Can optical diagnosis of small colon polyps be accurate? Comparing standard scope without narrow banding to high definition scope with narrow banding

AIM: To study the accuracy of using high definition(HD) scope with narrow band imaging(NBI) vs standard white light colonoscope without NBI(ST), to predict the histology of the colon polyps, particularly those < 1 cm.METHODS: A total of 147 African Americans patients who were referred to Howard University Hospital for screening or, diagnostic or follow up colonoscopy, during a 12-mo period in 2012 were prospectively recruited. Some patients had multiple polyps and total number of polyps was 179. Their colonoscopies were performed by 3 experienced endoscopists who determined the size and stated whether the polyps being removed were hyperplastic or adenomatous polyps using standard colonoscopes or high definition colonoscopes with NBI. The histopathologic diagnosis was reported by pathologists as part of routine care. RESULTS: Of participants in the study, 55(37%) were male and median(interquartile range) of age was 56(19-80). Demographic, clinical characteristics, past medical history of patients, and the data obtained by two instruments were not significantly different and two methods detected similar number of polyps. In ST scope 89% of polyps were < 1 cm vs 87% in HD scope(P = 0.7). The ST scope had a positive predictive value(PPV) and positive likelihood ratio(PLR) of 86% and 4.0 for adenoma compared to 74% and 2.6 for HD scope. There was a trend of higher sensitivity for HD scope(68%) compare to ST scope(53%) with almost the same specificity. The ST scope had a PPV and PLR of 38% and 1.8 for hyperplastic polyp(HPP) compared to 42% and 2.2 for HD scope. The sensitivity and specificity of two instruments for HPP diagnosis were similar.CONCLUSION: Our results indicated that HD scope was more sensitive in diagnosis of adenoma than ST scope. Clinical diagnosis of HPP with either scope is less accurate compared to adenoma. Colonoscopy diagnosis is not yet fully matched with pathologic diagnosis of colon polyp. However with the advancement of both imaging and training, it may be possible to increase the sensitivity and specificity of the scopes and hence save money for eliminating time and the cost of Immunohistochemistry/pathology.

Role of high definition colonoscopy in colorectal adenomatous polyp detection

AIM:To investigate the rates of polyp detection in a mixed risk population using standard definition (SDC) vs high definition colonoscopes (HDC).METHODS:This was a retrospective cohort comparative study of 3 colonoscopists who each consecutively performed 150 SDC (307,200 pixel) and 150 HDC (792,576 pixels) in a community teaching hospital.RESULTS:A total of 900 colonoscopies were evaluated (mean age 56,46.8% men),450 with each resolution.Polyps of any type were detected in 46.0% of patients using SDC and 43.3% with HDC (P=0.42).There was no significant difference between the overall number of polyps,HDC (397) and SDC (410),detected among all patients examined,(P=0.73).One or more adenomatous polyps were detected in 24.2% of patients with HDC and 24.9% of patients with SDC colonoscopy (P=0.82).There was no significant difference between HDC (M=0.41) and SDC (M=0.42) regarding adenomatous polyp (P=0.88) or advanced adenoma (P=0.56) detection rate among all patients examined.CONCLUSION:HDC did not improve yield of adenomatous polyp,advanced adenoma or overall polyp detection in a population of individuals with mixed risk for colorectal cancer.

Multicenter randomised controlled trial comparing the high definition white light endoscopy and the bright narrow band imaging for colon polyps

AIM To compare high definition white light endoscopy and bright narrow band imaging for colon polyps' detection rates. METHODS Patients were randomised to high definition white light endoscopy(HD-WLE) or the bright narrow band imaging(b NBI) during withdrawal of the colonoscope. Polyps identified in either mode were characterised using b NBI with dual focus(b NBI-DF) according to the Sano's classification. The primary outcome was to compare adenoma detection rates(ADRs) between the two arms. The secondary outcome was to assess the negative predictive value(NPV) in differentiating adenomas from hyperplastic polyps for diminutive rectosigmoid lesions.RESULTS A total of 1006 patients were randomised to HD-WLE(n = 511) or b NBI(n = 495). The mean of adenoma per patient was 1.62 and 1.84, respectively. The ADRs in b NBI and HD-WLE group were 37.4% and 39.3%, respectively. When adjusted for withdrawal time(OR = 1.19, 95%CI: 1.15-1.24, P < 0.001), the use of b NBI was associated with a reduced ADR(OR = 0.69, 95%CI: 0.52-0.92). Nine hundred and thirty three polyps(86%) in both arms were predicted with high confidence. The sensitivity(Sn), specificity(Sp), positive predictive value and NPV in differentiating adenomatous from non-adenomatous polyps of all sizes were 95.9%, 87.2%, 94.0% and 91.1% respectively. The NPV in differentiating an adenoma from hyperplastic polyp using b NBI-DF for diminutive rectal polyps was 91.0%.CONCLUSION ADRs did not differ between b NBI and HD-WLE, however HD-WLE had higher ADR after adjustment of withdrawal time. b NBI surpassed the PIVI threshold for diminutive polyps.

