应用磁共振灌注加权成像评估星形细胞肿瘤病理分级的研究

目的探讨MR灌注加权成像(PWI)评估星形细胞肿瘤病理分级的价值。资料与方法 110例经手术病理证实的星形细胞肿瘤于术前进行常规MRI平扫、增强和PWI。其中,低级别(Ⅰ～Ⅱ级)肿瘤40例,高级别(Ⅲ～Ⅳ级)肿瘤70例(Ⅲ级33例,Ⅳ级37例)。PWI采用梯度回复回波-回波平面成像(GRE-EPI)技术。盲法检测并计算肿瘤和瘤周区最高相对脑血容量(rCBV)值。比较和分析不同病理级别肿瘤间及瘤周区之间最高rCBV值的差异。两组间比较用t检验;多组间比较用方差分析,两两比较用LSD检验;检验水准α=0.05。应用受试者工作特征(ROC)曲线评估最高rCBV值的诊断效能。结果Ⅰ～Ⅱ级和Ⅲ～Ⅳ级肿瘤最高rCBV值分别为1.708±0.535,5.521±1.626;Ⅲ级和Ⅳ级分别为4.207±0.808和6.693±1.220;Ⅰ～Ⅱ级与Ⅲ～Ⅳ级间、Ⅰ～Ⅱ级与Ⅲ级和Ⅳ级间、Ⅲ级与Ⅳ级间肿瘤最高rCBV值差异均有统计学意义(均为P=0.000)。Ⅰ～Ⅱ级和Ⅲ～Ⅳ级瘤周区最高rCBV值分别为0.898±0.233和1.730±0.507,Ⅲ级和Ⅳ级分别为1.446±0.246和1.983±0.547;Ⅰ～Ⅱ级与Ⅲ～Ⅳ级...     

MR积分法与灌注成像在脑胶质瘤中的对照研究

目的比较MR积分法与灌注成像在脑胶质瘤术前分级诊断中的价值。方法对30例脑胶质瘤(低级8例,高级22例,世界卫生组织分级)术前行MR常规及灌注成像检查。MR积分法使用9个指标进行评价,灌注指标相对脑血容量(rCBV)由肿瘤及对侧正常脑白质的脑血容量(CBV)相比后得出。分别对低级、Ⅲ级和Ⅳ级胶质瘤的积分及rCBV值进行分析。结果低级胶质瘤的积分值(067±029)显著低于Ⅲ级(132±047)(t=-348,P=0003)和Ⅳ级(156±020)(t=-736,P=0000)。Ⅲ级和Ⅳ级之间差异无统计学意义(t=-139,P=0182)。低级胶质瘤的rCBV值(238±066)显著低于Ⅲ级(581±320)(t=-357,P=0003)和Ⅳ级(699±247)(t=-509,P=0001)。Ⅲ级和Ⅳ级之间差异无统计学意义(t=-093,P=0365)。结论在脑胶质瘤术前分级诊断中,常规MR和灌注成像均有重要价值,可相互补充,提高诊断准确率。     

MR灌注成像在脑胶质瘤术前分级中的价值

目的 :运用磁共振灌注成像 (PWI)技术 ,探讨脑血流容量 (rCBV)及其rCBV比值在脑胶质瘤术前分级中的价值。方法 :3 2例经病理证实的脑胶质瘤 ,其中Ⅰ级 2例 ,Ⅱ级 9例 ,Ⅲ级 14例 ,Ⅳ级 7例 ,行PI扫描 ,计算肿瘤最大rCBV及其rCBV比值 ,将结果与病理分级进行对照。结果 :低分级胶质瘤rCBV值为 43 .82± 15 .5 1,rCBV比值为 2 .89± 0 .83 ;高分级胶质瘤rCBV值为 12 4.3 2± 3 0 .5 4,rCBV比值为 7.82± 1.2 1;两组的rCBV值以及rCBV比值差异均有显著性意义 (P <0 .0 0 1)。结论 :不同分级的胶质瘤之间的rCBV及rCBV比值差异存在显著性意义 ,PWI技术有助于脑胶质瘤的术前分级。     

