阳江天然高本底辐射对儿童智力发育影响初探

本研究从高本底和对照地区各选择一个乡,对所在地区10～11岁儿童进行了智力测验.这些儿童出生并一直居住在当地.测验结果按年级、年龄和性别随机配对分组后发现两地区儿童的瑞文推理和学习能力的得分相似,而韦氏言语测验的量表分高本底地区儿童显著高于对照(P<0.01).再经多变量方差分析表明韦氏测验中类同和词汇得分高本底地区儿童优于对照(P<0.01),而常识、算术和理解两地无差异.影响智力发育的主要混淆因素两地大致相同.     

高本底和对照地区诱变因素的比较研究

本文报道了广东阳江高本底和对照地区社会环境诱变因素进一步比较研究的结果。研究的内容分二类; 一类是目前认为与突变有某种程度关联的因素, 包括有毒有害职业, 农药作业, 吸烟, 喝酒和医用X线照射等, 另一类是与突变无直接但可能有间接关联的因素。如一般社会经济状况等。研究采用个侧对照研究方法。结果表明, 第一类指标除医用x线诊断照射外, 两地区无显著性差异I第=类指标示对照地区文化生活水平高于高本底地区, 而高本底地区人群更为稳定。作者认为两地区仍基本符合“齐同对比”的原则, 但在评价该高本底辐射对居民健康的影响时, 需要进行多因素的统计分析。才能获得较为可靠的结论。     

中国广东省阳江高本底辐射地区居民营养情况调查分析

目的观察中国广东省阳江高本底辐射地区和对照地区居民目前的健康和营养状况。方法分别从高本底地区和对照地区各一个镇中随机选取50岁以上男性居民60和65名，调查居住史、疾病与治疗史、X线检查史等，测量身高和体重，计算身高体重指数（BMI）。测量血清总蛋白、白蛋白和球蛋白、甘油三酯、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、载脂蛋白A1和载脂蛋白B含量。结果两地区受检者BMI分布有一定差异，两地区受检者的血清生化指标平均值均在正常范围，经调整年龄后，对照地区居民的血清总蛋白、白蛋白和甘油三酯略高于高本底地区，高本底地区高密度脂蛋白胆固醇略高于对照地区。结论高本底地区和对照地区居民营养状况基本一致，高本底地区居民的动物蛋白和脂肪摄人量略低于对照地区。     

异丙肾上腺素对受1200拉德γ线照射小鼠的抗放作用

本文报道了广东高本底地区和对照地区1970～1980年恶性肿瘤调查结果.在此期间,在高本底地区累积调查了531,972人?年.对照地区563,507人?年.调查结果,高本底地区和对照地区恶性肿瘤标化死亡率分剐为41.19×10^-3和49.86 × 10^-3,高本底地区的结果显著地低于对照地区。就个别部位肿瘤而论,高本底地区的肺癌和肝癌也显著垃低于对照地区,其它恶性肿瘤两地也有差异,但无统计学意义,文中就资料的可靠性,恶性肿瘤的位次以及恶性肿癌与性别、年龄关系等问题进行了分析讨论。本文为阶段的调查结果,调查研究工作仍在继续进再中。     

高本底地区恶性肿瘤死亡调查小结(1970～1980年)

本文报道了广东高本底地区和对照地区1970～1980年恶性肿瘤调查结果.在此期间,在高本底地区累积调查了531,972人?年.对照地区563,507人?年.调查结果,高本底地区和对照地区恶性肿瘤标化死亡率分剐为41.19×10^-3和49.86 × 10^-3,高本底地区的结果显著地低于对照地区。就个别部位肿瘤而论,高本底地区的肺癌和肝癌也显著垃低于对照地区,其它恶性肿瘤两地也有差异,但无统计学意义,文中就资料的可靠性,恶性肿瘤的位次以及恶性肿癌与性别、年龄关系等问题进行了分析讨论。本文为阶段的调查结果,调查研究工作仍在继续进再中。     

