肝纤维化磁共振ADC值与病理学分期的相关性研究

目的 探讨磁共振ADC值、肝纤维化血清学指标与肝纤维化病理分期之间的相关性.方法 检测41例慢性肝病患者磁共振ADC值和肝纤维化血清学4项指标,包括透明质酸(HA)、Ⅳ型胶原(C-Ⅳ)、层粘连蛋白(LN)和Ⅲ型前胶原(PCⅢ),并与肝穿刺的病理纤维化分期结果进行相关性分析.结果 b=400 s/mm2时,S0～1期、S2～3期及S4期ADC值分别为(1661.5±94.4)、(1522.7±83.4)、(1408.3±110.3)×10-6 mm2/s;b=600 s/mm2时3组ADC值为(1448.3±75.1)、(1349.7±55.9)、(1222.6±79.9) ×10-6mm2/s;b=800 s/mm2时3组ADC值为(1361.4±48.1)、(1285.0±46.5)、(1214.3±50.2)×10-6mm2/s.随肝纤维化分期进展ADC值递减,差异均具有统计学意义(P＜0.01),且ADC值与肝纤维化分期之间具有很好的负相关性,以b=600 s/mm2时相关关系最密切(r=-0.786).肝纤维化血清学4项指标与ADC值之间存在不同程度的负相关性.结论 ADC值可以定量肝纤维化的严重程度,与血清学指标共同反映肝纤维化的特征性病理表现.     

磁共振弥散加权成像在乙型肝炎肝纤维化程度评估中的价值

目的：探讨磁共振弥散加权成像（DWI）在乙型肝炎肝纤维化程度评估中的价值。方法62例乙型肝炎肝纤维化患者根据肝脏穿刺及组织病理学检查分为S1期（n=15例）、S2期（n=16例）、S3期（n=16例）、S4期（n=15例）,同期选择23例未发生肝纤维化的乙肝患者作为对照组,选择24例门诊健康体检者作为正常组。所有研究对象均接受磁共振平扫及DWI检查,比较各组不同b值时ADC值,分析ADC值与乙型肝炎肝纤维化分期的相关性。结果 b值为100s/mm2、200s/mm2、400s/mm2时各组ADC值比较无显著性差异（P>0.05）,b值为600s/mm2、800s/mm2时,肝纤维化组S3及S4期ADC值明显低于S0、S1及S2期（P<0.05）;b值为100s/mm2、200s/mm2、400s/mm2时,不同分期ADC值间比较无显著性差异（P>0.05）,b值为600s/mm2、800s/mm2时,ADC值与肝纤维化分期有负相关性（P<0.05）,b值为800s/mm2时,相关性最明显。结论 DWI在乙型肝炎肝纤维化程度评估中具有较高的临床价值,尤其当b值为800s/mm2时,各肝纤维化分期的ADC值存在较大的差异性,值得临床推广应用。     

