Assessment of Dose and Lifetime Risk of Exposure Induced Cancer in Adult Common Computed Tomography Scans in Douala-Cameroon

Background: Among medical technologies that use ionizing radiation, CT is currently the radio diagnostic technic that can deliver the highest radiation to the Patient compared with other conventional procedures. In developing countries, the uses and risks of CT have not been well characterized. Objective: To estimate the lifetime attributable risk (LAR) incidence and mortality for cancer for each procedure for adult’s patients who had Computed Tomography examinations in 10 imaging centers in the city of Douala-Cameroon so as to provide a reference data. Materials and Methods: We conducted a cross-sectional study describing radiation dose associated with the 8 most common types of diagnostic CT studies performed on 1287 consecutive adult patients at 10 Douala radiology department. We estimated lifetime attributable risks of cancer by study type from these measured doses. Estimation of LAR for cancer incidence and mortality was based on the effective dose, patient’s sex and age at exposure using the BIER VII preferred models. Results: Mean effective dose from CT scans examinations varied from: 0.30 and 8.81 mSv. The highest doses were observed for lumbar spine CT (8.81 mSv), followed by abdomen-pelvis procedure (6.46 mSv), chest-abdomen-pelvic CT (6.61 mSv), chest CT (3.90 mSv), cervical Spine CT (3.05 mSv), head CT (1.7 mSv) and lower for sinus CT (0.30 mSv). The LAR values of all cancer from patients’ CT scans obtained vary from 67.13 excess per 100,000 (about 1 in 1489) and 0.45 excess per 100,000 (about 1 in 222,222). All cancer risk was high for lumbar spine CT in women 20 years old (67.13 excess deaths in 100,000 scans) followed by chest-abdomen-pelvic CT (50.36 excess deaths in 100,000 scans) and abdomen-pelvic CT (49.22 excess deaths in 100,000 scans) for the same age group. The LAR of incidence and mortality values were higher from female’s patients than males and higher for younger than older patients. Conclusion: This study was set out to estimate the LAR values associated with adult common CT scans procedures. The data indicates, LAR risks related to induced cancer from CT exposures were estimated to be low. This risk can be relatively significant for younger age group compared to older age group. The LAR values obtained will help to better evaluate radiation exposure risk, before ordering a CT scans examinations.

An Assessment of Both Patients and Medical Staff Awareness of the Risks of Ionizing Radiation from CT Scan in Cameroon

Objectives: To assess the patients and health personnel’s level of awareness on risks related to ionizing radiation during CT scan. Materials and methods: Three questionnaires were addressed to patients, prescribing physicians, and the medical imaging staff for three hospitals respectively. This permitted us to assess their knowledge on the benefits and risks of the required medical exam, based on the dangers of being exposed to X-rays, especially induced-radiation cancer following the amount of X-rays received during a CT scan and the possibility of not receiving radiation as tools of diagnosis. Results: 150 patients, 84 referring doctors of CT scan tests and 60 medical imaging personnel were retained. For patients, only 7.1% received information on the benefits and risks of their exams, and 34.4% believed that x-rays were harmful to their health. For the prescribers, 46.7% took into account the benefits/risk ratio before prescribing a test and only 16.7% of the referring doctors have informed the patient of the risks related to X-ray. 90% of the medical imaging staff ensures that the required test is justified, and 50% informed the patient on the risks associated with their radiation exposure, and the increased risk of developing cancer. 65% of the imaging staff could not estimate the dose that the patient will receive during the medical test. 25% mentioned the dose received during the acquisition in the patient’s exam report. Conclusion: This study confirms that the referring doctors, the patients, and the radiologists have a low knowledge concerning the risks associated with radiation exposure during a CT scan assessment. We will therefore say that patients and prescribers are not aware of the doses of radiation on CT and their possible risks, even though there is a risk of developing cancer.

The Scanning Characteristics of Spatial and Temporal Dynamic Pictures of the Seismicity in the South Yellow Sea and Its Coast Region

On the basis of the viewpoint of preparation of strong earthquakes in group, the spatial andtemporal scanning characteristics of the seismicity in the South Yellow Sea and its coast regionare studied, and some problems regarding the prediction of seismic hazard are also discussed.The results show that the seismic activity of M=4. 0 earthquakes has overall presented arelative stable state, but the partially concentrated area wbich evolves and migrates and theanomalous low b-value area have appeared in different periods, and the moderately strongearthquakes with M=5. 0～6. 0 have taken place on the edge of the anomalous area. Theaccumulative frequency of M=4. 0 earthquakes in the anomalous area presents non-linearindex acceleration and the moderately strong earthquakes have appeared in the late period ofthe non-linear index acceleration of M=4. 0 earthquakes or in the later anomalous tranquilperiotl. The spatial and temporal uneven Phenomenon of seismicity has some stability andreproducibility, and has

