Quantitative computed tomography analysis for stratifying the severity of Coronavirus Disease 2019

To examine the feasibility of using a computer tool for stratifying the severity of Coronavirus Disease 2019(COVID-19)based on computed tomography(CT)images.We retrospectively examined 44 confirmed COVID-19 cases.All cases were evaluated separately by radiologists(visually)and through an in-house computer software.The degree of lesions was visually scored by the radiologist,as follows,for each of the 5 lung lobes:0,no lesion present;1,<1/3 involvement;2,>1/3 and<2/3 involvement;and 3,>2/3 involvement.Lesion density was assessed based on the proportion of ground-glass opacity(GGO),consolidation and fibrosis of the lesions.The parameters obtained using the computer tool included lung volume(mL),lesion volume(mL),lesion percentage(%),and mean lesion density(HU)of the whole lung,right lung,left lung,and each lobe.The scores obtained by the radiologists and quantitative results generated by the computer software were tested for correlation.A Chi-square test was used to test the consistency of radiologist-and computer-derived lesion percentage in the right/left lung,upper/lower lobe,and each of the 5 lobes.The results showed a strong to moderate correlation between lesion percentage scores obtained by radiologists and the computer software(r ranged from 0.7679 to 0.8373,P<0.05),and a moderate correlation between the proportion of GGO and mean lesion density(r=-0.5894,P<0.05),and proportion of consolidation and mean lesion density(r=0.6282,P<0.05).Computer-aided quantification showed a statistical significant higher lesion percentage for lower lobes than that assessed by the radiologists(x^2=8.160,P=0.004).Our experiments demonstrated that the computer tool could reliably and accurately assess the severity and distribution of pneumonia on CT scans.

Comment on“Prognostic value of preoperative enhanced computed tomography as a quantitative imaging biomarker in pancreatic cancer”

Pancreatic ductal adenocarcinoma(PDAC)is one of the most lethal malignancies because of its high invasiveness and metastatic potential.Computed tomography(CT)is often used as a preliminary diagnostic tool for pancreatic cancer,and it is increasingly used to predict treatment response and disease stage.Recently,a study published in World Journal of Gastroenterology reported that quantitative analysis of preoperative enhanced CT data can be used to predict postoperative overall survival in patients with PDAC.A tumor relative enhancement ratio of≤0.7 indicates a higher tumor stage and poor prognosis.

Spectral CT imaging as a new quantitative tool? Assessment of perfusion defects of pulmonary parenchyma in patients with lung cancer

Objective： This study investigated the capability of dual-energy spectral computed tomography （CT） to quantitatively evaluate lung perfusion defects that are induced by central lung cancer. Methods： Thirty-two patients with central lung cancer underwent CT angiography using spectral imaging. A univariate general linear model was conducted to analyze the variance of iodine concentration/CT value with three factors of lung fields. A paired t-test was used to compare iodine concentrations and CT values between the distal end of lung cancer and the corresponding area in the contralateral normal lung. Results： Iodine concentrations increased progressively in the far, intermediate and near ground sides in the normal lung fields at 0.60±0.28, 0.93±0.27 and 1.25±0.38 mg/mL, respectively （P〈0.001）. The same trend was observed for the CT values [-（840.64±49.08）, -（812.66±50.85） and -（760.83±89.17） HU, P〈0.001]. The iodine concentration （0.70±0.42 mg/mL） of the lung field in the distal end of lung cancer was significantly lower than the corresponding area in the contralateral normal lung （1.19±0.62 mg/mL） （t=-7.23, P〈0.001）. However, the CT value of lung field in the distal end of lung cancer was significantly higher than the corresponding area in the contralateral normal lung [-（765.29±93.34） HU vs. -（800.07±76.18） HU, t=3.564, P=0.001]. Conclusions： Spectral CT imaging based on the spectral differentiation of iodine is feasible and can quantitatively evaluate pulmonary perfusion and identify perfusion defects that are induced by central lung cancer. Spectral CT seems to be a promising technique for the simultaneous evaluation of both morphological and functional lung information.

