Improvements to conventional X-ray tube-based cone-beam computed tomography system

Conventional X-ray tube-based cone-beam computed tomography(CX-CBCT) systems have great potential in industrial applications. Such systems can rapidly obtain a three-dimensional(3D) image of an object.Conventional X-ray tubes fulfill the requirements for industrial applications, because of their high tube voltage and power. Continuous improvements have been made to CX-CBCT systems, such as imaging time shortening,acquisition strategy optimization, and imaging software development, etc. In this study, a CX-CBCT system is developed. Additionally, some improvements to the CX-CBCT system are proposed based on the hardware conditions of the X-ray tube and detector. A near-detector(ND)geometry condition is employed to obtain a sharper image and larger detection area. An improved acquisition strategy is proposed to simplify operations and reduce total imaging time. In the ND geometry condition, a simplified method called FBP slice stacking(SS-FBP) is proposed, which can be applied to 3D image reconstruction. SS-FBP is timesaving relative to traditional methods. Furthermore, imaging software for the CX-CBCT system is developed in the MATLAB environment. Several imaging experiments were performed. The results suggest that the CX-CBCT system works properly, and that the above improvements are feasible and practical.

Ab initio Structure Determination of [Co(NH_3)_5Br]Br_2 Using Conventional X-ray Powder Diffraction

The crystal structure of [Co(NH3)5Br]Br2 has been determined ab initio from the conventional X-ray powder diffraction data. The approximate structure with all 7 indeyendent non-H atoms was solved by direct methods. The final orthorhombic unit-cell parameters after Rietveld refinement are: a=13.6927, b=10.7071, c=6.9400A, V=1017.47A3, F30=93(0.0075,43), M20=49, Z=4. Space group is Pnma. The structure agreement factors are: Rp=0.066,Rwp=0.090, RF=0.041, RB=0.042.

Comparative study of conventional urosonography without contrast enhancement and x-ray voiding cystourethrography for diagnosis of vesicoureteral reflux in children

Background:Vesicoureteral reflux is the most common urinary congenital anomaly in children.Given the risk associated with radiation exposure there has been an increasing need for radiation-free method in the diagnosis and follow-up of the vesicoureteral reflux.The aim of our study is to compare conventional urosonography without contrast enhancement and x-ray voiding cystourethrography.Patients and Methods:Children with recurrent urinary tract infection with suspected vesicoureteral reflux were included to the study.Vesicoureteral reflux is demonstrated and graded by x-ray voiding cystourethrography.DMSA is used for the evaluation of renal scar.Conventional sonographic procedure was performed in all patients.Ureterovesical junction insertion angle was evaluated.The diameter and length of the ureterovesical junction were also measured.Results:268 children enrolled to the study.Vesicoureteral reflux was demonstrated in 62 children by x-ray voiding cystourethrography.Ureterovesical junction insertion angle measurement had a statistically significant relation for right and left vesicoureteral reflux presence(right:r:.646,p:.01 and left:r:.446,p:.01).Diagnosis sensitivity of vesicoureteral reflux with conventional ultrasonography is 95.10%and specificity is 81%(Youden’s index 76.1%)for the cutoff value of the ureterovesical junction insertion angle is 28.6 degrees.Positive predictive value is 87.2%,negative predictive value is 94.73%and diagnostic accuracy is 86.29%with conventional ultrasonography.Conclusions:Measurement of ureterovesical junction insertion angle,length and diameter by conventional urosonography is an easy accessible and cheap technique with high sensitivity and specificity for the diagnosis and followup of the vesicoureteral reflux without exposure to ionizing radiation.

Full-field mapping of internal strain distribution in red sandstone specimen under compression using digital volumetric speckle photography and X-ray computed tomography

It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional （3D） straindistribution inside a rock specimen. And yet it is crucial that this information is available for fully understandingthe failure mechanism of rocks or other geomaterials. In this study, by using the newlydeveloped digital volumetric speckle photography （DVSP） technique in conjunction with X-ray computedtomography （CT） and taking advantage of natural 3D speckles formed inside the rock due to materialimpurities and voids, we can probe the interior of a rock to map its deformation pattern under load andshed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimenunder increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fieldsare obtained in the specimen as a function of the load, from which both the volumetric and the deviatoricstrain fields are calculated. Strain localization zones which lead to the eventual failure of the rock areidentified. The results indicate that both shear and tension are contributing factors to the failuremechanism. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

