Initial Abdominal CT and Laboratory Findings Prior to Diagnosis of Crohn’s Disease in Children

PurposeTo identify initial abdominal computed tomography (CT) and laboratory findings prior to a diagnosis of Crohn’s disease (CD) in children.Materials and MethodsIn this retrospective study, patients (≤18 year-old) who were diagnosed with CD from 2004 to 2019 and had abdominal CT just prior to being diagnosed with CD were included in the CD group. Patients (≤18 years old) who were diagnosed with infectious enterocolitis from 2018 to 2019 and had undergone CT prior to being diagnosed with enterocolitis were included as a control group. We assessed the diagnostic performances of initial CT and laboratory findings for the diagnosis of CD using logistic regression and the area under the curve (AUC).ResultsIn total, 107 patients (50 CD patients, 57 control patients) were included, without an age difference between groups (median 13 years old vs. 11 years old, p=0.119). On univariate logistic regression analysis, multisegmental bowel involvement, mesenteric vessel engorgement, higher portal vein/aorta diameter ratio, longer liver longitudinal diameter, lower hemoglobin (≤12.5 g/dL), lower albumin (≤4 g/dL), and higher platelet (>320×10³/µL) levels were significant factors for CD. On multivariate analysis, multisegmental bowel involvement [odds ratio (OR) 111.6, 95% confidence interval (CI) 4.778–2605.925] and lower albumin levels (OR 0.9, 95% CI 0.891–0.993) were significant factors. When these two features were combined, the AUC value was 0.985 with a sensitivity of 96% and specificity of 100% for differentiating CD.ConclusionMultisegmental bowel involvement on CT and decreased albumin levels can help differentiate CD from infectious enterocolitis in children prior to a definite diagnosis of CD.     

Quasi-Static Compression Response of Carbon Fiber Reinforced 2.5D Woven Composites at Different Loading Directions

2.5D woven composites have been increasingly used in aerospace and military applications due to their excellent mechanical properties. In this research, 2.5D woven composites were produced, and their compression responses were investigated in different directions by compression experiments. XR-CT (X-ray computed tomography) technology was used to observe the microstructural damage profiles, and to analyze the failure mechanism of the material. The results show that when subjected to compression loads, the maximum load-bearing capacity of the material in the thickness direction was better than the maximum load-bearing capacity in the warp and weft directions. The compressive strength of the material in the warp and weft directions was lower than that in the thickness direction, and compression damage patterns in each direction also differed.     

X-ray Fluorescence Analysis of Pigments in Gothic Frescoes,Coats of Arms,and Polychromy on Sculptures on the Triforium in St. Vitus Cathedral on the Territory of the Czech Kingdom in the 14th Century

Pigments in the paints used for the coats of arms, polychromy on sculptures, and pigments in frescoes characterize not only the epoch but also individual creators or groups of artists involved in their creation. X-ray fluorescence analysis is a non-destructive method suitable for determining the chemical composition of these artifacts. This article covers the results of measurements of selected objects, and compares them with similar objects from the territory of the Czech Kingdom in the 14th century.     

Position-Sensitive Bulk and Surface Element Analysis of Decorated Porcelain Artifacts

Non-destructive characterization of decorated porcelain artifacts requires the joint use of surface-analytical methods for the decorative surface pattern and methods of high penetration depth for bulk-representative chemical composition. In this research, we used position-sensitive X-ray Fluorescence Spectrometry (XRF) and Prompt-gamma activation analysis (PGAA) for these purposes, assisted by 3D structured-light optical scanning and dual-energy X-ray radiography. The proper combination of the near-surface and bulk element composition data can shed light on raw material use and manufacturing technology of ceramics.     

