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1.
目的:探讨三维动态增强结合磁共振扩散加权成像(DWI)对乳腺良、恶性病变诊断与鉴别诊断。方法回顾性分析经病理证实乳腺占位性病变46例患者,均行DWI和动态增强磁共振成像(MRI)扫描,按扩散敏感系数(b值)800及1000 s/mm^2各2次扫描数据做出各自表观扩散系数(ADC)图像。分别总结依据ADC值和时间-信号强度曲线评价乳腺良、恶性病变的统计学意义及其敏感性、特异性、阳性预测值、阴性预测值,统计综合考虑ADC值和时间-信号强度曲线类型评价乳腺良、恶性病变。结果46例乳腺肿瘤中恶性病变28例,良性病变18例。当b=800 s/mm^2时,良、恶性病变及正常乳腺组织ADC值分别(1.54±0.28)×10-3 mm^2/s、(1.01±0.09)×10-3 mm^2/s、(1.49±0.06)×10-3 mm^2/s;当b=1000 s/mm^2时,良、恶性病变及正常乳腺组织ADC值分别(1.45±0.28)×10-3 mm^2/s、(0.90±0.08)×10-3 mm^2/s、(1.49±0.09)×10-3 mm^2/s;良性与恶性及正常与恶性两者之间差异有统计学意义(P值<0.05)。在b值800×10-3 s/mm^2、1000×10-3 s/mm^2时,恶性病变ADC值的95%参考值范围分别为(0.97~1.05)×10-3 mm^2/s、(0.90~0.97)×10-3 mm^2/s,将ADC阈值定为1.050、0.969时,诊断乳腺恶性病变的敏感度分别为75%、70%,特异度100%、100%。时间-信号曲线:28例恶性病变中流出型(Ⅲ型)18例(64%),平台型(Ⅱ型)9例(32%),流入型(Ⅰ型)1例(3.5%);18例良性病变中流入型(Ⅰ型)13例(72%),平台型(Ⅱ型)3例(17%),流出型(Ⅲ型)1例(6%);时间-信号曲线诊断标准判断其敏感度96%(27/28),特异度83%(15/18)。结论单独采用DWI或三维动态增强在乳腺疾病诊断方面均存在局限性,联合运用二者,可互补彼此不足之处,提高对乳腺良、恶性肿瘤的鉴别能力。  相似文献   

2.
曲宁  罗娅红  赵英杰  何翠菊   《放射学实践》2010,25(5):515-518
目的:确定扩散敏感因子为800s/mm^2时乳腺良恶性病变的ADC界值,评价MR扩散加权成像(DWI)对乳腺良恶性病变鉴别诊断的价值。方法:回顾性分析经手术病理证实的70例(78个病灶)乳腺病变的DWI图像,其中良性病变26例(31个病灶),恶性病变44例(47个病灶)。测量DWI图像上显示的病变表观扩散系数(ADC)值。通过ROC曲线确定ADC值的诊断阈值,并以此值进行鉴别诊断,同时计算ROC曲线下面积。结果:良恶性病变的ADC值均符合正态性分布,良恶性病变的ADC平均值分别为(1.46±0.26)×10^-3mm^2/s和(1.02±0.19)×10^-3mm^2/s,恶性病变的ADC值明显低于良性病变(P〈0.05)。约登指数最大法确定的ADC诊断阈值为1.28×10^-3mm^2/s,以此值进行鉴别诊断时的敏感度、特异度和诊断符合率分别为93.6%,75.9%,86.8%;阳性似然比最大法确定的ADC诊断阈值为1.035×103mm^2/s,以此值进行鉴别诊断时的敏感度、特异度和诊断符合率分别为46.8%,96.6%,65.8%;ROC曲线下面积为0.905(95%可信区间为0.836-0.975)。结论:扩散敏感因子为800s/mm^2时乳腺良恶性病变的ADC界值确定为1.28×10^-3mm^2/s,DWI的ADC值测定有助于乳腺良恶性病变的鉴别诊断。  相似文献   

