(BF)、血容量(BV)、平均通过时间(MTT)、毛细血管表面通透性(PS)4项灌注参数值的差异.2种层厚的对照研究采用单变量计量资料中的配对t检验;不同频率选择采用配伍设计的方差分析.结果 通过cine模式、层厚5 mm连续扫描获得肾皮质的BF、BV、MTT、PS参数值分别为(407.10±86.69) ml·min-1·100 ml-1、(21.59±3.93) ml/100 g、(3.37±0.65) s、(56.42±16.30) ml·min-1·100 ml-1.与层厚为2.5 mm肾皮质的灌注参数值比较,不同层厚BF、BV、MTT和PS组间均无统计学意义(P>0.05).另与间隔1 s、间隔2 s、间隔3 s的肾皮质灌注参数值比较,前3种扫描时间间隔对BF、BV及PS灌注参数影响不大(P>0.05).间隔3 s的图像较少,得到的各项灌注参数值均明显不同于其他的序列,且相关性较差.结论 对肾皮质CT灌注成像,间隔1 s或2 s是值得提倡的扫描模式.5 mm和2.5 mm层厚的选择对CT灌注参数值没有影响.     

CT脑组织血流灌注成像方法的研究

目的 探讨CT灌注成像方法在颅脑疾病诊断中的初步临床应用。方法 采用Siemens Plus4和Perfusion CT/VA 10A扫描灌注系统,对8例进行常规扫描,然后选定基底节区层面做快速注药后的动态CT检查,对比剂为优维显300（300mgI/ml),注射速度10ml/s,剂量50ml,经高压注射器注射的同时进行扫描,共扫描32层。经后处理获得一系列反映不同时相的脑血流灌注图,然后进行综合分析。结果 4例正常脑血流灌注图清晰,脑灰白质交界分明、对称,染色均匀;2例缺血灌注图经伪彩染色后,病灶显示更加直观、清晰;2例肿瘤灌注图显示单发转移瘤异常供血血管、水肿区和过度灌注区。结论 快速注射对比剂和选用上矢状窦为参照血管计算脑血容量是获得高质量灌注图像的保证,为实现CT脑组织血流灌注的定量研究提供了新的方法。     

螺旋CT和胰腺癌的术前评估

为确定螺旋CT对胰腺癌术前评估的价值,作者对50例胰腺癌的术前螺旋CT及相关的外科和病理资料进行了回顾性分析。使用Somatom Plus-S螺旋CT机进行平扫和增强扫描。先于胰腺区行层厚10mm的CT平扫,再以3ml/s的速度注入非离子对比剂(Iohexol 350mgI/ml)150ml。当注射30s后嘱病人屏气24s,此时沿十二指肠第三段向头侧行螺旋CT扫描,层厚5mm、间隔4mm,然后改用     

CT脑灌注成像在基底节区腔隙性脑梗死的初步应用

目的 探讨CT脑灌注成像在基底节区腔隙性脑梗死的应用价值.资料与方法 对35例超早期(发病＜6 h)基底节区腔隙性脑梗死患者行常规CT头颅平扫及CT脑灌注成像.在常规轴位CT扫描后选取基底节区层面,经肘静脉团注45 ml非离子型对比剂,同时开始持续40 s的单层连续动态扫描,重组的40幅动态图像使用CT脑灌注软件进行处理,获得灌注图像.测量双侧基底节区感兴趣区的局部脑血流量(CBF)及局部灌注达峰时间(TTP),并进行定量分析.结果 35例基底节区腔隙性脑梗死患者中有29例被后期追踪CT或MRI证实为基底节区腔隙性脑梗死,其中20例梗死灶直径＞5 mm(＜20 mm),9例病灶＜5 mm;余6例CT复查为阴性而临床诊断为脑梗死.20例梗死灶直径＞5 mm(＜20 mm)中有17例CT灌注为阳性,表现为CBF明显低于正常侧,TTP明显长于正常侧;另外3例未发现灌注异常区.20例梗死灶直径＞5 mm(＜20 mm)患者患侧及对侧的局部灌注平均CBF分别为(384.9±118.7)ml·min-1·L-1和(256.2±80.3)ml·min-1·L-1,两者比较差异有统计学意义(t=5.898,P＜0.01);患侧及对侧的局部平均TTP分别为(12.8±3.4)s和(9.6±3.8)s,双侧对比差异亦有统计学意义(t=7.104,P＜0.01).9例病灶＜5 mm患者中,仅2例CT灌注为阳性,患侧及对侧局部灌注平均CBF分别为(448.0±137.8)ml·min-1·L-1和(422.2±229.6)ml·min-1·L-1,两者比较差异无统计学意义(t=0.664,P＞0.5);患侧及对侧局部平均TTP分别为(10.1±2.0)s和(9.3±1.3),两侧之间差异无统计学意义(t=1.039,P＞0.5).结论 CT脑灌注成像能为基底节区腔隙性脑梗死提供有价值的脑血流动力学信息,为临床超早期诊断和治疗提供依据.     