Characteristics of Rat Lumbar Vertebral Body Bone Mineral Density and Differential Segmental Responses to Sex Hormone Deficiency:a Clinical Multidetector Computed Tomography Study

Objective To investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. Methods Orchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. A rat vertebral body can be longitudinally divided into central portion, which contain more trabecular bone, and para-endplate portions which contain more compact bone. In matured male and female Wistar and Sprague-Dawley rat lumbar spines, we investigated baseline bone mineral density （BMD） characteristics and the differential segmental responses in bone loss within the lumbar vertebral body post gonadal surgery with clinical multidetector computed tomography. Results Para-endplate sections had a higher BMD than central sections. The cephalad para-endplate sections had a higher BMD than the caudad para-endplate sections. Eight weeks after gonadal removal, there was more bone loss in central sections than para-endplate sections. The relative difference of bone loss between para-endplate and central sections was more apparent in male rats than in female rats. There was more bone loss in caudad sections than cephalad sections; this lead to a further increase of BMD difference between caudad para-endplate sections and cephalad para-endplate sections post gonadal surgery. Conclusion The approach described in this study provided a consistent way to study BMD change within predominantly compact bone portion and trabecular bone portion of the vertebral body.

Computed tomography perfusion imaging evaluation of angiogenesis in patients with pancreatic adenocarcinoma

BACKGROUND Pancreatic adenocarcinoma is one of the most common malignant tumors of the digestive system.More than 80%of patients with pancreatic adenocarcinoma are not diagnosed until late stage and have distant or local metastases.AIM To investigate the value of computed tomography(CT)perfusion imaging in the evaluation of angiogenesis in pancreatic adenocarcinoma patients.METHODS This is a retrospective cohort study.Patients with pancreatic adenocarcinoma and volunteers without pancreatic diseases underwent CT perfusion imaging from December 2014 to August 2017 in Huashan Hospital,Fudan University Shanghai,China.RESULTS A total number of 35 pancreatic adenocarcinoma patients and 33 volunteers were enrolled.The relative blood flow(r BF),and relative blood volume(r BV)were significantly lower in patients with pancreatic adenocarcinoma than in the control group(P<0.05).Conversely,the relative permeability in patients with pancreatic adenocarcinoma was significantly higher than that in controls(P<0.05).In addition,r BF,r BV,and the vascular maturity index(VMI)were significantly lower in gradeⅢ-Ⅳpancreatic adenocarcinoma than in gradeⅠ-Ⅱpancreatic adenocarcinoma(P<0.05).Vascular endothelial growth factor(VEGF),CD105-MVD,CD34-MVD,and angiogenesis rate(AR)were significantly higher in gradeⅢ-Ⅳpancreatic adenocarcinoma than in gradeⅠ-Ⅱpancreatic adenocarcinoma(P<0.05).Significant correlations between r BF and VEGF,CD105-MVD,AR,and VMI(P<0.01)were observed.Moreover,the levels of r BV were statistically significantly correlated with those of VEGF,CD105-MVD,CD34-MVD,and VMI(P<0.01).CONCLUSION Perfusion CT imaging may be an appropriate approach for quantitative assessment of tumor angiogenesis in pancreatic adenocarcinoma.

Imaging in multiple myeloma: Computed tomography or magnetic resonance imaging?

Multiple myeloma(MM)is the second most common type of hematological disease with its incidence rising in the elderly.In MM,the extent of the bone disease increases both morbidity and mortality.The detection of lytic bone lesions on imaging,especially computerized tomography(CT)and magnetic resonance imaging(MRI)is crucial to separate asymptomatic from symptomatic MM patients even when no clinical symptoms are present.Although radiology is essential in the staging and management of patients with MM there is still high variability in the choice between MRI and CT.In addition,there is still suboptimal agreement among readers.The potential of medical imaging in MM is largely under-evaluated:artificial intelligence,radiomics and new quantitative methods to report CT and MRI will improve imaging usage.

