Diffusion kurtosis imaging of microstructural changes in brain tissue affected by acute ischemic stroke in different locations

The location of an acute ischemic stroke is associated with its prognosis. The widely used Gaussian model-based parameter, apparent diffusion coefficient(ADC), cannot reveal microstructural changes in different locations or the degree of infarction. This prospective observational study was reviewed and approved by the Institutional Review Board of Xiamen Second Hospital, China(approval No. 2014002).Diffusion kurtosis imaging(DKI) was used to detect 199 lesions in 156 patients with acute ischemic stroke(61 males and 95 females), mean age 63.15 ± 12.34 years. A total of 199 lesions were located in the periventricular white matter(n = 52), corpus callosum(n = 14), cerebellum(n = 29), basal ganglia and thalamus(n = 21), brainstem(n = 21) and gray-white matter junctions(n = 62). Percentage changes of apparent diffusion coefficient(ΔADC) and DKI-derived indices(fractional anisotropy [ΔFA], mean diffusivity [ΔMD], axial diffusivity [ΔD_a], radial diffusivity ΔDr, mean kurtosis [ΔMK], axial kurtosis [ΔK_a], and radial kurtosis [ΔK_r]) of each lesion were computed relative to the normal contralateral region. The results showed that(1) there was no significant difference in ΔADC, ΔMD, ΔD_a or ΔD_r among almost all locations.(2) There was significant difference in ΔMK among almost all locations(except basal ganglia and thalamus vs. brain stem; basal ganglia and thalamus vs. gray-white matter junctions; and brainstem vs. gray-white matter junctions.(3) The degree of change in diffusional kurtosis in descending order was as follows: corpus callosum > periventricular white matter > brainstem > gray-white matter junctions > basal ganglia and thalamus > cerebellum. In conclusion, DKI could reveal the differences in microstructure changes among various locations affected by acute ischemic stroke, and performed better than diffusivity among all groups.

Diversity shifts of rumen bacteria induced by dietary forages in dairy cows and quantification of the changed bacteria using a new primer design strategy

The partial 16 S r RNA gene sequences（100 to 500 bp） were widely used to reveal rumen bacterial composition influenced by diets, while quantification of the changed uncultured bacteria was inconvenient due to difficult designing of specific primers based on short sequences. This study evaluated the effect of forage resources on rumen bacterial diversity and developed new strategy for primer design based on short sequences to quantify the changed uncultured bacteria. Denaturing gradient gel electrophoresis（DGGE） analysis and subsequent band sequencing were used to reveal the distinct rumen bacteria composition in cows fed with two forage sources（single corn stover vs. mixed forages including alfalfa hay and corn silage）. The bacterial diversity in the rumen of dairy cows fed with corn stover was lower than that with mixed forages（P0.05）. The bacterium named R-UB affiliating to uncultured Succinivibrionaceae was identified, and it was abundant in the rumen of cows fed with mixed forages compared to corn stover. The full length 16 S r RNA gene sequences with identity of 97% to the R-UB 16 S r RNA gene sequence were obtained from Gen Bank and used to design specific primers to quantify uncultured bacterium R-UB. All sequences of amplicon from the new primers were of 100% identity to R-UB sequences indicating the high specificity of new primers. Quantitative PCR confirmed that abundance of R-UB in the rumen of cows fed with corn stover was lower than those fed with mixed forages（P0.01）. New strategy for designing primers based on partial 16 S r RNA genes to quantify targeted uncultured bacteria was successfully developed. The rumen bacteria descending significantly in the cows fed corn stover compared to those fed mixed forages was identified as uncultured R-UB from Succinivibrionaceae.