MR脑血流灌注成像在星形细胞肿瘤中的应用研究

目的　评价MR脑血流灌注成像在星形细胞肿瘤中的应用价值。方法　经手术及病理证实的星形细胞肿瘤共 2 6例。行常规MR及MR灌注成像检查。构建局部脑血容量 (rCBV)图 ,并计算肿瘤最大相对局部脑血容量 (rrCBV)值。评价星形细胞肿瘤的rCBV图表现 ,并分析平均最大rrCBV值与肿瘤病理学级别之间的关系。结果　 9例Ⅱ级星形细胞瘤的rCBV分布较均匀 ,接近或略高于对侧脑白质。 7例Ⅲ级和 10例Ⅳ级星形细胞肿瘤的rCBV分布明显不均匀 ,肿瘤实性区rCBV多有不同程度的升高 ;瘤内囊变坏死区和瘤周水肿区rCBV降低。增强MRI上 ,2例Ⅲ级和 2例Ⅳ级肿瘤内无明显强化区域 ,在rCBV图上脑血容量明显升高。Ⅱ～Ⅳ级肿瘤最大rrCBV的平均值分别为 0 91±0 18、3 5 1± 1 0 1和 4 75± 1 2 3;Ⅱ级与Ⅲ级 (t=6 79,P <0 0 1)、Ⅱ级与Ⅳ级 (t=9 75 ,P <0 0 1)、Ⅲ级与Ⅳ级之间 (t=2 19,P <0 0 5 )平均最大rrCBV值差异均有显著性意义。结论　MR脑血流灌注成像可观察星形细胞肿瘤的血流灌注变化 ,对判断星形细胞肿瘤的病理学分级有重要临床意义。     

磁敏感加权成像与动态磁敏感加权对比增强MR灌注加权成像联合应用在脑星形细胞瘤分级中的价值

目的 探讨磁敏感加权成像(SWI)与动态磁敏感加权对比增强(DSC) MR灌注加权成像联合应用在脑星形细胞瘤分级诊断中的价值.方法 82例经手术病理证实的脑星形细胞瘤患者行SWI与DSC MR灌注加权成像扫描,低级别星形细胞瘤15例(WHOⅡ级),间变性星形细胞瘤10例(WHOⅢ级),胶质母细胞瘤57例(WHOⅣ级).评价肿瘤内磁敏感信号(ITSS)与相对脑血容量(rCBV)最大值,应用Kruskal Wallis检验、Welch检验、Spearman相关系数、Pearson相关性分析和受试者工作特征曲线分析ITSS和rCBV单独使用和两者联合应用对星形细胞瘤分级的效能.结果 低级别星形细胞瘤14例未见到ITSS,间变性星形细胞瘤ITSS分级为1～3级,胶质母细胞瘤ITSS分级均为3级,3组间差异有统计学意义(H=71.96,P＜0.01).Ⅱ、Ⅲ和Ⅳ级星形细胞肿瘤内rCBV最大值分别是1.26 ±0.42、3.59 ±2.09和8.34±1.16,3组间差异有统计学意义(F'=681.72,P＜0.01).肿瘤内ITSS与rCBV最大值和病理分级呈正相关(r值分别为0.72、0.89,P值均＜0.01),rCBV与病理分级呈正相关(r=0.78,P＜0.01).SWI、DSC及SWI与DSC联合应用鉴别Ⅱ和Ⅲ级星形细胞瘤ROC曲线下面积分别是0.99、0.93、1.00,鉴别Ⅲ和Ⅳ级星形细胞瘤ROC曲线下面积分别是0.70、0.94、0.94,鉴别高低级别星形细胞瘤ROC曲线下面积分别是1.00、0.99、1.00.结论 脑星形细胞瘤ITSS可以对脑星形细胞瘤进行分级,SWI与DSC联合应用可以提高脑星形细胞瘤分级的准确性.     