阳江天然放射性高本底地区居民1979—1998年肺结核死亡危险分析

目的 探讨天然放射性高本底地区居民肺结核死亡危险.方法 建立一个包括89 694例暴露和35 385例非暴露的观察队列,采用队列研究方法,分阶段回顾性随访收集居民的死亡信息.将性别、到达年龄、随访年份和剂量率组（高、中、低和对照组）等作为分类变量计算人年列表,调整相应变量,计算高本底相对于对照地区各类传染病和寄生虫病,特别是肺结核的死亡相对危险（RR）.结果 高本底地区40岁以上4个年龄组（40～、50～、60～和≥70）居民的肺结核死亡危险均低于对照地区,RR值（95%CI）分别为0.75（0.42～1.34）、0.72（0.49～1.07）、0.71（0.53～0.95）和0.45（0.34～0.59）,其中60～和≥70年龄组两地区间的差异有统计学意义.各随访阶段均可观察到高本底地区居民肺结核死亡危险低于对照地区;两地区的肺结核死亡相对危险与累积剂量呈负向相关（P＜0.001）.肺结核死亡与受照剂量的超额相对危险ERR/Sv（95%CI）=-1.09（-1.34～-0.85）.在高本底的阳东和阳西两地区,不同诊断单位、不同年龄组及不同随访阶段的肺结核死亡危险在两地区一致.结论 高本底地区受低剂量电离辐射照射人群的肺结核死亡危险显著低于对照地区,且观察到了显著的剂量反应关系,这可能与高本底地区居民长期受低水平电离辐射全身照射导致的免疫功能增强有关.     

高本底地区遗传性疾病及先天性畸形调查

调查了世居在高本底地区和对照地区40年以上,12岁以下的儿童,并以31种遗传性疾病及先天性畸形作为调查指标.受检人数高本底地区为13,425人,对照地区为13.087人.受检率分别为89.1%和92.2%.结果表明.两地区遗传病及先天畸形总发生率无显著差别.在分别比较31种疾病发生率中表明:仅两地区问的白化病及先天愚型发生率有显著差异;高本底地区较高.进一步分析先天愚型发生率在高本底地区增高的原因认为,主要与患儿母亲生育年龄大.以及该病在较小群体的不同地区中分布不均匀有关。     

阳江天然放射性高本底地区第三阶段研究概况(1982～1984)

本文综合报道了广东省阳江县天然放射性高本底地区调查第三阶段的研究结果。本阶段使用高压电离室(RSS一1n型)和野外T一谱仪联合测量, 验证了前两阶段用热释光元件和荧光玻璃剂量计对人员直接测得的外照射数据, 给出了高本底地区居民年平均照射量率为330mR/a, 对照地区相应为114mR/a。恶性肿瘤死亡调查高本底地区和对照地区已分别累积观察了764, 696和777, 482人·年, 两地调整率分别为44.6和51.00×10^-5。对前两阶段检出的高本底地区先天愚型患病率(1.04‰)高于对照地区(0.3l‰)的原因作了进一步分析, 认为不能排除由于母亲生育年龄和受检儿童年龄诲成的影响。细胞遗传学和细胞免疫学的研究进一步证实了以前的研究结果, 高本底组与对照组相比, 染色体畸变率增加和免疫功能有增强的趋势。而且天然辐射以外的诱变因素的进一步研究仍表明两地区基本符合齐同对比的原则。     

