腹部低场强MRI中的半扫描技术

目的:探讨磁共振成像的半扫描技术在低场腹部扫描中的应用价值.材料和方法:使用0.2T开放式永磁型MRI仪对20例患者进行腹部SE-T1WI序列扫描,均采用Half-scan技术,NSA分别为4、6、8,并同时完成非Half-scan技术、NSA 4扫描作为对照.对上述4种图像的同一层面进行对比分析,包括SNR、运动伪影、图像质量及扫描时间.结果:与对照相比,Half-scan技术4次采集的扫描时间明显缩短,6次采集的运动伪影抑制效果最佳(t=6.28,P＜0.001)且扫描时间有所缩短,8次采集的伪影抑制效果较佳(t=3.25,P＜0.01)但扫描时间有所增加.SNR间无明显统计学差异.结论:低场MRI半扫描技术配合恰当的采集次数可显著抑制运动伪影,保证良好的SNR,缩短检查时间,从而获得优质的MR图像.     

参数选择对磁共振T2-FLAIR像中脑脊液高信号伪影的影响

目的:探讨磁共振T2-FLAIR成像中的参数选择与脑脊液高信号伪影抑制效果的关系.方法:用1.5T磁共振对50例患者行T2-FLAIR成像,根据检查参数不同分为以下4组:①下空间饱和带/采集间隔2;②下空间饱和带/流动补偿/采集间隔2;③下空间饱和带/流动补偿/定制射频脉冲/采集间隔2;下空间饱和带/流动补偿/定制射频脉冲/采集间隔3.观察分析4组不同成像参数T2-FLAIR像上桥前池、小脑延髓池等处脑脊液伪影的差别.结果:B组和A组在脑脊液伪影的抑制效果方面无明显差别(U=0.98,P＞0.05);C组对脑脊液伪影的抑制效果优于A组和B组(U=3.66,P＜0.01);D组对脑脊液伪影的抑制优于C组,效果最好(U=7.36,P＜0.01).结论:定制射频脉冲对磁共振脑脊液伪影有较好的抑制作用,可在T2-FLAIR序列中常规应用;定制射频脉冲结合3倍采集间隔可使脑脊液伪影更进一步地抑制.     

MR 3D-DESS和3D-True FISP对类风湿关节炎腕关节软骨损伤的诊断价值

目的 探讨3.0T MR三维双回波稳态(3D-DESS)序列及三维真实稳态进动快速成像(3D-True FISP)序列对类风湿关节炎(RA)腕关节软骨改变的应用价值.方法 对26例临床诊断为RA患者采用3D-DESS、3D-True FISP序列行腕关节扫描,共有20例患者完成2种序列扫描.观察该20例患者腕关节共340个关节面软骨形态学情况,按照形态学表现分为0、1、2级,分别计数3D-DESS、3D-True FISP序列所见腕关节软骨病变个数,比较2种序列对RA腕关节软骨病变个数检出的差异;同时计数20例腕关节出现扫描伪影例数.结果 3D-DESS与3D-True FISP序列发现腕关节软骨1级损伤个数分别为79个和50个,2级损伤个数分别为23个和33个,其差异有统计学意义(P<0.05).3D-True FISP序列共有14例患者出现低信号伪影,3D-DESS序列共有2例患者出现伪影.结论 3D-DESS序列相比3D-True FISP序列能更好地显示RA腕关节软骨改变,3D-DESS序列可以为RA的治疗及愈后判断提供一定的帮助.     