常规超声、超声萤火虫技术与X线钼靶摄影对乳腺导管原位癌的诊断价值

目的探讨常规超声、超声萤火虫技术与X线钼靶摄影对乳腺导管原位癌(DCIS)的诊断价值。方法选取120例疑似DCIS患者,术前均行常规二维超声、超声萤火虫技术及X线钼靶摄影检查,以病理诊断结果为金标准,评估常规二维超声、超声萤火虫技术、X线钼靶摄影单独及三者联合检查对DCIS的诊断价值。Kappa检验评估上述三种检查方法诊断DCIS的结果与病理诊断结果的一致性。结果病理结果显示,120例患者均为单发病灶,DCIS 72例,恶性48例。常规二维超声、超声萤火虫技术、X线钼靶摄影联合检查诊断DCIS的结果与病理结果一致性极好(Kappa=0.810),高于三者单独检查(Kappa=0.192、0.362、0.390),且超声萤火虫技术、X线钼靶摄影诊断DCIS的结果与病理检查结果的一致性均高于常规二维超声。受试者工作特征(ROC)曲线显示,常规二维超声、超声萤火虫技术及X线钼靶摄影联合检查诊断DCIS的曲线下面积(AUC)为0.906(95%CI:0.844~0.969),分别高于单独常规二维超声、超声萤火虫技术及X线钼靶摄影的AUC,此时灵敏度、特异度、准确度分别为91.67%、89.58%、90.83%,三者联合检查诊断DCIS的价值高于各指标单独检查。结论常规二维超声、超声萤火虫技术和X线钼靶摄影联合检查诊断DCIS可以优势互补、取长补短,且操作方便,可为临床早期诊断DCIS提供可靠依据,值得临床推广应用。

Detonation driving rules for cylindrical casings under asymmetrical multipoint initiations

The detonation wave-aiming warhead can effectively enhance the lethality efficiency. In the past, rules for casing rupture and velocity distribution under asymmetrical initiations were not adequately investigated. In this study, X-ray photography and numerical modelling are used to examine the casing expansions under centre point, asymmetrical one-point, and asymmetrical two-point(with central angles of 45° and 90°) initiations. The results indicate that early casing ruptures are caused by local high pressures, induced by the initiation, detonation wave interaction, and Mach wave onset. The fragment shapes are controlled by the impact angle of the detonation wave. The fragment velocity distributions differ under different initiation types, and the end rarefaction waves can affect the velocity distribution.This study can serve as a reference for the design and optimization of high-efficiency warheads.

口腔数码摄影用于口腔修复的效果及对患者美学满意率的影响

目的分析口腔数码摄影用于口腔修复的效果及对患者美学满意率的影响。方法选取2018年6月至2021年6月苏州口腔医院木渎诊所收治的50例需行前牙美学修复患者作为研究对象,按照随机数字表法分为参考组与分析组,每组25例。参考组选择常规比色法完成美学修复处理,分析组选择口腔数码摄影完成美学修复处理,比较两组修复效果、美学满意率。结果分析组色泽、形态、整齐度、密合度、舒适度评分均高于参考组,差异有统计学意义(P<0.05);分析组美学满意率高于参考组,差异有统计学意义(P<0.05)。结论口腔数码摄影运用于口腔修复中的效果优于常规比色法,还能提升患者美学满意率。

DR在脊柱结核及其各种病变鉴别诊断中的应用价值

目的:探讨直接数字X线摄影(DR)在脊柱结核及其各种病变鉴别诊断中的应用价值。方法:收集我院2009年9月～2011年2月收治的疑似脊柱结核患者68例,均行DR及常规X线摄影检查,以手术病理结果为对照,比较2种检查方法对脊柱结核及其各种病变的显示率。结果:以手术病理结果为对照,DR对脊柱结核诊断的灵敏度、特异度和准确度分别为93.5%、54.5%、80.9%,传统平片的灵敏度、特异度和准确度分别为84.8%、40.9%、70.6%,DR对脊柱结核诊断的灵敏度、特异度和准确度均明显高于传统平片(P<0.05),且DR在显示椎体骨质破坏和椎旁脓肿的灵敏度、特异度也明显高于传统平片(P<0.05)。结论:DR较传统平片对脊柱结核及其各种病变诊断更具有临床应用价值,可以提早发现脊柱结核,减少致残。

