11C-蛋氨酸PET/CT影像组学模型评估胶质母细胞瘤异柠檬酸脱氢酶1状态

目的 观察¹¹C-蛋氨酸(MET)PET/CT影像组学模型评估胶质母细胞瘤异柠檬酸脱氢酶1(IDH1)状态的价值。方法 回顾性分析157例接受¹¹C-MET PET/CT检查的胶质母细胞瘤患者资料,包括68例IDH1突变及89例野生型;按8 ∶ 2比例将其分为训练集(n=125)与验证集(n=32)。基于PET/CT图像勾画病灶ROI并提取、筛选影像组学特征,分别建立逻辑回归(LR)、支持向量机(SVM)及决策树(DT)影像组学模型;同时基于患者年龄及影像组学特征绘制列线图;对比观察影像组学模型及临床-影像组学列线图评估IDH1状态的效能。结果 DT影像组学模型评估训练集胶质母细胞瘤IDH1状态的曲线下面积(AUC)为0.910,大于LR(0.697)及SVM(0.698)模型(P均＜0.05)。验证集中,DT模型评估胶质母细胞瘤IDH1状态的AUC为0.805,大于LR模型(0.740)及临床-影像组学列线图(0.704)(P均＜0.05)。结论 基于DT的¹¹C-MET PET/CT影像组学模型有助于评估胶质母细胞瘤IDH1状态。     

基于增强CT影像组学术前预测胃腺癌淋巴结转移

目的 观察增强CT影像组学模型术前预测胃腺癌淋巴结转移（LNM）的价值。方法 回顾性分析193例经术后病理证实的单发胃腺癌的腹部双期增强CT资料,将其分为训练集（n=97）和验证集（n=96）,比较LNM （+）与LNM （－）肿瘤CT表现的差异。分别于增强动脉期和静脉期CT提取病灶影像组学特征,构建相应影像组学标签;将单因素分析有统计学意义的CT参数及其影像组学标签纳入多因素logistic回归分析,筛选胃腺癌LNM的独立预测因素,分别建立临床模型及影像组学列线图。采用受试者工作特征（ROC）曲线评估各模型预测胃腺癌LNM的效能,计算曲线下面积（AUC）,比较其差异。结果 训练集含54例LNM （+）和43例LNM （－）,验证集含58例LNM （+）和38例LNM （－）。LNM （+）患者肿瘤厚度和阳性淋巴结占比均高于LNM （－）者（P均<0.05）。肿瘤厚度及淋巴结状态均为LNM的独立预测因素（P均<0.01）并用于构建临床模型。淋巴结状态和静脉期影像组学标签是胃腺癌LNM的独立预测因素（P均<0.01）,以之构建的影像组学列线图在训练集和验证集中的AUC分别为0.810和0.778,与临床模型AUC差异均无统计学意义（0.772、0.762,Z=1.11、0.27,P=0.27、0.78）。结论 基于增强CT影像组学模型术前预测胃腺癌LNM效能较佳。     