Risk Factors for Stroke in Sulaimaniyah Iraqi Kurdistan Region-Iraq

Background: Stroke is a frequent medical problem and a leading cause of death and disability worldwide. Several conditions and lifestyle factors have been associated with stroke. Aim: To evaluate risk factors in stroke patients in Sulaimani city. Results: 110 patients with stroke were included in this study, hypertension was found to be the most common risk factor in current study. Out of 110 cases, 83 (75.5%) were hypertensive. Peak stroke-prone age was (60 - 69) year for male, (70 - 79) year for female. We found a statistically significant relation between level of TSC, LDL with ischemic stroke (r = 0.4047, P Conclusion: Hypertension is the leading risk factor of stroke. It is therefore essential to detect and treat hypertension at its outset. High value of atherogenic index mostly associated with ischemic stroke .while no relation found with haemorhagic stroke.

Incidence &Risk Factors Associated with Carotid Disease in Patients Undergoing Coronary Artery Bypass Grafting Surgery

Objective: The purpose of this study was to evaluate the true incidence and the risk factors associated with carotid disease in the sitting of high risk patients undergoing coronary artery bypass graft (CABG) using carotid duplex scan and to find out if routine preoperative carotid duplex scan is needed among all these patients. Methods: This retrospective study included 402 consecutive patients who underwent bilateral carotid duplex scan admitted for CABG during the period from January 2006 to December 2008. We excluded patients in cardiogenic shock who were taken to operating room emergently. Results: The prevalence of associated risk factors showed diabetes mellitus recorded the highest (93.3%) whereas peripheral vascular disease the lowest (1.7%), hypertension (89.3%), dyslipidemia (72.6%), smoker (21.1%), left main disease (4.7%), and previous stroke (3%). Patients undergoing CABG has high incidence of carotid disease (68.7%) and severe stenosis is more in patients aged 60 and above (13.5%) versus (2.3%) in age 60, previous stroke and left main disease). Conclusion: This study showed that carotid screening is recommended for all patients who are undergoing CABG due to high incidence of carotid disease.

Evaluation of the Knowledge of CT Scan Prescribers on Patients’ Radioprotection in Senegal

Medical imaging has enabled major improvements in the medical care of the patient. However, some of these tests have the disadvantage of using ionizing radiation at low doses. Although the CT scan is a powerful diagnostic tool, it remains a highly radiant imaging modality. In addition, the risk of radiation-induced cancer associated with low X-ray doses is established by the American Phase 2 study BEIR VII, and preventive measures require a good level of knowledge on radioprotection by imaging test prescribers. In our study, we evaluated the knowledge of CT scan prescribers in Senegal regarding patient radioprotection. These prescribers consisted of physicians and surgeons without distinction of specialty. Our objective was to have the required data for optimizing CT prescriptions in compliance with the principles of radioprotection. Our work focused on a descriptive analytical study of 107 doctors who prescribed CT scan in public health institutions in Senegal. Our results revealed poor knowledge of doctors prescribing CT scan on induced radio risks, even though the majority of them stated that they took those risks into account. Our data were not isolated, they were applicable to similar studies conducted outside Senegal. In summary, our study led on the one hand to recommendations on initial and continuing training and on the other hand on organizational and regulatory considerations.

校园网络安全风险评估方法研究与应用

随着高校网络规模的迅速扩张、用户数量的增长以及网络开放性的提升,校园网络作为提供多元化信息服务的平台,面临的安全挑战也日益凸显。根据校园的实际情况,综合运用多种风险评估方法进行系统的风险评估,包括流程图法、危害性分析方法、分解分析法、调查列举法等。针对校园网络安全风险评估的特性,提出基于探测技术的安全风险评估方法,对校园网络中不同类型安全风险进行识别和探测,能够有效获取资产的基础属性信息,并且通过实验验证该方法的可行性和实用性。

Radiation Risks of Kidney during Abdominal CT Procedures in Morocco: A Multicentre Study