Dynamic Interactions of Post Cleaved NS2B Cofactor and NS3 Protease Identified by Integrative Structural Approaches

Diseases caused by flaviviruses such as dengue virus (DENV) and West Nile Virus (WNV), are a serious threat to public health. The flavivirus single-stranded RNA genome is translated into a polyprotein which is cleaved into three structural proteins and seven non-structural proteins by the viral and cellular proteases. Non-structural (NS) protein 3 is a multifunctional protein that has N-terminal protease and C-terminal helicase domains. The NS3 protease requires co-factor NS2B for enzymatic activity and folding. Due to its essential role in viral replication, NS2B-NS3 protease is an attractive target for antiviral drugs. Despite the availability of crystal structures, dynamic interactions of the N- and C-termini of NS2B co-factor have been elusive due to their flexible fold. In this study, we employ integrative structural approaches combined with biochemical assays to elucidate the dynamic interactions of the flexible DENV4 NS2B and NS3 N- and C-termini. We captured the crystal structure of self-cleaved DENV4 NS2B₄₇NS3 protease in post cleavage state. The intermediate conformation adopted in the reported structure can be targeted by allosteric inhibitors. Comparison of our new findings from DENV4 against previously studied ZIKV NS2B-NS3 proteins reveals differences in NS2B-NS3 function between the two viruses. No inhibition of protease activity was observed for unlinked DENV NS2B-NS3 in presence of the cleavage site while ZIKV NS2B-NS3 cleavage inhibits protease activity. Another difference is that binding of the NS2B C-terminus to DENV4 eNS2B₄₇NS3Pro active site is mediated via interactions with P4-P6 residues while for ZIKV, the binding of NS2B C-terminus to active site is mediated by P1-P3 residues. The mapping of NS2B N- and C-termini with NS3 indicates that these intermolecular interactions occur mainly on the beta-barrel 2 of the NS3 protease domain. Our integrative approach enables a comprehensive understanding of the folding and dynamic interactions of DENV NS3 protease and its cofactor NS2B.     

CT检查在外伤性腰椎骨折中的诊断价值

目的:探讨外伤性腰椎骨折中采取CT检查的应用价值与优势.方法:本研究抽取2018年6月至2019年8月本院80例外伤性腰椎骨折患者作为研究对象,随机分组后,对照组采取X线检查,观察组采取CT检查,观察两组患者的诊断准确率、外伤性腰椎骨折评分.结果:X线片的准确率是72.50％(29/40),CT诊断准确率为95.00％...     

听骨链CT仿真内窥镜成像技术的临床应用价值

目的　探讨听骨链CT仿真内窥镜 (CTVE)成像技术的初步临床应用价值。方法　使用HiSpeedCT/i扫描机 ,层厚 1 0mm、螺距 1 0、骨算法、视野 9 6cm× 9.6cm、间隔 0 1mm重建 ,对 10例正常中耳和 2 1例临床怀疑中耳病变 (14例手术 )的患者进行CTVE成像。正常及异常中耳的观察阈值分别为 - 6 0 0～ - 2 0 0HU和 5 0～ 30 0HU。结果　CTVE能清楚显示正常听骨链的形态、大小及相互关系 ,锤骨、砧骨及锤砧关节的显示率为 10 0 % (38/38) ,镫骨底板的显示率为 32 % (12 /38) ,只有 2 1%(8/38)可以分辨镫骨的前、后脚 ;18例中耳炎患者中 12例胆脂瘤形成 ,CTVE上有不同程度的听小骨破坏。 1例中耳畸形显示听骨链发育异常。结论　CTVE是一种新的、非侵袭性的方法 ,能显示听骨链的立体影像 ,有利于听骨链病变的显示和诊断     