Glioma grading in children brain: using MR PWI

目的:采用磁共振灌注成像(MR PWI)探讨儿童不同级别脑胶质瘤的血流灌注特点及其临床诊断价值.方法:35例脑胶质瘤均经手术病理证实,其中Ⅰ～Ⅱ级胶质瘤(低级别胶质瘤组)28例,Ⅲ级胶质瘤(高级别胶质瘤组)7例,计算病灶内异常高灌注中心区(a区)、异常低灌注中心区(b区)、负性增强积分( NEI伪彩图与T1WI增强图上不匹配区(c区)的相对NEI值(rNEI)及NEI伪彩图与T1WI增强图像上病变面积的比值(N/C),分析rNEI及N/C与肿瘤病理学分级的相关性.结果:高级别胶质瘤组中a区和c区的rNEI分别为8.39±1.91和5.43±0.52,均大于低级别胶质瘤组(分别为5.10±2.05和4.05±0.66),差异均具有极显著性意义(P＜0.01).高级别及低级别胶质瘤组NEI伪彩图上异常灌注区面积均大于T1WI增强图像上的异常强化区,N/C分别为1.06±0.11和1.45±0.09,差异具有极显著性意义(P＜0.01).结论:采用正确的研究方法MR PWI能有效分析儿童脑胶质瘤的血流灌注情况,对儿童脑胶质瘤的浸润范围的界定及术前分级均能有效判断.     

磁共振3DASL灌注成像在胶质瘤分级中的诊断价值

目的 通过对不同级别胶质瘤三维动脉自旋标记成像(3 DASL)图像的研究,探讨其在判断胶质瘤术前分级方面的价值.方法 对25例胶质瘤患者术前进行3DASL扫描,并与术后病理结果对比.25例患者均行常规MR平扫、增强和3DASL扫描,测量病灶区的CBF值.根据病理结果,分析3DASL对胶质瘤分级的诊断价值.结果 25例患者中,WHOⅡ级4例,WHOⅢ级15例,WHOⅣ级6例,病变区的CBF值分别为(30.48±17.56);(56.15±38.43);(66.23±15.36);统计结果显示,低级别胶质瘤(WHOⅡ级组)与高级别胶质瘤(WHOⅢ级和WHOⅣ级)差异具有显著性意义(P＜0.001),而WHOⅢ级组与WHOⅣ级组无显著性差异.结论 作为一项无创性磁共振灌注成像新技术,3D ASL成像为胶质瘤术前分级提供了可靠的诊断依据.     

不同病理分级儿童脑胶质瘤MR灌注成像

目的:采用磁共振灌注成像(MR PWI)探讨儿童不同级别脑胶质瘤的血流灌注特点及其临床诊断价值。方法:35例脑胶质瘤均经手术病理证实,其中Ⅰ～Ⅱ级胶质瘤(低级别胶质瘤组)28例,Ⅲ级胶质瘤(高级别胶质瘤组)7例,计算病灶内异常高灌注中心区(a区)、异常低灌注中心区(b区)、负性增强积分(NEI)伪彩图与T1WI增强图上不匹配区(c区)的相对NEI值(rNEI)及NEI伪彩图与T1WI增强图像上病变面积的比值(N/C),分析rNEI及N/C与肿瘤病理学分级的相关性。结果:高级别胶质瘤组中a区和c区的rNEI分别为8.39±1.91和5.43±0.52,均大于低级别胶质瘤组(分别为5.10±2.05和4.05±0.66),差异均具有极显著性意义(P<0.01)。高级别及低级别胶质瘤组NEI伪彩图上异常灌注区面积均大于T1WI增强图像上的异常强化区,N/C分别为1.06±0.11和1.45±0.09,差异具有极显著性意义(P<0.01)。结论:采用正确的研究方法MR PWI能有效分析儿童脑胶质瘤的血流灌注情况,对儿童脑胶质瘤的浸润范围的界定及术前分级均能有效判断。     

