多时相CT影像组学模型预测胸腺瘤风险分类

目的 观察多时相CT影像组学模型预测胸腺瘤风险分类的价值。方法 纳入86例经病理确诊的单发胸腺瘤患者,包括32例高风险及54例低风险胸腺瘤,按照7∶3比例将其分为训练集(n=59)和验证集(n=27);采用单因素及多因素logistic回归分析训练集临床及CT特征,筛选胸腺瘤风险分类的独立预测因素,构建临床-CT模型。分别基于平扫、动脉期(AP)、静脉期(VP)、平扫+AP、平扫+VP、AP+VP及平扫+AP+VP提取并筛选最优影像组学特征,计算影像组学评分(Rad-score);采用受试者工作特征(ROC)曲线选取最佳影像组学模型,以之联合临床-CT特征构建联合模型。绘制ROC曲线,计算曲线下面积(AUC),评估各模型预测胸腺瘤风险分类的效能。结果 周围脂肪浸润是胸腺瘤风险分类的独立预测因素(OR=0.029,P=0.004)。ROC曲线显示,模型_AP+VP为最佳影像组学模型,其与联合模型预测训练集胸腺瘤风险分类的AUC分别为0.860及0.877,均高于临床-CT模型的0.736(Z=1.925、-2.464,P均＜0.05),预测验证集的AUC分别为0.835及0.847,亦高于临床-CT模型的0.641(Z=1.840、-2.137,P均＜0.05);模型_AP+VP与联合模型在训练集和验证集的AUC差异均无统计学意义(Z=-1.180、0.291,P均＞0.05)。结论 多时相CT影像组学模型可有效预测胸腺瘤风险分类。     

增强动脉期CT影像组学特征联合临床术前预测胃癌脉管浸润

目的 观察增强动脉期CT影像组学特征联合临床术前预测胃癌脉管浸润(LVI)的价值。方法 回顾性纳入298例胃癌患者,根据是否伴LVI将其分为阳性组(n=155)及阴性组(n=143),并按7 ∶ 3比例分为训练集(n=208)及测试集(n=90)。基于增强动脉期CT图提取病灶影像组学特征,采用logistic回归分析筛选胃癌LVI的临床影响因素;分别采用支持向量机(SVM)、逻辑回归(LR)、随机森林(RF)及极端梯度提升树(XGBoost)建立影像组学模型、临床模型及临床-影像组学模型,评估各模型预测胃癌LVI的效能。结果 以SVM、LR、RF及XGBoost建立的影像组学模型预测训练集胃癌LVI的曲线下面积(AUC)分别为0.896、0.821、1.000及1.000,其在测试集的AUC分别为0.744、0.801、0.740及0.747。基于4种机器学习建立的临床模型在训练集的AUC均为0.810,在测试集均为0.840。基于SVM、LR、RF及XGBoost建立的临床-影像组学模型预测训练集胃癌LVI的AUC分别为0.920、0.900、1.000及1.000,其在测试集的AUC分别为0.900、0.890、0.840及0.790。测试集中,基于SVM、LR及RF的临床-影像组学模型的AUC均大于影像组学模型和临床模型(P均＜0.05)。结论 增强动脉期CT影像组学联合临床有助于术前预测胃癌LVI。     

CT影像组学预测结直肠癌肝转移术后患者1年内无进展生存期

目的 评价CT影像组学模型预测结直肠癌肝转移(CRLM)患者术后1年无进展生存期(PFS)的价值。方法 回顾性分析147例CRLM术前末次CT资料,将其分为训练集(n=100)及验证集(n=47),依据临床预后分为预后良好(PFS≥12个月)及预后不佳(PFS＜12个月)。手动分割CT所示肝转移灶,提取及选择特征后,基于训练集数据构建影像组学模型,以多因素logistic回归构建临床模型及联合模型。绘制受试者工作特征曲线,计算曲线下面积(AUC),评价并比较各模型预测CRLM患者术后PFS的效能。结果 共选出7个特征用于构建影像组学模型。临床模型中,原发灶N分期、有无基因突变及有无术后化疗是预测CRLM患者术后PFS的独立因素;联合模型中的独立因素还包括影像组学评分。影像组学模型、联合模型预测训练集CRLM患者术后PFS的AUC均大于临床模型(0.89、0.93及0.67,P均＜0.05);其在验证集的AUC依次为0.77、0.78及0.56,前二者的效能优于临床模型(P＜0.05)。结论 影像组学模型及联合模型预测CRLM患者1年内PFS的效能均较好。     