联合含瘤周肿瘤全体积CT影像组学特征及临床相关独立预测因子列线图预测肺腺癌淋巴血管侵犯

目的 观察基于含瘤周的肿瘤全体积(GPTV) CT影像组学特征及临床相关独立预测因子构建的联合模型列线图预测肺腺癌淋巴血管侵犯(LVI)的价值。方法 回顾性分析142例经病理证实的肺腺癌患者,以7 ∶ 3比例将其随机分为训练集(n=100,40例LVI阳性、60例LVI阴性)和验证集(n=42,17例LVI阳性、25例LVI阴性)。以单因素分析及多因素logistic回归分析筛选肺腺癌LVI的临床相关独立预测因子,以之构建临床模型。分别基于肿瘤全体积(GTV)及含瘤周3 mm、6 mm、9 mm的GPTV (GPTV₃、GPTV₆和GPTV₉)的增强动脉期CT图提取并筛选最佳影像组学特征,构建影像组学模型,即GTV、GPTV₃、GPTV₆和GPTV₉模型并筛选最佳者;基于后者的影像组学评分和临床相关独立预测因子构建联合模型,绘制列线图进行可视化。以受试者工作特征(ROC)曲线评估各模型预测肺腺癌LVI的效能,以决策曲线分析(DCA)评价联合模型列线图的价值。结果 性别、吸烟和毛刺征均为肺腺癌LVI的临床相关独立预测因子(P均＜0.05)。分别基于GTV、GPTV₃、GPTV₆及GPTV₉筛选出7、16、10及8个最佳影像组学特征,用于构建GTV、GPTV₃、GPTV₆及GPTV₉模型。GPTV₃模型预测训练集、验证集肺腺癌LVI的曲线下面积(AUC)分别为0.82、0.77,均高于GTV (0.79、0.72,Z=3.74、2.62,P均＜0.01)、GPTV₆(0.80、0.72,Z=2.40、2.06,P均＜0.05)及GPTV₉(0.77,0.72,Z=3.03、2.59,P均＜0.01),为最佳影像组学模型。联合模型列线图(0.86、0.73,Z=2.66、2.31,P均＜0.05)及GPTV₃模型(0.82、0.77,Z=2.23、2.54,P均＜0.05)于训练集和验证集的AUC均高于临床模型(0.73、0.61),而联合模型列线图与GPTV₃模型的AUC差异均无统计学意义(Z=1.57、0.88,P均＞0.05)。阈值取0.20~0.50时,联合模型列线图与GPTV₃模型的净获益相当,且均大于临床模型。结论 基于GPTV₃影像组学特征及临床相关独立预测因子的列线图可有效预测肺腺癌LVI。     

垂体相关临床及MRI影像组学特征联合列线图鉴别特发性中枢性性早熟与单纯乳房早发育

目的 观察垂体相关临床及MRI影像组学特征联合列线图鉴别特发性中枢性性早熟(ICPP)与单纯乳房早发育(PT)的价值。方法 纳入67例ICPP及51例PT共118例患儿,按照7 ∶ 3比例随机分为训练集(n=83)和验证集(n=35),记录其垂体相关临床资料,以多因素logistic回归分析筛选并建立临床模型。采集垂体MRI,基于矢状位T1WI提取垂体影像组学特征,以最大相关最小冗余、最小绝对收缩和选择算子及多因素logistic回归筛选最佳影像组学特征,构建影像组学模型。联合应用临床、MRI及影像组学特征构建列线图模型。绘制受试者工作特征曲线,评估模型鉴别诊断效能;以决策曲线分析(DCA)观察临床获益度。结果 训练集ICPP与PT患儿年龄、骨龄、体质量、黄体生成素(LH)基础值、卵泡刺激素基础值及垂体高度差异均有统计学意义(P均＜0.05)。骨龄及LH基础值是鉴别ICPP与PT的独立因素(OR=1.807、1.422,P均＜0.05),以之建立的临床模型鉴别训练集、验证集ICPP与PT的曲线下面积(AUC)分别为0.849和0.812。共提取垂体1 781个影像组学特征,于其中筛选出1个形态特征、1个一阶特征及1个灰度区域大小矩阵特征建立影像组学模型,其鉴别训练集和验证集ICPP与PT的AUC分别为0.956和0.947。基于最终得出的2个临床及3个垂体MRI影像组学特征构建的列线图模型鉴别训练集、验证集ICPP与PT的AUC分别为0.981、0.977,均优于临床模型(P均＜0.05),而与影像组学模型差异无统计学意义(P均＞0.05)。一定危险阈值范围内,列线图模型净收益最大。结论 基于垂体相关临床及MRI影像组学特征建立的联合列线图模型用于鉴别ICPP与PT具有较高价值。     