不同b值DWI对大鼠肝纤维化、肝硬化病理分级的意义

目的:探讨1.5 T MRI不同b值DWI下的ADC值、e ADC值与大鼠肝纤维化、肝硬化分级的相关性。方法:清洁级SD大鼠100只,雄性,体质量180~200 g。将大鼠随机分为实验组84只,对照组16只,实验组采用硫代乙酰胺(TAA)腹腔定点注射,对照组同期腹腔注射同剂量生理盐水。常规MRI检查后,DWI采用FSE-EPI,按b=300、600 s/mm2分为2组,生成ADC图及e ADC图,并测量相应ADC及e ADC值;根据病理结果将肝损伤分为肝纤维化0期(对照组)、肝纤维化I~Ⅱ期(早期)、肝纤维化Ⅲ~Ⅳ期(晚期)、肝硬化结节期。结果:共59只(实验组47只,对照组12只)大鼠成功行DWI检查。1b=300 s/mm2时,实验组ADC值均低于对照组,对照组与实验组各期之间及肝硬化结节期与其余各组之间差异均有统计学意义(均P0.05);e ADC值均高于对照组,肝硬化结节期与其余各组间差异均有统计学意义(均P0.05),对照组与肝纤维化晚期组之间差异有统计学意义(P0.05)。b=600 s/mm2时,实验组ADC值均低于对照组,肝硬化结节期与其余各组间差异有统计学意义(均P0.05),对照组与肝纤维化晚期组之间差异有统计学意义(P0.05);肝硬化结节组e ADC值与各组两两比较差异均有统计学意义(P0.05)。2ADC值与SD大鼠肝纤维化、肝硬化病理分级之间呈负相关,b=300 s/mm2时,r=-0.463(P0.05);b=600 s/mm2时,r=-0.606(P0.05)。e ADC值与SD大鼠肝纤维化、肝硬化病理分级之间呈正相关,b=300 s/mm2时,r=0.504(P0.05);b=600 s/mm2时,r=0.435(P0.05)。结论:ADC值和e ADC值能对肝纤维化、肝硬化进行分级,且有一定的相关性。b=600 s/mm2时,ADC值与肝纤维化、肝硬化分级之间相关性最好。     

肝纤维化和肝硬化的MR扩散成像及与病理对照、CT灌注参数的相关性研究

目的利用扩散加权成像(DWI)检查技术测定肝纤维化和肝硬化患者表观扩散系数(ADC)值并与正常对照组及相应病理对照来反映肝纤维化程度,同时分析其与血流动力学指标的相关性。资料与方法分别对44例肝纤维化患者、49例肝硬化患者及46名正常对照者利用DWI(b=500s/mm2)技术进行ADC值测定,并与病理改变及CT灌注参数作对照研究。结果肝纤维化组、肝硬化组ADC值降低;对照组、S2、S3组ADC值逐渐降低;Child-PughA、B、C分级组中ADC值无差别;肝纤维化不同分级与Child-PughA、B、C分级组中S3组ADC值降低而ChildC组ADC升高;对照组及肝纤维化组ADC值均与CT灌注参数间无相关性;肝硬化组ADC值与CT灌注参数(BV、BF)正相关。结论b值为500s/mm2时可显示肝纤维化及肝硬化患者ADC值降低,肝硬化患者ADC值较肝纤维化患者ADC值升高与肝血流量增加有关。     

MR扩散加权成像评价慢性病毒性肝炎肝纤维化的临床研究

目的 探讨MR DWI对肝纤维化程度定量分析的能力.方法 应用1.5 T MR对12名志愿者、47例慢性乙型或丙型肝炎患者进行常规扫描及DWI检查,b值选择0、250、500、750及1000 s/mm~2,联合b值b_(250～1000)及b_(500～1000)分别取b=250、500、750和1000 s/mm~2及b=500、750和1000 s/mm~2的ADC平均值.采用Scheuer法进行纤维化(S)分期和炎症(G)分级,探讨病理分期与ADC值的相关性,采用Mann-Whitney U检验及Logistic回归分析评价ADC预测不同纤维化分期的能力.结果 当b=750 s/mm~2时,S0、S1、S2、S3、S4期纤维化下ADC平均值分别为(1.41±0.11)×10~(-3)、(1.37±0.09)×10~(-3)、(1.27±0.05)×10~(-3)、(1.26±0.04)×10~(-3)、(1.22±0.06)×10~(-3)mm~2/s,ADC值在不同S分期间差异最大(F=18.31,P<0.01).随着S分期的增加,各b值下的ADC平均值逐渐下降,两者存在负相关性,b_(250～1000)相关性最强(r=-0.727,P<0.01).选择b_(750)及b_(250～1000)、b_(500～1000)时,ADC值在S2期以上(与S0和S1相比)及S3期以上(与S0和S1相比)纤维化时均明显降低(P<0.01);在预测S2期以上纤维化时,选择b(750)时曲线下面积(AUC)最大(0.909),敏感性85.7%,特异性100.0%(ADC标准≤1.35×10~(-3)mm~2/s);在预测S3期以上纤维化时,选择b_(250～1000)时AUC最大(0.864),敏感性69.6%,特异性95.8%(ADC标准≤1.53×10~(-3)mm~2/s).结论 DWI对于预测S2期以上及S3期以上肝纤维化程度具有良好的效果,b值b_(750)、b_(250～1000)或b_(500～1000)均适合慢性病毒性肝炎患者的纤维化评价.     