基于CT密度联合纹理参数建模预测垂体大腺瘤质地

目的 探讨基于CT平扫图像密度联合纹理参数预测垂体大腺瘤质地的价值。方法 收集50例经手术病理证实的垂体大腺瘤,根据术中垂体质地分为质软组（n=30）与质硬组（n=20）。于CT图像肿瘤最大层面手动勾画ROI,测量病变CT值,并提取纹理特征参数。比较2组间CT值及纹理特征差异,对有统计学意义的变量采用多因素Logistic回归分析建立预测垂体腺瘤质地的模型,绘制ROC曲线评价其预测效能。结果 质软组与质硬组间CT值差异有统计学意义（P=0.031）,其预测肿瘤质地的AUC为0.662。基于CT平扫图像共提取77个纹理参数,经筛选获得4个2组间差异有统计学意义的参数,包括第90百分位数、惯量、方差和对比度,其预测肿瘤质地的AUC分别为0.662、0.663、0.672和0.663。多因素Logistic回归分析建立的纹理特征模型预测垂体腺瘤质地的AUC为0.690,CT值结合纹理参数模型的AUC为0.782。结论 CT值结合纹理参数建立的模型对于预测垂体腺瘤质地具有较高价值,可为临床选择手术方案提供帮助。     

脾脏CT表现用于预测进展期胃腺癌分化程度

目的 观察脾脏CT表现用于预测进展期胃腺癌分化程度的价值。方法 回顾性分析182例经术后病理证实的进展期胃腺癌患者,根据病理结果将其分为低分化组(n=89)及中-高分化组(n=93),比较2组临床资料,以及肿瘤及脾脏CT表现。采用多因素logistic回归分析筛选进展期胃腺癌分化程度的独立影响因素;绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),评估各单一独立影响因素及其联合预测进展期胃腺癌分化程度的效能。结果 组间患者年龄、性别、肿瘤厚度、肿瘤最长径、Borrmann分型、cT分期、cN状态、cTNM分期及动脉期脾脏CT值差异均有统计学意义(P均＜0.05)。多因素logistic回归分析显示,患者年龄、性别、Borrmann分型、cT分期、cTNM分期及动脉期脾脏CT值均为进展期胃腺癌分化程度的独立影响因素(P均＜0.05);以之单一及联合预测进展期胃腺癌分化程度的AUC分别为0.639、0.577、0.621、0.690、0.714、0.606及0.861。结论 脾脏CT表现有助于预测进展期胃腺癌分化程度,动脉期脾脏CT值为有效预测指标;联合临床及肿瘤CT特征可进一步提高预测效能。     

平扫CT深度学习模型预测经保守治疗后排出输尿管结石

目的 观察基于平扫CT建立的神经网络深度学习(DL)模型预测保守促排石治疗后排出输尿管结石的价值。方法 纳入915例接受保守促排石治疗的输尿管结石患者,随机分为训练集(n=700)、验证集(n=100)及测试集(n=115)。基于平扫CT标记结石三维形状,分别针对训练集和验证集获取三维卷积神经网络(3D-CNN)、二维卷积神经网络(2D-CNN)及全连接神经网络(FCN)最佳参数并建立模型,以测试集检测模型预测能力;绘制受试者工作特征曲线,比较各模型及结石最大径预测测试集经保守治疗后可否排出输尿管结石的效能。结果 915例中,229例经保守治疗后排出输尿管结石。3D-CNN模型预测测试集排出输尿管结石的效能最佳,其曲线下面积(AUC)为0.956,高于2D-CNN模型(0.865)、FCN模型(0.813)及结石直径(0.818)(P均＜0.01);2D-CNN模型预测AUC高于FCN模型及结石直径(P均＜0.05)。结论 利用DL模型、尤其3D-CNN能准确预测输尿管结石可否于保守治疗后排出。     