3.
MR扩散加权成像在乳腺良恶性病变鉴别诊断中的价值   总被引:4,自引:0,他引:4  
目的 探讨MR扩散加权成像(diffusion weighted imaging,DWI)及表观扩散系数(apparent diffusion coeffi-cient,ADC)在乳腺良恶性病变鉴别诊断中的价值.资料与方法 43例经钼靶或彩超诊断为乳腺肿瘤的患者采用单次激发回波平面成像(echo planar imaging,EPI)技术行双侧乳腺DWI,扩散敏感系数(b值)分别为600、750、1000 s/mm2.同时选取10名知情的健康志愿者及4例患者对侧正常乳腺作为对照组.观察乳腺病变在DWI上的大小、形态及信号特征,测量24个正常乳腺、手术病理证实的24个恶性病灶、23个良性病灶分别在b=600、750、1000 s/mm2时的ADC值,比较良、恶性病变、正常腺体间ADC值差异及b=600、750、1000 s/mm2时ADC值差异.根据恶性组平均ADC值的95%可信区间的上限,计算3组不同b值下诊断乳腺癌的敏感性、特异性和准确性.结果 乳腺良、恶性病变、正常腺体间ADC值差异均有统计学意义(F=101.113,P<0.0001),恶性病变ADC值明显低于良性病变和正常腺体组织(P<0.0001),良性病变ADC值明显低于正常腺体组织(P<0.0001);3组b值间ADC值差异均有统计学意义(F=15.539,P<0.0001),b值越低,ADC值越大(P<0.05).b=600、750、1000 s/mm2时,根据恶性组平均ADC值的95%可信区间的上限诊断乳腺癌的敏感性分别为91.7%、70.8%和79.1%,特异性分别为89.4%、89.4%和93.6%,准确性分别为93.0%、69.0%和88.7%.结论 根据ADC值可以对乳腺良、恶性病变做出鉴别诊断,其敏感性、特异性和准确性较高,具有较高的临床应用价值.  相似文献   

4.
目的 探讨磁共振扩散加权成像(DWI)及表观扩散系数(ADC)在乳腺良恶性病变鉴别诊断中的价值.方法 DWI采用自旋回波-回波平面成像(SE-EPI),扩散敏感系数(即b值)分别为500 s/mm2、1 000 s/mm2.测量正常乳腺组(80例)、经手术病理证实的良性(32个病灶)和恶性病变组(48个病灶)共75例ADC值,比较同b值下3组间ADC值差异的统计学意义及不同b值(b = 500 s/mm2、1 000 s/mm2)时各组内ADC值差异的统计学意义.以恶性组平均ADC值的95%可信区间的上限值作为良恶性病变的界值,与病理结果比较,计算b值为500 s/mm2、1 000 s/mm2时诊断的灵敏度、特异度、阳性预测值、阴性预测值、正确率、Youden指数、阳性似然比、阴性似然比.结果 乳腺良、恶性病变在DWI图上均呈高信号.乳腺良、恶性病变,正常腺体间ADC值差异均有统计学意义;2组b值间ADC值差异有统计学意义,并且b值越低,ADC值越大;根据恶性组平均ADC值的95%可信区间的上限值作为诊断乳腺癌的阈值,b值为500 s/mm2、1 000 s/mm2时诊断的各项诊断指标均较高.结论 DWI及ADC值可以作为乳腺良恶性病变诊断及鉴别诊断的重要依据,与MRI其他扫描序列结合可提高乳腺癌的早期诊断率.  相似文献   

5.
目的探讨MR扩散加权成像(DWI)在胃肠道良、恶性病变诊断中的价值。资料与方法对69例胃肠道病变进行常规MR平扫和DWI,扩散敏感梯度(b值)分别为0和700s/mm^2,测量病变的表观扩散系数(ADC)值,其中29例同时续行增强扫描。结果59例恶性病变的平均ADC值为(0.96±0.11)×10^-3mm^2/s,10例良性病变的平均ADC值为(1.49±0.12)×10^-3mm^2/s,两组病变之间比较差异有统计学意义(P〈0.01)。将恶性病变ADC值95%可信区间上界1.16×100mm^2/s定位为良、恶性病变鉴别的界值,诊断敏感性为86.6%,特异性为95.8%。结论DWI有助于对胃肠道良、恶性病变的诊断和鉴别。  相似文献   

