Erbium filtration: a cost-effective, dose-reducing filter which maintains abdominal image quality

The current study investigated the effect of erbium filtration on an anteroposterior abdominal image. The radiation dose reductions achieveable and the costeffectiveness of this filter were also evaluated. An assessment of the radiation dose delivered employing either the standard total filtration (3 mm Al equivalent) or 0.1 mm of erbium filtration added to the standard filtration was undertaken on 21 patients. Image quality was assessed using the Commission of European Communities (CEC) criteria. Significant reductions of 64.6 % in entrance surface (p = 0.0001) and 23.4 % in effective dose (p = 0.0099) were recorded with erbium filtration. Image quality was maintained and the cost per manSievert saved was ￡ 128. More widespread use of this dose reducing filter is advocated. Received: 7 August 1998; Revised: 19 February 1999; Accepted: 19 April 1999     

高本底辐射诱发居民外周血淋巴细胞染色体畸变的剂量效应关系

目的通过人群调查探讨高本底辐射诱发居民染色体畸变的剂量效应关系,为建立环境小剂量辐射剂量效应模型和评估群体剂量提供参考。方法３９名调查对象选自高本底和对照地区１３个家庭中的祖、父、子三代成员。个体累积剂量分别为２３９～２６１３和５２～２９８ｍＧｙ。分离淋巴细胞培养法制备染色体标本,总计观察细胞数约１０００００。结果①在高本底组每一家庭中均观察到个体染色体畸变率随年龄增加而升高,其趋势在户间差异无显著性。②高本底组不同年龄个体染色体畸变率与年龄和累积剂量密切相关,可拟合为线性一次式：Ｙａｇｅ＝００４４８Ｘ＋０４９１３（Ｒ２＝０７８１４）;Ｙｄｏｓｅ＝００１５６Ｘ＋０５７１５（Ｒ２＝０７０６１）;③对照组个体间畸变率差异不显著,其平均畸变率接近正常人群自发畸变率。结论高本底持续照射诱发的人体内双着丝点加环畸变随受照时间的延长而持续升高。双加环畸变分析可作为小剂量持续照射的可信赖的生物剂量仪,但存在一个应用上的累积剂量阈值,其值约为５０ｍＧｙ。     

The association between recipient alcohol dependency and long-term graft and recipient survival.

BACKGROUND: The causative role of alcohol consumption in renal disease is controversial, and its effect on renal graft and recipient survival has not been previously studied. METHODS: We analysed the association between pre-transplant [at the time of end-stage renal disease (ESRD) onset] alcohol dependency and renal graft and recipient survival. The United States Renal Data System (USRDS) records of kidney transplant recipients 18 years or older transplanted between 1 January 1995 and 31 December 2002 were examined. We used Kaplan-Meier analysis and Cox regression models adjusted for covariates to analyse the association between pre-transplant alcohol dependency and graft and recipient survival. RESULTS: In an entire study cohort of 60 523, we identified 425 patients with a history of alcohol dependency. Using Cox models, alcohol dependency was found to be associated with increased risk of death-censored graft failure [hazard ratio (HR) 1.38, P < 0.05] and increased risk of transplant recipient death (HR 1.56, P < 0.001). Subgroup analysis demonstrated an association of alcohol-dependency with recipient survival and death-censored graft survival in males (but not in females), and in both white and non-white racial subgroups. CONCLUSIONS: We concluded that alcohol dependency at the time of ESRD onset is a risk factor for renal graft failure and recipient death.     

Can rotatory knee laxity be predicted in isolated anterior cruciate ligament surgery?

Purpose

Despite the overall success of the surgical anterior cruciate ligament (ACL) reconstruction, some patients still present with instability symptoms even after the surgery, mainly due to the presence of associated lesions. At present, the pivot shift test has been reported to be the benchmark to assess rotatory knee laxity. The purpose of this study was to quantitatively evaluate rotatory knee laxity at time-zero in order to determine whether detected post-reconstruction laxity was predictable by its value measured before the reconstruction, which was hypothized to be influenced by the presence of associated lesions.

Methods

Rotatory knee laxity was retrospectively analysed in 42 patients, including two different ACL reconstructions. The maximal anterior displacement and the absolute value of the posterior acceleration reached during the reduction of the tibial lateral compartment were intra-operatively acquired by using a navigation system and identified as discriminating parameters. For each parameter, statistical linear regression analysis (line slope and intercept) was performed between pre- and post-reconstruction values.

Results

No statistically significant influence of the initial posterior acceleration on the post-reconstruction outcome was found (line slope, p > 0.05), although a statistically significant line intercept was indeed identified (p < 0.001). A statistically significant influence on the surgery outcome was instead found for the initial value of the anterior tibial displacement (line slope = 0.39, p = 0.004), meaning that, on average, about 40 % of the post-reconstruction lateral compartment displacement could be explained by the corresponding pre-reconstruction value. Both of these findings highlighted the importance of intra-operative quantification of rotatory knee laxity to identify correct indications for the surgery.