数字化X线摄影在骨外伤诊断价值的分析

目的:分析数字化X线摄影在骨外伤诊断临床价值与应用。方法:选取本院2014年6-12月68例骨外伤病患临床资料,病患都采用数字化X线摄影与常规X线摄影检查,对数字化X线摄影诊断正确率进行总结,并分析数字化X线摄影诊断骨外伤漏诊原因。结果:摄片质量上,数字化X线摄影比常规X线胸片明显要高,检查结果上,数字化X线摄影诊断骨外伤检出率是97.06%,常规X线摄影诊断骨外伤检出率为76.47%。数字化X线摄影检出率比常规X线摄影明显要高,两组结果具备明显差异,具有统计学意义(P<0.05),都未出现任何不良反应。结论:在骨外伤诊断中,数字化X线摄影可以取得不错诊断效果,弥补了常规X线摄影不足,提供更为高效摄影质量,对病变可以清晰显示,提升诊断正确率,可作为骨外伤病患X线检查首选,为临床提供更为可靠诊断依据与价值信息,应当得到大力推广及应用。

三维路图在经颈静脉门体分流术中导引门静脉穿刺的应用价值

目的 比较经颈静脉门体分流术(TIPS)中三维路图和常规间接门静脉造影引导门静脉穿刺的效果。方法 回顾性分析2018年4月至2021年2月连续121例接受TIPS治疗患者临床资料。根据TIPS术中门静脉穿刺导引方式分为三维路图组(研究组,n=42)、常规间接门静脉造影组(对照组,n=79)。采用Mann-Whitney检验分析两组患者间技术/血流动力学成功率,门静脉穿刺次数、穿刺时间、X线透视剂量,成像辐射剂量及图像质量的差异;Kendall’s tau-b相关系数分析图像质量相关性。结果 两组患者基线差异均无统计学意义(P>0.05)。两组技术成功率和血流动力学成功率均为100%。两组门静脉穿刺针数、穿刺时间、透视剂量、穿刺相关并发症差异均无统计学意义(P=0.30、0.61、0.55、1.00)。研究组门静脉成像辐射剂量(63.1±23.3) Gy/cm2低于对照组(209.9±49.5) Gy/cm2(P>0.01)。研究组与对照组门静脉图像质量差异有统计学意义(P=0.04)。研究组(tau-b=0.79,P<0.01)、对照组(tau-b=0.71,P<0.01)图像质量,均与门静脉穿刺导引效果呈显著正相关。对照组图像质量与穿刺透视剂量呈负相关(tau-b=-0.2,P=0.02)。结论 三维路图和常规间接门静脉造影均能成功导引TIPS术中门静脉穿刺,但三维路图导引辐射剂量更低,可有效减少患者所受射线辐射。

DR与常规X线摄影在脊柱结核临床诊断中的应用及价值对比

目的:对比研究DR与常规X线摄影在脊柱结核临床诊断中的应用价值。方法:选取本院2011年3月-2014年9月收治的疑似脊柱结核患者55例,所有患者均在相同条件下,分别实施脊柱正侧位/正斜位常规X线摄影和DR诊断,分别对两种方式诊断脊柱结核的特征性表现进行观察和分析,将两种手段检查结果与患者的手术病理诊断结果进行比较,计算比较不同方法的诊断准确率、灵敏度、特异性。结果:经手术病理诊断可见,55例患者中,确定为脊柱结核的患者47例,诊断阳性率为85.45%。以病理诊断结果为依据,对常规X线摄影诊断和DR诊断结果进行比较,可见,常规X线摄影诊断的准确率、灵敏度和特异性分别为67.27%、74.47%、25.00%,DR诊断的准确率、灵敏度和特异性分别为90.91%、93.62%、75.00%,DR诊断结果均显著优于常规X线摄影,比较差异均有统计学意义(P<0.05)。DR诊断各种脊柱结核具体临床表现的检出率均明显优于常规X线摄影,比较差异均有统计学意义(P<0.05)。结论:DR检查是对X线诊断的升级,分辨率显著提高,在诊断脊柱结核的过程中,灵敏度和特异性大大提高,为早期脊柱结核的诊断提供可靠的依据,具有临床推广和应用价值,诊断准确率比较高,效果显著,值得临床大范围内应用和推广。