Improving sessile serrated adenoma detection rates with high definition colonoscopy:A retrospective study

BACKGROUND Sessile serrated adenomas(SSAs)are important premalignant lesions that are difficult to detect during colonoscopy due to poor definition,concealment by mucous caps,and flat appearance.High definition(HD)colonoscopy may uniquely aid in the detection of these inconspicuous lesions compared to standard definition(SD)colonoscopes.In the absence of existing clinical guidelines to obligate the use of HD colonoscopy for colorectal cancer screening in average-risk patients,demonstrating the benefit of HD colonoscopy on SSA detection rate(SSADR)may help strengthen the evidence to recommend its use in all settings.AIM To evaluate the benefit of HD colonoscopy compared to SD colonoscopy on SSADR in average-risk patients undergoing screening colonoscopy.METHODS Data from screening colonoscopies for patients aged 50-76 years two years before and two years after the transition from SD colonoscopy to HD colonoscopy at our large,academic teaching center were collected.Patients with symptoms of colorectal disease,positive occult blood test,history of colon polyps,cancer,polyposis syndrome,inflammatory bowel disease or family history of colon cancer or polyps were excluded.Patients whose endoscopists did not perform colonoscopies both before and after scope definition change were also excluded.Differences in individual endoscopist SSADR,average SSADR,and overall SSADR with SD colonoscopy vs HD colonoscopy were also evaluated for significance.RESULTS A total of 3657 colonoscopies met eligibility criteria with 2012 colonoscopies from the SD colonoscopy period and 1645 colonoscopies from the HD colonoscopy period from a pool of 11 endoscopists.Statistically significant improvements of 2.30%in mean SSADR and 2.53%in overall SSADR were noted with HD colonoscopy(P=0.00028 and P=0.00849,respectively).On the individual level,three endoscopists experienced statistically significant benefit with HD colonoscopy(+5.74%,P=0.0056;+4.50%,P=0.0278;+4.84%,P=0.03486).CONCLUSION Our study suggests that HD colonoscopy statistically significantly improves sessile serrated adenoma detection rate in the screening of average risk patients during screening colonoscopy.By improving the detection and removal of these lesions,adoption of HD colonoscopy may reduce the significant premalignant burden of sessile serrated adenomas.

ZTE IPTV Low Bit Rate High Definition Transcoding Solution Nominated for Global IPTV Industry Award

ZTE Corporation announced on 1 March that its innovative IPTVlowbitrate highdefinition transcoding solution has been nominated for the World＇s Best Component or Enabler Award by the IPTV World Forum. The ZTE solution is on display at the Mobile World Congress 2012 （MWC 2012） in Barcelona.

Optical diagnosis of colorectal polyps using high-definition i-scan: An educational experience