This study aimed to estimate renal effective dose during abdominal CT scans in order to assess the renal risks of cancer and heredity per procedure in Moroccan hospitals. It’s consisted of examining a total of 120 patients referred to three radiology departments for an abdominal CT scan at the rate of 40 per hospital. The data that collected for this diagnostic exam included scanner acquisition parameters, number of series, use of the contrast medium, and rotation time as well as slice thickness, the displayed CT dose index (CTDIvol) and the Dose Length Product (DLP). Renal dose, effective dose and biological risks were estimated using the International Commission on Radiological Protection (ICRP) conversion factor. The patients included in this study were an average age of the (46.49 ± 14.16) years and an average weight of (73.34 ± 7.58) kg. For the mean effective dose (E) and average kidney dose (DK) received per patient during an abdominal CT scan, it were respectively of (6.67 ± 2.73) and (18.26 ± 7.74) mSv. The distribution of these values according to the hospital variable shows a difference in mean effective dose of the order of 0.26, 0.38 and 1.45 mSv and a difference in the mean renal dose of the order of 8.76, 4.94 and 0.48 mSv respectively for H1, H2 and H3. The induction cancer risk of abdominal and kidney per 105 procedures was respectively of 3 and 10. The kidney cancer risk by procedure is two to three times more likely than abdominal. For hereditary risk of abdominal and renal exposure per 106 procedures, it is 14 and 21 respectively. The renal stochastic effect by procedure is also two to three times more likely than that of the abdomen. Our values are relatively higher than those of published in some previous studies. Cancer risk and heredity estimation highlights the need to limit radiation dose. This first ever survey confirmed the need to improved training of health professionals involved in computed tomography on factors affecting image quality, doses and protocols optimization.

CT增强检查中碘对比剂外渗病人皮肤损伤风险预测模型的构建

目的:探讨CT增强检查中碘对比剂外渗病人皮肤损伤发生风险的影响因素,构建并验证风险预测模型。方法:采用便利抽样法抽取2023年1月—7月在广西医科大学第一附属医院放射科接受CT增强检查的碘对比剂外渗病人286例作为研究对象,自制CT增强检查碘对比剂外渗病人皮肤损伤风险调查问卷对病人进行调查,采用单因素分析、Logistic回归分析筛选CT增强检查中碘对比剂外渗病人皮肤损伤发生风险的影响因素,构建风险预测模型,绘制列线图,运用受试者工作特征(ROC)曲线、校准曲线评价模型。结果:CT增强检查中碘对比剂外渗病人皮肤损伤发生率为18.5%。Logistic回归分析结果显示,过敏史、碘对比剂黏稠度、碘对比剂注射速度是CT增强检查中碘对比剂外渗病人皮肤损伤的影响因素(P<0.05),基于上述结果构建的预测模型建模组ROC曲线下面积为0.842[95%CI(0.770,0.915)],约登指数为0.667,最优截断值灵敏度为0.893,特异度为0.774;验证组ROC曲线下面积为0.924[95%CI(0.872,0.975)],约登指数为0.793,最优截断值灵敏度为0.891,特异度为0.902。Hosmer-Lemeshow检验结果显示,χ2=9.566,P=0.221 5,校准曲线与参考线相接近。结论:CT增强检查中碘对比剂外渗病人皮肤损伤风险预测模型预测效能良好,可为医务人员制订个性化的预防措施提供参考。

双源CT双动脉期增强扫描对肝动脉-门静脉瘘的评估价值及风险因素分析

目的:探讨双源CT双动脉期增强扫描模式对肝动脉-门静脉瘘(HAPVF)的评估价值及风险因素分析。方法:选取HAPVF和非HAPVF患者各60例,分别为HAPVF组和非HAPVF组,行双源CT双动脉期增强扫描,比较2组临床指标及CT征象差异。以DSA为金标准,对比动脉早期、动脉晚期和双动脉期对HAPVF的诊断敏感度、特异度,以及对HAPVF分型的诊断准确率。应用logistic回归分析探讨HAPVF的危险因素,采用ROC曲线评估危险因素预测HAPVF的价值。结果:双动脉期诊断HAPVF的敏感度、特异度、阳性预测值、阴性预测值及分型准确率均明显高于单独2期(均P<0.05)。2组肝癌大小、包膜类型、门静脉癌栓比较,差异均有统计学意义(均P<0.05)。logistic回归分析显示,肝癌大小、包膜类型、门静脉癌栓均是HAPVF的独立危险因素。ROC曲线表明,单因素预测HAPVF效果最好的是包膜类型,其次是门静脉癌栓,再次是肝癌大小。综合多因素联合预测分析显示,肝癌大小+包膜类型+门静脉癌栓预测效果最好。结论:双源CT双动脉期增强扫描模式对HAPVF的诊断敏感度、特异度较高,且在HAPVF分型中具有较好的诊断效果。HAPVF的临床及影像学征象具有一定特点,其中肝癌大小、包膜类型、门静脉癌栓均是HAPVF的独立危险因素,三者联合预测效果最好,能为临床及时诊治提供可靠依据。

