99Tcm-MIBI肿瘤阳性显像的临床应用

探讨了99Tcm-MIBI肿瘤阳性显像在多种恶性肿瘤临床诊断中的应用价值.静脉注射99Tcm-MIBI15～30min后,用美国GE公司SPX-6型SPECT行病变局部平面和断层显像,计算肿瘤与本底比值(T/B),当T/B≥1.5时判定显像结果为阳性;肝脏肿瘤诊断则比较胶体显像和阳性显像时肿瘤部位是否有填充,若有填充则为阳性.21例受检者中病理诊断为恶性肿瘤17例,良性肿瘤4例.17例恶性肿瘤99Tcm-MIBI阳性显像15例阳性,2例阴性;4例良性肿瘤患者显像结果均为阴性.本组病例99Tcm-MIBI阳性显像的敏感性为88%,特异性为100%,阳性预测值为100%,阴性预测值为66.7%,准确率为90%.结果表明99Tcm-MIBI阳性显像诊断和鉴别诊断良恶性肿瘤具有良好的临床应用前景.     

术中探测99Tcm-MIBI分布判断肺部肿瘤及淋巴结良恶性的临床价值

用手持式γ探测仪(GDP)探测术前注射^99Tc^m-MIBI的30例肺部病变患者原发病灶及淋巴结中的分布以判定其良恶性。结果显示肺癌患者的原发灶GDP检测结果均为阳性，而良性病变患者的检测结果均为阴性。在本工作条件下，GDP探测淋巴结转移的阳性检出率为100％，特异性93．6％，准确率94．4％。此研究证明^99Tc^m-MIBI术中γ探测判断肺部肿瘤及淋巴结良恶性可较好克服常规临床显像的不足，具有阳性检出率高、准确性好、特异性强的优点。     

18F-FDG hPET/CT显像在肿瘤诊断中的应用

采用双探头单光子发射型计算机断层（Single photon emission computed tomography,SPECT）显像仪（Hawkeye,1英寸NaI晶体）对109例确诊或疑有恶性肿瘤者进行了^18F-脱氧葡萄糖（^18F-Fluoro-2-deoxyglucose,18F-FDG）符合线路显像,每位患者在空腹状态下静脉注射^18F-FDG 222-296 MBq,安静休息约40-60 min后开始采集图像数据.经CT自动生成的衰减校正图校正,用迭代法预先分组最大期望值法（Ordered subsets expectation maximization,OSEM）进行图像重建,获得横断面、矢状面和冠状面图像,以及三维（3D）、CT和同机FDG图像融合.显示109例患者中最后确诊为恶性肿瘤者89例,进行^18F-FDG检查后,发现显像阳性者87例,灵敏度为94.38%（84/89）,其中假阳性3例,阳性预测值96.6%（84/87）;显像阴性者22例,其中假阴性4例,特异性为90%（18/20）,阴性预测值81.8%（18/22）.^18F-FDG符合线路显像（hybrid positron emission computed tomography,hPET）显像结果与CT或B超检查结果相一致的有26例（24%）、不一致的有73例（66.97%）,其中^18F-FDG检查结果中其病变范围较CT或B超病灶数增多的有52例（71.23%）,而病灶数减少的仅有5例（6.85%）.表明18F-FDG-hPET显像对肿瘤的诊断具较良好的灵敏度与特异性.采用FDG显像与CT同机融合技术能进一步改进病灶的定位,从而有助于肿瘤良恶性的鉴别;肿瘤患者的分期与再分期;残留肿瘤组织和复发的检测;手术、化疗或放疗方案的制定和随访;以及预后的估测.随着临床经验的积累和技术的改进,^18F-FDG符合线路显像必将更广泛得到应用.但是由于受SPECT分辨率的限制,以及种种炎性病变所致假阳性等,在实际的应用中,必须结合临床资料和其他影像资料加以考虑,才能作出正确诊断.     