脑胶质瘤血流容积与肿瘤微血管密度的相关性研究

目的　运用磁共振灌注成像 (PWI) ,探讨肿瘤血流容积 (rCBV)与微血管密度 (MVD)的相关性。资料与方法　 30例星形细胞瘤 (AS) ,其中低分级 (Ⅰ～Ⅱ级 ) 12例 ,高分级 (Ⅲ～Ⅳ级 ) 18例。常规MRI扫描后 ,行PWI扫描 ,计算肿瘤rCBV值及其与正常脑白质的比值 ,并用免疫组织化学技术测量MVD ,观察PWI结果与病理分级和MVD的相关性。结果　低分级ASrCBV值为 4 1.5 4± 2 5 .16 ,rCBV比值为 2 .83± 1.12 ,MVD为 37.2 4± 2 5 .78;高分级ASrCBV值为 14 2 .0 0± 82 .75 ,rCBV比值为 9.0 4± 2 .36 ,MVD为 73.6 7± 19.85。两组rCBV值、rCBV比值均有显著统计学差异 (P <0 .0 0 1) ,rCBV和MVD密切相关 (r=0 .86 ,P <0 .0 0 1)。结论　不同分级的胶质瘤rCBV差别显著 ,肿瘤rCBV和MVD间有良好的相关性     

脑胶质瘤灌注成像与病理对照研究

目的运用磁共振灌注成像(PWI)获取对比剂首过期间的兴趣区图像,评价rCBV和rCBF在术前评估脑胶质瘤组织学分级中的价值.材料和方法本组共30例颅脑胶质瘤,均经病理证实.常规MRI扫描后行PWI,PWI序列为GRE-EPIRIT2*WI,由灌注资料获取rCBV、rCBF图像,计算最大rCBV和rCBF并与组织病理学分级对照.结果Ⅲ～Ⅳ级胶质瘤(18例)的rCBF、rCBV分别为1.8～7.4和2.67～10.48,均值分别为5.4±1.8和5.75±3.85.I～Ⅱ级胶质瘤(12例)rCBF、rCBV分别为0.5～1.7和1.36～3.16,均值分别为1.4±0.3和1.75±0.65.两组间rCBF和rCBV差别有显著性(P＜0.01,studentt检验).结论灌注成像对颅脑胶质瘤的术前分级有重要价值.     

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European Radiology -     

家族性多发性神经纤维瘤病(附5例报告)

本文报道了家族性神经纤维瘤病5例,着重讨论了本病较少见的胸部X线改变,主要表现为:(1)胸廓畸形及部分肋骨纤细扭曲;(2)肺间质纤维变;(3)纵膈神经源性肿瘤;(4)心脏改变。并述及其它部分骨的异常X线改变和有关的鉴别诊断。     

(3)He-particle-induced reactions on (nat)Sb for production of (124)I.

Excitation functions of the reactions (nat)Sb((3)He,xn)(124,123,121)I were measured from their respective thresholds up to 35 MeV, with particular emphasis on data for the production of the medically important radionuclide (124)I. The conventional stacked-foil technique was used. From the experimental data the theoretical yields of the three investigated radionuclides were calculated. The yield of (124)I over the energy range E9(30He) = 35 --> 13 MeV amounts to 0.95 MBq/microA h. The radionuclidic impurities are discussed. A comparison of (3)He- and alpha-particle-induced reactions on antimony for production of (124)I is given. The alpha-particle-induced reaction on enriched (121)Sb and the (3)He-particle-induced reaction on enriched (123)Sb would lead to comparable (124)I yields, but the level of impurities in the latter case would be somewhat higher.     

PEG coating reduces NMR relaxivity of Mn(0.5)Zn(0.5)Gd(0.02)Fe(1.98)O4 hyperthermia nanoparticles

Purpose:

To investigate both T1 and T2 MR relaxation enhancement of Gd substituted Zn‐Mn ferrite magnetic nanoparticles. Both uncoated and polyethylene glycol (PEG) coated particles were used.

Materials and Methods:

Chemical co‐precipitation was used to synthesize particles in the form Mn_0.5Zn_0.5Gd_0.2Fe_1.98O₄ suitable for hyperthermia applications. Physical characterization of the magnetic nanoparticles included SEM, TEM, ICP, and SQUID. T1 and T2 measurements were performed at 1.5 Tesla (T).

