基于体素内不相干运动的扩散加权成像对乳腺肿块病灶良恶性的诊断价值

目的 探讨基于体素内不相干运动(IVIM)的扩散加权成像(DWI)对乳腺肿块病灶的诊断价值.方法 前瞻性纳入术前行MRI检查且动态对比增强(DCE)表现为乳腺肿块的患者78例(87个病灶),分为良性组(n=29)与恶性组(n=58).通过单、双指数模型分别获得表观扩散系数(ADC)、单纯水分子扩散系数(D)、灌注相关的扩散系数(D*)和灌注分数(f)参数值.采用独立样本t检验分析组间各参数差异.绘制受试者工作特征曲线(ROC),分析各参数对乳腺肿块病灶的诊断效能.结果 恶性组ADC、D低于良性组(P ＜0.001),恶性组D*高于良性组(P=0.04).恶性组与良性组间f无明显差异(P＞0.05).以病理为金标准,ADC、D、D*值诊断乳腺恶性肿块病灶的曲线下面积(AUC)分别为0.88、0.92、0.62,D与ADC间差异有统计学意义(P=0.03).ADC、D、D*分别以1.19×10-3mm2/s、1.05×10-3mm2/s、7.55×10-3mm2/s为诊断阈值,敏感度分别为86.2％、89.7％、89.7％,特异度分别为89.7％、93.1％、37.9％,准确率分别为87.4％、89.7％、55.2％.结论 IVIM参数D对乳腺肿块病灶的诊断效能优于ADC,具有较高的敏感度和特异度,D*诊断效能一般,f诊断价值有限.     

IVIM与DSC灌注成像在脑星形细胞瘤分级中的诊断价值

目的：探讨 MR 体素内不相干运动(IVIM)成像与动态磁敏感对比增强(DSC)灌注成像在脑星形细胞瘤分级中的诊断价值。方法对手术病理证实的22例高级别及28例低级别星形细胞瘤患者术前行 MR 常规扫描及 IVIM、DSC 扫描,定量测量2组肿瘤实质区 IVIM 成像参数值,包括标准扩散系数(ADCstandard )、慢扩散系数(D)、快扩散系数(D?)、灌注分数(f)和 DSC 灌注成像参数值,包括相对脑血容量(rCBV)、相对脑血流量(rCBF),采用两独立样本 t 检验分析各参数值在高、低级别脑星形细胞瘤中是否有统计学差异,应用受试者工作特征曲线(ROC)评价单独及联合应用 IVIM 成像和 DSC 灌注成像的诊断效能。结果肿瘤实质区ADCstandard 值、D 值、rCBV 值、rCBF 值在脑星形细胞瘤分级中有明显统计学差异(P <0.01);D?值、f 值在脑星形细胞瘤分级中无统计学差异(P=0.130,P=0.379);各参数值对脑星形细胞瘤分级的 ROC 曲线下面积为：ADCstandard 值0.823,D 值0.854,rCBV 值0.858,rCBF值0.871,D 值与 rCBV 和 rCBF 值联合应用0.952,0.953。结论D 值及 rCBV、rCBF 值可以对脑星形细胞瘤进行分级,联合应用IVIM 成像与 DSC 灌注成像可以提高脑星形细胞瘤分级的准确性。     