基于地平线扫描的产业风险预警体系框架研究

[研究目的]产业在发展过程中受到各维度风险因素的影响,建立科学的产业风险扫描和预警体系有助于政府和产业各主体识别、发现潜在风险,以提前做好应对策略。[研究方法]基于地平线扫描和风险预警的相关理论方法,构建面向产业环境、社会和产业治理(ESG)维度的地平线扫描过程,并以此为基础构建产业风险预警体系框架,探讨框架在实际应用中的关键问题。[研究结论]该框架有助于对产业风险进行全面扫描、识别、评估和预警,发现可能仍处于早期的弱信号,为产业风险预警工作提供新的理论和实践路径,未来建议依托产业信息服务平台等系统实现并优化相关预警服务。

压力容器宏观结构风险智能识别的应用前瞻

风险智能识别的指导思想就是将设备大量的结构信息数据化。通过建立一个统一的智能管理系统,把设备各类型的数据进行汇总与综合分析,制定可靠的风险识别策略,并模拟工艺流程变化、设备状态改变、外部环境影响等可能发生的事件,对设备运行状态进行及时、高效、准确、全天候的风险智能识别与管理监控,以保障生产系统安全、稳定运行。

岩土工程勘察数字化技术与实现分析

岩土工程勘察正经历一场数字化变革,其中GIS、遥感技术、3D扫描和GPR等工具正引领这一变革。这些先进技术的应用不仅极大提高了数据收集的效率和精确性,还通过深入的数据分析为地质风险评估带来了新的维度。从GIS的空间分析到遥感技术的NDVI分析,再到3D扫描的精密对齐,每种技术都在为岩土工程勘察提供更全面的视角。这不仅仅是技术的进步,更是对传统勘察方法的一次颠覆性改进,预示着未来工程的发展趋势。

基于列线图模型分析CT增强高压注射外渗的风险因素及预防对策分析

目的基于列线图模型分析CT增强高压注射外渗的风险因素,并分析预防CT增强高压注射外渗发生的对策。方法回顾2020年1月~2023年6月期间于本院进行CT增强扫描发生高压注射外渗的患者的临床资料(外渗组,n=72),另回顾未发生高压注射外渗患者的临床资料(无外渗组,n=216)。采用Logistic回归模型分析明确导致CT增强高压注射外渗的危险因素,并根据独立危险因素构建列线图预测模型,采用受试者工作特征曲线(ROC)、Bootstrap法验及Calibration曲线对模型进行评价。结果外渗组年龄≥60岁、BMI≥24kg/m^(2)、手腕注射、未对比剂加热、注射速率≥3mL/s、化疗史人数占比均高于无外渗组(P<0.05);Logistic回归模型分析结果显示,年龄≥60岁、手腕注射、注射速率≥3mL/s、化疗史是影响高压注射外渗的独立危险因素(P<0.05);ROC曲线显示,预测模型的AUC为0.828(95%CI:0.780~0.870),灵敏度90.28%、特异度78.70%、约登指数0.690;Bootstrap验证结果显示,C-index值为0.762(95%CI:0.651~0.816),Calibration曲线显示,Hosmer-Lemeshowχ^(2)=0.628,P=0.317。结论年龄≥60岁、BMI≥24 kg/m^(2)、手腕注射、未对比剂加热、注射速率≥3 mL/s、化疗史是CT增强扫描发生高压注射外渗的独立危险因素,基于上述因素构建的预测模型对CT增强高压注射外渗具有较高的预测效能。

碱改性凹凸棒石对土壤中镉化学形态及环境风险的影响

凹凸棒石进行碱改性后性能的提高,为其钝化修复重金属污染土壤提供重要基础。本文采用不同比例的氢氧化钠对凹凸棒石进行改性,利用扫描电镜(SEM)、X射线衍射(XRD)和傅里叶变换红外光谱法(FTIR)分析改性前后凹凸棒石理化特性的变化,并在人工配制的重金属Cd污染土壤上进行钝化实验,研究氢氧化钠改性凹凸棒石对污染土壤中Cd的化学形态变化以及环境风险的影响。结果表明:与对照相比,添加氢氧化钠与凹凸棒石质量比为1∶2的改性材料,土壤pH值显著升高0.85个单位。酸溶态Cd含量显著降低46.25%,残渣态Cd含量显著增加1.99倍;土壤中Cd的风险评价指数和潜在风险指数分别由36.70%和207.90降至20.08%和86.40,有效降低了土壤中Cd的迁移能力和环境风险。SEM、XRD和FTIR分析表明,凹凸棒石经过改性后表面粗糙程度增加,Si—O—Si键等化学键打开,用于吸附重金属的活性位点增加。碱改性凹凸棒石主要通过吸附作用,硅羟基和氢氧根与Cd^(2+)反应生成沉淀来固定土壤Cd,从而达到钝化修复Cd污染土壤的效果。因此碱改性凹凸棒石可对土壤中Cd进行有效钝化,在重金属污染土壤修复中具有较显著的应用前景。