增强CT影像组学列线图预测膀胱尿路上皮癌肌层浸润

目的 评价增强CT影像组学列线图预测膀胱尿路上皮癌肌层浸润的可行性。方法 纳入91例膀胱尿路上皮癌患者,根据手术病理结果分为非肌层浸润性膀胱癌（NMIBC）组（n=51）和肌层浸润性膀胱癌（MIBC）组（n=40）,比较组间CT特征差异。利用Mazda软件提取病变纹理参数,以Lasso算法筛选,联合十折交叉验证构建Logistic回归影像组学列线图。绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUC）,评估列线图预测膀胱尿路上皮癌肌层浸润的效能。结果 CT形态不规则多见于MIBC组,NMIBC组与MIBC组肿瘤CT形态特征差异具有统计学意义（P<0.05）。Logistic回归组学列线图预测肌层浸润AUC为0.881,特异度为76.5%,敏感度87.5%,危险因素包括动脉期S（3,3）SumAverg、S（4,-4）InvDfMom及静脉期S（3,-3）DifEntrp、Perc.90%。结论 增强CT影像组学列线图有助于术前预测膀胱尿路上皮癌肌层浸润。     

自动乳腺全容积扫描影像组学联合临床和超声特征列线图鉴别良、恶性乳腺导管内病变

目的 观察自动乳腺全容积扫描(ABVS)影像组学联合临床及超声特征列线图鉴别良、恶性乳腺导管内病变的价值。方法 回顾性分析144例经病理证实乳腺导管内病变女性患者的临床及超声资料;按照2 ∶ 1比例将其随机分为训练集(n=96)及验证集(n=48)。基于ABVS图像提取并筛选最优影像组学特征,构建影像组学模型,计算影像组学评分(Radscore);将临床、超声特征及Radscore纳入单因素和多因素logistic回归分析,筛选鉴别良、恶性乳腺导管内病变的独立影响因素,构建临床-超声模型,并联合影像组学模型构建列线图模型;以受试者工作特征(ROC)曲线评估各模型鉴别良、恶性乳腺导管内病变的效能。结果 患者年龄 、病变边缘 、微小钙化灶 及Radscore 均为良、恶性乳腺导管内病变的独立影响因素。影像组学模型、临床-超声模型及列线图模型鉴别良、恶性乳腺导管内病变的曲线下面积(AUC)在训练集分别为0.766、0.866及0.901,在验证集分别为0.770、0.765及0.854。结论 ABVS影像组学联合临床及超声特征列线图鉴别良、恶性乳腺导管内病变效能良好。     

基于超声影像组学特征列线图模型术前鉴别早期与中晚期宫颈鳞癌

目的 观察基于经阴道超声影像组学特征建立的列线图模型术前鉴别早期与中晚期宫颈鳞癌的价值。方法 回顾性收集经术后病理证实的227例宫颈鳞癌患者,利用3D-Slicer软件于术前经阴道声像图中勾画ROI,提取并经冗余性分析、最小绝对收缩和选择算子(LASSO)和10折交叉验证筛选影像组学特征,构建影像组学模型并得到Radscore评分;利用多因素logistic回归纳入Radscore及临床资料构建列线图模型。比较2个模型术前鉴别早期与中晚期宫颈鳞癌的受试者工作特征曲线下面积(AUC);评估列线图模型的校准度及临床收益。结果 最终纳入18个超声影像组学特征;以之构建术前鉴别早期与中晚期宫颈鳞癌的影像组学模型在训练集和验证集的AUC分别为0.839和0.744;联合年龄、流产次数及Radscore评分构建的列线图模型在训练集和验证集的AUC分别为0.882和0.773。DeLong检验结果显示,上述2模型在训练集的AUC差异有统计学意义(P＜0.05)。Hosmer-Lemeshow检验显示,列线图模型在训练集和验证集的校准度均佳(χ²=5.053、7.063,P均＞0.05);决策曲线分析(DCA)显示其在0.01~1.00阈值区间净收益相对较大。结论 基于经阴道超声影像组学特征的列线图模型可于术前较好地鉴别早期与中晚期宫颈鳞癌。     