阳江天然放射性高本底和对照地区居民鼻咽癌死亡病例对照研究

目的 探讨阳江高本底辐射调查地区居民鼻咽癌的相关危险因素,为正确评价高本底辐射致癌危险提供基础。方法 选择固定队列中1987～1995年间鼻咽癌死亡病例作为研究对象,随机选择对照,1∶2配对。研究的因素包括职业、文化程度、居住史与生活环境等一般社会经济状况,农药使用,吸烟、饮酒、饮食、医用X射线照射和鼻咽癌家族史等。资料收集采用面访方式。资料采用条件Logistic回归分析,计算比数比(OR)及相应的95%置信区间和P值。结果 有效访问了102例病例和202例对照。单因素Logistic回归分析发现,经常摄入咸鱼、咸菜、豆豉和腊肉,慢性鼻炎史,家族鼻咽癌史等因素与鼻咽癌有显着性关联;多因素Logistic回归分析的结果显示,经常摄入咸鱼,慢性鼻炎史和家族鼻咽癌史是鼻咽癌独立的危险因素;在控制某些因素后,引入高本底辐射,吃咸鱼和豆豉,吸烟和饮酒等因素进行多因素Logistic回归分析,结果显示吃咸鱼为鼻咽癌发病唯一危险因素(OR=2.8,95%CI:1.52～5.18);吸烟(OR=1.2,95%CI:0.65～2.22)、饮酒(OR=0.83,95%CI:0.38～1.78)和高本底辐射(OR=0.86,95%CI:0.44～1.68)与鼻咽癌的发病无明显关联。结论 经常吃咸鱼是鼻咽癌发病的重要危险因素;高本底地区居民的鼻咽癌发病与本底辐射关明异关系。     

阳江天然放射性高本底地区居民1987～1995年非肿瘤死亡再分析

目的　进一步分析阳江天然放射性高本底地区居民非肿瘤性疾病危险及其影响因素。方法　采用定群队列研究方法对居住在高本底地区和对照地区居民进行调查 ,现场调查分为队列成员追踪随访和死因确认。按外照射年剂量水平 ,将居住在高本底地区的人群分为高、中、低剂量 3个组 ,进行内比较。高本底地区 3个剂量组与对照组之间的比较采用相对危险 (RR) ,并计算了个人终生累计剂量与超额相对危险 (ERR/Sv)。结果　高本底地区居民非肿瘤死亡比对照地区增加 9% ,死亡危险明显高于对照地区 ,RR =1 0 9,P =0 0 1;危险显著增加的非肿瘤疾病主要是消化系统疾病 ,RR =1 4 6 ,P =0 0 0 4 ,其中慢性肝炎与肝硬化为RR =1.98,P =0 0 0 4 ;危险显著降低的主要是传染和寄生虫疾病 (RR =0 81,P =0 0 4 ) ,其中肺结核死亡为RR =0 .5 8,P <0 0 0 1。对各种死因及肝硬化危险在不同剂量组间的齐性检验结果表明 ,消化系疾病 (P =0 0 1)及肝硬化 (P =0 0 4 )组间差异有显著性 ,其ERR(95 %CI) /Sv也分别为 2 18(0 2 2 ,7 6 4 )和 10 94 (1 34,NA)。结论　高本底地区居民消化系疾病中的慢性肝炎和肝硬化死亡率高于对照地区且有统计学意义 ,不同于癌症死亡的结果 ;肺结核死亡则显著低于对照地区。但由于目前资料的局限性 ,     

Stress MR imaging for evaluation of popliteal artery entrapment

The popliteal artery entrapment (PAE) syndrome has been recognized as a cause of arterial occlusion in young people. It is the result of an anomaly of the relationship between the popliteal artery and the gastrocnemius muscle. Eight young healthy volunteers (16 legs) and six patients (10 legs) with suspected PAE underwent magnetic resonance (MR) imaging. Gradient-echo images were obtained in axial planes with the leg at rest and during active plantar flexion against resistance. Imaging at rest allowed identification of PAE signs in only one leg, which had an anomalous medial course of the popliteal artery. In the other cases, only the stress technique was able to show signal loss in the popliteal artery due to muscular compression (two legs) or the presence of accessory muscle slip around the vessel (two legs), as confirmed at surgery. MR imaging is therefore a useful technique for the diagnosis of PAE because of its capability of combining information obtainable with other modalities.     

MR imaging of muscle and tender points in fibromyalgia

Fibromyalgia is a syndrome manifested by chronic, diffuse muscu-loskeletal aching and soreness, palpable muscle tender points, and other symptoms. Standardized clinical diagnostic criteria have recently been developed. Skeletal muscle has been postulated as the end organ in this disease. Biochemical, histologic, electromyographic, and conventional radiographic studies have demonstrated no definitive abnormality. This study sought to establish whether magnetic resonance (MR) imaging could demonstrate any abnormality in these patients. Eighteen patients were entered in the study, 14 of whom were able to complete their examinations. T1 -weighted, T2-weighted, gradient-echo, and STIR (short-tau inversion-recovery) sequences were performed in all patients, with selected patients examined with T1weighted, gadopentetate dimeglu-mine-enhanced sequences. The trapezius and suboccipital regions were imaged in patients who, clinically, had active fibro-myalgia. No abnormalities could be detected. The authors conclude that the conventional MR imaging used in this study was unable to depict any primary skeletal muscle abnormality in fibromyalgia.     