CT灌注参数和围手术期临床资料用于预测成年烟雾病患者接受联合搭桥术后发生脑过度灌注综合征

目的 观察术前CT灌注(CTP)参数及围手术期临床资料用于预测联合搭桥术治疗成年人烟雾病(MMD)后过度灌注综合征(CHS)的价值。方法 回顾性收集60例接受联合搭桥术的成年MMD患者,根据术后是否发生CHS分为CHS组(n=18)和非CHS组(n=42);比较组间术前1周内头颅CTP参数和围手术期临床资料差异,采用logistic回归分析评估术后CHS的危险因素,并以受试者工作特征曲线评估各参数预测CHS的效能。结果 组间术前脑血容量(CBV)、流量提取乘积(FEP)及术后当日平均动脉压(MAP)差异均有统计学意义(P均＜0.05)。术前FEP及术后当日MAP较高是联合搭桥术治疗成年MMD后发生CHS的危险因素。以术前CBV、FEP及术后当日MAP预测联合搭桥术治疗成年MMD后发生CHS的曲线下面积(AUC)分别为0.712、0.771及0.665,三者联合AUC为0.872,高于各单一因素(Z=2.17、2.77、3.13,P均＜0.05)。结论 术前CBV、FEP及术后当日MAP有助于预测成年MMD患者接受联合搭桥术后发生CHS;联合应用三者可提高预测效能。     

超声评估儿童克罗恩病活动度

目的 观察超声评估儿童克罗恩病(CD)活动度的价值。方法 回顾性分析24例经肠镜及活检病理确诊CD患儿,根据儿童CD活动指数(PCDAI)将其分为活动期(PCDAI ≥ 10.0,n=17)及缓解期(PCDAI<10.0,n=7),比较其超声所示病变肠壁厚度、肠壁分层、肠壁血供(Limberg分级)、肠系膜淋巴结肿大与否及肠外并发症的差异,分析肠壁厚度与C反应蛋白(CRP)及红细胞沉降率(ESR)的相关性。结果 活动期CD累及肠壁厚度、肠壁分层缺失占比及Limberg 分级均高于缓解期CD(P均<0.05),肠系膜淋巴结肿大占比则与缓解期CD差异无统计学意义(P>0.05)。超声于活动期CD患儿中检出3例肛周脓肿、2例腹腔积液及1例肛瘘;于缓解期CD患儿未见明确并发症。24例CD累及肠壁厚度均与CRP(r_s=0.60,P=0.01)及ESR(r_s=0.71,P<0.01)呈正相关。结论 超声可用于评估儿童CD活动度。     

临床、CT影像组学及融合模型预测肝细胞癌分化程度

目的 评价临床、CT影像组学及融合模型预测肝细胞癌（HCC）分化程度的可行性。方法 纳入330例HCC患者,根据病理所见分化程度分为高分化组（n=85）、中分化组（n=161）及低分化组（n=84）,比较组间临床资料及CT征象差异。按3∶1比例随机将各组分为训练集及测试集。提取训练集CT影像组学特征,构建临床模型、影像组学模型及融合模型。绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUC）,评估各模型鉴别不同分化程度HCC的效能。结果 共纳入352个CT影像组学特征,109个来自高、中分化HCC,84个来自中、低分化HCC,159个来自高、低分化HCC。临床模型鉴别高、低分化HCC的AUC为0.85;CT影像组学模型鉴别高分化与中、低分化HCC的AUC分别为0.80及0.79;融合模型鉴别高、低分化HCC的AUC为0.88。结论 临床、CT影像组学及融合模型预测高、低分化HCC的效能均较高。CT影像组学模型可较好地预测高、中分化HCC。     

MSCT双期增强扫描诊断局灶性自身免疫性胰腺炎

目的 探讨MSCT双期增强扫描在诊断局灶性自身免疫性胰腺炎(f-AIP)中的价值。方法 对经临床或病理证实的26例f-AIP患者进行MSCT平扫、动脉期及门静脉期扫描。观察病灶动脉期、门静脉期的CT表现,并比较CT值。结果 f-AIP特征性CT表现包括均匀稍低密度灶(n=26)、门静脉期均匀强化(n=26)、鞘膜征(n=19)、胆总管下段狭窄及胰管狭窄(n=9)。f-AIP动脉期、门静脉期CT值分别为(60.21±6.03)HU、(87.13±6.06)HU,门静脉期的CT值高于动脉期(t=22.65,P<0.05)。结论 MSCT双期增强扫描在f-AIP诊断中具有重要价值。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.