多脏器超声联合临床指标预测有创机械通气患者脱机后结局

目的 基于多脏器超声联合临床指标构建预测有创正压通气(IMV)患者脱机结局列线图,评估其临床价值。方法 前瞻性收集357例接受IMV的呼吸衰竭患者,依脱机后结局分为生存组(n=200)和死亡组(n=157);以单因素分析和单、多因素logistic回归分析IMV患者多脏器超声参数及临床指标,筛选脱机后死亡相关独立危险因素,以之构建预测IMV患者脱机结局的列线图。将患者随机分为训练集(n=178)和验证集(n=179),绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),评估列线图预测脱机结局的效能;基于验证集应用校准曲线评价列线图的拟合优度,以决策曲线分析(DCA)评估其临床价值。结果 左心室射血分数、每搏输出量、三尖瓣环收缩期位移、下腔静脉塌陷率、肺超声B线评分、右膈肌浅快呼吸指数,以及合并神经系统疾病、休克、IMV时间、急性生理学与慢性健康状况评分系统Ⅱ(APACHE Ⅱ)评分均为IMV患者脱机后死亡的独立危险因素(P均<0.05)。列线图预测训练集及验证集IMV患者脱机后死亡的AUC分别为0.86、0.99,其预测性能良好,且概率阈值为0.2~0.8时临床净获益较高。结论 基于多脏器超声联合临床指标的列线图可有效预测IMV患者脱机后结局。     

基于非小细胞肺癌双能CT表现及影像组学列线图模型预测其血管生成拟态

目的 基于非小细胞肺癌(NSCLC)双能CT (DECT)表现及影像组学构建联合列线图模型,分析其预测NSCLC血管生成拟态(VM)的价值。方法 回顾性分析137例经手术病理证实的单发NSCLC患者,以7 ∶ 3比例将其分为训练集和验证集。基于肺窗CT提取及筛选最优影像组学特征,计算影像组学评分。以单因素分析及多因素logistic回归分析筛选NSCLC表达VM的独立预测因素,分别以之构建临床、能谱及影像组学模型;基于独立预测因素构建联合列线图模型。采用受试者工作特征曲线评估各模型预测NSCLC VM的效能,以校准曲线分析模型的拟合度,以决策曲线分析评估模型的临床获益。结果 最终筛选出6个最优影像组学特征。病灶最大径、毛刺征、CT_{140 keV}及影像组学评分为NSCLC VM的独立预测因素(OR=2.25、9.69、0.99、-14.44,P均＜0.05)。临床、能谱及影像组学模型预测验证集NSCLC VM的曲线下面积(AUC)分别为0.83、0.85、0.87,均低于联合列线图模型(AUC=0.95,Z=2.14、2.10、2.07,P均＜0.05)。联合列线图模型预测结果与实际结果的一致性较好,且其临床获益较高。结论 基于DECT及影像组学构建的联合列线图模型能可有效预测NSCLC VM。     

基于CT机器学习模型预测肺腺癌气腔播散

目的 探讨基于胸部CT建立机器学习模型预测肺腺癌气腔播散（STAS）状态的价值。方法 回顾性分析462例经手术病理证实的原发性肺腺癌，90例STAS阳性（STAS阳性组），372例STAS阴性（STAS阴性组），比较组间一般资料及CT征象差异。按7 ：3比例将患者随机分为训练集（n=323）和验证集（n=139），采用随机森林算法针对差异有统计学意义的变量建立预测肺腺癌STAS的模型，对训练集进行训练，获得平均AUC最大的模型，以之对验证集进行预测，并计算AUC，评价其诊断效能。结果 组间年龄及12个CT征象差异均具有统计学意义（P均<0.05）。以上述13个变量建立的预测模型对训练集进行预测，获得最大AUC为0.80的模型，其预测训练集和验证集肺腺癌STAS的AUC、敏感度及特异度分别0.80、0.78及0.77和0.77、0.78及0.73。结论 基于胸部CT的机器学习模型可有效预测肺腺癌STAS状态。     

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.     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.