Anti-tumor necrosis factor α therapy associates to type 17 helper T lymphocytes immunological shift and significant microbial changes in dextran sodium sulphate colitis

BACKGROUND Anti-tumor necrosis factor α(TNFα) represents the best therapeutic option to induce mucosal healing and clinical remission in patients with moderate-severe ulcerative colitis. On the other side gut microbiota plays a crucial role in pathogenesis of ulcerative colitis but few information exists on how microbiota changes following anti-TNFα therapy and on microbiota role in mucosal healing.AIM To elucidate whether gut microbiota and immune system changes appear following anti TNFα therapy during dextran sulfate sodium(DSS) colitis.METHODS Eighty C57 BL/6 mice were divided into four groups: "No DSS", "No DSS + antiTNFα", "DSS" and "DSS + anti-TNFα". "DSS" and "DSS + anti-TNFα" were treated for 5 d with 3% DSS. At day 3, mice whithin "No DSS+anti-TNFα" and"DSS+anti-TNFα" group received 5 mg/kg of an anti-TNFα agent. Forty mice were sacrificed at day 5, forty at day 12, after one week of recovery post DSS. The severity of colitis was assessed by a clinical score(Disease Activity Index), colon length and histology. Bacteria such as Bacteroides, Clostridiaceae, Enterococcaceae and Fecalibacterium prausnitzii(F. prausnitzii) were evaluated by quantitative PCR.Type 1 helper T lymphocytes(Th1), type 17 helper T lymphocytes(Th17) and CD4+ regulatory T lymphocytes(Treg) distributions in the mesenteric lymph node(MLN) were studied by flow cytometry.RESULTS Bacteria associated with a healthy state(i.e., such as Bacteroides, Clostridiaceae and F. prausnitzii) decreased during colitis and increased in course of anti-TNFαtreatment. Conversely, microorganisms belonging to Enterococcaceae genera,which are linked to inflammatory processes, showed an opposite trend.Furthermore, in colitic mice treated with anti-TNFα microbial changes were associated with an initial increase(day 5 of the colitis) in Treg cells and a consequent decrease(day 12 post DSS) in Th1 and Th17 frequency cells. Healthy mice treated with anti-TNFα showed the same histological, microbial and immune features of untreated colitic mice. "No DSS + anti-TNFα" group showed a lymphomononuclear infiltrate both at 5 th and 12 th d at hematoxylin and eosin staining, an increase of in Th1 and Th17 frequency at day 12, an increase of Enterococcaceae at day 5, a decrease of Bacteroides and Clostridiaceae at day 12.CONCLUSION Anti-TNFα treatment in experimental model of colitis improves disease activity but it is associated to an increase in Th17 pathway together with gut microbiota alteration.

Interconnections between governance and socioeconomic conditions:Understanding the challenges in sub-Saharan Africa

Given that challenges on the issue of socioeconomic development faced by countries in sub-Saharan Africa(SSA)have been identified as critical to strengthening the inherent link between governance and socioeconomic conditions,this study examines the interconnections between governance and socioeconomic conditions in SSA.With a focus on 25 countries in SSA between 2005 and 2019,we conduct the analysis based on the Panel-Corrected Standard Error and System Generalized Method of Moments estimations and panel causality tests.The results show that SSA does not seem to have the means of effective governance to spur improved socioeconomic conditions.Moreover,the pervasiveness of institutional problems in many countries of SSA has been responsible for the poor socioeconomic conditions in the region.Likewise,governance quality and socioeconomic conditions are found to influence each other.An improvement in socioeconomic conditions could result in better governance quality.On the other hand,governance quality is viewed as a vital ingredient in achieving needed socioeconomic development outcomes.Thus,it is suggested that there is a need for countries in SSA to streamline governing systems toward engendering improved well-being.The introduction and implementation of transformative policies through effective governance are also necessary for ensuring critical structural changes and increasing social service provision.Overall,there should be a proactive identification of ineffective policies and procedures by policymakers to enhance meaningful impacts in the region.

Early Cretaceous Climate Changes Recorded in Magnetic Susceptibility and Color Index Variations of the Lower Liupanshan Group, Central China

This study carried out comprehensive analysis on sedimentology, magnetic susceptibility （7of） and color data of the continental sediments of the Liupanshan Group in Central China so as to obtain climatic change information during the 129.14-122.98 Ma interval. Based on the results of the Xlf and of the redness （a＊）, the section can be divided into two segments： （1） 129.14-126.3 Ma, with the lowest Xlf values and strongly variable relatively high values of redness and （2） 126.3-122.98 Ma, with high Elf values and relatively low redness. Analysis of the lithology and facies as well as the magnetic minerals and their contents points to a detrital origin of the magnetic minerals and this allow us to interpret the relationship between magnetic susceptibility variations and climate changes. Our study shows that the climate was significantly dry and hot during the whole studied interval although the interval between 126.3 Ma and 122.98 was a little bit cooler with increased humidity.