AIM:To examine performances regarding prediction of polyp histology using high-definition (HD) i-scan in a group of endoscopists with varying levels of experience. METHODS:We used a digital library of HD i-scan still images, comprising twin pictures (surface enhancement and tone enhancement), collected at our university hospital. We defined endoscopic features of adenomatous and non-adenomatous polyps, according to the following parameters:color, surface pattern and vascular pattern. We familiarized the participating endoscopists on optical diagnosis of colorectal polyps using a 20-min didactic training session. All endoscopists were asked to evaluate an image set of 50 colorectal polyps with regard to polyp histology. We classified the diagnoses into high confidence (i.e., cases in which the endoscopist could assign a diagnosis with certainty) and low confidence diagnoses (i.e., cases in which the endoscopist preferred to send the polyp for formal histology). Mean sensitivity, specificity and accuracy per endoscopist/image were computed and differences between groups tested using independent-samples t tests. High vs low confidence diagnoses were compared using the pairedsamples t test. RESULTS:Eleven endoscopists without previous experience on optical diagnosis evaluated a total of 550 images (396 adenomatous, 154 non-adenomatous). Mean sensitivity, specificity and accuracy for diagnosing adenomas were 79.3%, 85.7% and 81.1%, respectively. No significant differences were found between gastroenterologists and trainees regarding performances of optical diagnosis (mean accuracy 78.0%vs 82.9%,P = 0.098). Diminutive lesions were predicted with a lower mean accuracy as compared to non-diminutive lesions (74.2% vs 93.1%, P = 0.008). A total of 446 (81.1%) diagnoses were made with high confidence. High confidence diagnoses corresponded to a significantly higher mean accuracy than low confidence diagnoses (84.0% vs 64.3%, P = 0.008). A total of 319 (58.0%) images were evaluated as having excellent quality. Considering excellent quality images in conjunction with high confidence diagnosis, overall accuracy increased to 92.8%. CONCLUSION:After a single training session, endoscopists with varying levels of experience can already provide optical diagnosis with an accuracy of 84.0%.

A Reliable Adaptive High-Definition Transmission System for Distance Learning

There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.

HIGH-EFFICIENCY CODING FOR PAL COLOR TELEVISION SIGNAL

Proceeding from the specific characteristics of PAL television signals adopted in China this paper points out that if the fs = 2fsc of sub-Nyquist sampling and DPCM encoding is used for PAL complete signal and if the blanking time is utilized to transmit code of effective area, it is possible to transmit a color TV signal over PCM three-group channel.

Prevalence of metabolic syndrome in type 2 diabetic patients: A comparative study using WHO, NCEP ATP III, IDF and Harmonized definitions

To determine the prevalence of metabolic syndrome (MetS) in Malaysian type 2 diabetic patients using WHO, NCEP ATP III, IDF and the new Harmonized definitions, and the concordance between these definitions. This study involved 313 patients diagnosed with type 2 diabetes mellitus (T2DM) at two Malaysian tertiary hospitals. Socio-demographic data were assessed using a pre-tested interviewer-administered structured questionnaire. Anthropometric measurements were carried out according to standard protocols. Clinical and laboratory characteristics were examined. Kappa (k) statistics were used for the agreement between the four MetS definitions. The overall prevalence rates of MetS (95% CI) were 95.8% (93.6-98.1), 96.1% (94.0-98.3), 84.8% (80.8-88.9) and 97.7% (96.1-99.4) according to the WHO, NCEP ATP III, IDF and the Harmonized definitions, respectively. The Kappa statistics demonstrated a slight to substantial agreement between the definitions (k = 0.179-0.875, p k = 0.875, p hest specificity (100%) in identifying MetS. In conclusion, the new Harmonized criteria established the highest prevalence of MetS among the four definitions applied. There was a very good concordance between the WHO and NCEP ATP III criteria. The extremely high prevalence of MetS observed in type 2 diabetic patients indicates an impending pandemic of CVD risk in Malaysia. Aggressive treatment of MetS components is required to reduce cardiovascular risk in T2DM.

高分辨CT扫描结合迭代重建技术在冠状动脉支架评估中的应用

目的探讨高分辨CT(HDCT)扫描结合迭代重建技术在冠状动脉支架血管评估中的价值。方法收集亳州市人民医院2020年8月至2022年12月经皮冠状动脉介入术后行冠状动脉血管造影(CCTA)检查病人61例。根据不同重建方法(Stand+ASiR-V:0%、Stand+ASiR-V:50%、HD Stand+ASiR-V:0%、HD Stand+ASiR-V:50%)重建出A、B、C、D四组图像。分别测量四组图像主动脉、心包脂肪、支架管腔内CT值、SD值(CT_(主)、SD_(主)、CT_(脂)、SD_(脂)、CT_(支)、SD_(支))、支架可视内径,计算CT_(差)、SNR_(主)、CNR_(主)、SNR_(支)、CNR_(支),评估图像主观质量评分,并进行统计学分析。结果A、B组CT_(支)(569.06±85.05、561.51±79.74比506.37±78.45、507.39±69.25)、CT_(差)(30.31±78.59、20.75±79.78比−32.83±74.98、−29.88±73.33)高于C、D组,支架可视内径低于C、D组[(1.85±0.46)mm、(1.89±0.41)mm比(2.15±0.43)mm、(2.14±0.45)mm],差异有统计学意义(P<0.05);A、B两组间及C、D两组间CT_(支)、CT_(差)值差异无统计学意义(P>0.05)。四组间CNR_(支)、SNR_(主)、CNR_(主)均为B组最高,A、D组次之,C组最低,差异有统计学意义(P<0.05)。支架可视内径对CT_(支)、SNR_(支)、CNR_(支)有负面影响,对SD支有正面影响,差异有统计学意义(P<0.05)。图像主观质量评分为D组最高,C组次之,A、B组最低,差异有统计学意义(P<0.001)。结论HDCT扫描能提高支架管腔清晰度,结合迭代重建技术能有效减低图像噪声,提高图像质量,有利于更准确评估冠状动脉支架血管情况。

