首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 943 毫秒
1.
为确定脑瘤的磁化传递(MT)半剂量增强MRI能否替代非磁化传递的标准剂量增强MRI,作者用该技术在1.0T或1.5 T场强条件下对25例患者共32个经组织证实的颅内肿瘤进行前瞻性研究。男8例,女17例,15~70岁,其中转移瘤8个,胶质瘤7个,脑膜瘤6个,淋巴瘤、脉络丛乳头状瘤、垂体腺瘤、神经鞘瘤各2个,血管母细胞瘤、颅咽管瘤及未能确定的脑内肿瘤各1个。SE序列矢状位T_1WI、横断面T_2WI平扫后,在多平面行SE序列标准剂量Gd-DTPA(0.1mmol/kg)增强T_1WI。一周内,每例患者静脉注射半剂量Gd-DTPA(0.05mmol/kg)分别行SE序列MT和非MT T_1WI。两  相似文献   

2.
MRI FSE T2和GRE T2*成像技术在脊椎转移瘤中的应用   总被引:2,自引:0,他引:2  
目的 比较快速自旋回波T2 加权 (FSET2 WI)和梯度回波T2 加权 (GRET2 WI)在脊椎转移瘤中的应用效果。资料与方法  5 0例脊椎转移瘤患者进行FSET2 WI和GRET2 WI扫描。分别测得正常骨髓、异常骨髓和脊柱背面的信号强度。计算其对比度 /噪声比值 (C/Ns)、信噪比 (SNR)并进行t检验。还对FSET2 WI和GRET2 WI序列对转移灶边界的清晰度进行比较。结果 GRET2 WI所有病灶的C/Ns和SNR均高于FSET2 WI。脊椎转移灶在GRET2 WI上的C/Ns和SNR分别为 2 2 .2 2± 11.5 0和 2 6 .2 1± 15 .96 (平均值±标准差 ) ,在FSET2 图像上分别为4 .19± 5 .0 8和 17.2 3± 11.0 8,两者C/Ns具有显著差异 (t=10 .14 ,P <0 .0 0 1) ;SNR也有明显差异 (t =3.2 7,P <0 .0 1)。并且GRET2 WI对脊椎转移灶边界的显示比FSET2 WI更清晰 (P <0 .0 0 5 )。结论 GRET2 WI比FSET2 WI能更清晰地显示脊椎转移瘤。  相似文献   

3.
骨骼肌肉恶性肿瘤增强减影MRI   总被引:5,自引:2,他引:3  
目的 评估增强减影在骨骼肌肉恶性肿瘤MRI中的临床应用价值。方法  5 0例骨骼肌肉恶性肿瘤病人进行MR增强扫描 ,MR对比剂采用钆喷替酸葡甲胺 (Gd DTPA ,0 1mmol/kg) ,用T1W增强后的图像与增强前的图像进行减影。通过对比度 /噪声比值 (C/Ns值 )以及肿瘤影像征象清晰程度的比较 ,对MR减影与否进行评估。结果 MR对比增强减影图像比传统的T1W增强图像显示更清晰、更直观。所有病例都经手术和病理证实。 5 0例骨骼肌肉恶性肿瘤图像MR减影的C/Ns值比传统T1W增强图像的C/Ns值高。MR减影图像的C/Ns值为 10 9 74± 5 10 ( x±s) ,传统T1W增强图像的C/Ns值为 2 3 6 1± 3 16 (t=10 1 5 1,P <0 0 5 )。减影前后肿瘤影像征象的比较结果显示 :不规则边缘 (χ2 =7 86 ,P <0 0 5 )、肿瘤分叶 (χ2 =7 16 ,P <0 0 5 )和环形强化 (χ2 =7 4 4 ,P <0 0 5 ) ,对肿瘤影像征象清晰度差异的检出具有显著性意义。结论 MR对比增强减影比传统T1WI增强更能有效地显示骨骼肌肉恶性肿瘤。对比增强减影为检出和评估骨骼肌肉恶性肿瘤方面 ,提供了一个全新的诊断工具。  相似文献   

4.
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。  相似文献   

5.
目的 探讨磁化传递对比(MTC)成像在大鼠肝硬化的初步应用价值。材料与方法 二乙基亚硝胺诱导的单纯性肝硬化Wistar大鼠6只,5只正常大鼠作为对照组;全部大鼠均行附加磁化传递(MT)脉冲前后SE序列T1WI及FSE序列T2WI扫描。测量感兴趣区平均信号强度、背景噪声,计算信噪比及磁化传递率(MTR)。结果 6只大鼠病理证实均为单纯性肝硬化。电镜下见肝硬化细胞间隔增宽,胶原纤维明显增多。T1WI上正常肝实质附加MT脉冲后信噪比(SNR)低于无MT脉冲图像(P=0.002);肝硬化附加MT后SNR明显低于无MT时(P=0.000);肝硬化的MTR显著高于正常肝实质(P=0.000)。T2WI上正常肝实质附加MT后SNR低于无MT时(P=0.021);肝硬化附加MT后SNR显著低于无MT时(P=0.000);肝硬化的MTR较正常肝实质明显增高(P=0.002)。结论 MTC成像能间接反映肝硬化组织中胶原成分变化,为肝硬化的诊断和分期提供依据,可作为评价肝硬化的有效手段。  相似文献   