Conclusions

This study provided important implications for the future possibility of defining a quantifying tool able to assess rotatory knee laxity during ACL reconstruction. This could allow detection of additional injuries to secondary restraints by easily performing rotatory knee laxity tests, which in turn could reduce post-surgical recurrence of knee instability.     

SAPS 3 is not superior to SAPS 2 in cardiac surgery patients

Objectives. Cardiac surgery patients are excluded from SAPS2 but included in SAPS3. Neither score is evaluated for this exclusive population; however, they are used daily. We hypothesized that SAPS3 may be superior to SAPS2 in outcome prediction in cardiac surgery patients. Design. All consecutive patients undergoing cardiac surgery between January 2007 and December 2010 were included in our prospective study. Both models were tested with calibration and discrimination statistics. We compared the AUC of the ROC curves by DeLong's method and calculated OCC values. Results. A total of 5207 patients with mean age of 67.2 ± 10.9 years were admitted to the ICU. The mean length of ICU stay was 4.6 ± 7.0 days and the ICU mortality was 5.9%. The two tested models had acceptable discriminatory power (AUC: SAPS2: 0.777–0.875; SAPS3: 0.757–893). SAPS3 had a low AUC and poor calibration on admission day. SAPS2 had poor calibration on Days 1–6 and 8. Conclusions. Despite including cardiac surgery patients, SAPS3 was not superior to SAPS2 in our analysis. In this large cohort of ICU cardiac surgery patients, performance of both SAPS models was generally poor. In this subset of patients, neither scoring system is recommended.     

影像组学及其在肝癌中的进展

肝癌(hepatocellular carcinoma,HCC)是全球癌症相关死亡的第二大原因,因此早期发现和治疗反应的预测对HCC患者有很大益处。 目前,穿刺活检和常规医学成像在HCC患者的管理中发挥重要且基础的作用,而这两种方法分别存在样本误差和操作者依赖性的不足。 影像组学是一种新兴的非侵入性技术,可以突破时空限制来获取肿瘤的综合信息,用以反映肿瘤的情况,从而弥补上述方法的不足。影像组学的基本步骤包括图像的获取,感兴趣区的划分与重建,特征的提取、划分与分类,模型的建立与效能评价。影像组学在HCC的诊断、治疗和评价方面取得了一定的进展,具有应用前景。     

图像引导放疗技术下癌症治疗质量保证和质量控制的研究进展

国内恶性肿瘤患者病例数越来愈多,死亡率也居高不下。放射治疗是目前治疗癌症的三大有效方式之一,放疗环节中的质量保证和质量控制对于提高肿瘤患者的治愈率有重要的作用,先进的图像引导下的放疗技术能够在治疗过程中准确的核定治疗的位置,保证剂量投射的精度,较大程度的提高了肿瘤患者的治疗效果。同时放疗计划的二维及三维模体剂量验证也是质量保证的重要部分,其在一定程度上确保放疗物理师设计的放疗剂量与直线加速器出束的剂量能相对一致。如何精确有效地保证放疗各环节中的治疗质量是放射治疗界的重点研究方向。本文主要探讨目前放射治疗中图像引导技术实施及放疗计划剂量验证中的质量保证与控制,同时针对日新月异的设备与技术,探索新的放疗质量保证措施。     

数据科学驱动下ESI潜力学科入围预测方法的实践探索

为研究“双一流”建设过程中ESI潜力学科入围全球前1%的预测方法与“暗数据”可视化分析思路的耦合关系，定期抓取与追踪ESI学科数据，合并使用WOS-SCIE、InCites、ESI、SQL数据库，联用SWOT分析法、文献调研法和回归分析法等，实现机构学科潜力全景分析，构建潜力学科入围所需论文篇数的线性预测公式，并分别从绝对指标和相对指标的不同维度搭建入围预测的绝对指标和相对指标2个数据模型，尝试对ESI潜力学科进行趋势预测，拟归纳合理或通用的预测方法，以期进一步挖掘未来的潜力学科。     

基于贝叶斯网络不确定性推理的肺癌风险预测模型

目的 将贝叶斯网络与Cox模型相结合,预测包含缺失协变量的个体的肺癌发病风险。方法 研究使用的数据来自于英国生物样本库,采用单因素Cox回归分析筛选与肺癌发病相关的预测因素;基于识别出的肺癌潜在预测因素,应用上述联合模型建立个体化肺癌风险预测模型;从鉴别和校准两方面评价模型的预测性能。结果 建立的预测模型具有较好的鉴别和校准能力,训练和验证队列的AUC分别为0.854(95%CI:0.836～0.870)和0.885(95%CI:0.871～0.897)。结论 本研究构建了基于贝叶斯网络和Cox模型的肺癌风险预测模型;该模型具有良好的鉴别和校准能力,能有效预测肺癌发病高危人群;联合模型在存在缺失预测因子的情况下提供了一种有效的风险预测方法,可为肺癌预防控制提供理论支撑。