类风湿性关节炎中骨髓水肿与软骨损伤的MR研究

目的利用3.0T磁共振探讨类风湿性关节炎中腕骨骨髓水肿和软骨损伤之间的相关性。方法通过对38例类风湿性关节炎患者和28例正常对照者先后两年进行腕关节磁共振检查,对腕关节软骨损伤、骨髓水肿及骨侵蚀、滑膜炎进行评分并探讨其统计学意义。结果 RA与对照组之间两年MRI软骨评分在评分者1中P值为0.048,评分者2中P值为0.038,均具有统计学差异。两个时间点MRI软骨评分在RA中MRI软骨分数明显增加(评分者1和2分别P=0.046、P=0.033)并具有统计学意义。RA损伤各种影响因素分析结果发现MRI软骨评分(R~2=0.67)优于MRI骨侵蚀评分(R~2=0.47)。两年间分别出现在桡骨、月骨及舟状骨的骨髓水肿与相邻软骨的MRI软骨分数增加具有统计学意义(P值分别为0.0001、0.0012)。结论类风湿性关节炎中出现骨髓水肿和滑膜炎之前已经出现软骨损伤,因此软骨损伤可作为导致关节畸形的独立致病因素。     

对比剂在多层螺旋CT显示胃部病变中的应用护理

目的 探讨口服和注射对比剂在多层螺旋CT(MSCT)显示胃部病变中的诊断价值和护理体会.方法 95例疑诊胃部疾病的患者,分别口服不同对比剂(碘、水、气体),进行MSCT三期增强扫描.通过胃充盈度、胃壁层次、病灶细节、伪影四个指标评价MSCT图像质量.结果 碘对比剂显示胃壁层次(x2=9.657,P＜0.01)和伪影(x2=19.477,P＜0.001)均不及水和气体.所有患者均无中重度毒副反应,轻度反应6人.结论 正确合理应用对比剂并做好相关护理工作是MSCT成功检查胃部疾病的关键.     

钆塞酸二钠和钆喷酸葡胺肝脏多期动态增强呼吸伪影对比研究

目的:比较静脉注射钆塞酸二钠(Gd-EOB-DTPA)和钆喷酸葡胺(Gd-DTPA)的动脉期呼吸伪影,寻求减少Gd-EOB-DTPA动脉期呼吸伪影的可能方案.方法:搜集在1年内行Gd-EOB-DTPA和Gd-DTPA磁共振动态增强扫描的患者75例,由两位有经验的磁共振医师采用盲法对两种对比剂扫描方案的动脉期、门脉期及延迟期图像采用5分法评分,以≤3分定义为中重度伪影.两种对比剂扫描方案的呼吸伪影比较采用Wilcoxon秩和检验和配对卡方检验.结果:Gd-EOB-DTPA组发生动脉晚期呼吸伪影的比例明显高于Gd-DTPA组(分别为49.3％和6.7％,Z=-5.058,P＜0.001),其中中重度伪影的比例亦明显高于Gd-DTPA(分别为33.33％和2.67％,x2=21.04,P＜0.001);而Gd-EOB-DT-PA组动脉早期出现呼吸伪影和中重度呼吸伪影的比例与Gd-DTPA组差异无统计学意义(Z=-1.513,P=0.130;x2=0.25,P=0.625).结论:静脉注射Gd-EOB-DTPA较Gd-DTPA更易引起动脉期伪影,减少单期屏气时间和采用动脉期监测技术可能提高Gd-EOB-DTPA动脉期采集的图像质量.     

DTI常用扫描序列原理及比较

磁共振弥散张量成像技术是利用水分子的弥散各向异性进行成像,可用于脑白质纤维研究,常用扫描技术包括单次激发平面回波成像(EPI),线阵扫描弥散成像,导航自旋回波弥散加权成像(LSDI),半傅立叶探测单发射快速自旋回波成像等。每种成像技术各有其优缺点,EPI扫描时间短,图像信噪比高,但存在化学位移伪影、磁敏感性伪影、几何变形;LSDI精确度高,几乎无伪影及变形,但扫描时间过长;导航自旋回波弥散加权成像运动伪影少,但扫描时间长;半傅立叶探测单发射快速自旋回波成像扫描时间短,但图像模糊。综合比较,单次激发平面回波成像是用于临床研究较适宜的方法。     