MR imaging of disorders of the brachial plexus

The authors evaluated 64 consecutive patients with suspected brachial plexus (BP) abnormalities of diverse cause with magnetic resonance (MR) imaging, using the body coil and a standardized protocol. Of the 43 patients for whom follow-up was available, 25 were suspected of having neoplastic involvement of the BP, nine had sustained injuries, and nine presented with BP symptoms of uncertain cause. MR imaging was 63% sensitive, 100% specific, and 77% accurate in demonstrating the abnormality in this diverse patient population. When patients with neoplastic and traumatic disorders were considered separately, sensitivity increased to 81%, accuracy to 88%, and specificity remained unchanged. In the patients with a clinical diagnosis of idiopathic or viral plexitis, the MR imaging findings were normal, serving to exclude other structural abnormalities. It is concluded that MR imaging is valuable in the assessment of a wide range of BP disorders.     

MR angiography of congenital heart disease: Value of segmented two-dimensional inflow technique and maximum-intensity-projection display

Magnetic resonance (MR) angiography of the cardiovascular system was evaluated in 41 patients with congenital heart disease by using a two-dimensional (2D) inflow technique based on a magnetization-prepared gradient-echo pulse sequence with segmented k-space data acquisition and electrocardiographic gating at 0.5 T. Inversion and saturation prepulses were used to suppress stationary tissue and enhance intravascular signal. Presaturation slabs were applied where certain vascular structures had to be suppressed. Sequence parameters were optimized by evaluating signal intensity and contrast characteristics for various flip angles and inversion and saturation delay times. The heart and intrathoracic vasculature were encompassed with 40–50 overlapping sections. Both 2D angiograms and maximum-intensity-projection images were evaluated. Combining data sets acquired in the sagittal and transverse orientations provided the most satisfactory information about the pulmonary arteries. The highest signal-to-noise ratios were obtained with a flip angle of 65° and short prepulse delay times. Two-dimensional MR angiography can provide useful diagnostic information but requires a thorough understanding of in-plane and hemodynamically induced signal intensity changes.     

MR imaging characteristics of noncancerous lesions of the prostate.

Radical prostatectomy specimens from 53 men with clinical stage A or B prostate cancer were retrospectively reviewed and compared with correlative axial T2-weighted magnetic resonance (MR) images obtained just before surgery. Non-cancerous lesions were evaluated for signal intensity and location. Focal high-signal-intensity areas (n = 72) were present in 81% of patients. The 26% of lesions seen in the central gland all correlated with cystic atrophy. Of the 53 lesions seen in the peripheral prostate, 47 (89%) were cystic atrophy without associated cancer, four (7.5%) cystic atrophy with cancer, and two (3.8%) focal inflammation. Focal low-signal-intensity areas (n = 42) were present in 60% of patients. Of the 31% of lesions in the central prostate, one-fifth correlated with benign prostatic hyperplasia (BPH) and four-fifths with fibrous tissue. Of the 69% of peripheral lesions, 83% corresponded to fibrous tissue, 10% to BPH, and 7% to normal tissue. Mixed lesions (n = 42) were present in 64% of patients; 86% of these were located centrally and 14% peripherally. All mixed central lesions were BPH; the peripheral lesions were areas of combined cystic atrophy and fibrosis. BPH of low or mixed signal intensity can extend into the peripheral prostate and mimic cancer. High-intensity cystic atrophy associated with cancer can mimic normal tissue.     

