正常腰椎MRI体素不相干运动成像中轴位及矢状位扫描对骨髓各参数一致性的影响

目的探讨正常腰椎在MRI体素不相干运动(IVIM)成像中采用矢状位及轴位两种扫描方式对骨髓IVIM成像各参数一致性的影响。方法 33例正常志愿者参与本研究。所有受试者均在3.0T MR扫描仪上接受腰椎常规MRI、L3椎体轴位及矢状位IVIM扫描检查。测量IVIM成像各参数值,包括慢速表观扩散系数(slow ADC值)、快速表观扩散系数(fast ADC值)及快速成分所占比例(fraction of fast ADC,ffast)。比较IVIM两种扫描方式,L3椎体骨髓各参数测量值的差异,计算组内相关系数(ICC),并采用Bland-Altman分析法对两组测量结果进行对比。结果 L3椎体轴位及矢状位IVIM成像骨髓各参数测量值差异均无统计学意义,各参数值的ICC均大于0.6。此外,轴位及矢状位L3椎体骨髓fast ADC值、slow ADC值、ffast值相比较时,97%(32/33)、100%(33/33)、91%(30/33)的测量值位于95%一致性区间范围内,表示两者具有较好的一致性。结论腰椎IVIM成像过程中,矢状位及轴位扫描骨髓各参数测量具有较好的一致性,因此,两种扫描方式获得的测量值之间具有可比性。     

磁共振体素内不相干运动成像和扩散峰度成像在正常肾脏成像中的初步研究

目的:探讨正常人肾脏磁共振体素内不相干运动成像(IVIM)和扩散峰度成像(DKI)的定量参数指标特点.方法:对27名健康志愿者行肾脏IVIM和DKI检查,通过后处理分析,获得双肾皮髓质IVIM相关参数ADC、Dffast、Dslow、fp以及DKI相关参数MD、MK的测量值.分析同一测量者前后2次测得数据的一致性,比较正常肾脏左右侧以及同侧肾脏不同部位IVIM、DKI各参数间的差异,比较正常肾脏皮质、髓质各参数均值间的差异.结果:IVIM序列的ADC值、Dslow值、fp值和DKI序列的MD值、MK值前后两次测量总体一致性较好,Dfast值一致性一般;IVIM、DKI各参数测量值在双侧肾脏间均没有统计学差异(P值为0.058～0.954),同侧肾脏皮髓质不同部位各参数测量值间亦均没有统计学差异(P值为0.171～0.995);正常肾脏皮质ADC值、Dslow值高于髓质(t=7.072,P＜0.05;t=10.057,P＜0.05),皮髓质Dfast值、fp值差异不具有统计学意义(P＞0.05);正常肾脏皮质MD值高于髓质(t=10.268,P＜0.05),髓质MK值高于肾皮质(t=-10.228,P＜0.05).结论:正常肾脏IVIM和DKI成像能显示皮髓质间差异,反映肾脏生理功能,提示在评估肾脏疾病具有潜在应用价值,整体检查结果具有一定稳定性.     

定位像胸部横径与CT值调制前瞻性序列扫描冠状动脉成像管电流的研究

目的 探讨定位像胸部横径(LD)与平均CT值(CTchest)在前瞻性心电触发序列扫描冠状动脉成像(Prospective ECG-gated CT coronary angiography,PG CTCA)管电流调制中的临床应用价值.方法 将连续进行CTCA扫描的194例患者按例数不等的完全随机区段分组法分为3组,即回顾性心电触发序列组(RG组)69例,前瞻性心电触发序列组(PG1组)68例及PG2对照组57例.其中RG组固定600 mA扫描,于前后位定位像上测量第10胸椎椎体上缘水平LD、右侧膈肌上方锁骨中线处肋间隙的CTchest;相同高度侧位像胸部前后径(APD),以及CTCA图像冠状动脉左主干层面的升主动脉噪声(SD);拟合各测量参数与SD的关系,推算管电流换算公式及速查表.PG1组扫描管电流依据推导的管电流速查表进行选择.PG2组依据体质量固定选择管电流(＜77 kg者取400 mA,≥77 kg者取500 mA).对3组图像质量评分、SD、CTDIvol、DLP、有效剂量(E)进行比较和评估.SD与LD、APD及CTchest的关系采用多元回归分析;3组间定位像胸部LD、CTchest、SD,以及CTDIvol、E比较均采用单因素方差分析;图像质量评分比较采用R×2列联表的x2检验.结果 管电流换算公式:mA=600/282·(0.487LD+0.064CTchest+13.7)2(R2 =0.53,F=36.13,P=0.00).3组胸部LD及CTchest大小比较,差异均无统计学意义(P ＞0.05);SD、扫描毫安值和CTDIvol差异均有统计学意义(F=44.96、167.37和1 071.26,P＜0.05);但图像质量评分及可评估血管差异无统计学意义(x2=6.89,2.54,P＞0.05).结论 根据胸部定位像LD及CTchest选择PG CTCA个体化管电流,可在满足诊断需求的前提下,更科学合理地控制X射线剂量.     