Results:

The saturation magnetization was 12.86 emu/g while the particle's magnetic moment was 1.86 × 10^?19 J/T. The particle size increased due to coating, while 1/T1 and 1/T2 relaxivities (26°C) decreased from 2.5 to 0.7 and from 201.3 to 76.6 s^?1 mM^?1, respectively, at a magnetic field 1.5T.

Conclusion:

The reduction in both 1/T1 and 1/T2 is attributed to increased distance of closest approach between the protons and the magnetic core caused by the shielding provided by the high molecular weight PEG. 1/T2 data are compared with existing theoretical models using a modified radius that takes into account both possible agglomeration of the particles and increased inter‐particle separation induced by PEG coating. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.

     

Excitation functions of (alpha,xn) reactions on (nat)Rb and (nat)Sr from threshold up to 26 MeV: possibility of production of (87)Y, (88)Y and (89)Zr.

Excitation functions were measured by the stacked-foil technique for (nat)Rb(alpha,xn)(87m,87m+g,88)Y and (nat)Sr(alpha,xn)(86,88,89)Zr reactions from their respective thresholds up to 26 MeV. The samples for irradiation were prepared by sedimentation and pellet pressing techniques. The measured data were compared with those available in the literature. From the excitation functions, integral yields of the products were calculated. The suitable energy ranges for the production of (87)Y and (88)Y via (nat)Rb(alpha,xn) processes and of (89)Zr via the (nat)Sr(alpha,xn) process are E(alpha)=26-->20 MeV, E(alpha)=26-->5 MeV and E(alpha)=20-->8.5 MeV, respectively. The respective yields amount to 8.2, 0.08 and 0.9 MBq/microA h. Production of (88)Y is feasible if a waiting time of about 2 months is allowed to let the impurities decay out. Also, (87)Y can be produced with a relatively low impurity of (88)Y. The yields of both (88)Y and (87)Y via the present routes are, however, appreciably lower than those via the (nat)Sr(p,xn) processes. There is a possibility to produce (89)Zr via the alpha-particle irradiation of (nat)Sr. The yield is rather low but would be considerably increased if enriched (86)Sr would be used as target material. The radionuclidic impurity levels in all the three products are discussed.     

Uptake of hexakis(t-butylisonitrile) technetium (I) and hexakis(isopropylisonitrile) technetium (I) by neonatal rat myocytes and human erythrocytes

The uptake mechanism of two potential cardiac imaging agents [99mTc]hexakis(t-butylisonitrile) technetium (I) (TBI) and [99mTc]hexakis(isopropylisonitrile) technetium (I) (IPI) has been studied using neonatal rat myocytes and human erythrocytes. Uptake of these complexes was rapid, of greater magnitude than seen previously for 42K, and was unaffected by either 0.15 mM ouabain or 10 mM KCI. Both [99mTc]isonitrile complexes had a high affinity for the membranes of the myocytes and erythrocytes. The data suggest that the uptake is not dependent on the membrane Na+/K+ ATPase but may be related to the lipophilicity of these agents as evidenced by the rapidity, tenacity, and quantity of the binding observed.     

Index of Authors (with Titles) (Vol. 62)

Epidermal stem cells accelerate their repopulation rate during fractionated irradiation. To study the changes in keratinocyte differentiation associated with radiationinduced repopulation, we investigated the expression of a panel of 14 monoclonal or polyclonal antibodies against keratins, involucrin and others, as well as the expression of 15 lectins in the irradiated mouse leg skin. Tissue samples were collected after 1, 2, and 3 weeks of daily irradiation with 3 Gy per fraction. Abnormal morphological appearance of the irradiated epidermis suggested disturbed terminal differentiation. Keratin 16 (K16) was negative in normal epidermis but intense staining was observed in the irradiated epidermis. Involucrin was expressed in the outmost suprabasal layers only in the normal epidermis but extended to the lower layers in the irradiated epidermis. The lectin binding patterns for agglutinins from Soybean, Dolichos biflorus, and Helix pomatia showed differences between the normal and the irradiated epidermis. From these characteristic changes in staining patterns we concluded that accelerated repopulation of the epidermis during fractionated irradiation is associated with a deficiency in terminal squamous differentiation.