IVIM-DWI参数分析宫颈癌的组织学特征及其临床诊断价值

【摘要】目的:探讨宫颈癌在MRI体素不相干运动扩散加权成像（IVIM-DWI）上的特点及临床价值。方法:对经病理证实的、未经放化疗的40例宫颈癌患者行9个ｂ值（0～1000s/mm2）IVIM-DWI扫描。测量并计算宫颈癌组织和自体子宫肌层的单指数成像ADC值，IVIM-DWI定量参数值，包括纯扩散系数（D）、伪扩散系数（D*）和灌注分数（f）。按子宫颈癌组织学及临床分期进行分组，用统计学方法分析比较各组子宫颈癌和正常子宫肌层的上述参数。结果：宫颈癌组ADC、f、D、D*值分别为（0.76±0.13）×10-3mm2/s、（10.78±4.42）%、（0.88±0.35）×10-3mm2/s、〖JP3〗（16.31±15.39）×10-3mm2/s，〖JP〗均低于正常子宫肌层组（P<0.05）。宫颈低分化鳞癌组ADC、f、D、D*值分别为（0.74±0.14）×10-3mm2/s、（10.85±6.02）%、（0.93±0.39）×10-3mm2/s、（22.12±20.69）×10-3mm2/s；宫颈中分化鳞癌组ADC、f、D、D*值分别为（0.78±0.11）×10-3mm2/s、（12.37±5.01）%、（0.86±0.25）×10-3mm2/s、（13.71±9.12）×10-3mm2/s；宫颈腺癌组ADC、f、D、D*值分别为（0.76±0.16）×10-3mm2/s、（7.68±3.76）%、（0.80±0.41）×10-3mm2/s、（8.82±3.88）×10-3mm2/s；各组数值两两比较无统计学意义（P＞0.05）。早期宫颈癌组ADC、f、D、D*值分别为（0.76±0.13）×10-3mm2/s、（7.82±4.73）%、（0.87±0.25）×10-3mm2/s、（17.39±20.88）×10-3mm2/s；晚期宫颈癌组ADC、f、D、D*值分别为(0.75±0.14)×10-3mm2/s、(12.21±5.22)%、(0.87±0.39)×10-3mm2/s、(15.78±12.39)×10-3mm2/s。早期宫颈癌组f值明显低于晚期宫颈癌组(P=0.014)，有统计学意义；ADC、D、D*值在两组间无统计学意义（P＞0.05）。结论:在IVIN-DWI定量参数分析中，宫颈癌组ADC、f、D、D*值与正常子宫肌层具有不同，宫颈低分化鳞癌组、宫颈中分化鳞癌组及宫颈腺癌无差别。早期宫颈癌f值明显低于晚期宫颈癌组。研究结果显示IVIM参数能定量反映宫颈癌组织特性，在宫颈癌MR诊断中有一定的应用价值。     

体素不相干运动扩散加权成像在鉴别头颈部鳞癌淋巴结转移中的应用

目的 评价基于体素不相干运动(IVIM)模型计算出的真实扩散系数(D)、灌注相关扩散系数(D*)、灌注分数(f)和表观扩散系数(ADC)在鉴别头颈部鳞癌(HNSCC)淋巴结转移中的价值.方法 回顾性分析2013年9月至2014年12月间HNSCC及良性淋巴结增生(LNH)患者46例临床资料,其中26例确诊HNSCC患者(男18例,女8例,平均年龄48岁)为A组,20例确诊LNH患者(男12例,女8例,平均年龄41岁)为B组.所有患者均进行3.0 T MR扫描,并于MR检查结束后2周通过手术或穿刺取得病理结果.IVIM-DWI采用13个b值.使用Mann-Whitney检验比较两组间D,D*,f和ADC值,用ROC曲线评价ADC、D和D*值的诊断效能.结果 A组共检出33个淋巴结,B组共检出22个淋巴结(最小直径均＞5 mm).A组ADC值为(1.08 ±0.26) ×10-3mm2/s,和B组(1.25 ±0.19)×10-3mm2/s相比,差异有统计学意义(P =0.035).A组的D值为(0.57 ±0.12)×10-3mm2/s,B组为(0.74±0.21) ×10-3 mm2/s,A组较B组显著降低(P＜0.01).A组的f值为0.20 ±0.02,B组为0.32 ±0.05,差异有统计学意义(P＜0.01);而A组D*值为(120.89 ±26.94)×10-3mm2/s,B组为(68.78±17.71)×10-3mm2/s,A组较B组显著增高(P＜0.01).D*值的ROC曲线下面积(AUC)为0.952,大于D值(0.78)和ADC值(0.67).结论 IVIM DWI技术在HNSCC淋巴结转移的鉴别诊断中是可行的,恶性淋巴结中降低的D值反映了高核浆比,而升高的D*值在一定程度上可反映恶性淋巴结增多的新生血管与组织灌注.     