Quantitative Analysis of Glomeruli Lesions in Patients with Mesangial Proliferative Glomerulonephritis

By using computer imaging analysis system combined with light microscopy, the glomeruli lesions on biopsy specimens sections were quantitatively analysed. The patholoical changes of mesangial proliferative glomerulonephritis (MsPGN) in children were quantitatively evaluated and the correlation between the mesangial matrix area (MA) and some clinical data were also analysed. The results indicated that the levels of various glomerular parameters in MsPGN group were higher than those of normal controls. No correlation was found between MA and 24 h urinary protein excretion, but a negative correlation was revealed between MA and estimated GFR. MA was also correlated with the duration of MsPGN recovery. It was suggested that the quantitative analysis of glomerular parameters by computer is a reproducible methods. The parameter of MA may be used for evaluation of the renal function, determination of the duration of therapy and evaluation of prognosis of MsPGN in children.

Validation of quantitative computed tomography-derived areal bone mineral density with dual energy X-ray absorptiometry in an elderly Chinese population

Background The performance of computed tomography X-ray absorptiometry （CTXA） against the dual energy X-ray absorptiometry （DXA） as standard has not been studied in Chinese population. The aim of this study was to evaluate the precision of this measurement and validate the value of quantitative computed tomography （QCT） by comparing CTXA results with DXA results in an elderly Chinese population. Methods One hundred and three females of 46 to 76 years old and 49 males of 52 to 76 years old were recruited from the Prospective Urban Rural Epidemiology study. All subjects underwent hip scans by both QCT and DXA on the same day. For precision determination, 30 subjects had duplicate DXA hip scans. The hip QCT data of a subset of 27 subjects were separately analyzed by two observers and reanalyzed by one observer at a different time. The inter- and intra-observer variations of CTXA measurement were assessed, and the difference and correlation between CTXA and DXA results were analyzed. Results The inter- and intra-observer variations of CTXA were 0.070 and 0.024 g/cm^2 in the femoral neck （FN）, and 0.030 and 0.012 g/cm2 in the total hip （TH）, which were comparable to the DXA inter-scan variations （0.013 g/cm2 for FN and 0.014 g/cm2 for TH）. The results of CTXA bone mineral density （BMD） were highly correlated with those of DXA （R2 = 0.810 for FN and R2 = 0.878 for TH）. The BMD values of CTXA in FN and TH were lower than those of DXA by 21.0% and 17.8% （P〈0.05）, respectively. However, after appropriate transformation, the difference was eliminated and a comparable T score could be obtained. Conclusions CTXA shows good agreement with DXA for the measurement of BMD in the proximal femur, which makes QCT suitable for the quantification of bone mineral content in the hip and helpful for the diagnosis of osteoporosis.

应用瑞加诺生负荷D-SPECT评价定量血流分数在经皮冠状动脉介入治疗中的作用

目的应用瑞加诺生负荷动态单光子发射计算机断层扫描(dynamic single-photon emission computed tomography,D-SPECT)评价定量血流分数(quantitative flow ratio,QFR)在经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)中的作用。方法选择2021年6月31日至2023年6月31日在河北医科大学第一医院心内科住院行择期PCI术的200例不稳定型心绞痛患者,年龄(57.56±8.23)岁,按照随机数字表法分为常规组(n=100)和QFR组(n=100),试验采用双盲法进行。常规组根据医师经验行PCI术治疗,QFR组根据QFR测定结果行PCI治疗。所有入选患者术前及PCI术后7 d,应用瑞加诺生负荷D-SPECT,分别采集短轴、垂直长轴、水平长轴的图像,计算心肌17节段分布下心肌灌注总积分、心肌缺血总节段数情况。结果PCI术前两组患者心肌缺血节段数(7.59±3.14 vs.7.48±3.36,P=0.811)、心肌灌注总积分(15.87±7.61 vs.15.63±5.97,P=0.860)差异无统计学意义,QFR组PCI术后7 d的心肌缺血节段数(5.58±3.36 vs.6.51±2.14,P=0.020)和心肌灌注总积分(10.55±4.41 vs.12.96±6.50,P=0.002)显著优于常规组(P<0.05)。结论应用QFR指导PCI可以更好改善患者心肌缺血程度。

