超急性期放射性脑损伤的MRS和DTI研究

目的:探讨MRS和扩散张量成像(DTI)对超急性期放射性脑损伤的诊断价值.方法:18例经病理证实的鼻咽癌初诊患者,在放疗前及放疗后接受总放射剂量分别为20Gy、40Gy和60Gy时,进行颅脑MRI常规扫描、双侧颞叶1H-MRS多体素成像和DTI,将不同时期MRS检查所获得的颞叶Cho/Cr、NAA/Cr和NAA/Cho及DTI检查所测量的表观扩散系数(ADC)和部分各向异性(FA)值进行对比分析.结果:接受放射总剂量60Gy后,所有患者常规MRI扫描均未发现异常信号.MRS检查显示双侧颞叶前部的各代谢物比值在接受放射治疗后降低,并且所测各值的变化与放疗剂量呈负相关改变;DTI结果显示ADC值升高,FA值降低.结论:MRS和DTI能从组织细胞功能代谢水平对放射性脑损伤超急性反应进行评价,为临床对该疾病的病理发展过程进行研究提供客观可行的检测方法.     

鼻咽癌放射性脑损伤的MR扩散张量成像研究

目的 应用MR扩散张量成像(DTI)监测鼻咽癌放射性脑损伤急性期和亚急性期的颞叶微观结构变化.资料与方法 对2006年7月至2009年5月间80例确诊为鼻咽癌并首次接受放射治疗(简称放疗)的患者,在放疗前和接受剂量为20 Gy、40 Gy、60 Gy以及其中放疗结束后的47例第1、2、3个月分别进行常规颅脑MRI和DTI,动态观察不同时间段DTI的表观扩散系数(ADC)和部分各向异性(FA)值的变化趋势,并进行分析.结果 自放疗开始至结束后3个月常规颅脑MRI未见异常信号.放疗过程中和放疗结束后3个月ADC值升高、FA值减低,FA值放疗后3个月的降低幅度大于放疗期间的降幅,ADC值和FA值在放疗期间不同剂量阶段差异无统计学意义(P＞0.05),放疗后3个月差异具有统计学意义(P＜0.05).结论 虽然鼻咽癌放射性脑损伤的急性期和亚急性期常规MRI未见异常,但仍存在微观结构上的变化,导致细胞内外水分子扩散减慢.DTI从分子水平评价放射性脑损伤的优势在亚急性期更明显,为预防不可逆性脑损伤提供客观依据.     

鼻咽癌放疗后颞叶脑放射性损伤的磁共振扩散张量成像的表现

目的 探讨扩散张量成像(diffusion tensor imaging,DTI)在早期放射性脑损伤中的应用价值.方法 23例鼻咽癌放疗后常规MR表现正常者和28例健康正常人均做DTI,在双侧颞叶脑白质区域测量各向同性扩散张量(ADCiso)值和各向异性指数值.结果 鼻咽癌放疗组ADCiso值(644.08±56.80)×10-6mm2/s,部分各向异性(FA)值0.394±0.074、相对各向异性(RA)值0.344±0.075及1减容积比(1-VR)值0.182±0.072均比正常对照组各值降低,与正常对照组比较差异有显著性意义(P<0.05).结论 DTI能探测到鼻咽癌放疗后常规脑MR表现所不能显示的改变,对放射性脑损伤的早期诊断提供了一种新的影像学诊断手段.     

鼻咽癌放疗后早期放射性脑损伤的磁共振扩散加权成像研究

目的：探讨磁共振扩散加权成像（DWI）在观察鼻咽癌患者放疗后早期放射性脑损伤方面的价值。方法选取健康志愿者20名,男性10名,女性10名。年龄24-65岁,平均年龄为（43±4）岁。20例鼻咽癌患者,男性11例,女性9例。年龄27-78岁,平均年龄为（50±5）岁。所有健康志愿者均行磁共振成像（MRI）常规平扫及DWI成像,DWI成像时b值分别采用0和1000 s/mm2。结果健康志愿者双侧颞叶的表观弥散系数（ADC）值与鼻咽癌患者放疗前的双侧颞叶的ADC值比较差异无统计学意义。鼻咽癌患者放疗前的双侧颞叶的ADC值与首次放疗后3 d及放疗后3个月双侧颞叶白质的ADC值之间差异有统计学意义,放疗后6个月、12个月及18个月时的双侧颞叶的ADC值与放疗前比较差异无统计学意义。结论磁共振DWI能够反映鼻咽癌放疗后放射性脑损伤的病理变化,是一种能够发现早期放射性脑损伤的影像学诊断方法。     

