Symmetry based prostate cancer detection

Objective:

To retrospectively assess the value of left and right half symmetry analysis in prostate T₂ weighted images (T2WI) for improving prostate cancer (PCa) screening.

Methods:

T2WI and other data of a total of 66 males were collected; the control group and cancer group had 33 patients each. Thresholding geometric active contours algorithm was used for prostate region segmentation, and the measure of local reflectional symmetry algorithm was applied to extract the longitudinal symmetry axes. After that, cross-correlation coefficients (CCs) of the left and right halves of each prostate were obtained.

Results:

Data analysis showed that the mean and variance of the value of the left and right half CCs of prostate T2WI in the cancer group and control group were 0.73 ± 0.05 and 0.82 ± 0.06, respectively. The area under the receiver operating characteristic curve was 0.87, and the specificity and the sensitivity were 91% and 70%, respectively. The p < 0.001 indicated that the value of CCs of the prostates between the two groups was significantly different.

Conclusion:

The symmetry in T2WI is a potential useful index for PCa screening and has a potential value for PCa detection and localizations of tumours for biopsy.

Advances in knowledge:

Texture bilateral symmetry of prostate T2WI is employed to screen the suspected prostate tumour.Prostate cancer (PCa) is the second most common cancer among males worldwide¹ and the most common cancer among Western males.^2,3 With rapid increase, especially, in old people, the number of total sufferers is expected to increase so that by 2020, it is only exceeded by lung cancer.^4–7 PCa was the sixth most frequently diagnosed cancer among males during 2008 in the Asia–Pacific region, behind cancers of the lung, stomach, liver, colorectum and oesophagus. This pattern was mainly driven by Eastern Asia, and in particular China, which represents about 62% of the region''s male population.⁸ More than that, PCa is now becoming an emerging health priority in East Asia. Because East Asia remains the world''s most populous region, the number of individuals with PCa will increase substantially in the coming decades.⁹Currently, PCa screening relies on digital rectal examinations (DREs) and serum prostate specific antigen (PSA) levels. But PCa diagnosis is based on histological tissue analysis, which is most often obtained via needle biopsy, guided by transrectal ultrasound (TRUS). However, it has been reported that its accuracy is only 20–25% in patients with PSA levels between 4 and 10 g ml⁻¹ owing to the inevitable inaccurate positioning during TRUS, and often leads to the failure to detect cancer.^10,11 Additionally, repetitive biopsies will not only increase the suffering of patients but also lead to increased rate of complications. For these reasons, image modalities and suspicious lesion identification via computer-aided diagnosis (CAD) methods are expected to provide more accurate detection and localization of prostate tumours. MRI is commonly employed in some areas to assist in the diagnosis of PCa and provide locations of suspicious tumours before biopsy, and accurate CAD methods are urgently needed.^11–18In recent years, many efforts have been made to evaluate MR-based suspected prostate lesions. Firstly, Dickinson et al¹⁹ developed a standardized reporting scheme that may be widely adopted and validated to ensure comparability of research outputs and optimal clinical practice. Secondly, dynamic contrast-enhanced MRI (DCE-MRI) has been extensively used for the diagnosis of PCa. DCE-MRI is an important imaging technique because it can detect angiogenesis and vasculogenesis of tumours. Jackson et al¹² calculated the accuracy of DCE-MRI for cancer detection by a pixel-by-pixel correlation of quantitative DCE-MRI parameter maps and pathology, and the results showed a significant difference between the benign peripheral zone and tumour for the parameters K^trans, v_e and k_ep. Based on DCE-MRI, Puech et al¹⁵ provided a standardized cancer suspicion score for suspicious foci based on the median wash-in and wash-out values of peripheral zone cancer, peripheral zone benign, transitional zone cancer and transitional zone benign to provide useful data for an unbiased and reproducible assessment of hypervascularized prostatic areas in routine practice.T₂ weighted images (T2WI) play a crucial role in clinical practice, by distinguishing between normal and abnormal foci in prostate zonal anatomy and periprostatic structures.²⁰ With fast spin-echo techniques, T2WI was adopted by Sommer et al²¹ to detect some early stages of PCa, such as pelvic lymph nodes or pelvic bone metastases,^22–24 and it is already routinely used in prostate lesion identification.Some recent studies have provided clinical assessments utilizing the prostate T2WI features. Madabhushi et al¹⁰ firstly presented a CAD system for detecting PCa from high-resolution MRI studies, which used three-dimensional (3D) texture operators to capture a wider range of variation in appearance, size, orientation and anisotropy of the cancer. Lv et al¹⁶ offer a robust MR-based indicator to distinguish prostate tumours from normal tissue with a fractal analysis to extract the features of the prostate texture and intensity distribution on T2WI as indices in the differential diagnosis of PCa. Local texture patterns in T2WI were considered in previous computer-aided approaches for automatic prostate lesion detection, but the morphological characteristics, such as symmetry, which is easily observed in prostate T2WI, were ignored. Bilateral symmetry appears commonly in nature, including many organs in our bodies such as the brain, bones, skin and prostate. As for a developing lesion, asymmetry gradually appears with symmetry breaking down in tissue because of differentiation of perfusion, blood supply and metabolism beyond normal tissues.²⁵ Radiologists have reported that symmetry in prostate MRI can be important to detect PCa.²⁶ Litjens et al²⁷ also investigated a fully automated computer-aided detection system for the diagnosis of PCa that includes feature of symmetry, local contrast and shape. In this study, texture bilateral symmetry of prostate T2WI is employed to screen the suspected prostate tumour, which is a potential useful index to help identify and localize the lesions or tumours in patients who undergo PCa screening.     