冠脉CT血管造影斑块人工智能定量参数与血流储备分数的关系

目的 探讨冠脉CT血管造影(CCTA)斑块人工智能(AI)定量参数与CT血流储备分数(FFR-CT)的相关性。方法 收集怀疑冠心病患者共84例,男52例,女32例,年龄27~81岁,平均(58.1±11.9)岁,均行CCTA检查。将图像传输至数坤软件并对冠脉血管标记、斑块分析、计算相应FFR-CT值。斑块AI参数包括长度、体积、最小管腔面积(MLA)、最狭窄程度(MLD)、脂类体积及占比、纤维脂类体积及占比、纤维体积及占比、钙化体积及占比。FFR-CT≤0.8定义为可能存在血流动力学异常或心肌缺血。评估斑块参数与FFR-CT相关性,采用二元logistic回归筛选冠脉血流储备异常(FFR-CT≤0.8)的独立危险因素,采用ROC曲线及曲线下面积(AUC)评价其诊断效能,计算灵敏度、特异度及模型预测准确率。结果 84例患者主要症状为胸痛(39例,占46.4%)与胸闷(27例,占32.1%)。Spearman相关分析结果显示FFR-CT与MLA呈正相关(r=0.49,P <0.000 1),与长度、体积、脂类体积、纤维脂类体积、纤维体积及钙化体积呈负相关(r=-0.44、-0.56、-0.40、-0.36、-0.42、-0.40,P <0.05),其中与MLD呈中等程度负相关(r=-0.60,P <0.000 1)。单因素logistic回归分析结果显示斑块长度、体积、MLA、MLD、脂类体积、纤维脂肪体积、纤维体积、钙化体积等参数是FFR-CT≤0.8的独立危险因素(P <0.05)。经调整后的多因素logistic回归分析结果显示,MLD是FFR≤0.8的独立危险因素(OR=1.082,95%CI:1.034~1.133,P=0.001),预测模型为logit(P)=0.079X1-4.052,X1为MLD值,预测准确率为85.2%。斑块长度、MLD、脂类体积、纤维体积及钙化体积诊断冠脉血流动力学异常(FFR-CT≤0.8)的AUC分别为0.796、0.886、0.711、0.754、0.698,灵敏度与特异度分别为47.83%、73.91%、73.90%、52.17%、60.87%与92.11%、73.68%、60.53%、84.21%、89.47%,5种指标联合诊断的AUC为0.906,灵敏度与特异度为73.91%、71.05%。结论 冠脉斑块AI参数与FFR-CT存在不同程度相关性,MLD是FFR-CT≤0.8的独立危险因素,具有较高的诊断效能。

定量CT评价胸椎骨密度及与年龄相关的骨丢失

目的探讨胸椎定量CT(QCT)测量骨密度及骨丢失率的可行性。方法选取因健康体检及急腹症行全腹部CT扫描的患者708例,使用QCT软件测量T10-L3椎体骨密度。将受检者按每10岁为一个年龄段分组。计算每个年龄组的胸椎及腰椎骨密度,并计算各组别的峰值骨密度及骨丢失率。胸椎与腰椎骨密度及其与年龄的相关性采用Pearson相关分析。结果男性、女性骨密度峰值均在20~29岁年龄组,30岁以后胸腰椎骨密度开始不同程度减低,80~89岁女性胸椎及腰椎累计骨丢失率分别为60.61%及61.34%,而男性分别为44.45%及49.35%。男性与女性胸腰椎骨密度均与年龄呈负相关(P<0.01)。胸椎与腰椎骨密度呈正相关(男性r=0.96、女性r=0.98,P<0.01)。结论胸椎及腰椎QCT均能准确地显示不同年龄组的骨密度及骨丢失情况,胸椎QCT可以作为评价和监测骨丢失的一种方法。

教育定量研究范式:价值、困境与创新路径

教育定量研究范式是以实证主义为基础,运用数学工具或统计分析等手段对教育现象或教育过程进行测量,依据数据资料检验理论假设,揭示教育现象中各种因素相关关系的研究范式。它是提升教育研究科学化的关键,是引领教育高质量发展的工具,也是适应教育数字化转型需要的必然趋势。但是,当前教育定量研究在推动教育学走向科学化与实证化的过程中面临着多重困境,表现为方法的“内生性”问题、量化的“前提性”问题和研究的“规范性”问题。我国教育研究向实证研究范式的转型、信息技术的迅猛发展、数据共享与公开机制的形成,为定量研究范式创新提供了现实可能。未来,教育定量研究范式应在多种维度上进行变革和创新,推行复制性研究,发展计算教育学,加强教育预测研究。