迟发性放射性脑损伤DTI临床研究

目的:观察鼻咽癌迟发性放射性脑病(radiation encephalopathy,REP)的磁共振扩散张量成像(magnetic resonancediffusion tensor i maging,MR DTI)表现,并探讨MR DTI对REP的诊断应用价值。方法:对29例共40个颞叶病灶和健康正常人28例56个颞叶的MR DTI资料进行回顾性分析。在鼻咽癌放射治疗30月~9年行MRI检查,成像序列包括T1WI、T2WI、MR DTI和T1WI Gd-DTPA增强,分析REP磁共振及DTI表现特点。结果:29例REP中累及单侧颞叶18例,双侧颞叶11例,共40个病灶。40个病灶均有颞叶脑白质指状水肿。28个(70%)颞叶REP病灶Gd-DTPA增强扫描双侧颞极下部见不规则点片状强化影,23个(57.5%)病灶同时伴有明显的脑灰质受累。6个(15%)颞叶病灶伴有脑白质坏死囊性变。病变区各向同性值(ADCiso)升高,而各向异性值(RA、FA及1-VR)均有降低,与正常对照组比较统计学上有显著性差异。结论:鼻咽癌放射性脑病表现具有多样性,病灶内脑组织内水分子扩散异常,MR结合MR DTI可提高鼻咽癌放疗后迟发性放射性脑损伤的诊断准确性,同时鼻咽癌放疗后放射性脑病DTI异常表现也有助于脑肿瘤放疗后疗效的评估。     

鼻咽癌放射治疗后放射性脑损伤的扩散张量成像与1H-MR波谱研究

目的 探讨双侧颞叶脑组织在鼻咽癌放射治疗后不同时期的DTI与1H-MRS变化特点.方法 选择48例鼻咽癌放射治疗后常规MRI表现正常的患者(患者组)及24名健康志愿者(正常组)行DTI及1H-MRS检查,将扫描图像进行后处理和波谱分析,测量双侧颞叶DTI的各向异性分数(FA)值、ADC值及3个本征值λ1、λ2、λ3,以及1H-MRS中双侧颞叶前部白质N-乙酰天冬氨酸(NAA)/胆碱(Cho)、NAA/肌酸(Cr)及Cho/Cr比值,并将鼻咽癌放射治疗后患者按放射治疗后不同时期分为放射治疗后0～6、6～12、>12个月,分别定义为患者组1(16例)、2(6例)、3(26例),计算放射治疗后双侧颞叶脑组织各测量指标数值.所得数据采用单因素方差分析.结果 鼻咽癌放射治疗后6个月内、6～12个月、12个月后以及正常组DTI的FA值分别为0.445±0.017、0.460±0.016、0.461±0.025、0.473±0.023,ADC值分别为(8.51±0.43)×10-4、(8.48±0.34)×10-4、(8.40±0.33)×10-4、(8.68±0.57)×10-4mm2/s,3个本征值中最大本征值λ1分别为(1.251±0.065)×10-3、(1.293±0.051)×10-3、(1.317±0.074)×10-3、(1.350±0.091)×10-3 mm2/s,以上3个指标组间差异均有统计学意义(F值分别为10.873、3.399、9.750,P值均<0.05).λ2、λ3值组间比较差异无统计学意义.1H-MRS的NAA/Cho分别为0.910±0.112、0.972±0.101、1.060±0.095、1.261±0.105,NAA/Cr分别为1.212±0.236、1.208±0.183、1.228±0.236、1.435±0.225,组间差异均有统计学意义(F值分别为52.840、8.176,P值均<0.01).Cho/Cr组间比较差异无统计学意义.结论 DTI结合1H-MRS在鼻咽癌放射治疗后监测评价脑组织的放射损伤程度方面具有一定的指导作用,可为放射性脑损伤的动态早期监测提供科学依据.     

鼻咽癌放疗和非放疗患者脑白质微结构差异及其与认知的相关性研究

目的 使用扩散张量成像(DTI)和基于纤维束追踪的空间统计分析(TBSS)方法对鼻咽癌(NPC)患者放疗前、后脑白质显微结构动态变化进行评价,并分析其和患者整体认知分数的关系.方法 80例鼻咽癌患者被纳入本研究,按照放疗前后不同时期分为4组:G1为放疗前组(n=22),G2为放疗后0～6个月组(n=21),G3为放疗后6 ～12个月组(n=20),G4为放疗后＞12个月组(n=17).全部患者均行DTI及常规MRI扫描.计算患者的部分各向异性(FA)和平均扩散率(MD).采用简易精神状态评价(MMSE)量表评价患者的整体认知功能.结果 与放疗前组(G1)相比,放疗后6个月内(G2)右侧顶叶、右侧枕叶和右侧额叶白质FA值显著下降,放疗12个月后(G4)右侧顶叶、右侧额叶白质FA值仍显著低于放疗前水平;放疗后6个月内(G2)双侧颞叶、左顶叶、左额叶、左侧半卵圆中心、右枕叶白质MD值比放疗前(G1)显著升高,放疗12个月后(G4)右枕叶白质MD值仍显著高于放疗前水平(P＜0.05).右枕叶白质FA值与MMSE分值呈正相关(r=0.483,P=0.027),左额叶白质MD值与MMSE分值呈负相关(r=-0.487,P=0.025).结论 放疗可引起鼻咽癌患者较广泛的脑白质损害,而且是动态、暂时性的变化.放射性脑白质异常可影响患者的认知功能.     