6.
并行采集MR扩散技术对乳腺良恶性病变的临床应用价值   总被引:2,自引:1,他引:1  
目的 评价并行采集MR扩散加权成像(DWI)对乳腺良、恶性病变的临床应用价值. 资料与方法 采用GE 1.5T 超导MRI仪及4通道乳腺相控阵线圈,应用ASSET EPI并用2组b值(b=0,600 s/mm2及0,1000 s/mm2)对56例患者及20名健康志愿者行ASSET-DWI、SE T1WI、FSE T2WI检查,对其中的16例患者及7名健康志愿者双侧乳腺还分别进行横轴位结合ASSET技术的EPI及常规EPI,对ASSET-DWI图像质量及诊断价值进行分析. 结果 ASSET-DWI较常规DWI采集时间缩短50%,常规DWI乳腺及3个病变不同程度变形,ASSET-DWI乳腺变形减轻,病灶无明显变形.ASSET-DWI b值为600 s/mm2或1000 s/mm2时,恶性病变、良性病变及正常腺体ADC值均明显不同(P<0.05).分别以恶性病变95%可信区间上限1.44×10-3 mm2/s (b值600 s/mm2)及1.18×10-3 mm2/s (b值1000 s/mm2)定为良、恶性病变诊断阈值,诊断灵敏度分别为80%(32/40)和77.5%(31/40),特异度均为95%(19/20). 结论 应用ASSET-DWI对乳腺检查可以缩短采集时间,减少图像畸变.b值为600 s/mm2或1000 s/mm2时,根据病变ADC值,ASSET-DWI均可以鉴别多数乳腺良、恶性病变,ADC诊断阈值应与所用b值相匹配.  相似文献   

7.
MR扩散加权成像鉴别乳腺良恶性病变的研究   总被引:50,自引:2,他引:48  
目的 探讨磁共振扩散加权成像(diffusion weightedMRimaging, DW MRI)的表观扩散系数(apparentdiffusioncoefficient, ADC)在乳腺病变鉴别诊断中的价值。方法 DW- MRI采用单次激发平面回波成像(echo planarimaging, EPI)技术, 扩散敏感系数(b值)分别为0、500、1000s/mm2。计算26个正常乳腺、手术病理证实的24个恶性病灶、30个良性病灶分别在b=1000~0、1000~500、500~0s/mm2 时的ADC值,比较良恶性病变、正常腺体间ADC值差异的统计学意义及b=1000~0、1000~500、500~0s/mm2 间ADC值差异的统计学意义。结果 乳腺良、恶性病变、正常腺体间ADC值差异均有统计学意义(F= 565. 74,P<0 .01),恶性病变ADC值明显低于良性病变和正常腺体组织,良性病变ADC值明显低于正常腺体组织; 3组b值间ADC值差异均有统计学意义(F=21. 30,P<0 .01),b值越低,ADC值越大;把恶性肿瘤ADC值95%可信区间上界( 1. 01×10-3 )mm2 /s定为良恶性病变鉴别的界值,诊断敏感性为64 .0%,特异性为96 .7%。结论 根据ADC值可以对乳腺良恶性病变做出鉴别诊断,其特异性较高,但敏感性较低。  相似文献   

8.
目的探讨3.0TMR扩散加权成像(DWI)在鉴别乳腺良恶性病变中的价值。资料与方法 65例经穿刺活检或手术病理证实的乳腺病变患者行MRI及DWI检查,b值取50、450、850s/mm2。计算DWI的病灶检出率,比较不同b值时正常腺体组织、良性病变、恶性病变的表观扩散系数(ADC),以及肿块样病变和非肿块样病变的ADC值。以恶性病变ADC值95%可信区间上限作为诊断阈值,计算不同b值的诊断敏感性、特异性、准确率、阳性预测值、阴性预测值。结果 DWI对病灶的检出率为95.4%(62/65),包括32例恶性病灶和30例良性病灶;3例导管原位癌未显示。b=50~850s/mm2时诊断敏感性、特异性、准确率、阳性预测值、阴性预测值分别为87.5%、83.3%、85.5%、84.8%、86.2%,高于b=50~450s/mm2时的84.4%、80.0%、82.3%、81.8%、82.8%。不同b值时正常腺体组织、良性病变、恶性病变之间ADC值差异均有统计学意义(P<0.01)。肿块样与非肿块样良恶性病变之间ADC值差异均有统计学意义(P<0.01)。结论 3.0TMR扩散加权成像有助于良恶性病变的鉴别,但诊断时需结合常规MR扫描避免漏诊、误诊。  相似文献   