Military medical research on internal diseases in modern warfare:new concepts,demands,challenges,and opportunities

Battlefield internal medicine aims at the treatment of combatants and noncombatants with various internal diseases on the battlefield.The military medical research on battlefield internal diseases focuses on the pathogenesis,clinical management,and prevention of internal diseases under military war conditions.In both wartime and peacetime,the soldiers suffer from more internal diseases than surgical wounds.With the introduction of high-tech weapons,including chemical,physical,and biological agents,a large number of special internal illnesses and casualties will appear in future wars.The battles often occur in special environments,such as high or low temperatures,plateau or polar areas,and micro-or hyper-gravity.The current theories of battlefield internal medicine are mainly derived from wars decades ago and cannot meet the needs of military medical support under the conditions of modern warfare.Therefore,the military medical research on battlefield internal medicine should be based on contemporary military situations,focus on the purpose of treating battlefield internal diseases,and adhere to the actual needs of the troops in peacetime and wartime.We should investigate the pathogenesis of battlefield internal diseases and explore the threats that may arise in future wars to ensure the advancement of battlefield internal medicine.This review highlights new concepts,demands,challenges,and opportunities for the further development of military medical research on battlefield internal medicine.

Recent Advance in Division of Carbohydrate and Protein Fractions of Ruminant Feed and Their Metabolism in Digestive Tract

Accurate assessment of feed's Carbohydrate( CHO) and protein nutritional values and rumen metabolism are significant for dairy production. Cornell Net Carbohydrate and Protein System( CNCPS) as an important method to evaluate feedstuff nutritional values,hasn't been widely used in China. In order to illustrate updates of CNCPS systems deeply,the following sections were reviewed:( i) CHO and protein fractions were updated,CA was subdivided into CA1,CA2,CA3 and CA4 in CNCPS v6. 1,protein was reclassified into PA1,PA2,PB1,PB2 and PC after CNCPS v6. 1. Content of CHO and protein fractions vary in different feedstuff and affected by feed processing;( ii) Degradation rates( Kd) values for the new CA expanded scheme were updated to 0,7,5,40- 60 % h^(-1)respectively,Kd for PA and PB1 decreased to 200 % h^(-1)and 10- 40 % h^(-1);( iii) Equations for passage rate( Kp) initially includes Kpf( Kp of forages) and Kpc( Kp of concentrates),and adjusted by effective NDF( e NDF),while in CNCPS v5. 0,Kpl( Kp of liquids) equation was added and e NDF was replaced by physically effective NDF( pe NDF). In CNCPS v6. 1,Fp BW and Cp BW were integrated into Kp equations and pe NDF was abandoned.( iv)The relationship and difference among Weende system of proximate analysis,Van Soest fiber analysis~[35],NRC( 2001)~[28]and CNCPS were analyzed. The first two systems laid the foundation for NRC( 2001) and CNCPS system. The latter two systems are different in CHO and protein division,also NRC( 2001) developed separate Kp equations for wet and dry forages but no equation for Kpl. CNCPS developed a Kp equation that work for wet and dry forages,and Kpl equation was established. In conclusion,the division and development of CHO and protein fractions,the update of Kd and Kp equation were reviewed systematically.