18F-FDG符合线路成像在肿瘤及其转移灶探测中的临床应用

为评价^18氟-脱氧葡萄糖(^18F-FDG)符合线路成像在诊断肿瘤性质或肿瘤转移的临床应用价值，对87例临床怀疑为恶性肿瘤或肿瘤转移复发的患者，空腹肘静脉注射^18F-FDG259—298MBq后40-60min，采用GEHAWKEYE符合线路单光子发射型计算机断层(SPECT)进行卧位显像；经迭代法处理和重建，获得经X线衰减校正后的横断面、冠状面和矢状面三维断层图像；以目测双盲阅片进行诊断分析，并与手术病理或CT／MRI以及临床随访作出的最后诊断进行了对比。结果显示：87例患者中显像阳性61例，其中假阳性5例，真阳性56例；阴性26例，其中假阴性2例，真阴性24例。87例患者中共检出病灶136个，其中淋巴结和远处转移灶41个。符合线路成像对肿瘤或其转移灶诊断的灵敏度为96．6％(56／58)，特异性为82．8％(24／29)，阳性预测值91．8％(56／61)，阴性预测值92．3％(24／26)，诊断准确率92．0％(80／87)。表明 ^18F-FDG符合线路成像对于肿瘤的诊断具有较高的灵敏度和特异性；在肿瘤定性、肿瘤复发和转移灶的寻找方面有着独特的优势，是临床肿瘤诊断研究的有效手段。     

18F-FDG hPET/CT显像在肿瘤诊断中的应用

采用双探头单光子发射型计算机断层(Single photon emission computed tomography,SPECT)显像仪(Hawkeye,1英寸NaI晶体)对109例确诊或疑有恶性肿瘤者进行了18F-脱氧葡萄糖(18F-Fluoro-2-deoxyglucose,18F-FDG)符合线路显像,每位患者在空腹状态下静脉注射18F-FDG 222-296 MBq,安静休息约40-60 min后开始采集图像数据.经CT自动生成的衰减校正图校正,用迭代法预先分组最大期望值法(Ordered subsets expectation maximization,OSEM)进行图像重建,获得横断面、矢状面和冠状面图像,以及三维(3D)、CT和同机FDG图像融合.显示109例患者中最后确诊为恶性肿瘤者89例,进行18F-FDG检查后,发现显像阳性者87例,灵敏度为94.38%(84/89),其中假阳性3例,阳性预测值96.6%(84/87);显像阴性者22例,其中假阴性4例,特异性为90%(18/20),阴性预测值81.8%(18/22).18F-FDG符合线路显像(hybrid positron emission computed tomography,hPET)显像结果与CT或B超检查结果相一致的有26例(24%)、不一致的有73例(66.97%),其中18F-FDG检查结果中其病变范围较CT或B超病灶数增多的有52例(71.23%),而病灶数减少的仅有5例(6.85%).表明18F-FDG-hPET显像对肿瘤的诊断具较良好的灵敏度与特异性.采用FDG显像与CT同机融合技术能进一步改进病灶的定位,从而有助于肿瘤良恶性的鉴别;肿瘤患者的分期与再分期;残留肿瘤组织和复发的检测;手术、化疗或放疗方案的制定和随访;以及预后的估测.随着临床经验的积累和技术的改进,18F-FDG符合线路显像必将更广泛得到应用.但是由于受SPECT分辨率的限制,以及种种炎性病变所致假阳性等,在实际的应用中,必须结合临床资料和其他影像资料加以考虑,才能作出正确诊断.     