综合模拟实验在院内急救护理教学中的应用

目的探讨综合模拟实验在急危重症护理教学的院内急救环节中的应用与效果。方法以110名护理三年级本科学生为研究对象,完成3学时的心肺复苏、球囊面罩通气、除颤团队训练后,进行2学时的院内急救临床情境模拟教学,课后使用自制反馈问卷进行测评。结果各评价条目得分均在4分以上;90.9%以上的学生认为观察患者的能力和解决问题的能力得到提高,82.7%能有效应对患者的病情变化,90.9%对自身课堂表现感到满意。≥90.0%的学生掌握了急诊分诊流程、处理口头医嘱、心肺复苏团队配合知识与技能、外伤出血包扎等内容。结论综合模拟实验在急重症护理教学中取得良好效果,为课堂多元化教学拓宽了思路。     

结核病区医务人员医用防护口罩佩戴现状及影响因素分析

目的了解结核病区医务人员医用防护口罩佩戴状况及影响因素,为有针对性地做好职业防护提供参考。方法对广州军区5所三甲综合性医院的结核病区195名医务人员采用自行设计的问卷进行佩戴医用防护口罩行为现状调查,分析医务人员佩戴医用防护口罩行为的影响因素。结果结核病区医护人员佩戴医用防护口罩的行为得分为(17.93±3.37)分,结核病区医护人员佩戴医用防护口罩细节行为条目得分较低;职业、教育培训、监管机制、经济因素是结核病区医务人员佩戴医用防护口罩行为的主要影响因素(P0.05,P0.01)。结论结核病区医务人员佩戴医用防护口罩的主动意识较强,但较易忽视佩戴的细节行为。职业防护须重视细节行为,加大教育培训、双重监管和经济投入力度,以预防结核病医院感染,促进医务人员职业防护。     

衡阳市社区老年人积极老龄化现状及其影响因素的研究

目的了解社区老年人积极老龄化现状,并分析其影响因素,为社区护理工作者开展健康促进工作,提高社区老年人的健康水平提供参考。方法采用一般问卷调查表、休闲态度量表和积极老龄化量表对衡阳市某国家级示范社区卫生服务中心275名老年人进行问卷调查。结果老年人休闲态度总分为(3.16±0.55)分,积极老龄化总分为(3.24±0.61)分。不同年龄、文化程度、居住情况、休闲类型和身体机能的社区老年人积极老龄化得分比较,差异有统计学意义(均P0.01);社区老年人休闲态度与积极老龄化呈正相关(均P0.01)。回归分析结果表明,身心健康和自我发展是影响积极老龄化的重要因素。结论社区老年人积极老龄化水平和休闲态度水平均待提高,社区护理工作者应采取措施提高社区老年人的休闲态度水平,促进其达到积极老龄化。     

急诊科护士遭受躯体暴力的预测线索探讨

目的探讨急诊科护士发生躯体暴力的预测线索。方法对四川省和重庆市5所医院的急诊科进行观察性研究,由专人观察和记录患方的行为线索,并根据行为变化是否转化为躯体暴力分为躯体暴力组和非躯体暴力组,统计分析两组行为变化的例数和躯体暴力的行为方式,采用Logistic回归分析确定护士发生躯体暴力的特定预测线索。结果共观察287例患者,非躯体暴力组219例,转化为躯体暴力组68例,躯体暴力发生率23.7%。Logistic回归分析显示当患方出现紧握双拳(OR=6.334)、挑衅(OR=5.672)、抵制护理措施(OR=5.164)、大声争吵(OR=4.651)、紧跟护理人员(OR=3.334)或鲁莽(OR=3.172)是发生躯体暴力的最强预测线索(P0.05,P0.01)。结论急诊科发生躯体暴力比较普遍,应快速、方便、有效地评估患方潜在的躯体暴力风险,采取相应的防范措施,以减少躯体暴力风险的发生,避免急诊科护士受到身体和心理伤害。     