9.
扩散加权成像中不同扩散敏感系数对乳腺病变的诊断价值   总被引:1,自引:1,他引:0  
目的 研究扩散加权成像(DWI)中不同扩散敏感系数(b值)对乳腺病变的诊断价值及影响因素,并探讨其鉴别良、恶性乳腺肿瘤的最佳界值.资料与方法 对155例患者行不同b值的DWI检查,其中136例选取b值(0,500 s/mm2),122例选取b值为(0,1000 s/mm2).所有病例结果均经手术病理证实,将DWI表现与组织病理学进行对照.结果 两组b值中恶性病变的ADC值均明显低于良性病变,且乳腺良、恶性病变的表观扩散系数(ADC)值均随b值增大而降低.采用非参数法受试者操作特性曲线(ROC)统计学分析方法确定鉴别良、恶性病变的最佳界值,应用此界值对乳腺病变诊断的敏感性和特异性分别为83.3%和56.9%(b=500 s/mm2)、73.6%和80.0%(b=1000 s/mm2).结论 高b值DWI对乳腺病变诊断的特异性高于低b值DWI,是乳腺动态增强成像检查的一个有益的补充.  相似文献   

10.
目的:探讨3.0T扩散加权成像(DWI)在乳腺良恶性病变鉴别诊断中的诊断价值并对b值使用进行优化。方法:34例患者共20个良性和16个恶性乳腺病灶纳入研究,同期20例正常乳腺受检者列为对照组。采用3.0T MR行乳腺DWI成像检查,b值分别取0,750 s/mm2,1000 s/mm2,1250 s/mm2。比较不同b值DWI图像质量,测量病灶的对比噪声比(CNR)以及表观扩散系数(ADC)值,以病理诊断为金标准,计算诊断乳腺癌的敏感度、特异度及准确性,绘制受试者工作特征曲线(ROC)并进行比较。结果:不同b值时DWI图像主观质量评分没有统计学差异(F=3.02,P=0.0516>0.05)。b=750 s/mm2时病灶的CNR明显优于b=1000s/mm2及1250s/mm2时(P值为0.004及0.000),而b=1000s/mm2与1250s/mm2之间没有统计学差异(P=0.800>0.05)。相同b值时,正常乳腺组织的平均ADC值>乳腺良性病变>乳腺恶性病变(P均=0.000)。以各b值恶性病变平均ADC值95%可信区间的上限作为界定乳腺癌ADC的阈值,则b=750 s/mm2、1000 s/mm2、1250s/mm2时,ADC阈值分别为1.33×10-3mm2/s、1.25×10-3mm2/s、1.16×10-3mm2/s。以上述阈值判断乳腺癌的敏感度、特异度及准确性分别为81.25%、87.5%、85.71%,81.25%、77.5%、78.57%及81.25%、82.5%、82.14%。三个b值的ROC曲线下面积无显著性差异(P=0.1925>0.05)。结论:乳腺的3.0T DWI中,以b=750s/mm2时病灶CNR最高,值得推荐应用。应用DWI鉴别乳腺良恶性病变时,需要结合ADC值判断。  相似文献   

11.
本文介绍了在临床实际中利用功能性参数,对冠状动脉DSA心肌血流灌注成像、冠状动脉血流量测定、左心室功能测定、肺动脉高压程度的评价等项目研究结果。重点讨论了提取DSA功能性参数的一般方法,认为功能性参数在现代影像诊断学中的作用是对疾病做出程度、定量、动态及功能诊断。  相似文献   

12.
Optical imaging techniques use visual and near infrared rays. Despite their considerably poor penetration depth, they are widely used due to their safe and intuitive properties and potential for intraoperative usage. Optical imaging techniques have been actively investigated for clinical imaging of lymph nodes and lymphatic system. This article summarizes a variety of optical tracers and techniques used for lymph node and lymphatic imaging, and reviews their clinical applications. Emerging new optical imaging techniques and their potential are also described.  相似文献   