“实证法学”的概念术语回顾与回归--基于文献的实证法学研究整合路径

伴随着实证研究概念和范畴的思想大讨论,法学界在过去几十年涌现出大量相关的方法或学科术语。虽然各种术语本来根植于实证研究,但由于每种术语未对既有术语作细致的文献回顾和概念分析,而呈现出术语间前后矛盾、自我否定、相互攻击、相互整合的泛化和分化现象。从方法和学科层面来看,要实现实证研究的发展和繁盛,就必然需要在开放和团结的学术平台下统一学术理念,“实证法学”应该是整合研究队伍的最妥当路径。将当代实证法学研究的源头定位在二十世纪八十年代,了解钱学森和吴世宦所引领的法学研究方法大讨论对实证法学的影响,可以澄清有关起源问题的误解。实证法学的传统术语在早期都包含定量和定性,近十年才因个人理解或方法偏爱引发术语之争。新兴术语虽然在定量或定性、样本大小、理念内涵、技术方法上有所差异,但都是基于实证研究发展起来的,其术语之争也源于割裂文献所致的自创概念。回归实证研究的本质,停止术语和概念之争,只要正确和恰当地定义实证法学,便可以实现整合实证法学研究的目标。

胸部定量CT对COPD患者治疗反应预测因素分析

目的分析胸部定量CT扫描对慢性阻塞性疾病(COPD)患者治疗反应的预测因素。方法回顾性分析2018年8月至2021年2月接受治疗COPD患者120例的临床资料,对其随访1年,根据肺功能检测结果将其分为有治疗反应组[n=24,第1秒用力呼气容积(FEV_(1))增加≥0.225 L]和非无治疗反应组(n=96,FEV_(1)增加<0.225 L)。对2组一般资料进行单因素分析,对其中差异有统计学意义的变量进行多因素Logistic回归分析,从而筛选出预测COPD患者治疗反应的因素。结果单因素分析结果显示,有治疗反应组和无治疗反应组在EI、ATI、Pi10、WA%、T方面的差异有统计学意义(P<0.05),而2组间性别比、年龄、体重指数、GOLD分期、入院肺功能检测的差异无统计学意义(P>0.05)。多因素Logistic回归分析结果显示,Pi10为预测COPD患者治疗反应的因素(OR=2.321,P<0.05)。ROC曲线显示,Pi10在预测COPD患者治疗反应中具有极高的临床价值,ROC曲线显示,Pi10预测COPD患者治疗反应的曲线下面积为0.701,95%CI为0.610~0.781,约登指数为0.354,最佳截断值为4.65 mm,灵敏度为85.40%,特异度为50.00%。结论胸部定量CT扫描参数Pi10能够帮助预测COPD患者治疗反应。

气体泄漏扩散规律验证实验平台开发

开发了一个气体泄漏扩散规律验证的教学实验平台。平台由风场模拟模块、气体泄漏模块、数据采集模块及对应的计算流体力学(CFD)模型所组成,可开展多种工况下的气体泄漏扩散规律验证实验。在教学实验中开展不同工况的泄漏实验及CFD数值模拟,对实验采集的气体浓度数据与数值模拟结果进行对比分析。应用效果表明,该平台有助于学生直观地认识气体泄漏扩散规律,并为理解CFD方法在定量风险评估中的应用及其有效性提供了便捷途径。