3.0T MR弥散加权成像评价肝纤维化的临床应用

目的 探讨肝脏弥散加权成像ADC值评价肝纤维化程度的临床应用价值.方法 选取肝纤维化、肝硬化患者50例及正常人14例行肝脏常规MRI及DWI,依据纤维化程度分为6组:S0(14例)、S1(9例)、S2(14例)、S3(7例)、S4(3例)、肝硬化(17例).DWI采用4个b值(b=300,600,800,1000 s/mm2)成像,ADC分析软件进行图像后处理,获得平均ADC值.Spearman相关分析评价ADC值与肝纤维化程度的相关性.ROC曲线分析各b值条件下ADC值诊断S≥1、S≥2、 S≥3及肝硬化的效力.结果 肝脏ADC值与肝纤维化程度显著负相关(P＜0.001),4个b值条件下,ADC值在不同程度肝纤维化组间的差别均有统计学意义(P＜0.01).ROC分析结果显示各b值条件下,ADC值用来评价纤维化程度均有统计学意义(P＜0.05),诊断S≥3时的AUC相对最高;诊断同一程度纤维化时,以b取600 s/mm2时,AUC相对较高,但各b值下AUC的95%置信区间有交叉.b取600 s/mm2时,以ADC值≤1.489×10-3mm2/s为标准,诊断S≥1的灵敏度为84%,特异度为78.6%,准确性为84.4%;取1.453×10-3mm2/s为诊断界值,ADC诊断S≥2的 灵敏度为80.5%,特异度为73.9%,准确性 为83.5%;以ADC值≤1.414×10-3mm2/s为标准,诊断S≥3的灵敏度为81.5%,特异度为73%,准确性85.5%;以ADC值≤1.339×10-3mm2/s为标准,诊断肝硬化的灵敏度70.6%,特异度87.2%,准确性82.4%.结论 MR-DWI可以定量评价肝纤维化,有一定的临床应用价值.     

钆塞酸二钠增强T1-mapping 成像和DWI对肝纤维化分期的评估价值

【摘要】目的：探讨钆塞酸二钠（Gd-EOB-DTPA）增强T1-mapping成像和DWI对肝纤维化分期的评估价值。方法：共99例被检者符合入组标准并纳入研究,其中对照组23例（健康志愿者,S0）,病例组76例。病例组中,慢性乙型肝炎肝纤维化S1期13例,S2期13例,S3期26例,S4期24例。采用Look-Locker序列于增强前及Gd-EOB-DTPA增强后20min（肝胆期）采集T1-mapping图像,并测量肝组织弛豫时间T1,同时计算肝胆期弛豫时间T1减低率（ΔT1）。进行DWI检查并测量肝脏ADC值。采用单因素方差分析比较不同组别ADC值、ΔT1及肝胆期弛豫时间T1（T1HBP）。应用ROC曲线分析ADC、T1HBP、ΔT1对肝纤维化≥S2期、≥S3期的诊断效能。采用Spearman相关分析评价各参数与肝纤维化分期的相关性。结果：S0组（对照组）的ADC、T1HBP、ΔT1分别为（1.57±0.16）×10-3mm2/s、( 239.08±20.63)ms、( 69.24±4.64)% ;S1组分别为( 1.44±0.12)×10-3mm2/s、(273.57±53.75)ms、( 64.27±9.94)% ;S2组分别为( 1.31±0.12)×10-3mm2/s、( 375.74±97.86)ms、(61.14±5.61)% ;S3组分别为( 1.18±0.09)×10-3mm2/s、( 561.59±56.55)ms、( 38.76±6.08)% ;S4组分别为( 1.03±0.08)×10-3mm2/s、( 564.69±68.62)ms、 ( 37.01±6.80)% 。S0、S1、S2、S3、S4组的ADC值、ΔT1 和T1HBP均具有统计学差异(P均＜0.05)。ADC值、ΔT1和T1HBP诊断肝纤维化≥S2期的曲线下面积（AUC）分别为0.903,0.987,0.984;诊断肝纤维化≥S3期的AUC分别是0.817,0.930,0.847。ADC值与肝纤维化分期呈负相关（r=－0.790,P=0.000）,T1HBP与肝纤维化分期呈正相关（r=0.822,P=0.000）,ΔT1与肝纤维化分期呈负相关（r=－0.832,P=0.000）。结论:Gd-EOB-DTPA增强T1-mapping成像和DWI对肝纤维化分期的评估具有一定的价值。     