融合高精度地图的多激光雷达路侧智能感知方法

在车路协同路侧感知研究中,由于点云数据量庞大且存在着不可避免的目标遮挡情况,导致检测效率低、目标轨迹不稳定和跟踪精度低的问题。针对上述问题,提出了1种融合高精度地图的多激光雷达路侧智能感知方法,通过融合高精度地图信息,提高感知结果的准确性和可靠性。该方法分为3个部分:①通过多激光雷达的标定结果,利用高精度地图完成三维点云区域中感兴趣区域的提取,从而有效减少待处理点云的数量,提升计算效率;②基于极化图高斯混合背景模型的背景建模方法,利用极化图完成运动目标快速检测,避免大规模激光点云的直接处理,有效提升检测效率;③利用车辆航向与车道线方向一致性约束,将高精度地图中的车道方向转化为卡尔曼滤波框架下的车辆状态线性约束,改善车辆检测与轨迹跟踪的性能。实验中,分别在仿真交叉路口与实车实验道路双T形路口对算法与模型进行测试验证。相比于其他方法,所提出的方法数据量减少了55%,目标检测准确率提高了12%,耗时减少了56%,目标跟踪的误差极值、误差均值以及均方根误差均有所降低。实验结果表明:所提的方法能有效融合高精度地图信息,在大范围道路场景下实现对道路运动目标的快速检测与稳定跟踪。

中国式现代化建设中影视剧的传播实践与集体应答

近年的影视作品深入参与中国式现代化发展,对其进行了立体的阐释、宣传和推动。一大批优秀的影视剧集体行动,从国家站位和叙事到百姓视角和交流,从发现问题、正视问题到解决问题、激励引导,肩负起了对中国式现代化的“特别报道”“深度报道”“系列报道”“对外报道”。这些优秀作品实现了对中国式现代化五大特征的全覆盖传播,并具有整体—局部—个体的空间层次、历史—当下—未来的时间层次、你—我—他共同奋斗的主体层次。但现有作品在对外传播、传播领域、传播系统等方面仍存在不足,需要在新质生产力发展理念下积极改善。

量化参数对H.266压缩标准4K视频质量影响实验

多功能视频编解码方式(H.266/VVC)在每一个编码环节上都采取了多项改进措施,诸多措施的总体效果使其编码效率比高效视频编码方式(HEVC)提高了一倍。该文对几种动态情况各异的视频序列(*.yuv)采用H.266编解码器进行压缩和解压,通过改变量化参数(QP)取值,研究在不同比特率条件下,视频压缩后编码效率和时间损耗的差异。实验表明,对于较低的比特率和4K视频常用的比特率(20 Mbps)附近,在编码效率和峰值信噪比上都有着很大的优势,但在超大比特率的情况下,两者表现近乎相同。对时间倍数和码率节省进行计算后发现,每个视频序列的结果差距较大,说明编码复杂度和编码性能与选取的视频序列本身有很大关系。H.266对复杂度较高的视频序列提升明显,编码复杂度有了显著提升,在某些比特率的情况下甚至可达到100倍之多,H.266同时对硬件的算力带来了很大挑战,需要在之后进行进一步优化。

地理信息智能技术发展分析

进入21世纪,智能化成为科技革命发展的主要方向,大数据、物联网、云计算和人工智能等技术更与各行各业加速融合,一个领域如果缺乏对智能的认知和实践,未来可能会在发展中没有足够动力。地理信息是时空框架的描述者、建立者与服务者,在多领域信息融合、无人化导航服务中,发挥着重要作用。本文从系统理论、高精度时空基准、全域感知、智能处理、高清刻画表达、智慧服务6个方面,梳理了地理信息相关智能技术,对比了国内外发展现状与差距,总结竞争发展的焦点,为地理信息领域智能化发展提供参考和借鉴。