Dynamic contrast-enhanced MR imaging assessment of vascularized free fibular grafts

Magnetic resonance (MR) imaging may be a noninvasive method for assessing perfusion of vascularized bone grafts placed for treatment of avascular necrosis. One proximal femur of seven beagles was devascularized, with insertion of a vascularized fibular graft. MR imaging at 1 week (seven dogs) and 6 weeks (five dogs) after surgery included pre- and postcontrast spin-echo sequences, unenhanced twodimensional time-of-flight (TOF) vascular imaging, and dynamic gradient-echo imaging during infusion of gadolinium. Relative signal intensity values of selected regions obtained from the dynamic gradientecho images were plotted as percent enhancement versus time. In the operated hip, MR imaging did not show enhancement in six of seven femoral heads and greater trochanters at 1 week after surgery, with similar results after 6 weeks. MR imaging of fibular grafts 6 weeks after surgery showed an initial rapid increase in enhancement and a subsequent slower increase in five of five dogs, although no enhancement was seen in six of seven dogs at 1 week. These findings contrasted with a rapid initial increase in enhancement followed by slow decline in non-operated hips. Two-dimensional TOP imaging did not show the vascular pedicle of the graft in any dog. Findings of radionuclide bone scanning performed 1 week after surgery were consistent with devascularization of the operated femur and fibular graft. However, tetracycline distribution and histologic findings confirmed the viability of five of five grafts within the devascularized femurs 6 weeks after surgery. Thus, dynamic contrast-enhanced MR imaging at 6 weeks after surgery is valuable for assessing vascular bone graft perfusion, while similar imaging at 1 week may suggest otherwise.     

Influence of in vivo copper on MR images of the liver in rats

To investigate the effects of in vivo copper on magnetic resonance (MR) images, the authors studied Long-Evans cinnamon rats, which develop hepatitis and hepatocellular carcinoma as a result of abnormal copper metabolism. The livers of the rats were imaged before hepatitis developed; the absence of hepatic disease was confirmed histopathologically. The copper that accumulated in the liver of the rats was thought to exist in the form of divalent ions, which were suspected of reducing the T1 and T2 of neighboring protons. However, the signal intensities of the liver on T1- and T2*-weighted images did not change, suggesting that in vivo copper, even when accumulated abnormally, does not influence the signal intensity of MR images.     

Localized proton MR spectroscopy of the brain in children

Small-voxel (3.0–8.0 cm³), magnetic resonance (MR) imaging–guided proton MR spectroscopy was performed in 54 patients (aged 6 days to 19 years) with intracranial masses (n = 16), neurodegenerative disorders (n = 34), and other neurologic diseases (n = 4) and in 23 age-matched control subjects without brain disease. A combined short TE (18 msec) stimulatedecho acquisition mode (STEAM) and long TE (135 and/or 270 msec) spin-echo point-resolved spatially localized spectroscopy (PRESS) protocol, using designed radio-frequency pulses, was performed at 1.5 T. STEAM spectra revealed short T2 and/or strongly coupled metabolites; prominent resonances were obtained from N-acetyl aspartate (NAA), choline-containing compounds (Cho), and total creatine (tCr). Lactate was well resolved with the long TE PRESS sequence. Intracranial tumors were readily differentiated from cerebrospinal fluid (CSF) collections. All tumors showed low NAA, high Cho, and reduced tCr levels. Neurodegenerative disorders showed low or absent NAA levels and enhanced mobile lipid, glutamate and glutamine, and inositol levels, consistent with neuronal loss, gliosis, demyelination, and amino acid neuro-toxicity. Preliminary experience indicates that proton MR spectroscopy can contribute in the evaluation of central nervous system abnormalities of infants and children.     

Percutaneous needle biopsy of the spine

The purpose of this review article is to provide a brief overview of the recent literature on the two main types of percutaneous biopsy methods done in the spinal column: fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB). FNAB is the process of obtaining a sample of cells and bits of tissue for examination by applying suction through a fine needle attached to a syringe. Core needle biopsy involves extracting a cylindrical sample of tissue using a large, hollow needle. The decision for needle biopsy is a joint effort between the clinician, pathologist, radiologist, surgeon, and patient. Specific techniques and approaches with varying needle systems are described for each spinal region. Percutaneous image-guided spine biopsy is a safe and effective procedure. It is the procedure of choice in definitive diagnosis of pathologic lesions of the spine.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.