Stages of care for patients with chronic hepatitis C at a hospital in southern Brazil

BACKGROUND Hepatitis C virus(HCV)is defined as a public health problem by the World Health Organization(WHO)and since then has defined targets through the HCV elimination.The HCV cascade of care highlights the progress towards these goals and essential interventions that need to be delivered along this continuum care.AIM To document the treatment cascade for patients with HCV infection at the Hospital Nossa Senhora da Conceição(HNSC),defining the percentage of antibody-positive patients who collected molecular biology tests(polymerase chain reaction),attended outpatient clinic assistance,underwent treatment,and achieved a virologic cure termed sustained virologic response(SVR).METHODS With the retrospective cohort design,patients diagnosed with HCV infection in the period between January 1,2015 and December 31,2020 were included.Data from HCV notification forms,electronic medical records,Computerized Laboratory Environment Manager System,and Medicine Administration System(evaluation of special medications)were collected in 2022 and all information up to that period was considered.The data were analyzed with IBM SPSS version 25,and Poisson regression with robust simple variance was performed for analysis of variables in relation to each step of the cascade.Variables with P<0.20 were included in the multivariate analysis with P<0.05 considered significant.Pearson’s chi-square test was applied to compare the groups of patients who persisted in follow-up at the HNSC and who underwent follow-up at other locations.RESULTS Results were lower than expected by the WHO with only 49%of candidates receiving HCV treatment and only 29%achieving SVR,despite the 98%response rate to direct acting antivirals documented by follow-up examination.The city of origin and the place of follow-up were the variables associated with SVR and all other endpoints.When comparing the cascade of patients who remained assisted by the HNSC vs external patients,we observed superior data for HNSC patients in the SVR.Patients from the countryside and metropolitan region were mostly assisted at the HNSC and the specialized and continuous care provided at the HNSC was associated with superior results,although the outcomes remain far from the goals set by the WHO.CONCLUSION With the elaboration of the HCV cascade of care using local data,it was possible to stratify and evaluate risk factors associated with losses between each step of the cascade,to inform new strategies to guide elimination efforts in the future.

Congenital Absence of Pericardium:The Largest Systematic Review in the Field on 247 Worldwide Cases(1977-Now)

Background:Congenital absence of pericardium(CAP),also known as pericardial agenesis,represents an uncommon cardiac abnormality and mostly incidental finding.It can be subdivided into complete and partial(left or right-sided)forms.Because of its infrequency,just case reports and a few case series have been released so far.This paper represents the largest systematic review in the field.Nine features(age at diagnosis,type,gender,clinical presentation,electrocardiography,imaging(ultrasounds,CT/MRI),concomitant cardiac defects,and outcome)were analysed.Methods:The electronic database PubMed was investigated from its establishment up to July 15th,2023.Just case reports and case series were included.Animal studies,papers that were not in English,Spanish,and Italian,and those manuscripts not reporting at least seven of the nine analysed features.were ruled out.The analysed data were reported mostly in terms of percentage.Results:One hundred eighty studies were included encompassing 247 patients.More than half of reviewed CAP cases were in males(63.2%).The mean age at diagnosis was 31.8±19.3 years;a range of 32 weeks of gestation-81 years).23.5%of the patients did not report any symptoms.The most common clinical presentations were chest pain(35.2%)and dyspnoea(29.2%).The most commonly seen ECG changes were right axis deviation(28.7%)and right bundle branch block(23.9%).CAP was suspected or diagnosed by echocardiography in 20.1%of cases.The diagnosis was made by CT and/or MRI in 61.9%of cases.CAP was left-sided in 71.2%,complete in 23.1%,and right-sided in 5.7%.A concomitant congenital heart defect was found in 22.7%,especially in the form of atrial septal defect(6.5%)and patency of ductus arteriosus(2.8%).The pericardial repair was required in 12.9% of the incomplete forms of the disease.Never did the complete form require surgical correction.The outcome appeared favourable in the vast majority of cases,with just 18 deaths(7.3%).Discussion:The main limitation of this systematic review is that it is based just on case reports and case series,due to the lack of large studies on CAP.However,it represents the largest analysis in the field.Due to the rarity of CAP establishing an International Registry is recommended.

Numerical simulation of turbulent combustion: Scientific challenges

Predictive simulation of engine combustion is key to understanding the underlying complicated physicochemical processes,improving engine performance,and reducing pollutant emissions.Critical issues as turbulence modeling,turbulence-chemistry interaction,and accommodation of detailed chemical kinetics in complex flows remain challenging and essential for highfidelity combustion simulation.This paper reviews the current status of the state-of-the-art large eddy simulation(LES)/probability density function(PDF)/detailed chemistry approach that can address the three challenging modelling issues.PDF as a subgrid model for LES is formulated and the hybrid mesh-particle method for LES/PDF simulations is described.Then the development need in micro-mixing models for the PDF simulations of turbulent premixed combustion is identified.Finally the different acceleration methods for detailed chemistry are reviewed and a combined strategy is proposed for further development.