99mTc-MAA肺灌注显像诊断小儿肾病综合征并发肺栓塞的临床价值

为观察小儿肾病综合征并发肺栓塞的临床特点,用^99mTc-MAA肺灌注显像方法,检查30例血D2聚体阳性的肾病综合征患儿。结果检出肺栓塞患儿14例（占46．7％）,肺栓塞节段分别为1－7段。表明行肝素为主的抗凝治疗2周后,绝大多数患儿痊愈好转。说明小儿肾小球疾病并发肺栓塞为临床常见,用^99mTc-MAA肺灌注显像诊断肺栓塞方法可靠、灵敏,对治疗效果也有一定价值。     

白塞氏病与慢性结节性红斑患者的99Tcm标记人免疫球蛋白显像

为探讨^99Tc^m标记人免疫球蛋白（HIgG）显像在白塞氏病早期诊断和疗效评估中的价值,对已确诊的5例慢性结节性红斑及6例伴有结节性红斑样损害的白塞氏病患者进行了^99Tc^m HIgG显像,并在治疗后进行重复显像。结果：5例慢性结节性红斑患者^99Tc^m HIgG显像：在皮下见异常放射性浓聚区。治疗后,原放射性分布增高区消失或淡化。6例白塞氏病患者^99Tc^m HIgG显像：在皮下及大血管周围见异常放射性浓聚区。其中2例患者,尚可见关节周围异常放射性分布增高区。治疗后显像：血管周围及关节部位的异常浓聚区基本消失。结论：^99Tc^m-HIgG显像是一种简便、安全、无创伤的检查方法,它有助于早期诊断白塞氏病,改善患者预后,及评估疗效,指导临床进一步的治疗。     

前哨淋巴结核素显像在早期宫颈癌盆腔淋巴结清除术中的初步应用

通过在早期宫颈癌治疗中应用核素淋巴结显像确定前哨淋巴结（SLN）,探讨其在盆腔淋巴结清除术中的价值。对15例宫颈癌患者先行核素淋巴显像,18h内行宫颈癌根治性子宫切除术及盆腔淋巴结清除术,用7探测器找出比周围放射性计数高出10倍以上的区域即为前哨淋巴结区,并将该区的前哨淋巴结与非前哨淋巴结做HE染色并进行统计。结果显示,15例病人中14例检出SLN,占93．3%,共取得淋巴结217枚,其中SLN18枚;术后经病理证实1枚SLN确诊为淋巴结转移,其余17枚为阴性SLN,再行免疫组化均为阴性。其灵敏度为100％,准确度为92．9％,阴性预测值为100％,假阴性率为0。以上结果表明,前哨淋巴结核素显像对早期宫颈癌淋巴结清除术具有一定的指导价值。     

18F-FDG符合显像在肿瘤诊断的应用研究

目的：研究^18F—FDG符合显像在肿瘤诊断中的应用价值。方法：回顾性收集101例临床怀疑肿瘤患者进行术前^18F—FDG符合显像,通过视觉分析及靶／本比半定量分析获得诊断结果,与术后病理结果比较。结果：^18F—FDG符合显像探测肿瘤的灵敏度为84．6l％,特异性为78．26％,准确性为83．1％;对病灶≤2cm患者,探测灵敏度80％,特异性为100％,准确性为82．35％。T／N≥2．0为阳性诊断标准,计算灵敏度85．90％,特异性为82．61％,准确性为85．15％。视觉分析与半定量分析相结合分析,诊断灵敏度88．50％,特异性为87．0％,准确性为88．11％。结论：^18F—FDG符合显像对肿瘤诊断具有较高的应用价值,视觉分析及靶／本比半定量分析相结合可提高临床诊断的准确性。     