基于定量CT身体组分、^(18)F-FDG PET/CT显像预测手术联合新辅助化疗治疗早期乳腺癌预后的价值

目的 分析定量CT (QCT)身体组分、^(18)F-氟脱氧葡萄糖正电子发射型计算机断层显像(^(18)F-FDG PET-CT)对手术联合新辅助化疗(NAC)治疗早期乳腺癌患者预后的预测效能,为临床治疗提供参考。方法 选取2020年3月至2022年10月于南阳市第二人民医院接受手术联合NAC治疗的82例早期乳腺癌患者纳入研究,在NAC前和化疗1、3个周期后检测记录QCT参数[L_(1)、L_(2)水平的皮下脂肪面积(SFA)、内脏脂肪面积(VFA)、骨密度(BMD)、L_(3)水平的椎旁肌肉面积(TMA)]、^(18)F-FDG PET/CT显像的最大标准摄取值(SUV_(max))、肿瘤代谢体积(MTV)。NAC结束后进行手术,随访12个月(失访2例),依据有无复发转移分为预后良好组43例和预后不良组37例,比较不同预后患者的QCT参数、^(18)F-FDG PET/CT显像指标,采用受试者工作特征(ROC)曲线获取曲线下面积(AUC)分析其对早期乳腺癌患者预后的预测效能。结果化疗1个周期后,预后良好组患者的SFA、BMD、VFA、MA水平分别为(45.23±4.07) cm^(2)、(128.97±26.53) mg/m^(2)、(78.07±6.69) cm^(2)、(37.36±5.74) cm^(2),明显高于预后不良组的(42.52±3.32) cm^(2)、(112.54±25.82) mg/m^(2)、(73.73±7.25) cm^(2)、(32.94±5.31) cm^(2),差异均有统计学意义(P<0.05);化疗3个周期后,预后良好组患者的SFA、BMD、VFA、MA水平分别为(40.95±3.92) cm^(2)、(113.55±15.87) mg/m^(2)、(73.59±6.17) cm^(2)、(32.67±4.98) cm^(2),明显高于预后不良组的(37.51±3.56) cm^(2)、(95.18±17.45) mg/m^(2)、(70.30±5.14) cm^(2)、(28.52±4.42) cm^(2),差异均有统计学意义(P<0.05);化疗1个周期后,预后良好组患者的SUV_(max)、MTV分别为5.43±1.25、(3.86±0.87)×10^(4)mm,明显低于预后不良组的6.04±1.07、(4.27±0.85)×10^(4)mm,差异均有统计学意义(P<0.05);化疗3个周期后,预后良好组患者的SUV_(max)、MTV分别为3.94±1.06、(2.61±0.70)×10^(4)mm,明显低于预后不良组的4.73±1.21、(3.05±0.93)×10^(4)mm,差异均有统计学意义(P<0.05);经ROC曲线分析结果显示,SFA、BMD、VFA、MA、SUV_(max)、MTV联合预测手术联合NAC治疗早期乳腺癌患者预后的AUC分别为0.898 (95%CI:0.809~0.954)、0.919 (95%CI:0.836~0.968)。结论 NAC过程中检测QCT参数、^(18)F-FDG PET/CT显像指标可预测手术联合NAC治疗早期乳腺癌患者的预后,联合预测的价值较高。

探讨定量CT及生物电阻抗测定内脏脂肪面积和骨密度的关系

目的:探讨采用定量CT(Quantitative computer tomography,QCT)及生物电阻抗(Bioelectrical impedance analysis,BIA)测定内脏脂肪面积(Visceral fat area,VFA)与骨密度(Bone density,BMD)的关系。方法:回顾性选取郑州大学第一附属医院健康管理中心1131例体检者行QCT和BIA测定的VFA及BMD,采用Pearson相关系数、多因素线性回归、单因素和多因素Logistic回归分析二者的相关性;并采用Bland-Altman评估两者测定VFA的一致性。结果:Pearson相关分析显示QCT和BIA测定的VFA与BMD呈负相关(r=-0.197和r=-0.288)。多因素Logistic回归分析显示VFA(BIA)是骨量下降的危险因素(OR=1.010,95%CI:1.005~1.015);VFA(QCT)是骨量下降的危险因素(OR=1.003,95%CI:1.001~1.005);Bland-Altman分析显示,QCT和BIA测量VFA具有较高的一致性。结论:VFA是骨量下降的危险因素,测定VFA的QCT和BIA两者具有较高的一致性,可以采用BIA测定的VFA评估骨量下降。