某三甲医院73名护士离职原因及再就业情况调查分析

目的分析某三甲医院73名护士离职原因及再就业情况,探讨提高护士工作满意度,减少护士离职的对策。方法对73名护士采取电话访谈方式了解离职原因及再就业情况。结果护士离职的主要原因依次为护理工作紧张压力大(87.67%)、工作环境不满意(50.69%),科室人际关系紧张(41.10%)及考取外单位在编编制(38.36%)等6项原因。再就业包括继续从事护理专业(56.16%)、非护理专业(10.96%)、暂时休息(20.55%)等。结论应合理配置护士人力资源,缓解工作压力,实施更为人性化的管理,做好护士职业生涯规划等,以提高护士工作满意度,降低离职率。     

新疆多民族地区ICU临终患者家属放弃治疗真实体验的质性研究

目的了解新疆多民族地区ICU临终患者家属对放弃治疗的真实体验,为制定有效的干预措施、促进ICU放弃治疗的临终患者家属身心健康提供依据。方法采用质性研究中的现象学研究方法,对15名ICU放弃治疗的临终患者家属进行半结构式深入访谈,应用Colaizzi分析法进行资料分析。结果 ICU临终患者家属放弃治疗的真实体验提炼出5个主题:预后差,救治希望渺茫;文化背景及宗教信仰;经济负担过重;注重患者的生命质量;放弃治疗后表现出复杂的负性心理。结论新疆多民族地区ICU临终患者家属放弃治疗的原因多样,家属经历严重的负性情绪。需构建更完善的社会支持系统,逐步建立由患者、家属和医护人员共同组成的决策共享模式,以减轻家属因签署放弃治疗而导致的巨大心理压力。     

早期导尿管球囊扩张联合冰刺激治疗脑卒中后吞咽障碍

目的 促进脑卒中患者吞咽功能的康复.方法 将首次发病的脑卒中后吞咽障碍患者60例随机分为扩张组和对照组各30例,对照组给予常规的药物治疗、功能锻炼,扩张组在此基础上,应用尿管球囊扩张环咽肌、冰水注入球囊刺激咽喉部.结果 扩张组留置胃管时间、住院时间显著短于对照组,吞咽功能康复疗效显著优于对照组(P＜0.05,P＜0.01).结论 对脑卒中后吞咽障碍患者早期采取尿管球囊扩张联合冰刺激干预,可促进脑卒中患者吞咽功能康复,缩短住院时间.     

Association of serum sclerostin level with mineral disorder and bone density in patients on maintenance hemodialysis

Objective To explore the relationship between serum sclerostin level, and mineral metabolism, bone density, abdominal aortic calcification in maintenance hemodialysis (MHD) patients. Methods Serum sclerostin levels from 175 cases of MHD patients were measured by ELISA. Calcaneus bone mineral density (BMD) was measured by quantitative ultrasound (QUS). The abdominal aortic calcification was detected by abdomen lateral plain radiographs. Interrelations among above parameters were examined statistically. Results The median sclerostin concentration of 175 patients was 160.50(100.67, 256.39) pmol/L. Serum sclerostin levels were correlated positively with age, BMI, serum calcium and serum 25(OH)-vitamin D, while negatively with spKt/v and serum iPTH. In multiple regression analysis, serum sclerostin levels were associated significantly and independently with age, sex, BMI and serum iPTH. Compared to patients with normal BMD (T score≥-1s), the patients with low BMD (T score<-1s) had lower serum sclerostin level [142.97(99.52, 226.02) vs 201.13(107.40, 327.84) pmol/L, P=0.035]. Serum sclerostin levels were correlated significantly and positively with calcaneus BMD. Multivariate logistic regression analysis showed that serum sclerostin level was an independent protective factor for low BMD in MHD patients[OR=0.241, 95%CI (0.078, 0.749), P=0.014]. Conclusions Serum sclerostin levels are associated with mineral disorder and bone density. Sclerostin may become a promising marker of bone turnover in MHD patients.