扫描参数改变对FSE T_2WI序列金属伪影的影响

目的探讨不同扫描参数对FSE T_2WI序列金属伪影的影响,以通过调整扫描参数来减小金属伪影。方法选用镍铬合金制成左下6标准桩核冠模型,将模型固定于水模中。应用1. 5T MRI扫描仪,头线圈,对桩核冠模型行横断面FSE T_2WI序列扫描,扫描参数为西门子1. 5T MRI扫描仪的推荐值。在不影响图像质量的前提下保持其它参数与标准扫描序列参数一致,逐一改变以下各参数进行成像:TR、TE、ETL、NEX、FOV、Matrix、BW、Thk、FA。确定伪影最大的层面并测量伪影面积。应用SAS V8统计学软件进行统计学分析。结果调整不同ETL值,镍铬合金伪影大小差异有统计学意义(F=6. 19,P=0. 04 0. 05)。调整不同NEX值,镍铬合金伪影大小差异有统计学意义(F=6. 98,P=0. 03 0. 05)。结论在FSE T_2WI序列中,可以通过增加回波链长度和激励次数来减小金属伪影。     

Diffusion Tensor Imaging in Children with Development Delay

目的 应用磁共振扩散张量成像(DTI)研究发育迟缓婴幼儿脑白质的各向异性(FA)值,探讨其与正常婴幼儿脑白质有无差异.资料与方法 对40例发育迟缓和40例正常婴幼儿进行了常规MRI及DTI扫描,并以常规MRI表现将发育迟缓组分为常规MRI表现正常和常规MRI表现脑白质发育迟缓.分别测量5个深部脑白质与4个浅部脑白质的FA值,并对结果进行统计学比较.结果 发育迟缓组各测量部位FA值低于对照组,除内囊后肢外差异均有统计学意义(P＜0.05).发育迟缓常规MRI表现正常患儿深部脑白质FA值低于正常组,但差异无统计学意义(P＞0.05);浅部脑白质FA值低于正常组,差异有统计学意义(P＜0.05);发育迟缓常规MRI表现发育迟缓脑白质FA值均低于正常组,差异有统计学意义(P＜0.05).结论 应用DTI FA值的测量能定量诊断婴幼儿脑白质发育迟缓,尤其常规MRI正常的发育迟缓患儿浅部脑白质FA值低于对照组,可明确诊断发育迟缓.     

3T MRI关节软骨成像序列的比较和探讨

目的:通过分析比较各3T MRI关节软骨成像序列对关节软骨显示的能力与限度,探讨理想的3T MRI关节软骨成像序列组合.方法:收集因临床需要而检查的36例膝关节MRI,成像设备为SIEMENS3.0T VERIO高场MRI,关节软骨成像序列包括:自旋回波序列(SE),二维脂肪抑制质子密度加权像(FS-PD),二维短T1翻转恢复序列(2D-STIR),三维双重回波稳态(3D-DESS),三维平衡稳态序列(3D-True FISP)和关节软骨生理成像T2mapping.在股骨髁间凹中央层面上分别测量股骨髁软骨信号噪声比(SNR)、软骨-关节液对比度噪声比(CNR),比较各序列对于软骨和周围关节液的显示能力.结果:3D-DESS,3D-True FISP和FS-PD序列软骨SNR最高(P<0.001);同时3D-DESS,3D-True FISP和FS-PD序列软骨-关节液对比度噪声比(CNR)高于2D-STIR,但软骨-关节液边界对比以3D-DESS序列最好,能显示关节软骨水含量变化的只有T2mapping成像.结论:二维脂肪抑制质子密度加权像(FS-PD)加上三维双重回波稳态(3D-DESS)是进行软骨MRI的理想序列组合,T2mapping可以显示关节软骨含水量的变化.     