以社会共治促进预制菜产业健康发展的策略研究

首先解读了预制菜的最新定义和范围,梳理了国外预制食品产业发展的历史和经验,从中汲取了其对于我国预制菜发展的启示和教训。随后分析了国内预制菜产业发展面临的问题及优势,展望了预制菜产业的未来发展趋势,发现预制菜产业的健康发展不仅仅需要依靠政府推动,还离不开市场的自发行为、群众对预制菜的科学认知以及社会媒体的正确引导。由此,紧跟预制菜前沿动态,立足于国内预制菜产业的实际发展状况,提出了以社会共治促进预制菜产业健康发展的策略,为我国预制菜产业高质量发展提供了思路和参考。

面向车-路-图协同的分布式自动驾驶仿真平台架构及应用

为解决车路图协同仿真环境下的单机式测试平台效率低下、系统可扩展性不足的问题,本文提出了一种面向车-路-图协同的分布式自动驾驶仿真平台架构,并将该平台命名为VIMS(vehicle-infrastructure-map system)。VIMS平台以CARLA作为虚拟仿真引擎,通过引入真实高精地图,接入驾驶模拟器、信号机等硬件在环设备,形成了虚实结合的交通场景;考虑功能的交互作用,VIMS平台分为主世界、智能车、智能路侧和高精地图4个模块,采用ROS分布式架构实现模块内部的相对独立和模块间的互联互通;考虑到平台的计算可靠性与可用性,采用分布式计算实现4个模块间的独立计算。通过车道保持和车路图协同定位算法为例进行应用验证,通过平台实现了数据采集、传输和算法的验证测试与评价,结果表明,本文所提出的平台可以实现车、路、图协作的实时仿真,保证模块的有机运行,系统架构可扩展性高。

高清晰度血流成像检测胎儿大脑中动脉M1段不同位置收缩期参数对子痫前期胎儿窘迫的预测价值

目的:探究高清晰度血流成像(high definition flow imaging,HD-Flow)检测胎儿大脑中动脉(middle cerebral artery,MCA)M1段不同位置收缩期参数对子痫前期(preeclampsia,PE)胎儿窘迫(fetal distress,FD)的预测价值。方法:选取2019年6月—2023年6月在河北医科大学第一医院行HD-Flow检测的PE患者120例为研究对象,根据是否发生FD分为未发生FD(NFD)组(n=64)和FD组(n=56),对比分析2组患者临床资料以及M1段远端和M1段近中1/3处收缩期参数。LASSO逻辑回归分析模型筛选发生FD的潜在因素,Logistic多因素回归分析影响FD发生的危险因素。构建发生FD的风险预测模型并验证。分析各指标对发生FD的预测能力。绘制受试者工作特征(receiver operating characteristic,ROC)曲线并计算曲线下面积(area under the curve,AUC),分析不同位置收缩期参数对发生FD的预测价值。结果:LASSO回归分析筛选出15个预测因子,Logistic分析结果显示,胎龄、宫内感染、妊娠期糖尿病、二氧化碳分压(PCO_(2))、M1段远端和近中1/3处的阻力指数(resistance index,RI)、搏动指数(pulsatility index,PI)、收缩期峰值流速(peak systolic velocity,PSV)和收缩期峰值流速与舒张末期流速比值(peak systolic velocity/end diastolic velocity,S/D)均是发生FD的独立危险因素。所构建预测模型ROC曲线验证前后的AUC分别为0.801(95%CI:0.696~0.845)和0.785(95%CI:0.688~0.829),说明模型区分度好,准确度高。胎龄、宫内感染、妊娠期糖尿病和PCO_(2)指标联合MCA中M1段远端和近中1/3处的收缩期参数的预测能力最优。M1段不同位置的收缩期参数有不同程度的预测价值,其中远端RI、近中1/3处RI和S/D的AUC分别为0.926(95%CI:0.992~0.826)、0.904(95%CI:0.979~0.785)和0.917(95%CI:0.984~0.807)。结论:胎儿MCA中M1段不同位置的收缩期参数均能在一定程度上预测FD的发生,其中M1段远端RI、M1段近中1/3处的RI和S/D的预测性能较高,构建的FD风险预测模型能较准确地预测PE患者发生FD的风险,以对其采取针对性干预措施。

高精度地图众源更新地理信息安全问题浅析

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