企业战略风险的形成机理分析及管理对策——基于能力理论的视角

环境的快速变化使企业面临的不确定性不断增加,从而给企业带来风险,其中战略风险会危及企业的生存和发展。企业战略主要受环境、资源和能力三个因素的影响,相对于环境理论和资源理论,企业能力理论居于核心地位。因此,有必要从能力的角度理解企业战略风险的本质并对其进行控制。本文在理论回顾的基础上,将企业的能力划分为管理控制能力、创新能力以及学习能力,并从能力的角度对企业战略风险形成的机理进行了分析,提出可以通过加强战略环境的扫描和企业内部能力的监控、建立经济情报收集系统、注重外部环境及内部能力变化的分析与评估、采用组织学习提高企业的能力柔性等途径对企业的战略风险进行管理。

对地震危险区的探索——以南黄海5.3级地震等预报为例

1991年11月5日在江苏射阳发生了4.7级地震、1992年1月23日在南黄海北部发生了5.3级地震,10月22日射阳东海域发生了4.8级地震,11月4日南黄海北部发生了4.6级地震,对上述4次地震笔者等曾作出过一定程度的年度中期预报。本文对该地震震前的预报概况、预报基本思路和主要科学依据作了概述,并讨论了给予的启示。认为在一定条件下对某些地震作出某种程度的科学预报还是可能的。

一种定量的网络安全风险评估系统模型

提出一个定量的网络安全风险评估系统模型和与之对应的定量风险评估体系,并为体系中资产、威胁、脆弱性和风险等各项指标提出了相应的计算方法;论述了模型系统中各个模块的设计和机理,其中采用基于免疫的入侵检测技术使得威胁评估模块具备发现新颖威胁的能力,插件设计保证了脆弱性模块较好的扫描效率和扩展性。最后,用实验验证了该定量评估模型对评价网络安全状态的有效性。

胎盘早期剥离的早期诊断(附46例临床分析)

目的 :探讨发病诱因、临床表现和超声检查对胎盘早期剥离 (PA)的诊断意义。方法 :对 1995年 1月～2 0 0 1年 12月我院 4 6例PA患者作回顾性分析。结果 :早产率 5 6 .6 2 % ,围产儿死亡率 4 1.3% ,新生儿青紫窒息 2 8.2 6 %。产后出血、子宫卒中各 15 .2 2 % ,DIC、失血性休克各 8.70 %。该组产前诊断率 5 4 .35 % ,B超检出率 6 0 .98%。临床表现主要为阴道流血 ,下腹疼痛 ,子宫张力增高。结论 :PA严重威胁母儿生命 ,应结合诱因、临床表现和B超等辅助检查尽早对其作出正确诊断。

危机管理护理方案对碘造影剂过敏高危患者过敏反应的预防作用

目的探讨危机管理护理方案对碘造影剂过敏高危患者过敏反应情况及CT扫描结果的影响。方法选取2017年1月至2020年7月在广州市花都区人民医院接受CT增强扫描的碘造影剂过敏高危患者500例为研究对象,使用随机数字表法分为对照组(n=250)和观察组(n=250),对照组接受常规护理,观察组在对照组基础上加用危机管理护理方案,对两组过敏反应情况、CT扫描结果及焦虑评分、碘造影剂过敏知识评分进行比较。结果观察组碘造影剂过敏反应发生率为2.00%,低于对照组的6.40%,差异有统计学意义(P<0.05);观察组CT扫描效果优良率为98.40%,高于对照组的94.40%,差异有统计学意义(P<0.05);两组干预前的焦虑评分、碘造影剂过敏知识评分比较,差异无统计学意义(P>0.05),干预后观察组焦虑评分低于对照组,碘造影剂过敏知识评分高于对照组,差异有统计学意义(P<0.05)。结论危机管理护理方案可减轻碘造影剂过敏高危患者过敏反应,提高CT扫描质量,减轻患者焦虑程度,提高碘造影剂过敏知识,值得推广。