99TCm-MDP、99TCm(V)-DMSA和99Tcm-Citrate显像对骨组织良恶性疾病鉴别诊断的对比研究

为评价^99Tc^m(V)-二巯基丁二酸钠(DMSA)显像和^99Tc^m-枸缘酸(Citrate)显像在骨转移癌和骨及骨关节炎症诊断中的意义，对骨转移癌患者和骨及骨关节炎症患者各18例分别进行^99Tc^m-亚甲基二膦酸(MDP)、^99Tc^m(V)-DMSA和^99Tc^m—Citrate全身显像，并比较了它们的显像结果。18例经病理学、CT或MRI证实有骨转移癌的患者，^99Tc^m-MDP显像共检出64个病灶，^99Tc^m(V)-DMSA显像显示在与^99Tc^m-MDP显像相同部位同检出49个病灶，而^99Tc^m—Citrate显像仅检出1个病灶。18例经细菌学、cT或MRI证实的骨及骨关节炎症患者，^99Tc^m—MDP显像共检出22个病灶，^99Tc^m(V)-DMSA显像显示在与^99Tc^m-MDP显像相同部位同检出l7个病灶，^99Tc^m-Citrate显像检出l6个病灶。本组病例^99Tc^m(V)-DMSA显像诊断骨转移癌的灵敏度为76．56％，特异性为22．73％；^99Tc^m-Citrate显像诊断骨转移癌的灵敏度仅为1．56％，特异性为27．27％,^99Tc^m(V)-DMSA显像诊断骨及骨关节炎症的灵敏度为77．27％，特异性为23．44％；^99Tc^m-Citrate显像诊断骨及骨关节炎症的灵敏度为72．73％，特异性为98．44％。以上结果表明，^99Tc^m（V）-DMSA显像在诊断骨转移癌和骨组织炎症时应该慎重，因为它不能区分骨组织的良恶性病变性质，其对骨组织的良恶性病变性质的鉴别诊断应排除外骨组织炎症、骨折等骨组织良性病变的干扰。而^99Tc^m—Citrate显像对于骨及骨关节炎症诊断特异性比^99Tc^m-MDP骨显像和^99Tc^m（V）-DMSA骨显像都高。     

Transport properties of U0.7Ce0.3O2 − x

We have determined a number of transport properties of $\text{U}{}_{0.7}\text{Ce}{}_{0.3}\text{O}{}_{\mathrm{2-x}}$ at 1273 K for various deviations from stoichiometry and compared them with available results on $\text{(UPu)O}{}_{\mathrm{2\; ?\; x}}$. They are: the electrical conductivity, Seebeck coefficient, effective charge number and chemical diffusion coefficient.A very characteristic behaviour is observed for the electronic properties of $\text{(UCe)O}{}_{\mathrm{2\; ?\; x}}$. A p-type conduction for all the studied deviations from stoichiometry (up to $\text{x = 3 × 10}{}^{\mathrm{?2}}$) is interpreted in terms of a high electronic disorder in the stoichiometric compound. Electronic disorder at stoichiometry is probably less important in $\text{(UPu)O}{}_{\mathrm{2\; ?\; x}}$, which presents a sharp p-n transition at $\text{x = 5 × 10}{}^{\mathrm{?3}}$.Ionic transport properties obtained on $\text{(UCe)O}{}_{\mathrm{2\; ?\; x}}$ indicate an approximate proportionality between the ionic conductivity resulting from oxygen ions transport and the deviation from stoichiometry. Results available on $\text{(UPu)O}{}_{\mathrm{2\; ?\; x}}$ do not appear to be compatible with ours and some arguments are presented which cast doubt on their validity.     

Equi-chemical-potential curves in ternary uranium oxides MyU1−yO2+x

Using Schuhmann's method the chemical potentials of three components in nonstoichiometric ternary uranium oxides $\text{M}{}_{\mathrm{y}}\text{U}{}_{\mathrm{1?y}}\text{O}{}_{\mathrm{2+x}}$(M = Mg and Pu) have been calculated. The obtained results are shown in the form of equi-chemical-potential curves (surface of partial molar free energy) in the composition triangle. In the hypostoichiometric region the contour lines of the surface are dense and run parallel with each other. Taking account of this fact the difficulty in attainment of homogeneity in the fabrication of mixed oxide fuel is discussed.     