DWI和超声瞬时弹性成像在肝纤维化诊断中的价值

目的 :对比DWI和超声瞬时弹性成像(Fibroscan,FS)对肝纤维化的诊断价值。方法 :对37例肝纤维化患者(研究组)及23例健康志愿者(正常对照组)行DWI(b=0、600 s/mm2)扫描,并测量ADC值;2组同时行FS检查,检测指标为肝脏弹性测量值(liver stiffness measurement,LSM)。分析并对比不同组间ADC值和LSM的变化规律。结果:LSM随肝脏纤维化分期(从S1~S4期)逐步呈升高趋势,而ADC值则呈降低趋势(P0.01)。肝纤维化各组与正常对照组间比较差异均有统计学意义,肝纤维化各组组间比较差异均有统计学意义。结论:在肝纤维化定量中,DWI和FS均具备一定的检测能力。在诊断肝纤维化敏感度方面,FS高于DWI;而在特异度方面,DWI优于FS,两者皆可检测重度肝纤维化及肝硬化。     

DWI和~1H-MRS在肝纤维化中的诊断价值

目的:探讨扩散加权成像(DWI)与氢质子波谱分析(1 H-MRS)在肝纤维化中的诊断价值。方法:使用腹腔注射CCl4溶液法诱导建立兔肝纤维化模型并进行DWI和1 H-MRS检查。DWI使用SE-EPI序列(b1=0s/mm2,b2=600s/mm2),1 H-MRS使用单体素点分辨波谱分析(PRESS)序列(TR 1500ms,TE 35ms),测量表观扩散系数(ADC)值及胆碱(Cho)和脂质(lipid)波峰下面积的比值(Cho/lipid)。以病理学肝纤维化分期为基础,将兔划分为无肝纤维化组(S0)、轻度-中度纤维化组(S1-S2)和重度纤维化及肝硬化组(S3-S4),比较不同组间ADC值和Cho/lipid变化规律。结果:随肝纤维化程度加重,ADC值依次降低(P<0.01),Cho/lipid依次升高(P<0.05);重度纤维化及肝硬化组与另两组ADC值及Cho/lipid差异均具有统计学意义(P均<0.05)。结论:DWI和1 H-MRS具备一定的定量肝纤维化及检测重度纤维化及肝硬化的能力。     

DWI及声辐射力脉冲成像在肝纤维化诊断中的价值

目的对比DWI和声辐射力脉冲成像(acoustic radiation force impulse imaging,ARFI)对肝纤维化的诊断价值。方法对50例肝纤维化患者(观察组)及16例健康志愿者(正常对照组)行DWI(b=0、600s/mm 2)扫描,并测量ADC值;2组同时行ARFI检查,检测指标为低频剪切波传播速度(shear wave velocity,SWV)。分析并对比不同组间ADC值和SWV的变化规律。结果SWV波速随肝脏纤维化分期(从S0~S4期)升高而递增,而ADC值则呈降低趋势(P<0.05)。肝纤维化各组与正常对照组间比较差异均有统计学意义,肝纤维化各组组间比较差异均有统计学意义。结论在肝纤维化定量中,ARFI和DWI均具备一定的检测能力。在诊断肝纤维化敏感度方面,ARFI高于DWI;而在特异度方面,DWI优于ARFI,两者皆可检测重度肝纤维化及肝硬化。     

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.     

