131I及132I对大鼠甲状腺致肿瘤效应

233只成年及断乳的纯种Wistar大鼠,一次腹腔注射不同剂量¹³¹I或¹³²I,对照大鼠同对注射灭菌生理盐水。实验结果表明,¹³²I致甲状隙肿瘤效应约为¹³¹I的6倍。如甲状腺肿癌发生率为50%,60%及70%时,¹³¹I中毒鼠所需的甲状腺吸收剂量(29、34及44Gy)约为¹³²I中毒鼠剂量(4.5,6及8Gy)的6倍。同一核素对断乳鼠的致肿瘤效应为成年鼠的1.1倍。如甲状腺吸收剂量相同(13Gy及60Gy)时,断乳鼠肿瘤发生率各为94%等及76%成年鼠为88%及72%两种碘核素致大鼠甲状腺肿痛效应的最适照射剂量;¹³¹I为59Gy、¹³²I为13Gy.     

甲状腺功能状态对131I在人体的内照射剂量估算的影响

我们对服用¹³¹I(Nal¹³¹I)人员进行了15天24小时尿碘分析以及外部放射性计数测量,推算出几种甲状腺功能状态下¹³¹I在人体的分布、滞留和内辐射剂量。结果表明;摄入¹³¹I后甲状腺受到的内辐射剂量与甲状腺摄碘率间呈一元线性函数关系。在此基础上进一步推算了苏州市及其近郊因进 行甲状腺摄碘检查所致的年集体有效剂量当量等指标。     

分化型甲状腺癌患者131I治疗后体内残留放射性活度的评估

目的 评估分化型甲状腺癌(DTC)患者¹³¹I治疗后体内残留放射性活度.方法 本次前瞻性研究包括49例DTC患者,分为“清甲”(¹³¹I摧毁术后残留的甲状腺组织)与“清灶”(¹³¹I治疗甲状腺床残留甲状腺癌、甲状腺床复发灶和转移灶)组,于服¹³¹I后收集患者每次排泄尿液,测定患者每天每次通过尿液排泄的放射性活度及排泄的总放射性活度,进而估算患者体内残留的放射性活度.分别于服¹³¹I后2、6、24、48、72 h进行1 m处剂量当量率的测定,估算患者体内残留放射性活度达到400 MBq时1 m处剂量当量率.结果 服¹³¹I后2、6、24、48、72 h体内残留¹³¹I活度占服¹³¹I初始活度的百分比,“清甲”组分别为99%、72%、25%、15%、7%,1 m处剂量当量率分别为157、120、35、11、9 μSv/h;"清灶"组对应百分比分别为99%、71%、18%、7%、3%,1 m处剂量当量率分别为232、182、48、11、2 μSv/h.体内残留的放射性活度与1 m处剂量当量率呈正相关(r=0.94,P<0.001).“清甲”与“清灶”组服¹³¹I后48~72 h体内残留放射性活度分别为548~259及451~248 MBq,对应的1 m处剂量当量率为8~10 μSv/h.结论 DTC患者于服¹³¹I后48~72 h体内残留放射性活度达到国家标准规定的400 MBq,即DTC患者1 m处剂量当量率达到8~10 μSv/h方可出院.     

切尔诺贝利核事故泄漏放射性物质对武汉地区的影响

为了解切尔诺贝利核电站事故对我省环境污染的情况,我院于5月2日8时开始对武汉地区环境放射性进行监测。着重监测沉降灰、雨水、气溶胶、东湖水、牛奶、蔬菜等样品的总口和¹³¹I放射性活度,同时进行了羊甲状腺中¹³¹I和沉降灰中¹³¹I、⁸⁹Sr、⁹⁰Sr、¹³⁷Cs等核素的分析。     

125I 131I 132I在大鼠甲状腺内的代谢参数及累积吸收剂量

本文报道¹²⁵I、¹³¹I、¹³²I在大鼠甲状腺内的代谢参数并计算了甲状腺对上述3种同性豢的最大吸收率,有效半减期和累积吸收剂量及其它有关的参数。在大鼠腹腔内分别注入¹²⁵I(NaI)溶液8.08μCi,¹³¹I溶液0.99μCi,¹³²I溶液12.2μCi,然后测得甲状腺的吸碘率分别为33%,17%和12%,最后计算得出犬鼠甲状腺的累积吸收剂量分别为7.94,3.09和2.58Gy,每注入1μCi的放射性碘同位索,大鼠甲状腺的平均吸收剂量分别为0.98、3.12和0.2lGy.     