体素内不相干运动成像对胰腺癌的诊断价值

目的:探究DWI单指数模型、体素内不相干运动成像双指数模型及拉伸指数模型对胰腺癌诊断的临床应用价值。方法:回顾性收集分析经证实胰腺癌30例;同期检查胰腺正常者25例,行3.0T MRI-DWIeDWI,HR DWI扫描。测量记录两组单指数模型、双指数模型、拉伸指数模型各参数值。结果:ADC.Standard ADC,D-mono,D*-mono,D*-Bi,DDC、α值差异均有统计学差异(P<0.05)。α值ROC曲线下面积>0.9,AUC为0.905,ADC,D-moono,D*-mono,D*-Bi,DDC值ROC曲线下面积在0.75~0.9之间,AUC分别为0.725,0.873,0.899,0.773,0.767,standard ADC曲线下面积>0.5,AUC值0.538结论:IVIM多个参数对PC的诊断效能较常规DWI序列ADC值更高;其中IVIM序列拉伸指数模型的α值是鉴别胰腺癌与正常组织的最佳参数.     

单、双指数模型DWI评价胃癌血管内皮生长因子的价值

目的 研究MR单指数扩散加权成像(DWI)表观扩散系数(ADC)值及双指数DWI真实扩散系数(D)值、相关扩散系数(D*)值、灌注分数(f)值对血管内皮生长因子(VEGF)表达水平的评价价值.方法 采用免疫组织化学染色方法检测28例胃癌组织切片及周围正常胃壁的VEGF表达并进行分级,分别分析ADC值、D值、D*值、f值在不同VEGF表达组间及胃癌不同分级间的差异.结果 不同VEGF分级间的ADC值、D值、f值差异有统计学意义,VEGF分级越高ADC值、D值越低,f值越高;高低分化胃癌的ADC值、D值、f值差异有统计学意义(P<0.05).结论 单指数模型DWI ADC值、双指数模型DWI D值、f值对评价胃癌VEGF表达有价值,可以反映胃癌血管生成.     

体素内不相干运动联合扩散峰度成像模型对乳腺良恶性病灶的鉴别诊断价值

目的:探讨体素内不相干运动(IVIM)技术联合扩散峰度成像(DKI)对乳腺良恶性病变的鉴别诊断价值.方法:137例女性患者(共153个病灶)行双侧乳腺多b值DWI检查(b=0～2000 s/mm2);分别使用IVIM、DKI模型获得病灶的真性扩散系数(D)、灌注相关扩散系数(D*)、灌注分数(f)以及平均扩散峰度系数(MK)、平均扩散系数(MD)和ADC值.分析这些参数在乳腺良恶性病变中的变化规律,采用受试者工作特性曲线(ROC)评估各参数的诊断效能.结果:良恶性病灶的D、f、MK、ADC和MD值的中位数差异有统计学意义(P值分别为0.000、0.020、0.000、0.000和0.000),良恶性病灶D*值的差异无统计学意义(P=0.480).D值与和MK、ADC和MD值在鉴别乳腺良恶性病变中的可靠性相当,两两比较差异无统计学意义(P值均大于0.1).当MK值及D、ADC和MD值的阈值分别取0.8073及0.9536×10-3、1.1436×10-3和1.5657×10 3mm2/s时,鉴别良恶性病灶的敏感度和特异度依次分别为(95.7％,84.2％)及(95.7％,81.6％)、(96.5％,84.2％)和(93.9％,84.2％).ROC曲线分析得出D值的诊断效能最大(AUC=0.91).联合D值和MK值的AUC这0.92.结论:采用1VIM和DKI模型获得的相关参数有助于乳腺良恶性病灶的鉴别,以IVIM模型中的真性扩散系数的诊断敏感性和特异性较高,联合真性扩散系数和扩散峰度系数的诊断效能最高.     