基于增强CT影像组学预测食管鳞癌淋巴血管侵犯状态的价值

目的:探讨基于增强CT影像组学预测食管鳞癌(ESCC)淋巴血管侵犯(LVI)的价值。方法:回顾性搜集行根治性切除术并经术后病理证实的224例食管鳞癌患者,其中包括66例LVI阳性和158例LVI阴性患者。所有患者均在术前2周内进行胸部增强CT扫描。将入组的患者按照7:3的比例随机分为训练集和测试集。使用3D Slicer软件逐层勾画全肿瘤感兴趣区(ROI),采用Python软件的Pyradiomics包提取肿瘤组织的影像组学特征,建立影像组学模型用于预测食管鳞癌的LVI状态并进行验证。采用受试者工作特征(ROC)曲线的曲线下面积(AUC)、敏感度、特异度、准确度、阳性预测值和阴性预测值来评价影像组学模型的诊断效能,使用校准曲线评价影像组学模型在训练集和测试集中的拟合程度。使用决策曲线分析(DCA)评价影像组学模型的临床应用价值。结果:从全肿瘤ROI中提取了1130个组学特征,经过筛选最终保留了7个影像组学特征,并使用多因素logistic回归建立影像组学预测模型。在训练集中,影像组学模型预测LVI的AUC值为0.930,敏感度为0.851,特异度为0.919,准确度为0.899,阳性预测值为0.816,阴性预测值为0.936;在测试集中,AUC值为0.897,敏感度为0.789,特异度为0.787,准确度为0.788,阳性预测值为0.600,阴性预测值为0.902。校准曲线显示影像组学模型在训练集及测试集中的预测概率与实际概率的一致性良好。DCA曲线显示影像组学模型具有良好的临床应用价值。结论:基于增强CT构建的影像组学模型,能够在术前有效预测食管鳞癌的LVI状态。

三维稳态采集快速成像序列在前交叉韧带损伤诊断中的应用

目的本研究旨在探讨二维快速自旋回波(two-dimensional fast spin echo,2D-FSE)序列及三维稳态采集快速成像(three-dimensional fast imaging employing steady state acquisition,3D-FIESTA)序列在前交叉韧带(anterior cruciate ligament,ACL)损伤诊断中的价值。方法本研究纳入2021年8月至2023年11月哈尔滨医科大学附属第一医院因膝关节损伤收治入院,并在1周内计划接受关节镜术的75例患者,其中男41例,女34例;年龄16~65岁,平均(39.02±12.32)岁。患者均接受包含3D-FIESTA序列和2D-FSE序列的MRI膝关节检查。通过关节镜术验证2D-FSE序列和3D-FIESTA序列在ACL损伤诊断中的准确性。结果2D-FSE序列的敏感度为90.2%,特异度为57.1%,准确性为84.0%,Kappa值为0.571,与关节镜诊断的一致性一般;同样条件下3D-FIESTA序列的敏感度为98.4%,特异度为78.6%,准确度为94.7%,Kappa值为0.846,与关节镜诊断的一致性较好。受试者工作特征曲线下面积分析显示,3D-FIESTA序列的诊断效能(0.932)明显优于2D-FSE序列(0.758)。结论MRI诊断ACL损伤方面,3D-FIESTA序列效果优于2D-FSE序列,结合临床查体可显著提高术前诊断的准确性,对决定是否进行手术及选择手术方法具有重要的指导意义。