切尔诺贝利核电站事故所致长春地区放射性污染的卫生学评价

本文介绍了苏联切尔诺贝利核电站事故后长春地区地面水、蔬菜中的总β放射性和牛奶、蔬菜中¹³¹I放射性污染水平,污染特点及污染类型,并介绍了在这次核电站事故中蔬菜对¹³¹I的吸附吸收规律,地区人群所受照射剂131I所致人群的剂量方法。     

131I大鼠甲状腺致癌作用的病理学研究

本文报道用雄性Wistar大鼠409只,腹腔分别注射¹³¹I 52.4、40.0、26.2; 12.5和2.5μCI／只,两年的观察结果。五个剂量组甲状腺吸收剂量分别为164、125、82、39和7.8Gy.12个月发生甲状腺良性瘤,观察到24个月时,39Gy以上各剂量组主要表现为耳状腺退行性变和良性癌生成;而7.8Gy剂量组甲状腺恶性瘤发生率达45.8%。¹³¹I诱发大鼠甲状腺良性肿瘤以滤泡性腺癌为主,其次是乳头状腺癌,恶性瘤以乳头状腺癌和混合癌为主,甲状腺肿瘤的发生与¹³¹I对甲状腺滤泡上皮细胞损伤、修复;在甲状腺轴内分泌紊乱(T₄降低、TSH升高)情况下,TSH反复刺激损伤的甲状腺上皮细胞有关。     

苏联切尔诺贝利核电站事故对我国的放射性污染与卫生学评价

本文采用前瞻性填表登记法于1984年9月1日至1985年8月31对全疆76个医院放射科X线诊断检查频数进行了调查。通过门诊收费或放射门诊量登记进行复核,填表率为90%,漏登率平均为15%。调查结果:新疆总检查颇数为199万人次,年频度为每千人口150人次,其中胸部透视为主要检查类型,占总频数的58%,其次是各类拍片.此项调查为我国医疗照射剂呈估算及制定受检者防护标准提供了新疆的医疗频度资料。木文报道了苏联切尔诺贝利核电站事故后在我国(除了台湾省外)全国范围内的环境放射性监测的结果。从5月1日以后,我国天部分地区都可测出环境中放射性水平有波动性升高。在大气沉降物、露天水源水、生长中的叶类蔬菜、牛奶等环境介质中有放射性碘存在,羊甲状腺中可测出明显量的¹³¹I,而且持续到6月中旬仍可测出。有的监测站用γ潜仪在飞机表而和地面环境样品中都测出人工放射性核素的存在,主要有¹³¹I、¹³²Te、¹³²I、¹⁴⁰Ba、¹⁴⁰La、¹⁰³RU、¹³⁴Cs、¹³⁷Cs等,表明这次苏联事放释放出的放射性物质已波及到我国,对我国环境造成一定的污染。根据一些食品(蔬菜和牛奶)中¹³¹I含量的监测数据,对我国居民甲状腺剂量做了估算,成人甲状腺有效剂最当量小于2μSv,婴儿小于30μSv,低国家放射卫生防护标准的剂最限值,不必采取防护措施。     

碘治疗工作人员甲状腺131I活度的测量与评价

目的 了解核医学科碘治疗工作人员甲状腺内¹³¹I的活度,并估算年待积有效剂量,分析碘治疗人员的内照射现状。方法 选择甲状腺内照射碘测量仪,对山东省6家医院进行调查并进行甲状腺¹³¹I活度测量,得出6家医院核医学科碘治疗工作人员甲状腺¹³¹I的检出率和活度值,进而计算摄入量和年待积有效剂量。结果 6家医院共有63名碘治疗工作人员接受测量,其中有52人甲状腺内检测到¹³¹I,检出率83%,测得¹³¹I活度大多低于200 Bq。估算的年待积有效剂量范围为0.23~7.78 mSv,其中有84.6％的人年待积有效剂量＜2 mSv。结论 核医学科碘治疗工作人员应进行常规内照射个人监测,各医院在辐射防护制度方面需进一步完善。     