鼻咽癌放射治疗后颞叶常规MRI表现正常脑白质的扩散张量成像初步研究

目的 利用DTI对鼻咽癌患者放疗后颞叶常规MRI表现正常脑白质进行监测.方法 回顾性分析经病理活检证实的75例鼻咽癌患者的临床和影像资料,所有患者均行全脑常规MR和DTI检查,且常规MRI未见异常.以放疗前的18例患者作为对照组,放疗后的57例患者为放疗组,并根据放疗后不同时间分为5组:组1(放疗后≤3个月,16例)、组2(放疗后＞3～6个月,12例)、组3(放疗后＞6 ～9个月,10例)、组4(放疗后＞9 ～12个月,8例)、组5(放疗后＞12个月,11例).测量各组患者的部分各向异性分数(FA)、平均扩散系数(MD)、表观扩散系数(ADC)、平行本征值(入‖)及垂直本征值(λ⊥),采用单因素方差分析对各组数据进行分析.结果 对照组及放疗后各组的平均λ⊥值分别为(6.075±0.341)×10-4、(6.700±0.379)×10-4、(6.976±0.527)×10-4、(6.621 ±0.388)×10-4、(6.751±0.460)×10-4、(6.222±0.256)×10-4 mm2/s,λ‖值分别为( 12.524 ±0.713)×10-4、( 11.764±0.574)×10-4、(11.842±0.471)×10-4、( 11.569±0.552)×10-4、(12.050 ±0.614)× 10-4、( 12.100±0.529)×10-4 mm2/s,FA值分别为0.452±0.030、0.379±0.028、0.382±0.028、0.389±0.032、0.388±0.022、0.423±0.232,各组间差异均有统计学意义(F值分别为10.485、4.625、16.539,P值均＜0.05).进一步多重比较,放疗后12个月内(组1～4)的平均λ⊥值均较放疗前明显升高,差异有统计学意义(P＜0.05).而放疗12个月后(组5)的平均λ⊥值基本恢复,与放疗前差异无统计学意义(P＞0.05).放疗后9个月内(组1～3)的平均λ‖值较放疗前明显降低,差异有统计学意义(P＜0.05);9个月以后(组4、5)的平均λ‖值与对照组比较差异无统计学意义(P＞0.05).所有放疗后组(组1～5)的平均FA值均比放疗前明显下降,差异有统计学意义(P＜0.05).放疗后各组平均ADC及MD值对比放疗前差异均无统计学意义(P＞0.05).结论 DTI可以在常规MRI发现异常之前检测到脑组织特别是白质微观结构的改变,可以为临床早期诊断和早期干预放射性损伤提供更多影像学证据.     

轻度认知障碍患者背外侧前额叶白质的DTI研究

目的用扩散张量成像(DTI)方法研究轻度认知障碍(MCI)患者背外侧前额叶白质的扩散特性,并探讨该区域可能的病理改变及DTI的临床诊断价值。资料与方法对17例MCI患者和18名年龄、性别和受教育程度相匹配的正常老年人进行全脑DTI扫描,测量其双侧背外侧前额叶白质的各向异性分数(FA)值、平均扩散率(MD)值和本征向量值(λ1、λ23),对两组数据进行统计学分析。结果MCI组两侧大脑半球背外侧前额叶白质的FA值较正常对照组减低而λ23值升高,且有显著的组间差异,而MD值和λ1值没有显著差异。结论MCI患者背外侧前额叶白质的FA值显著减低和λ23值升高,反映了MCI患者特定认知相关脑区白质微结构的早期病理改变,在MCI的诊断中具有较好的应用价值。     

DTI对HIV感染者脑白质细微结构病变的诊断研究

目的 探讨扩散张量成像(DTI)技术对人类免疫缺陷病毒(HIV)感染者脑白质细微病变的诊断和临床应用价值.方法选取80例HIV阳性者(阳性组)和83例HIV阴性者(对照组),均行MRI常规序列及DTI扫描.测定双侧内囊前支、内囊后支、内囊膝、胼胝体膝部、压部及双侧胼胝体干脑白质感兴趣区(ROI)的各向异性分数(FA)值和表观扩散系数(ADC)值,利用独立样本t检验比较2组间FA值及ADC值的差异.结果与正常对照组相比,阳性组双侧内囊前支及内囊膝、胼胝体膝部及双侧胼胝体干FA值均低于对照组,差异有统计学意义(P<0.05);阳性组双侧内囊前支、后支、膝部及双侧胼胝体干ADC值均高于对照组,差异亦有统计学意义(P<0.05).结论DTI通过FA值和ADC值的异常改变而发现HIV阳性患者内囊及胼胝体区脑白质结构的细微病变,为临床早期诊断和治疗干预提供参考依据.     

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.