无人机遥感技术在河湖岸线监管中的应用

为提高河湖管理效率,针对无人机遥感技术观测范围广、获取空间信息速度快等优点,在分析无人机遥感技术工作原理基础上,根据河湖水域岸线监管不同需求,从目前无人机的多种监测方式入手,结合岸线监管应用,分析适用于河湖监管的3种监测方式。具体应用结果表明:1)低空摄影技术适合于小面积河湖岸线日常巡察,获取航拍照片。2)常规摄影测量技术是将外业获取的影像、POS、控制点数据,采用PhotoScan软件生成高分辨率正射影像和数字表面模型,结合GIS软件,快速生成一些专题图,适合于中小型涉水侵占行为监测。3)倾斜摄影测量技术适合于大型涉水建筑监测,对涉水建筑构建真三维模型,精准获取违建区域面积、侵占防洪库容等几何信息。无人机遥感技术用于河湖岸线监测,能够有效制止侵占岸线的行为,为河湖岸线安澜提供技术支撑。

COVID-19 Automatic Detection Using Deep Learning

The novel coronavirus disease 2019(COVID-19)is a pandemic disease that is currently affecting over 200 countries around the world and impacting billions of people.The first step to mitigate and control its spread is to identify and isolate the infected people.But,because of the lack of reverse transcription polymerase chain reaction(RT-CPR)tests,it is important to discover suspected COVID-19 cases as early as possible,such as by scan analysis and chest X-ray by radiologists.However,chest X-ray analysis is relatively time-consuming since it requires more than 15 minutes per case.In this paper,an automated novel detection model of COVID-19 cases is proposed to perform real-time detection of COVID-19 cases.The proposed model consists of three main stages:image segmentation using Harris Hawks optimizer,synthetic image augmentation using an enhanced Wasserstein And Auxiliary Classifier Generative Adversarial Network,and image classification using Conventional Neural Network.Raw chest X-ray images datasets are used to train and test the proposed model.Experiments demonstrate that the proposed model is very efficient in the automatic detection of COVID-19 positive cases.It achieved 99.4%accuracy,99.15%precision,99.35%recall,99.25%F-measure,and 98.5%specificity.

X线检查漏诊肩锁关节脱位原因分析

目的:分析X线检查漏诊肩锁关节脱位的原因。方法:2008年11月-2013年9月收治外伤后经X线检查诊断的肩锁关节脱位患者250例,回顾性分析影像学资料。结果:3例漏诊的肩锁关节全脱位患者均合并邻近部位骨折,医师观察不细致导致漏诊。10例半脱位患者由于采用手握负重物、未将负重物系于腕部而导致漏诊。14例半脱位患者由于投射体位为卧位而导致漏诊。4例半脱位患者由于医师观察不细致而导致漏诊。结论:X线检查诊断肩锁关节脱位方便、快捷、直接,是首选检查方法,但由于各种原因漏诊率较高,严格遵守检查适应证、规范操作、仔细阅片可降低漏诊率。

Life-history traits in insect inclusions associated with bamboo galls

We examined the life-history traits of insect inclusions in bamboo galls induced by the gall maker, Aiolomorphus rhopaloides Walker (Hymenoptera: Eurytomidae) in a bamboo stand. Eight hymenopteran and one dipteran species were detected using soft X-ray photography of the galls and insect emergence from the galls. Aiolomorphus rhopaloides was the gall maker and Diomorus aiolomorphi Kamijo (Torymidae) was its inquiline.Homoporusjaponicus Ashmead (Pteromalidae) and Eupelmus sp. (Eupelmidae) are likely to be primary parasitoids of the larva ofA. rhopaloides. Eurytoma sp. (Eurytomidae),Sycophila sp. (Eurytomidae) and Norbanus sp. (Pteromalidae) are thought to be facultative hyperparasitoids. Cecidomyiidae sp. is thought to be the inquiline ofA. rhopaloides galls.Leptacis sp. (Platygastridae) probably parasitizes the larvae of Cecidomyiidae sp. Larvae of A. rhopaloides appeared in galls in July with the percentage of larvae decreasing in September, before overwintering as pupae. The growth ofD. aiolomorphi larvae within galls may be faster than that ofA. rhopaloides. The percentage of parasitoids in galls was low in July, but increased until winter. Aiolomorphus rhopaloides and D. aiolomorphi emerged from mid-April to early May, and from late April to early June, respectively. From overwintering galls, six other hymenopteran species emerged between late May and late June; one dipteran Cecidomyiidae sp. emerged between mid-April and early May.