接触131I放射性核素工作人员内照射剂量估算方法的初步研究

目的 探索接触¹³¹I放射性核素放射工作人员内照射剂量估算方法。方法 选择某¹³¹I放射性药物生产企业和某开展¹³¹I甲亢和甲状腺癌治疗的医院核医学科放射工作人员,使用便携式高纯锗（HPGe）γ谱仪,以7 d为周期,连续4次测量甲状腺部位¹³¹I活度,结合人员接触¹³¹I的轮岗方式,估算内照射剂量。结果 以监测月份为典型月份估算人员内照射剂量时,调查企业从事¹³¹I放射性药物分装的生产人员年待积有效剂量为0.09~1.93 mSv,调查医院核医学科工作人员内照射年待积有效剂量为0.06~0.58 mSv。对监测结果进行校正和结合轮岗方式后估算的工作人员内照射年待积有效剂量,放射性药物生产工作人员和核医学科工作人员分别为0.06~1.22 mSv和0.03~0.16 mSv。结论 在进行接触¹³¹I放射性核素工作人员内照射剂量估算时,仅以单次测量的结果估算全年受照剂量会带来较大的误差。在连续监测时,应根据前续监测周期的结果对后续监测周期结果进行校正。为准确估算人员内照射剂量,应充分考虑工作人员接触¹³¹I的方式、接触的时间、接触的频率、内污染的途径等因素。对于接触¹³¹I内照射剂量可能>1 mSv/年的工作人员,以14 d作为常规监测周期较为适宜。     

广东高本底地区部分中学生血清乙型肝炎表面抗原(HBsAg)的检测

本文应用RIA(放射免疫分析)研究了1.5月龄的雄性Wistar大鼠腹腔注射无载体医用Na¹³¹I溶液后甲状腺功能的改变.结果表明,甲状腺吸收剂量较低的7.8Gy和39.0Gy组,血清T,和T₄水平略高于对照组,剂量较高的82.0Gy和164.0Gy组,血清T₃,和T₄.水平明显低于对照值.血清r-TSH水平随甲状隙吸收剂量的增加明显升高,表明大鼠发生了原发性甲状腺功能低卞.根据镜下观察的组织学类型,T₃、T₄和r-TSH水平的统计分析表明,血清T₃,无明显变化,T₃水平的降低和r-TSH水平的升高似与甲状腺组织学改变有-定关系.     

Human pulmonary imaging and spectroscopy with hyperpolarized 129Xe at 0.2T

RATIONALE AND OBJECTIVES: Using a novel (129)Xe polarizer with high throughput (1-2 L/hour) and high polarization (approximately 55%), our objective was to demonstrate and characterize human pulmonary applications at 0.2T. Specifically, we investigated the ability of (129)Xe to measure the alveolar surface area per unit volume of gas, S(A)/V(gas). MATERIALS AND METHODS: Variable spin echo time (TE) gradient and radiofrequency (RF) echoes were used to obtain estimates of the lung's contribution to both T(2)* and T(2). Standard multislice ventilation images were obtained and signal-to-noise ratio (SNR) determined. Whole-lung, time-dependent measurements of (129)Xe diffusion from gas to septal tissue were obtained with a chemical shift saturation recovery (CSSR) method. Four healthy subjects were studied, and the Butler et al CSSR formalism (J Phys Condensed Matter 2002; 14:L297-L304) was used to calculate S(A)/V(gas). A single-breath version of the xenon transfer contrast (SB-XTC) method was implemented and used to image (129)Xe diffusion between alveolar gas and septal tissue. A direct comparison of CSSR and SB-XTC was performed. RESULTS: T(2)*=135+/-29 ms amd T(2)=326.2+/-9.5 ms. Maximum SNR=36 for ventilation images from inhalation of 1L 86% (129)Xe and voxel volume =0.225 mL. CSSR analysis showed S(A)/V(gas) decreased with increasing lung volume in a manner very similar to that observed from histology measurements; however, the absolute value of S(A)/V(gas) was approximately 40% smaller than histology values. SB-XTC images in different postures demonstrate gravitationally dependent values. Initial comparison of CSSR with XTC showed fairly good agreement with expected ratios. CONCLUSIONS: Hyperpolarized (129)Xe human imaging and spectroscopy are very promising methods to provide functional information about the lung.     

大鼠吸入239PuO2后的肺癌剂量效应关系

306只吸入²³⁰PuO₂气溶畦大鼠中,肺癌发生宰(Y,%)与肺累积平均吸收剂量(D,Gy)关系,符合于拟台方程Y=105exp[-3.57/(D+1.25)],由此方程推算出大鼠吸入。抽²³⁰PuO₂后肺癌终生危险度为2162／10⁶。吸入²³⁰PuO₂后死亡鼠肺癌累积发生率(F,％)与动物活存时问(T,天)及吸收剂量(D,Gy)三者的关系,可拟合为下列函数式：F=-1.35-0.069-1.58×10^-2D+(0.0236+2.18-10²D+1.68×10^-6D²)lnT 钚诱发肺癌的最短潜伏期为94天,11.3～17.6Gy可能是晟适致癌剂量。1只²³⁰PuO₂后37天死亡鼠,TLN发生原发性血管肉癌.     