基于神经网络的电力通信网故障量化计算方法

当前的电力通信网在故障诊断方面只能进行定性的故障诊断与分析,无法实现复杂通信环境下定量的故障诊断与分析,因此将神经网络方法应用于电力通信网的故障诊断中,以实现定量的故障诊断与分析。首先,确定电力通信网故障信息量化计算指标,构建电力通信网的故障危害性评价体系,并引入专家评估系统;通过专家评估系统处理电力通信网上的故障信息;引入神经网络方法,对电力通信网中的权重参数进行训练,构建基于神经网络的电力通信网故障定量分析模型,实现对故障的量化分析与处理。通过算例测试表明,所提方法能有效计算出电力通信网故障等级信息及定量报警值,与传统方法相比更先进,可进行大规模推广应用。

基于MR Q-Dixon序列和QCT测量小鼠肝脏脂肪含量的可行性研究

目的探讨定量CT(QCT,quantitative CT)与MR Q-Dixon序列测量小鼠肝脏脂肪含量的可行性研究。方法本研究采用高脂饮食诱导的肥胖(Dietinduced obesity,DIO)的小鼠动物模型,6周龄C57BL/6小鼠30只,随机分成三组,每组10只,第一组给予普通饲料饲养40周,第二组给予高脂饮食20周,第三组给予高脂饮食40周,2名医师利用QCT和MR Q-Dixon序列对小鼠肝脏脂肪含量进行测量,对QCT测得的肝脏脂肪含量(Fat%Q)和MR Q-Dixon序列测得的肝脏脂肪含量(Fat%M)进行一致性检验和相关性分析。结果本实验QCT肝脏脂肪含量测量值为17.6(6.00,28.95)%,MR Q-Dixon序列肝脏脂肪含量测量值为19.6(5.70,29.55)%。两种方法评估脂肪肝严重程度比较,无显著差异(χ^(2)=4.000,P=0.216),且一致性较高(Kappa=0.816,P<0.001);两种方法的测量结果呈正相关(r=0.978,P<0.01)。结论在定量测量小鼠肝脏脂肪含量方面,定量CT与MR Q-Dixon序列具有较好的一致性和相关性,即可在体定量研究小鼠脂肪肝动物实验。

双气相定量CT对轻中度COPD的评估价值研究

目的:通过配准的双气相定量CT对轻中度慢性阻塞性肺疾病(COPD)患者肺气肿定量指标的对比分析,寻找最优肺气肿定量指标。方法:回顾性收集健康体检对照组55例和慢性阻塞性肺疾病全球倡议(GOLD)1级21例,GOLD 2级31例。将CT原始DICOM数据导入“数字肺”分析平台,测定深吸气末LAA%_(-950)和深呼气末LAA%_(-910)。将呼气相与吸气相CT图像配准,根据阈值法计算出肺气肿区域百分比(PRM~(Emph%))、功能性小气道病变区域百分比(PRMfSAD%)和正常区域百分比(PRM~(Normal%))。肺功能指标包括FVC、FEV_1%、FEV_1/FVC。组间一般资料、CT定量指标和肺功能差异采用独立样本t检验、Mann-Whitney U检验或卡方检验,相关性采用Spearman相关分析。绘制受试者工作特征(ROC)曲线分析CT定量参数对轻中度COPD患者肺气肿的诊断效能。结果:轻中度COPD患者与正常对照组间性别、吸烟指数、FEV1%、FEV1/FVC、吸气相LAA%_(-950)、呼气相LAA%_(-910)、PRM~(Emph%)、PRMfSAD%及PRMNormal%差异均有统计学意义。吸气相LAA%_(-950)与FEV1/FVC呈负相关,呼气相LAA%_(-910)、PRM~(Emph%)与FVC、FEV1%、FEV1/FVC均呈负相关。ROC曲线分析结果显示吸气相LAA%_(-950)、呼气相LAA%_(-910)及PRM~(Emph%)曲线下面积分别为0.742、0.861、0.876,其中PRM~(Emph%)指标的曲线下面积最大,对应临界值为9.84%,敏感度76.90%,特异度94.50%。结论:定量CT肺气肿指标吸气相LAA%_(-950)、呼气相LAA%_(-910)及双气相PRM~(Emph%)都能够客观评估轻中度COPD患者的肺气肿情况,其中PRM~(Emph%)是最优评估指标。