深度学习图像重建算法对能谱CT单能量图像质量影响的体模研究

目的 探讨基于深度学习的图像重建算法(DLIR)对能谱CT单能量图像及能谱曲线图像质量的影响。方法 将9支装有不同管径及不同浓度碘造影剂及水和钙溶液的聚丙烯试管放置在1个直径为20 cm的圆柱形聚丙烯体模(QSP)内,采用Revolution APEX CT对体模进行能谱CT成像,利用能谱分析软件重建出40~140 keV单能量图像及能谱曲线,选取碘造影剂浓度为3.75 mgI/mL(可模拟延迟期或实质脏器增强等)、15 mgI/mL(可模拟动脉期的腹主动脉)及Water(可模拟平扫期及囊肿、肌肉等用于图像背景的非增强物质)3支试管进行数据测量,分别在FBP、40%ASIR-V(常规临床检查参数)及True FidelityTM(DLIR-L、DLIR-M、DLIR-H)5组图像测量单能量图像(40 keV、70 keV、100 keV)的CT值,计算图像的信噪比(SNR),对比5组图像质量的差异。结果 低浓度碘造影剂(3.75 mgI/mL)、高浓度碘造影剂(15.00 mgI/mL)及水试管内FBP、40%ASIR-V及True FidelityTM(DLIR-L、DLIR-M、DLIR-H)5组图像40 keV、70 keV、100 keV的CT值比较,差异无统计学意义(P>0.05)。40 keV、70 keV、100 keV图像噪声及图像信噪比5组比较,差异均有统计学意义(P<0.05)。True FidelityTM下的噪声值均较FBP及40%ASIR-V降低,图像信噪比提高(P<0.05),True FidelityTM-DLIR-H噪声最小,信噪比最高。结论 在能谱CT成像中,True FidelityTM较FBP及40%ASIR-V在单能量图像噪声降低,信噪比提高。

Omicron:a chimera of two early SARS-CoV-2 lineages

Dear Editor,The outbreak of the COVID‐19 that occurred in late 2019 has posed a remarkable threat to public health around the world.It is known that SARS-CoV-2 is a genetically diverse group that mutates continuously,leading to the emergence of multiple variants.1 Potential variants of concern(VOCs),variants of interest(VOIs),or variants under monitoring(VUMs)are regularly assessed based on the risk posed to global public health.Following the identification of a novel variant in South Africa on 24 November 2021,WHO designated Omicron(clade GRA,PANGO lineage B.1.1.529 and descendants BA.1 and BA.2)as the fifth SARS-CoV-2 VOC 2 days later due to its large number of variations.

列线图模型对浸润性乳腺癌伴腋窝淋巴结转移的预测价值

目的探讨列线图模型对浸润性乳腺癌伴腋窝淋巴结转移的预测价值。资料与方法回顾性分析2020年9月—2022年3月宁夏医科大学总医院疑诊乳腺癌患者122例,根据有无腋窝淋巴结转移分为转移组57例和非转移组65例。所有病灶经手术病理证实。两组接受合成磁共振、动态对比增强磁共振成像(DCE-MRI)及扩散加权成像扫描,测量乳腺病灶合成磁共振参数[T1、T2、质子密度(PD)]、时间-信号强度(TIC曲线)、表观扩散系数(ADC)。比较两组参数差异,并筛选出浸润性乳腺癌伴腋窝淋巴结转移的独立风险因素。结果Logistic回归结果显示Ki-67(OR=2.971,95%CI 1.306~6.762,P=0.009)、病灶大小(OR=1.652,95%CI 1.067~2.556,P=0.024)、ADCratio(OR=1.685,95%CI 1.014~2.801,P=0.044)、T2ratio(OR=3.015,95%CI 1.433~6.340,P=0.003)、PDratio(OR=2.782,95%CI 1.471~5.262,P=0.002)是浸润性乳腺癌伴腋窝淋巴结转移的独立风险因素。5种模型比较显示逻辑回归模型效能最优,曲线下面积为0.729(95%CI 0.621~0.789),准确度、特异度、敏感度分别为70.65%、62.79%、77.55%。对列线图模型准确性进行检验,得出C-index=0.844,即本次建立的列线图模型准确性良好,其截断风险为0.468,截断分数为143.50,当总分大于143.50时,发生腋窝淋巴结转移的风险将高于46.8%。结论列线图模型对浸润性乳腺癌伴腋窝淋巴结转移具有较好的预测能力。