MR T1 and T2 relaxations in cysts and abscesses measured by 1.5 T MRI

Objectives

The main objective of this study was to make a comparison between the relaxation rates in jaw cysts and abscesses. Such a comparison should provide quantitative information for MR image analysis.

Methods

A phantom containing 20 odontogenic jaw cysts and 11 jaw abscesses was imaged with 1.5 T MR. T₁ measurements were performed by using a mixed sequence of inversion recovery and spin echo, while T₂ measurements were carried out by the Carr–Purcell Meiboom–Gill (CPMG) sequence. Cystic fluids and abscesses were compared statistically.

Results

In cysts and abscesses, respectively, the mean 1/T₁ was 0.9355 s⁻¹ and 0.8245 s⁻¹ and the mean 1/T₂ was 2.4575 s⁻¹ and 4.7073 s⁻¹. The 1/T₂ in cysts was very highly significantly different from that in abscesses (p = 0.0001). Both T₁ and T₂ were linearly proportional to material contents. T₂ relaxivities [26.458 ml (g s)⁻¹ for abscesses and 21.455 ml (g s)⁻¹ for cysts] were higher than T₁ relaxivities [5.4766 ml (g s)⁻¹ for abscesses and 10.075 ml (g s)⁻¹ for cysts].

Discussion

Present T₂ measurements differentiate cysts from abscesses with a confidence interval of 95%. Because in vivo and in vitro image contrasts are changed by the same parameters, the T₂ findings should present valuable information for in vivo MRI. Hence the significant difference and the relaxivities may provide quantitative information for clinicians and researchers making image analyses.

Conclusion

T₂ may differentiate cysts from abscesses. The difference in T₂ is related to the material content of samples.     

Clinical Importance of Myocardial T2 Mapping and Texture Analysis

Late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) is valuable for diagnosis and assessment of the severity of various myocardial diseases owing to its potential to visualize myocardial scars. T₁ mapping is complementary to LGE because it can quantify the degree of myocardial fibrosis or edema. As such, T₁-weighted imaging techniques, including LGE using an inversion recovery sequence, contribute to cardiac MRI. T₂-weighted imaging is widely used to characterize the tissue of many organs. T₂-weighted imaging is used in cardiac MRI to identify myocardial edema related to chest pain, acute myocardial diseases, or severe myocardial injuries. However, it is difficult to determine the presence and extent of myocardial edema because of the low contrast between normal and diseased myocardium and image artifacts of T₂-weighted images and the lack of an established method to quantify the images. T₂ mapping quantifies myocardial T₂ values and help identify myocardial edema. The T₂ values are significantly related to the clinical symptoms or severity of nonischemic cardiomyopathy. Texture analysis is a postprocessing method to quantify tissue alterations that are reflected in the T₂-weighted images. Texture analysis provides a variety of parameters, such as skewness, entropy, and grey-scale non-uniformity, without the need for additional sequences. The abnormal signal intensity on T₂-weighted images or T₂ values may correspond to not only myocardial edema but also other tissue alterations. In this review, the techniques of cardiac T₂ mapping and texture analysis and their clinical relevance are described.     

Preparation and bioevaluation of a Tc-labeled chlorambucil analog as a tumor targeting agent

Chlorambucil belongs to a group of nitrogen mustards which are used for the treatment of variety of cancers. Hence, a chlorambucil derivative has been radiolabeled with [^99mTc(CO)₃(H₂O)₃]⁺ core and its efficacy as a tumor targeting agent has been evaluated. Radiochemical yield of the complex was >98% as observed by HPLC. The in vitro studies in MCF-7 breast cancer cells showed about 30% inhibition of the radiolabeled complex in presence of the cold chlorambucil derivative. Biodistribution studies in Swiss mice bearing fibrosarcoma tumor showed an uptake of 3.2±0.3% ID/g at 3 h.p.i.     

Preparation and preliminary bioevaluation of 99mTc(CO)3-11β-progesterone derivative prepared via click chemistry route