13.
PURPOSE: To investigate the use of a three-dimensional rapid acquisition with relaxation enhancement (RARE) pulse sequence for direct acquisition of phosphocreatine (PCr) images of the human myocardium. MATERIALS AND METHODS: A short elliptical birdcage radiofrequency (RF) body coil was constructed to produce a uniform flip angle throughout the chest cavity. In vivo images using a spectrally-selective RARE sequence with a spatial resolution of 1.2 cm x 1.2 cm x 2.5 cm (4 cm(3)) were acquired in nine minutes and 40 seconds. RESULTS: Scans of phantoms demonstrated excellent spectral selectivity. The signal-to-noise ratio in the myocardium ranged from 12.6 in the anterior wall to 5.3 in the mid septum. CONCLUSION: This study demonstrates that PCr data can be acquired using a three-dimensional RARE sequence with greater spatial and temporal resolution than spectroscopic techniques.  相似文献   

14.
RATIONALE AND OBJECTIVES: We sought to identify and describe the characteristics of molecular imaging (MI) programs in the United States and to determine the factors considered critical for their future. MATERIALS AND METHODS: In a cross-sectional study, a validated survey was sent to members of the Society of Chairmen in Academic Radiology Departments (SCARD) in the United States, and 26 variables were studied. RESULTS: The response rate was 40.3%; 67.9% of the departments surveyed have an MI program. The main focus of 47.4% of departments is oncology. The number of radiologists working for the department was the only variable found to be significantly positively correlated with (1) number of researchers in the MI program, (2) number of MI modalities available, (3) total number of grants, and (4) having ongoing MI clinical trials. These four variables plus the number of federal grants and the space used by MI programs were independent of the geographical region, hospital size (number of beds), and department size (number of radiological examinations per year). All the MI programs received grants during 2005. Only 16.1% have no alliances with industry. Among all the departments, 82% identified staff training and recruitment as the keys for success; 78.57% considered oncology the most important future application of MI and cancer management the hospital service most affected by MI. CONCLUSION: MI programs are starting to be more widespread throughout the United States, and the trend is for more academic radiology departments to become engaged in MI activities; their development is independent of department characteristics. Radiology departments strongly agreed about the key components for success of MI initiatives and the areas that will be most affected by MI applications.  相似文献   

15.
Although RARE and GRASE can produce single-shot images of excellent quality, their utility has been restricted because preparation of the magnetization with interesting contrast before imaging can cause severe artifacts. These artifacts relate to the strong sensitivity of multiple spin echo sequences to the phase of the prepared magnetization. Modifications of the RARE sequence to eliminate these artifacts are discussed, and an approach that eliminates the artifact producing signals from the very first echo is presented. The approach is applied to diffusion imaging of the human brain in normal volunteers and one patient.  相似文献   

16.
High-resolution computed tomography (CT) and magnetic resonance imaging (MRI) have become indispensable tools for the evaluation of conditions involving the head and neck. Complex anatomic structures and regions, such as the orbit, skull base, paranasal sinuses, deep spaces of the neck, larynx, and lymph nodes, require that the radiologist be familiar with the imaging modalities available and their appropriate applications. The purpose of this article is to review the techniques of CT and MRI and the roles they play in clinical practice, including head and neck disorders.  相似文献   

17.
An emerging suite of new imaging techniques offer the ability to monitor and quantify molecular and cellular processes in the lungs noninvasively. These techniques take advantage of dramatic advances in both imaging technology as well as molecular and cell biology. Molecular imaging is being used with increasing regularity in research protocols, and forms of molecular imaging have found their way into the patient care setting (eg, positron emission tomography imaging in cancer). Such techniques will afford the basic scientist as well as the clinician an unprecedented opportunity for in vivo study of the lung biology that drives normal pulmonary physiology as well as pathophysiology.  相似文献   