基于多参数磁共振瘤周区域的影像组学模型在脑胶质瘤预后评估中的应用价值

目的评估基于脑胶质瘤瘤周区域建立的影像组学模型的预后价值。方法回顾性分析138例脑胶质瘤患者,运用医学影像工具包(MITK)软件获取距离肿瘤边缘5、10、20 mm瘤周区域的核磁共振成像(MRI)图像并提取其纹理特征、进行特征筛选、建立影像组学模型,并计算影像组学分数(Rad-score)。建立临床预测模型及Rad-score与临床危险因素相结合的联合预测模型;将联合预测模型以列线图展示,并评估模型对脑胶质瘤患者生存率预测效能。结果在验证集中,基于T2加权像(T2WI)序列距肿瘤边缘10 mm瘤周区域建立的影像组学模型一致性指数(C-index)为0.663(95%CI=0.53~0.80),预测效能最佳。在训练集和验证集上,联合预测模型的C-index分别为0.770和0.730。模型对脑胶质瘤患者3年生存率的预测效能最高[训练集受试者工作特征曲线下的面积(AUC)=0.93,95%CI=0.83~0.98;验证集AUC=0.88,95%CI=0.76~0.99],校准曲线显示在训练集和验证集中联合预测列线图具有较好的校准效能。结论基于术前MRI T2WI序列距肿瘤边缘10 mm的瘤周区域建立的影像组学预测模型与临床病理危险因素建立的联合预测模型可以更准确地预测脑胶质瘤的预后情况,其中对脑胶质瘤3年生存率预测效果最好。

深度学习重建算法改善腹部门静脉期CT图像质量的应用价值

目的:探究深度学习重建算法(Deep learning image reconstruction,DLIR)、传统滤波反投影(Filered back-projection,FBP)及自适应迭代重建算法(Adaptive statistical iterative reconstruction-veo,ASIR-V)对改善腹部门静脉期CT图像质量差异及临床获益。方法:前瞻性纳入45例行腹部增强CT扫描患者,其中包括18例肝硬化失代偿期患者,对门静脉期图像进行FBP、30%ASIR-V、80%ASIR-V及DLIR-H重建,并测量比较4组重建图像肝脏、脾脏、脾静脉、门静脉及左右支CT值、噪声、信噪比(Signal-to-noise ratio,SNR)及对比信噪比(Contrast-to-noise ratio,CNR);比较各重建算法图像主观评价,包括18例肝硬化失代偿期患者交通支血管。结果:4组重建算法图像CT值无统计学差异(P>0.05),噪声、SNR、CNR均有统计学差异,两两比较FBP与30%ASIR-V,80%ASIR-V与DLIR-H在CNR、SNR值中无统计学差异(校正P<0.008),80%ASIR-V与DLIR-H算法在SD值无统计学差异(校正P<0.008),余均有统计学差异。主观评价DLIR图像整体质量、对比度、失真伪影与其他各组有显著性差异(校正P<0.008),仅图像噪声与80%ASIR-V无显著性差异(校正P≥0.008)。DLIR交通支血管轮廓、清晰度与各组有显著性差异(校正P<0.008),噪声与80%ASIR-V无显著性差异(校正P≥0.008)。结论:DLIR算法降低腹部CT图像噪声,改善图像质量具有优势,尤其是肝硬化失代偿期微小血管结构,该重建算法可能为患者的精准诊断、风险评估提供更多信息。