小体积肝动物模型的CT灌注成像研究

目的利用CT灌注成像(CTPI)技术观察小体积(SFS)肝动物模型的血流动力学变化以及降低门静脉灌注量(PVP)手术对其影响。材料与方法20只新西兰白兔分为两组,对照组(n=10)仅行扩大肝切除术建立SFS肝模型,调节组(n=10)行扩大肝切除术后加脾切除术以降低PVP,运用CTPI在术前术后分别测量两组动物的灌注参数,分析和比较灌注值的变化和预后。结果调节组术后7天生存率为40.0%,优于对照组的0.0%(P=0.020)。对照组术后PVP增加率为(193.7±55.1)%,与切除肝质量与体重比值(RLBWR)之间存在弱相关性(r=0.465,P=0.033),调节组术后PVP增加率为(101.4±32.5)%,与RLBWR之间无明显相关性(r=0.167,P=0.644)。术后PVP与血清谷草氨酸转氨酶、丙氨酸转氨酶和总胆红素均呈明显正相关(P值均<0.05)。结论运用CTPI可观察SFS肝的血流动力学变化特点和脾切除术对血流灌注的影响,降低PVP能改善SFS肝的预后。     

睾丸感染性和肿瘤性病变的CT表现及鉴别

目的 提高对睾丸感染性和肿瘤性病变的CT认识及诊断、鉴别诊断能力.方法 回顾性分析经病理证实的40例睾丸感染性和肿瘤性病变患者的临床和CT资料.结果 睾丸化脓性炎症8例,3例合并脓肿形成.CT表现为患侧睾丸明显肿大,实质内密度明显减低,增强扫描睾丸内坏死液化区无强化,周围包膜明显环形强化,同时累及附睾和周围皮肤软组织.睾丸结核7例,2例合并结核性脓肿形成.CT表现为患侧睾丸肿大,形态不规则,实质密度不均,可见结节及坏死区,增强扫描实性结节持续明显强化,合并脓肿者可见多发环状厚壁强化,与附睾及阴囊隔粘连、分界不清.睾丸肿瘤25例,精原细胞瘤(13例)CT表现为患侧睾丸稍低密度的均匀或不均匀密度肿块影,轻中度持续强化,散在少许坏死;淋巴瘤(4例)表现为边界清楚的类圆形睾丸肿块,密度均匀,呈中度均匀强化;另有腺泡状横纹肌肉瘤2例,畸胎瘤1例,表皮样囊肿1例,内胚窦瘤2例,胚胎性癌1例,神经内分泌癌1例.结论 睾丸感染性病变(化脓性炎症、结核)和肿瘤性病变的CT表现具有一定的特征性,结合临床表现如发病时间、年龄、血清肿瘤标志物等有助于正确诊断和鉴别.     

PET／CT代谢体积对进展期肠型胃癌新辅助化疗疗效的价值

目的探讨基于肿瘤^18F-FDG摄取的MTV在肠型胃癌新辅助化疗（NAC）疗效评价中的应用价值。方法回顾性分析NAC前后均行^18F-FDGPET／CT检查的41例肠型胃癌患者（男28例,女13例）,根据术后病理分级分为有效组和无效组。对化疗前后的原发灶SUVmax减少率、MTV减少率与病理分级的关系进行Spearman分析,利用ROC曲线分析比较MTV减少率、SUVmax减少率预测病理学反应的效能。同时以术后病理为“金标准”,利用x^2检验比较以传统影像学为基础的实体瘤疗效评价标准（RECIST）1．0与PET／CTMTV减少率预测NAC后病理学反应的准确性。结果41例患者中,有效组20例,无效组21例。化疗前后SUVmax减少率、MTV减少率与病理分级的r分别为0．434和0．763（均P〈0．01）,预测病理学反应的AUC分别为0．789和0．943,差异有统计学意义（Z=2．114,P〈0．05）。以MTV减少率49．4％为评价化疗有效的阈值,其预测病理学反应灵敏度为90．0％（18／20）,特异性为90．5％（19／21）,准确性高于RECIST1．0[90．2％（37／41）和80．5％（33／41）;x^2=7．14,P〈0．05]。结论在FDG摄取的胃癌患者中,^18F-FDGPET／CT可用于NAC治疗反应的评价。MTV可作为评价治疗反应有效性的重要指标。