MR体素内不一致运动序列预测和评价宫颈癌放化疗效果

目的 探讨磁共振体素内不一致运动序列(IVIM)在预测和评价宫颈癌放化疗效果方面的价值.方法 对62例接受同步放化疗(放疗+同步顺铂化疗)的宫颈癌患者于治疗前、治疗后1个月分别行MRI常规序列和双指数模型的IVIM序列扫描.测量治疗前后肿瘤最大径并根据疗效进行分组,测量并比较治疗前不同疗效组间IVIM参数值差异和各组治疗前后参数值差异.结果 (1)肿瘤稳定(SD)组治疗后ADC、D值高于治疗前(P=0.016,0.001);(2)肿瘤部分缓解(PR)组治疗后ADC、D值高于治疗前(P=0.01,0.01),D*值低于治疗前(P=0.044);(3)肿瘤完全消失(CR)组治疗后ADC、D和f值均高于治疗前(P=0.000,0.000,0.03),D*值低于治疗前(P =0.011);(4)治疗前SD组ADC依次低于PR组和CR组(P =0.000,0.000),但PR组和CR组间差异无统计学意义(P =0.094);SD组D值依次低于PR组和CR组,三组间差异均有统计学意义(P =0.000,0.000,0.003);SD组D*值高于其他两组,但仅SD组和CR组间差异有统计学意义(P =0.003),SD组D*值高于PR组和CR组(P=0.000,0.004),PR组和CR组间差异无统计学意义(P =0.212).结论 宫颈癌治疗前IVIM序列有助于预测治疗效果,治疗前后IVIM参数值改变对评价治疗效果具有重要作用.     

3D酰胺质子转移成像用于宫颈鳞癌和正常宫颈基质的鉴别诊断研究

【摘要】目的：探讨酰胺质子转移（APT）成像对宫颈鳞癌和正常宫颈基质的鉴别诊断价值。方法：2017年9月-2018年9月前瞻纳入27例2018 FIGO分期为ⅠB～Ⅳ期的宫颈鳞癌患者和27例正常志愿者,所有受试者于3T MR扫描仪行盆腔3D APT及DWI成像。两名放射科医师盲法测量病灶及正常宫颈基质最大层面的APT值及ADC值。计算观察者间组内相关系数以评估测量一致性。采用独立样本t检验比较宫颈鳞癌和正常宫颈基质的APT值和ADC值,行ROC曲线分析。结果：观察者间测量一致性良好（ICC均>0.9）。宫颈鳞癌APT值为2.80±0.36,显著高于正常宫颈基质APT值1.81±0.38（P<0.0001）。宫颈鳞癌ADC值为(0.98±0.17)×10-3mm2/s ,显著低于宫颈正常基质ADC值(1.56±0.32)×10-3mm2/s（P<0.0001）。鉴别宫颈鳞癌与正常宫颈基质,APT值ROC曲线下面积为0.996,ADC值ROC曲线下面积为0.963。结论：APT值在宫颈鳞癌与正常宫颈基质的鉴别中展现了与ADC值近似的诊断效能。     

多b值DWI在宫颈癌及CIN Ⅲ诊断中的应用

目的 分析正常宫颈及宫颈癌、宫颈高级别上皮内瘤变(CIN Ⅲ)的多b值扩散加权成像(DWI)的特点,探讨其对宫颈癌诊断和判断病理类型的价值.方法 收集经手术或活检证实宫颈癌患者54例(腺癌15例,鳞癌36例、神经内分泌癌3例)和CIN Ⅲ 9例,行常规MR和多b值DWI扫描.对比正常宫颈组织和宫颈癌组织的多b值表观扩散系数(ADC)值.对测得的不同病理类型宫颈癌、CIN Ⅲ与正常宫颈的ADC值进行比较.结果 正常宫颈的宫颈内膜、结合带及肌层3层结构可以在不同b值的DWI上显示,各层之间的ADC值差异有统计学意义(P<0.05);宫颈癌的多b值ADC值与正常宫颈之间的差异有统计学意义(P<0.05);宫颈鳞癌、腺癌、CIN Ⅲ、神经内分泌癌的平均ADC值差异有统计学意义(P<0.05).结论 多b值DWI的ADC值有助于宫颈癌及CIN Ⅲ的诊断,并与宫颈癌的病理类型存在相关性.应用多b值DWI检查可以提高宫颈癌、CIN Ⅲ定性诊断的准确性.     