Structural characterization of Nd-doped Hf-zirconolite Ca1−xNdxHfTi2−xAlxO7 ceramics

Because of its high incorporation capacity and of the high thermal neutron capture cross-section of hafnium, Hf-zirconolite (CaHfTi₂O₇) ceramic can be envisaged as a potential waste form for minor actinides (Np, Am, Cm) and plutonium immobilization. In this work, Nd-doped Hf-zirconolite Ca_1−xNd_xHfTi_2−xAl_xO₇ (x = 0; 0.01 and 0.2) ceramics have been prepared by solid state reaction. Neodymium has been used as trivalent actinide surrogate. The ceramic samples structure has been studied by X-ray diffraction and refined by the Rietveld method. This revealed that Nd³⁺ ions only enter the Ca site, whereas part of Hf⁴⁺ ions substitute titanium into Ti(1) sites and Al³⁺ ions mainly occupy the Ti(2) split sites and Ti(3) sites of the zirconolite structure. Using various spectroscopic techniques (electron spin resonance, optical absorption and fluorescence), the environment of Nd³⁺ cations in Hf-zirconolite has been studied and compared with that of Nd³⁺ cations in Zr-zirconolite (CaZrTi₂O₇). Different local environments of Nd³⁺ cations have been detected in Hf-zirconolite that can be attributed to the existence of an important disorder around Nd in the Ca site probably due to the statistical occupancy of the next nearest cationic site of neodymium (a split Ti site) by Ti⁴⁺, Al³⁺ cations and vacancies. No significant differences were observed concerning Nd³⁺ cations environment and distribution in Hf- and Zr-zirconolite ceramics.     

Phase relation and defect structures of nonstoichiometric U4O9±y and UO2+x at high temperatures

Phase relations in the composition range from $\text{UO}{}_{\mathrm{2+x}}$ to $\text{U}{}_3\text{O}{}_{\mathrm{8?z}}$ were studied by electrical-conductivity measurements and X-ray diffraction in the ranges $\text{1025°C ? T ? 1140°C}$ and . The plot of log σ versus log showed straight lines with distinct slopes, which corresponded to four regions ($\text{UO}{}_{\mathrm{2+x}}$, $\text{U}{}_4\text{O}{}_{\mathrm{9?y}}$, $\text{U}{}_4\text{O}{}_{\mathrm{9+y}}$ and $\text{U}{}_3\text{O}{}_{\mathrm{8?z}}$). The existence of the hyperstoichiometric $\text{U}{}_4\text{O}{}_{\mathrm{9+y}}$ phase was suggested in the temperature range from 1025 to 1126°C. The peritectoid temperature ($\text{U}{}_4\text{O}{}_{\mathrm{9\pm y}}\text{= UO}{}_{\mathrm{2+x}}\text{+ U}{}_3\text{O}{}_{\mathrm{8?z}}$) was estimated to be present between 1126 and 1131°C. The partial free enthalpies and entropies for the two-phase equilibrium ($\text{U}{}_4\text{O}{}_{\mathrm{9+y}}\text{+ U}{}_3\text{O}{}_{\mathrm{8?z}}$, and $\text{U}{}_4\text{O}{}_{\mathrm{9?y}}\text{+ UO}{}_{\mathrm{2+x}}$) were calculated and compared with previous results. From the dependence of the electrical conductivity on the oxygen partial pressure the nonstoichiometric defect structures of $\text{UO}{}_{\mathrm{2+x}}$ and $\text{U}{}_4\text{O}{}_{\mathrm{9\pm y}}$ were interpreted as consisting of doubly charged oxygen interstitials (O_i'') and doubly charged oxygen vacancies (V_O''). At room temperature, the homogeneity range of the U₄O₉ phase was investigated with a Debye-Scherrer camera.     

Neutron production cross sections and energies for the reactions 7Li(p,n)7Be and 7Li(p,n)7Be1

Center-of-mass best values for the normalized Legendre coefficients and the 0° differential cross sections as functions of input energy have been derived from various experimental results for the reactions ⁷Li(p,n)⁷Be and ${}^7\text{Li}\text{(p,n)}{}^7\text{Be}{}^1$ (431 keV). This information has been used to calculate laboratory differential cross sections as functions of the laboratory proton energy and neutron emission angle which are given in tabular form together with the corresponding neutron energies.     