颈动脉颅外段血管成像的最佳速率选择

目的：通过比较使用不同注射速率所获得的多层螺旋CT颈动脉造影(CTC)重建图像，优化注射速率的选择。方法：85例患者随机分为2组，各为30例和55例，注射速率分别为2．0ml／s或3．5ml／s，首先于第六颈椎水平行同层面动态扫描，对比剂剂量为0．3ml／kg，利用小剂量试验软件绘制出时问一密度曲线，确定最佳延迟扫描时问。然后，对每个病例分别以与同层动态扫描时相同的速率进行多层螺旋CT颈动脉造影，并对其CTC重建图像评分。结果：速率3．5mL／s与速率2．0ml／s所得CTA图像综合评分差异具有显著性意义。3．5ml／s所得图像明显优于2．0ml／s所得图像。结论：快速法(3．5ml／s)多层螺旋CT颈动脉造影的成像质量优于慢速法(2．0ml／s)。     

Knee injury and Osteoarthritis Outcome Score (KOOS) - validation of a Swedish version

The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered instrument measuring outcome after knee injury at impairment, disability, and handicap level in five subscales. Reliability, validity, and responsiveness of a Swedish version was assessed in 142 patients who underwent arthroscopy because of injury to the menisci, anterior cruciate ligament, or cartilage of the knee. The clinimetric properties were found to be good and comparable to the American version of the KOOS. Comparison to the Short Form-36 and the Lysholm knee scoring scale revealed expected correlations and construct validity. Item by item, symptoms and functional limitations were compared between diagnostic groups. High responsiveness was found three months after arthroscopic partial meniscectomy for all subscales but Activities of Daily Living.     

Endovascular management of carotid-cavernous fistulas

Objective To investigate endovascular treatment of traumatic direct carotid-cavernous fistulas （CCF） and their complications such as pseudoaneurysms. Methods： Over a five-year period, 22 patients with traumatic direct CCFs were treated endovascularly in our institution. Thirteen patients were treated once with the result of CCF occluded, 8 twice and 1 three times. Treatment modalities included balloon occlusion of the CCF, sacrifice of the ipsilateral internal carotid artery with detachable balloon, coll embolization of the cavernous sinus and secondary pseudoaneurysms, and covered-stem management of the pseudoaneurysms. Results All the direct CCFs were successfully managed endovascularly. Four patients developed a pseudoaneurysm after the occlusion of the CCF with an incidence of pseudoaneurysm formation of 18.2% （4/22）. A total number of 8 patients experienced permanent occlusion of the ICA with a rate of ICA occlusion reaching 36.4% （8/22）. Followed up through telephone consultation from 6 months to 5 years, all did well with no recurrence of CCF symptoms and signs. Conclusion Traumatic direct CCFs can be successfully managed with endovascular means. The pseudoaneurysms secondary to the occlusion of the CCFs can be occluded with stent-assisted coiling and implantation of covered stents.     

The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

Do Balance Board Training Programs Reduce the Risk of Ankle Sprains in Athletes?

Introduction Ankle sprains are the most common musculo-skeletal injury that occurs in athletes,particularly in sports that require jumping and landing on one foot such as soccer,and basketball(1-4).These injuries often result in significant time loss from participation,long-term disability,and have a major impact on health care costs and resources(5-8).     

High Intensity Interval Training:New Insights

KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief，intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.，≥90%of VO2 peak).     

Developmental validation of the PowerPlex(®) ESI 16 and PowerPlex(®) ESI 17 Systems: STR multiplexes for the new European standard

In response to the ENFSI and EDNAP groups’ call for new STR multiplexes for Europe, Promega^® developed a suite of four new DNA profiling kits. This paper describes the developmental validation study performed on the PowerPlex^® ESI 16 (European Standard Investigator 16) and the PowerPlex^® ESI 17 Systems. The PowerPlex^® ESI 16 System combines the 11 loci compatible with the UK National DNA Database^®, contained within the AmpFlSTR^® SGM Plus^® PCR Amplification Kit, with five additional loci: D2S441, D10S1248, D22S1045, D1S1656 and D12S391. The multiplex was designed to reduce the amplicon size of the loci found in the AmpFlSTR^® SGM Plus^® kit. This design facilitates increased robustness and amplification success for the loci used in the national DNA databases created in many countries, when analyzing degraded DNA samples. The PowerPlex^® ESI 17 System amplifies the same loci as the PowerPlex^® ESI 16 System, but with the addition of a primer pair for the SE33 locus. Tests were designed to address the developmental validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM), and those of the DNA Advisory Board (DAB). Samples processed include DNA mixtures, PCR reactions spiked with inhibitors, a sensitivity series, and 306 United Kingdom donor samples to determine concordance with data generated with the AmpFlSTR^® SGM Plus^® kit. Allele frequencies from 242 white Caucasian samples collected in the United Kingdom are also presented. The PowerPlex^® ESI 16 and ESI 17 Systems are robust and sensitive tools, suitable for the analysis of forensic DNA samples. Full profiles were routinely observed with 62.5 pg of a fully heterozygous single source DNA template. This high level of sensitivity was found to impact on mixture analyses, where 54–86% of unique minor contributor alleles were routinely observed in a 1:19 mixture ratio. Improved sensitivity combined with the robustness afforded by smaller amplicons has substantially improved the quantity of data obtained from degraded samples, and the improved chemistry confers exceptional tolerance to high levels of laboratory prepared inhibitors.