增强MRI肝胆期影像组学在肝细胞癌病理分化中的预测价值

目的:探讨基于钆塞酸二钠增强MRI肝胆期影像组学在肝细胞癌(HCC)病理分化程度中的预测价值。方法:回顾性收集145例经术后病理证实为HCC患者资料,根据病理分级将患者分为低危险组(100例)和高危险组(45例),前者包括高分化(11例)、中-高分化(11例)、中分化(78例)HCC,后者包括低分化(21例)、中-低分化(24例)HCC。所有患者术前2周均行钆塞酸二钠增强MRI检查。通过分析得出对HCC有影响的临床及传统影像学特征,建立临床-影像模型;利用ITK⁃SNAP软件在肝胆特异期图像上手动勾画肿瘤感兴趣区(ROIs),利用FAE(FeAture Explorer V.0.5.5)软件提取特征,使用最大相关最小冗余法对特征降维,通过建立XGBoost二分类模型来预测诊断效能;最终将临床-影像模型与影像组学模型相结合,建立联合模型。采用受试者工作特征(ROC)曲线下面积、准确度、灵敏度、特异度等指标来评价各模型诊断效能。结果:测试组中临床-影像模型、影像组学模型以及联合模型的ROC曲线下面积值分别为0.66、0.70、0.76,准确度分别为63.6%、63.6%、77.3%,灵敏度分别为71.4%、85.7%、57.1%,特异度分别为60.0%、53.3%、86.7%。结论:基于钆塞酸二钠增强MRI肝胆期影像组学的模型在预测HCC病理分化中有一定的价值。

结合监测点优化的能谱扫描在双低剂量下肢动脉血管CT成像中的应用价值

目的:探讨能谱扫描结合腘动脉水平监测在双低剂量(低辐射剂量和低对比剂剂量)下肢动脉血管CT成像(CTA)中的应用价值。方法:前瞻性纳入需行下肢CTA检查的111例患者,分为A、B、C三组。A组(35例)采用常规扫描模式,对比剂105 mL,监测腹主动脉;B组(38例)采用能谱扫描模式,对比剂95 mL,监测腹主动脉;C组(38例)采用能谱扫描模式,对比剂85 mL,监测腘动脉。记录3组的辐射剂量与对比剂剂量。对于B、C两组,生成50 keV单能图像进行分析。由2位医师采用5分法对3组图像腹髂段(AIS)、股腘段(FPS)和膝下段(LKS)进行图像质量评分。测量CT值及噪声值,计算信噪比(SNR)及对比噪声比(CNR)。比较3组图像间的客观参数、主观评分、辐射剂量和对比剂剂量。结果:C组对比剂剂量较A组降低了19.04%,ED降低了14%,差异均有统计学意义(P均<0.05)。B、C两组在各血管处CT值均高于A组(P<0.05)。从腹主动脉到踝动脉,C组的客观图像质量优势逐渐显现,在踝动脉处的SNR和CNR最高,其次为B组,A组最低,差异均有统计学意义(P均<0.05)。图像质量主观评分方面,AIS段3组图像质量评分差异无统计学意义;FPS段B、C组评分高于A组;LKS段C组评分最高,B组次之,A组最低,差异有统计学意义(P<0.05)。结论:与传统下肢CTA、腹主动脉点监测扫描方案相比,能谱结合腘动脉水平监测点扫描方案在双低剂量下可提高下肢动脉的图像质量,尤其提高了对膝下血管的显示能力,具有较高的临床应用价值。

基于定量磁敏感图的纹理分析对帕金森病的诊断价值

目的通过定量磁敏感图(QSM)序列分析大脑灰质核团和脑白质的纹理特征,探讨纹理分析在帕金森病(PD)的诊断及病程评估方面的价值。资料与方法前瞻性纳入2019年7月—2020年11月于南通大学附属江阴医院ESWAN序列扫描的30例PD患者与22例正常对照者,通过后处理得到两组的QSM图,手动获取双侧尾状核头、苍白球、壳核、黑质、红核、小脑齿状核及半卵圆中心白质的感兴趣区并提取纹理特征,对其降维筛选后得到一组最佳纹理特征构建随机森林预测模型。对模型的诊断效能及可靠性进行评价,并对筛选出的纹理特征与PD患者的临床量表进行相关性分析。结果QSM图得到一组(5个)最佳纹理特征参数,各参数独立预测PD的曲线下面积为0.697~0.823,随机森林模型的曲线下面积为0.910,交叉验证的准确度为0.888。PD组的纹理特征r4_wavelet_LLL_firstorder_Energy与简易精神状态评价量表评分呈负相关(r=0.470,P=0.011)。结论基于QSM的纹理分析对PD有较高的诊断价值,左侧壳核的纹理特征与PD患者的认知功能有一定的相关性。