IntroductionProgesterone receptors (PRs) overexpressed in breast cancers serve as potential targets for developing radiotracers for use in nuclear medicine. Hence, suitably derivatized progesterone can be envisaged as a potential vector for targeting overexpression of receptors in breast cancer. In the present article, we report the preparation of a ^99mTc(CO)₃-progesterone triazole using the Cu(I)-catalyzed novel click chemistry route. Preliminary evaluation of the radiolabeled derivative has been carried out in binding studies with MCF 7 cell lines.Methods11-Hydroxyprogesterone has been synthetically derivatized to 11-azidoprogesterone. Subsequently, the cycloaddition reaction between progesterone azide and propargyl glycine was carried out to prepare 1,4-bifunctionalized progesterone triazole analogue. The clicked progesterone triazole derivative was radiolabeled with ^99mTc and characterized by HPLC. The chemical characterization of ^99mTc(CO)₃-progesterone triazole has been carried out by preparing its corresponding rhenium complex using the [NEt₄]₂[Re(CO)₃Br₃] precursor. While in vitro studies were carried out in MCF7 cell lines, in vivo distribution studies were performed in female Swiss mice.ResultsThe radiolabeled complex could be prepared in >95% radiochemical yield as determined by HPLC. In vitro studies of ^99mTc(CO)₃-progesterone complex in MCF7 cell lines overexpressing receptors for breast cancer showed binding up to 30%. In vivo distribution studies in female Swiss mice have shown uterine uptake of 0.41 (0.06) % ID/g at 3 h postinjection (pi) and retention therein till 24 h pi.ConclusionThe present study demonstrates a novel and facile route for preparation of ^99mTc-labeled progesterone complex using click chemistry. This strategy can be further extended towards preparation of radiolabeled complexes of other steroidal derivatives.     

Case Report: Unstable angina with flow-fatty acid metabolism mismatch and reverse flow-glucose metabolism mismatch patterns

A 79-year-old man with unstable angina underwent an emergency coronary angiography, and percutaneous balloon angioplasty was performed for LCX. Left ventriculography showed hypokinesis in the posterior wall, inferior and apical wall immediately after the PCI therapy. The defects on 123I-BMIPP SPECT seen in the inferior, posterior and lateral wall were more extensive than those observed on 99mTc-MIBI SPECT, and a flow-fatty acid metabolism mismatch pattern was observed. The 18F-FDG PET showed reduced uptake in the lateral segment, although 13N-NH3 PET showed normal perfusion, and a reverse flow-glucose metabolism mismatch pattern was observed. Left ventriculography showed significant improve to normal contraction on the 3-month follow up, and there was not significantly reduced uptake in 99mTc-MIBI SPECT, 123I-BMIPP SPECT, 13N-NH3 PET or 18F-FDG PET.     

Performance assessment of O-18 water purifier

In the synthesis of 18F-FDG by the nucleophilic substitution method, 18O-H2O is usually used as target water. The target water should be recovered after synthesis and reused, because it is expensive, but recovered water contains impurities such as organic substances, and it must be purified before reuse. For this reason Sumitomo Heavy Industries, Ltd. developed an O-18 water purifier for elimination of organic substances in recovered water. This instrument consists of a UV irradiation unit and low-temperature distillation unit. Our institution had an opportunity to test use this instrument and evaluated its performance. The concentrations of organic substances after UV irradiation was greatly reduced, and recovery efficiency after distillation by the low-temperature distillation unit was very satisfactory at 99.3 +/- 0.5%. Furthermore, the yield of 18F-FDG from 18O-H20 purified with this instrument was sufficient for the clinical use.     

Comparative study of the sensitivity of ADC value and T2 relaxation time for early detection of Wallerian degeneration

Background and purpose

Wallerian degeneration (WD), the secondary degeneration of axons from cortical and subcortical injuries, is associated with poor neurological outcome. There is some quantitative MR imaging techniques used to estimate the biologic changes secondary to delayed neuronal and axonal losses. Our purpose is to assess the sensitivity of ADC value and T₂ relaxation time for early detection of WD.

Methods

Ten male Sprague-Dawley rats were used to establish in vivo Wallerian degeneration model of CNS by ipsilateral motor-sensory cortex ablation. 5 days after cortex ablation, multiecho-T₂ relaxometry and multi-b value DWI were acquired by using a 7 T MR imaging scanner. ADC-map and T₂-map were reconstructed by post-processing. ROIs are selected according to pathway of corticospinal tract from cortex, internal capsule, cerebral peduncle, pons, medulla oblongata to upper cervical spinal cord to measure ADC value and T₂ relaxation time of healthy side and affected side. The results were compared between the side with cortical ablation and the side without ablation.

Results

Excluding ablated cortex, ADC values of the corticospinal tract were significantly increased (P < 0.05) in affected side compared to the unaffected, healthy side; no difference in T₂ relaxation time was observed between the affected and healthy sides. Imaging findings were correlated with histological examinations.

Conclusion

As shown in this animal experiment, ADC values could non-invasively demonstrate the secondary degeneration involving descending white matter tracts. ADC values are more sensitive indicators for detection of early WD than T₂ relaxation time.