6.
目的:探讨肝脏病变在SPIO增强扫描T1WI上呈现高信号的机制.方法:肝脏局灶病变39例(56个病灶),其中33个恶性病灶(肝细胞癌10个、转移瘤21个、胆管细胞癌2个)和良性病灶23个(海绵状血管瘤9个,肝囊肿14个).平扫序列包括SE T1WI、FSPGR T1WI及FSE T2WI.SPIO(菲立磁)增强扫描序列包括FSE T2WI、SE T1WI(TE值分别为8 ms、20 ms)和 FSPGR T1WI(TE值分别为1.5 ms、4.2 ms).分析不同序列图像上病灶及肝实质的的信号变化.结果:在SPIO增强T1WI上,随着TE的延长,肝实质信号降低,肝内局灶病变信号相对增高.在SPIO增强长TE T1WI上,大部分恶性病灶及全部血管瘤呈相对高信号.结论:在SPIO增强T1WI上,SPIO对肝实质的T2*效应可能是部分局灶病变呈高信号的主要原因.  相似文献   

7.
目的:探讨肝细胞特异性对比剂泰乐影增强扫描时最优的T1WI序列及成像参数。方法:对13例病例20个病灶行MR SE T1WI序列、FFE T1WI in phase序列、FFE T1WI out phase序列扫描,测量各序列肝脏病变及正常肝实质的平均信号强度,计算并比较各序列信噪比(signal/noise, S/N)、对比噪声比(contrast/noise, C/N)及对比伪影比(con trast/artifact,C/A)。结果:out phase和in phase序列图像的呼吸运动伪影最小,20个病灶中仅有2个(10%)有呼吸运动伪影,而SE序列则有8例(90%)有呼吸运动伪影。out phase序列显示肝内门静脉及肝静脉优于SE序列,显示病变比SE序列清楚。结论:FFE T1WI out phase序列为肝细胞特异性对比剂泰乐影T1WI成像的最优序列,TR 25 ms、TE 6.9 ms、翻转角20°为其最优成像参数。  相似文献   

8.
T1WI常用于显示人体解剖结构,在脑转移瘤的诊断中,增强T1WI通过肿瘤的强化,可更清楚地显示肿瘤的边界,并有助于发现更多的转移灶.T1WI一般多采用自旋回波(SE)序列(T1 WSE),而反转恢复(IR)序列的T1WI(T1WIR)具有较高的组织分辨率,但成像时间长[1-2].  相似文献   

9.
增强FLAIR序列和磁化传递对比在脑转移瘤的应用价值   总被引:1,自引:0,他引:1  
目的 探讨增强液体衰减反转恢复(FLAIR)和磁化传递对比(MTC)两种序列对脑转移瘤的显示价值.资料与方法 对60例拟诊脑转移瘤的患者行MR常规扫描后采用T1WI、FLAIR、MTC序列再行增强扫描,并分别统计三种序列各自显示的病灶位置和个数及三种序列上转移瘤的病灶/正常组织信号强度比.结果 60例患者中42例发现脑转移瘤,共计131个病灶,增强后常规T1WI显示112个,FLAIR显示126个,MTC显示125个,三种序列上转移瘤的病灶/正常组织信号强度比差异有统计学意义.结论 增强后FLAIR序列和MTC对部分脑转移瘤的显示和诊断具有特殊意义,联合使用能提高脑转移瘤的诊断准确率.  相似文献   

10.
DWI及ADC图对脑瘤及瘤样病变诊断价值的探讨(附57例分析)   总被引:3,自引:0,他引:3  
目的 :探讨磁共振扩散加权图像 (DWI)与表观扩散系数 (ADC)图对脑瘤及瘤样病变的诊断价值及相关的生物物理学机制。方法 :对 5 7例病理或临床证实为脑瘤或瘤样病变的患者进行常规MR检查及EPI SE扩散成像检查。其中胶质瘤 2 5例 ,转移瘤 14例 ,脑膜瘤 11例 ,原始神经外胚层瘤 1例 ,恶性纤维组织细胞瘤 1例 ,造血系统肿瘤累及脑 1例 ,脑脓肿 2例 ,病毒性脑炎 2例。测定并比较各种类型脑瘤、级别不同胶质瘤、不同组织成分的ADC值。比较DWI、ADC图与增强T1WI,T2 WI鉴别病灶组织成分的能力及差别。结果 :胶质瘤、转移瘤、脑膜瘤的ADC值分别为 ( 1.16± 0 .2 1)、( 0 .97± 0 .2 6 )、( 1.0 9± 0 .2 8)× 10 -9m2 /s,无明显差异 (P =0 .0 6 ;P =0 .4 4 )。脑内炎性病变和粒细胞白血病脑内浸润灶的ADC值比较低。低级别星形细胞瘤 ( 1.2 8± 0 .16 )× 10 -9m2 /s比间变型 ( 1.11± 0 .13)× 10 -9m2 /s和胶质母细胞瘤 ( 0 .82± 0 .13)× 10 -9m2 /s的ADC值高 (P <0 .0 5 )。瘤灶、水肿、坏死等各组织成分ADC值分别为 ( 1.11± 0 .16 )、( 1.6 2± 0 .19)、( 2 .39±0 .18)× 10 -9m2 /s,有显著差异 (P <0 .0 0 1)。DWI可显示未增强星形细胞瘤 ,较增强T1WI及T2 WI敏感。结论 :ADC值对胶质瘤、转移瘤、脑膜瘤无  相似文献   

11.
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.  相似文献   

12.
13.
14.
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.  相似文献   

15.
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.  相似文献   

16.
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).  相似文献   

17.
18.
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).  相似文献   

19.
20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号