DSA功能性参数的提取与利用

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。     

Current Status of Optical Imaging for Evaluating Lymph Nodes and Lymphatic System

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.     

Fast imaging of phosphocreatine in the normal human myocardium using a three-dimensional RARE pulse sequence at 4 Tesla

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.     

Molecular imaging of the lungs

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.     

Molecular imaging programs in the United States: results of a national survey

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.     

Dynamic bioluminescence imaging for quantitative tumour burden assessment using IV or IP administration of <Emphasis Type="SmallCaps">d</Emphasis>-luciferin: effect on intensity,time kinetics and repeatability of photon emission

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 (PE_max) 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, PE_max 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). PE_max 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).     

Phase insensitive preparation of single-shot RARE: Application to diffusion imaging in humans

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.     

Head and neck imaging: the role of CT and MRI

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.     

A Velocity k-Space Analysis of Flow Effects in Echo-Planar and Spiral Imaging

A velocity k-space formalism facilitates the analysis of flow effects for imaging sequences involving time-varying gradients such as echo-planar and spiral. For each sequence, the velocity k-space trajectory can be represented by k_v (k)_r; that is, its velocity-frequency (k_r) position as a function of spatial-frequency (k_r) position. In an echo-planar sequence, k_r is discontinuous and asymmetric. However, in a spiral sequence, k_r is smoothly varying, circularly symmetric, and small near the k_r origin. To compare the effects of these trajectory differences, simulated images were generated by computing the k-space values for an in-plane vessel with parabolic flow. Whereas the resulting echo-planar images demonstrate distortions and ghosting that depend on the vessel orientation, the spiral images exhibit minimal artifacts.     

CAIPIRINHA-Dixon-TWIST (CDT)-volume-interpolated breath-hold examination (VIBE) for dynamic liver imaging: Comparison of gadoterate meglumine,gadobutrol and gadoxetic acid

Purpose

CAIPIRINHA-Dixon-TWIST (CDT)-VIBE is a robust method for abdominal magnetic resonance imaging providing both high spatial and high temporal resolution. The purpose of this study was to examine the influence of different gadolinium based contrast agents (GBCA) on image quality (IQ) with CDT-VIBE.

Materials and methods

In this IRB-approved, retrospective, inter-individual comparison study, 86 patients scanned at 3T were included. Within 28 s, 14 high-resolution 3D datasets were acquired using CDT-VIBE. 37 patients received 0.1 mmol/kg gadoterate meglumine, 28 patients 0.1 mmol/kg gadobutrol, and 19 patients 0.1 mL/kg gadoxetic acid. Two blinded, board-certified radiologists assessed the image quality on a 5 point scale, as well as the number of hepatic arterial dominant (HAD) phases.

Results

Regardless of the GBCA utilized, CDT-VIBE resulted in good IQ in terms of best IQ achieved among all 14 datasets (gadobutrol 4.3, gadoterate meglumine 3.9, gadoxetic acid 3.7). With respect to worst IQ, the three groups showed statistically significant differences with gadobutrol receiving the highest rating (3.6) and gadoxetic acid the lowest (2.4) (gadoterate meglumine 3.0; 0.0014 < p < 0.0485). No statistically significant differences were found in the mean number of acquired HAD phases (gadobutrol 3.4, gadoterate meglumine 3.9, gadoxetic acid 3.1; 0.18 < p < 0.57).

Conclusion

Different gadolinium-based contrast agents can be utilized for dynamic liver imaging with CDT-VIBE resulting in good image quality.