Effects of ion irradiation on the mechanical properties of SiNawOxCyHz sol-gel derived thin films

A study of the effects of ion irradiation of hybrid organic/inorganic modified silicate thin films on their mechanical properties is presented. NaOH catalyzed SiNa_wO_xC_yH_z thin films were synthesized by sol-gel processing from tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) precursors and spin-coated onto Si substrates. After drying at 300 °C, the films were irradiated with 125 keV H⁺ or 250 keV N²⁺ at fluences ranging from 1 × 10¹⁴ to 2.5 × 10¹⁶ ions/cm². Nanoindentation was used to characterize the films. Changes in hardness and reduced elastic modulus were examined as a function of ion fluence and irradiating species. The resulting increases in hardness and reduced elastic modulus are compared to similarly processed acid catalyzed silicate thin films.     

Damage creation in ion irradiated Si1−xGex/Si structures

Strained SiGe/Si structures have been proposed as substrates for fabrication of high speed metal oxide semiconductor transistors. However, influence of strain and/or presence of Ge atoms on damage creation during ion irradiation have not been explored to a significant extent. In this study, Rutherford backscattering spectrometry (RBS) was used to characterize Si_1−xGe_x/Si structures irradiated by 140 keV He⁺ ions at room temperature. When compared with pure Si, strained samples show enhanced damage accumulation as a function of He fluence. Channeling angular scans did not reveal any specific configuration of displacements. Possible mechanisms for enhanced damage in strained Si are discussed.     

Investigations on UAlx-Al dispersion fuels for high-flux reactors

The paper outlines the preparation of $\text{UAl}{}_{\mathrm{x}}\text{-Al}$ dispersion fuel plates for thermal high-flux reactors. The work described includes the preparation of UAl₂, UAl₃ and UAl₄ compounds by induction melting and their processing to Al-clad fuel plates using the picture-frame technique. Induction melting in alumina crucibles and subsequent homogenisation can be used to produce relatively homogeneous $\text{UAl}{}_{\mathrm{x}}$ compounds. After comminution to a predetermined size range and blending with Al, the pressed compacts can be rolled into Al-clad fuel plates. UAl₃ and UAl₂ compounds react with Al forming UAl₄. The reactions begin at about 673 K, and have an activation energy of 52.6 and 42.6 kcal/mol, respectively. The measured properties of the dispersions and UAl-phases such as thermal expansion, thermal and electrical conductivity, tensile strength, microhardness and hot hardness are affected by the concentration of the dispersed phase and can be explained in the light of existing theoretical models. Due to its potential as a high-flux reactor fuel with higher uranium content the preparation and properties of UAl₂-Al dispersions as well as the preliminary data about their stability under irradiation may be of particular interest.     

Statistical thermodynamic study of the ternary compounds ThXyHx (X = C,N;y < 1;x < 2)

The stability and the nature of bonding in hypostoichiometric ThH₂, hcp ThC_0.46H_x and fcc ThN_yH_x (y = 0.486 and 0.692) are studied on the basis of statistical thermodynamics. The discussions are made in terms of the atomic partition function of H in these condensed phases and of the interaction energy terms. It is concluded that the nature of bonding in ThN_yH_x is approximately the same as that in ThH₂. On the other hand, the nature of bonding in ThC_yH_x is found to be significantly different from that in ThH₂.     

Wavelengths and classifications of emission lines due to 2s22pn−2s2pn + 1 and 2s2pn−2pn + 1 transitions, Z ≤ 28

Tables of wavelengths and classifications of observed emission lines due to 2s²2pⁿ?2s2p^{n + 1} and 2s2pⁿ?2p^{n + 1} transitions are presented. The accuracy of data derived from different experimental methods is discussed. Revised and predicted wavelengths are added. Energy levels are derived from the wavelength data.