零点充填技术提高增强磁共振血管成像内径测量准确性的模型研究

目的:探讨零点充填技术提高增强磁共振血管成像血管内径测量准确性的价值。方法:应用一个仿真血管模型,高空间分辨率序列使用零点充填技术。宽度中点法确定血管边缘后计算血管内径,两种序列对不同大小仿真血管内径测量结果的比较采用配对t检验。结果:两种序列的内径测量结果均比真实值高,但高空间分辨率序列的高估程度小,对于中等大小的血管,高空间分辨率序列与常规序列测量结果的差别无统计学意义(P>0.05),而对于小血管则两者差别有统计学意义(P<0.05和P<0.01)。结论:增强磁共振血管成像中有必要应用零点充填技术,该技术的应用能够提高小血管腔内直径测量的准确性。     

正常肝脏扩散峰度成像的可行性及可重复性研究

目的 研究正常肝脏扩散峰度成像(DKI)的可行性及参数测量的可重复性.方法 使用飞利浦1.5TMR扫描仪和相同的序列及参数,对35名年轻志愿者进行2次肝脏DKI扫描,生成平均扩散系数(MD)图和平均峰度系数(MK)图.在左、右肝内分别选取上、中、下3个代表性层面的左、中、右9个测量位置,每个位置放置大小相同的感兴趣区(ROI),分别测量并比较各ROI的MD值和MK值及左、右肝各9个ROI的平均参数值,并评估各参数测量的可重复性.结果 前后2次DKI扫描b=800 s/mm2图像上肝脏的信噪比(SNR)较好,差异无统计学意义(P＞0.05).2次扫描左、右肝内不同测量部位的MD、MK值差异均无统计学意义(P＞0.05),其中右肝中层及左肝下层的MD、MK值可重复性较好.左肝的平均MD值、MK值较右肝高(t=-5.665 ～8.095,P＜0.001),但左肝的平均MD、MK值可重复性均较右肝差;MD值、MK值的可重复性相近.结论 初步研究结果表明,正常肝脏DKI是可行的,右肝中层和左肝下层的MD、MK值的可重复性较好;左肝的平均MD、MK值较右肝高,但可重复性较右肝差,MD、MK值的可重复性相似.     

脑肿瘤T_1WI-FLASH 3D序列直接增强扫描的伽玛刀定位价值

目的探讨T1WI-FLASH 3D(fast low angle shot,FLASH)序列直接增强扫描作为伽玛刀定位图像的价值。方法回顾性的分别对60例颅脑肿瘤患者的增强扫描SE T1WI图像与T1WI-FLASH 3D图像对比研究。由2名放射主任医师、2名放射技师双盲法对两组图像进行分析,分别测量病灶个数、信噪比(SNR)、对比噪声比(CNR),并对两组图像显示程度进行评分。两组图像SNR、CNR比较采用配对样本t检验。结果 T1WI-FLASH 3D图像SNR为87.2±18.8,SE T1WI图像SNR为60.3±9.4,低于T1WI-FLASH3D图像,差异具有统计学意义(t值=9.913,P0.05)。T1WI-FLASH3D图像CNR为40.3±12.6,SE T1WI图像CNR为30.2±3.1,低于T1WI-FLASH3D图像,差异有统计学意义(t值=6.029,P值0.05)。结论以T1WI-FLASH 3D序列直接增强扫描图像作为伽玛刀定位序列优于SE T1WI图像。     

弥漫性轴索损伤磁敏感加权成像的实验研究

目的:用磁敏感加权成像(SWI)观察大鼠弥漫性轴索损伤(DAI)后的变化规律。方法:采用液压颅脑损伤模型制备32只DAI的SD大鼠模型,并于模型制作前、DAI后6h和24h分别进行常规磁共振成像和SWI成像(GE 3.0T超导磁共振成像仪)。比较各序列图像上DAI病灶检出数,在各时间点SWI图像上测量双侧皮髓质交界处感兴趣区(ROI)的相位弧度值,并分析其变化规律。结果:SWI对DAI病灶的检出率显著高于常规的MRI序列(P<0.05)。伤后6h,骨窗侧出血灶相位弧度值较致伤前变为负值;对侧相位值升高,差异有统计学意义(P<0.05),伤后24h,DAI鼠出血灶部位的相位弧度值较伤后6h相位弧度值变化差异无统计学意义(P>0.05);结论:磁敏感加权成像(SWI)检出弥漫性轴索损伤病灶的敏感性高于常规MRI序列,相位弧度值的变化反映了DAI的宏观变化过程,其变化规律与顺磁性物质有关。     

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.