Optical tomography of the neonatal brain

A new method of assessing neurological function and pathology in the newborn infant is being developed based on the transmission of near-infrared light across the brain. Absorption by blood over a range of wavelengths reveals a strong dependency on oxygenation status, and measurements of transmitted light enable the spatial variation in the concentrations of the oxygenated and de-oxygenated forms of hemoglobin to be derived. Optical tomography has so far provided static three-dimensional maps of blood volume and oxygenation as well as dynamic images revealing the brain’s response to sensory stimulation and global hemodynamic changes. The imaging modality is being developed as a safe and non-invasive tool that can be utilized at the cotside in intensive care. Optical tomography of the healthy infant brain is also providing a means of studying neurophysiological processes during early development and the potential consequences of prematurity.     

弥散张量成像技术在星形细胞肿瘤中的应用价值初探

目的：评价MRI弥散张量成像技术在星形细胞肿瘤中的应用价值。材料和方法：采用GE1.5T超导MR成像系统，对16例1-2级星形细胞肿瘤及15例3-4级星形细胞肿瘤进行了MRI检查，检查序列包括T1WI、T2WI、FLAIR、弥散张量序列（diffusion tensor imaging，DTI）及增强后T1WI。结果：正常脑白质纤维在不同解剖平面，如半卵圆中心、内囊、胼胝体、视放射、锥体束、锥体交叉及内外侧丘系等，各向异性分数图（FA）均为高信号，白质纤维受到破坏后表现为低信号，而这些表现在常规T1WI、T2WI及FLAIR图上未能清楚显示。结论：DT1可以无创性检查脑白质纤维，用于脑肿瘤诊断及术前手术方案的制定。     

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.     

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.     

扩散加权成像在胰腺癌诊断中的价值初探

目的探讨MR扩散加权成像(DWI)在胰腺癌诊断中的价值。资料与方法健康自愿者20名,经手术病理和随访证实的胰腺癌患者21例、慢性胰腺炎患者12例,分别行常规MRI和DWI检查。应用自旋回波-回波平面成像(SE-EPI)并采用采集空间敏感性编码技术(ASSET),取b=0和600s/mm2获得DWI图像。分别测量感兴趣区(ROI)的表观扩散系数(ADC)值,行配对t检验。结果健康自愿者胰腺DWI呈中等信号,胰头、胰体尾部ADC值分别为(1.535±0.247)×10-3mm2/s、(1.643±0.375)×10-3mm2/s。21例胰腺癌肿瘤区DWI呈均匀或稍不均匀高信号,ADC值为(1.192±0.117)×10-3mm2/s。健康自愿者胰头与胰体尾部ADC值差异无统计学意义(P>0.05),胰头及胰颈部肿瘤患者胰体尾部ADC值与健康自愿者间差异有统计学意义(P<0.001),胰腺肿瘤ADC值与胰头及体尾部之间差异有统计学意义(P<0.001)。慢性胰腺炎DWI呈不均匀等或稍高信号,ADC值为(1.437±0.385)×10-3mm2/s,与胰腺癌间差异有统计学意义(P<0.05)。结论DWI可以清楚显示肿瘤病灶及范围,ADC值的测定在一定程度上有助于胰腺癌的诊断。     

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.     

Nuclear magnetic resonance imaging of the heart

NMR imaging is a noninvasive technique that has been shown to provide high-quality images of the heart. Due to the signal characteristics of flowing blood, inherent contrast between blood pool and myocardium is achieved without the use of contrast media. This paper briefly describes technical aspects of NMR imaging of the heart, normal cardiovascular anatomy, applications of the technique in patients with ischemic heart disease, and the potential of NMR imaging for functional studies in various forms of heart disease.Dedicated to Prof. Heinz Hundeshagen on the occasion of his 60th birthday