螺距的选择对老年慢性阻塞性肺疾病患者成像质量的影响

目的探讨螺距的选择对64层CT螺旋扫描模式对老年慢性阻塞性肺疾病(COPD)胸部图像质量的影响。方法选择老年(COPD)患者100例,分为两组,A组(50例)采用螺距为0.984、B组(50例)采用螺距为1.375进行胸部CT扫描。使用GE Lightspeed sys#vct 64层CT机,120kV,200mA,层厚5mm,0.8s/r。应用SPSS11.5软件分别对A组和B组的CT图像运动伪影出现率进行χ~2检验,两组间图像质量比较、噪声比较、扫描时间进行t检验。结果 A组患者出现伪影17例,B组4例,较A组减少26%。A组患者平均扫描时间为7s,B组为5.3s,较A组扫描时间平均减少1.7s。结论在进行COPD胸部CT检查中,管电压和管电流恒定不变的情况下选择大螺距扫描,可以减少扫描时间、降低辐射剂量,在保证图像质量的同时,呼吸运动伪影减少,从而达到优化图像的同时降低辐射剂量的目的。     

动态增强MRI对于鉴别血清学阴性的手早期类风湿关节炎和骨性关节炎的价值

目的 研究动态增强MRI对于鉴别血清学阴性的手早期类风湿关节炎(RA)和骨性关节炎(OA)的价值.方法 53例疑诊为手RA或OA且X线阴性患者经3～6个月随访直至明确诊断,将其中符合早期RA诊断标准且初诊时血清阴性者18例(RA组)和符合早期OA诊断标准者18例(OA组)纳入研究,另选取18名志愿者(正常对照组);均行全手MR平扫、增强扫描及单层动态增强扫描,测量病变部滑膜强化率、曲线斜率和滑膜厚度,观察RA组和OA组MRI异常征象,滑膜强化率和滑膜强化曲线斜率3组间及3组间两两比较均采用秩和检验;滑膜厚度3组间及3组间两两比较均采用方差分析;RA组与OA组的其他MR征象比较采用秩和检验.结果 RA组、OA组、正常对照组滑膜强化率分别为(100.78±61.96)%、(40.44±15.43)%和(23.56±9.14)%,RA组与OA组比较,u=3.101,P=0.002;RA组与正常对照组比较,u=4.669,P=0.000;OA组与正常对照组比较,u=3.482,P=O.000.滑膜强化曲线斜率值分别为72.50°±13.34°、45.39°±9.94°及14.56°±5.75°,RA组与OA组比较,u=8.002,P=0.000;RA组与正常对照组比较,u=17.102,P=0.000;OA组与正常对照组比较,u=9.100,P=0.000.滑膜厚度分别为(3.3±0.5)、(2.8±0.7)、(1.4±0.6)mm,RA组与OA组比较,q=2.622,P=0.011;RA组与正常对照组比较,q=9.583,P=0.000;OA组与正常对照组比较,q=6.961,P=O.000.滑膜动态强化曲线RA组呈快速上升平台型,OA组呈缓慢上升型,正常对照组呈极慢速上升型.结论 动态增强MR扫描通过滑膜强化率和滑膜厚度等量化指标可以在血清学阴性的早期阶段鉴别RA和OA.RA患者比OA患者的滑膜强化率更高,速度更快,滑膜厚度更大.多种MR征象对于鉴别RA患者与OA患者有价值.     

SENSE技术在磁共振腹部动态增强血管成像中的应用

目的：探讨磁共振敏感编码技术在腹部动态增强血管成像(DcE—MRA)中的应用优势。方法：将疑有腹部血管疾病的40例患者分为二组，实验组20例使用SENSE技术扫描；另外20例为对照组，直接行DCE—MRA扫描。结果：对照组20例中，13例因患者呼吸配合好，图像清晰，其中5例显示了动、静脉不同时相，8例由于扫描时间长，得到动、静脉均显影的图像。其余7例因屏气配合不好，图像出现伪影，为诊断带来了困难。实验组20例患者由于扫描时间明显缩短，均获得了清晰且不同时相的图像。结论：sENsE技术的使用大大地缩短了扫描时间，使腹部DCE—MRA可不受呼吸影响，并能获得不同时相血管强化图像，明显改善了DcE—MRA影像的质量，提高了诊断准确性。     

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.