18.
Introduction In vivo bioluminescence imaging (BLI) is a promising technique for non-invasive tumour imaging. d-luciferin can be administrated intraperitonealy or intravenously. This will influence its availability and, therefore, the bioluminescent signal. The aim of this study is to compare the repeatability of BLI measurement after IV versus IP administration of d-luciferin and assess the correlation between photon emission and histological cell count both in vitro and in vivo. Materials and methods Fluc-positive R1M cells were subcutaneously inoculated in nu/nu mice. Dynamic BLI was performed after IV or IP administration of d-luciferin. Maximal photon emission (PEmax) was calculated. For repeatability assessment, every acquisition was repeated after 4 h and analysed using Bland–Altman method. A second group of animals was serially imaged, alternating IV and IP administration up to 21 days. When mice were killed, PEmax after IV administration was correlated with histological cell number. Results The coefficients of repeatability were 80.2% (IV) versus 95.0% (IP). Time-to-peak is shorter, and its variance lower for IV (p < 0.0001). PEmax was 5.6 times higher for IV. A trend was observed towards lower photon emission per cell in larger tumours. Conclusion IV administration offers better repeatability and better sensitivity when compared to IP. In larger tumours, multiple factors may contribute to underestimation of tumour burden. It might, therefore, be beneficial to test novel therapeutics on small tumours to enable an accurate evaluation of tumour burden. Marleen Keyaerts is a Ph. D. fellow of the Research Foundation—Flanders (Belgium; FWO).  相似文献   

19.
目的比较3.0 T与1.5 T MR正常乳腺组织扩散加权成像(DWI)的图像质量,从而评价3.0 T乳腺MRDWI的可行性。方法对44名女性乳腺受检者分别在3.0 T MR与1.5 T MR上行DWI。3.0 T DWI应用选择性水激励(Water excitation)技术行脂肪抑制,1.5 T DWI应用频率选择脂肪饱和(Fatsat)技术行脂肪抑制,b值均为0,1000 s/mm2,其他参数相同。比较3.0 T及1.5 T乳腺MR DWI图像的主观质量评分,测量并计算3.0 T及1.5 T乳腺MR DWI乳腺组织信噪比(SNR)及表观扩散系数(ADC)值,进行统计学分析。结果 3.0 T乳腺MR DWI的图像质量平均评分为(3.07±0.79),主观质量评分达到3分(可以诊断)及以上者为34名,占总检查例数的77.27%。1.5 T乳腺MR DWI的图像质量平均评分为(3.23±0.52),主观质量评分达到3分及以上者为42例,占总检查例数的95.45%。两者比较差异无统计学意义(P=0.1615,>0.05)。3.0 T乳腺MR DWI的乳腺组织SNR为(52.28±19.34),1.5 T乳腺MR DWI的乳腺组织SNR为(49.97±17.99)。3.0 T乳腺MR DWI图像乳腺组织平均SNR略高于1.5 T,但二者差异无统计学意义(P=0.5500,>0.05)。3.0 T MR DWI的平均ADC值为(1.80±0.44)×10-3mm2/s,1.5 T MR DWI的平均ADC值为(1.73±0.32)×10-3 mm2/s,两者比较差异无统计学意义(P=0.0652,>0.05)。结论 DWI可用于3.0 T MR乳腺成像,图像质量可以达到1.5 T MR DWI的效果,且ADC值与1.5 T的ADC值无明显差异。  相似文献   

20.
MR灌注成像在评价脑内胶质瘤残留或复发方面的价值   总被引:4,自引:0,他引:4  
目的 用受试者操作特性(ROC)分析方法评价常规MR和灌注成像(PWI)对脑内胶质瘤术后早期残存与复发的诊断价值。资料与方法 回顾性分析经手术与病理证实的脑内胶质瘤86例,其中术后残留或复发50例,均经二次手术证实;其余36例术后随诊18个月以上无复发表现。所有患者均行常规MR/和PWI,获得相对脑血流容积彩图,并计算肿瘤相对血容积比值。采用Windows98版ROCKIT软件进行ROC分析,使用微软Excel2000软件绘制ROC曲线图。结果 86例胶质瘤术后的影像资料经ROC分析显示,常规MR曲线的a值(截距)为0.12,b值(斜率)为0.95,Az为0.5343;结合PWI的方法a值为0.56,b值为1.23,Az为0.6370。两种方法ROC曲线的Az差异有统计学意义(P=0.0001,〈0.01)。在胶质瘤术后残存或复发的诊断方面,结合PWI的MRI诊断方法明显优于常规MRI。结论 在术后早期,对胶质瘤残存与复发的监测方面,常规MR/结合PWI能明显提高特异性和敏感性。  相似文献   

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