乳腺对比增强能谱X线摄影的研究现状北大核心

对比增强能谱X线摄影(contrast enhancement spectral mammography, CESM)是在普通X线检查的基础上结合血管造影剂进行检查的一种新技术,是通过注射造影剂有效消除组织重叠对病灶的遮盖,实现对肿块真实形态显示,并提供血供信息。目前临床上对CESM进行了一系列的研究,本文就CESM成像原理、对乳腺癌的诊断、应用前景几个方面进行综述。     

双源CT多定量参数对胃癌的诊断价值及与HER2的相关性

目的:探讨门脉期双源CT多个定量参数与胃腺癌病理分化程度及HER2的相关性。方法: 回顾性分析2018年7月至2019年4月间于陕西省人民医院行双源CT双能量扫描的48例经胃镜活检(21例)或手术病理证实（27例）的胃腺癌及30例正常胃的影像学资料，其中27例HER2指标明确，通过西门子第二代双源CT扫描获得静脉期双能量图像，利用syngo.via软件获得曲线斜率、门脉期碘浓度、标准化碘浓度；将患者分为胃腺癌与正常胃壁组，高、中、低分化胃腺癌组，HER2阳性组（+，++，+++）与HER2阴性组（-）。统计学方法采用Kappa一致性检验、ROC曲线法、两独立样本t检验及方差分析。结果:活检与术后病理结果具有较强的一致性（Kappa系数为0.701），两者无明显差异；胃腺癌与正常胃壁两组间能谱曲线斜率（1.35±0.24、2.19±0.71）及标准化碘浓度（0.31±0.079、0.54±0.157）均具有统计学意义（P<0.05），曲线下面积分别为0.992、0.919；低分化、中分化及高分化胃腺癌能谱曲线斜率值（3.07±0.67，2.63±0.57，2.01±0.39）组间及组内差异均具有统计学意义（P<0.05），低分化、中分化及高分化胃腺癌门脉期标准化碘浓度(0.60±0.167，0.52±0.089，0.36±0.039)组间差异具有统计学意义（P<0.05），中分化组与低分化组差异无统计学意义（P>0.05），高分化组与中、低分化组均具有统计学差异（P<0.05）。HER2阳性组与阴性组的能谱曲线斜率及标准化碘浓度值无统计学差异（P>0.05）。结论:能谱曲线斜率及门脉期标准化碘浓度值有助于对胃腺癌进行诊断并推测病理分化程度；双源CT定量参数与免疫组化指标HER2无相关性。     

Changes in electroencephalographic power and bicoherence spectra according to depth of dexmedetomidine sedation in patients undergoing spinal anesthesia

Background: Assessment the depth of dexmedetomidine sedation using electroencephalographic (EEG) features can improve the quality of procedural sedation. Previous volunteer studies of dexmedetomidine-induced EEG changes need to be validated, and changes in bicoherence spectra during dexmedetomidine sedation has not been revealed yet. We aimed to investigate the dexmedetomidine-induced EEG change using power spectral and bicoherence analyses in the clinical setting.Patients and Methods: Thirty-six patients undergoing orthopedic surgery under spinal anesthesia were enrolled in this study. Dexmedetomidine sedation was conducted by the stepwise increase in target effect site concentration (Ce) while assessing sedation levels. Bispectral index (BIS) and frontal electroencephalography were recorded continuously, and the performance of BIS and changes in power and bicoherence spectra were analyzed with the data from the F3 electrode.Results: The prediction probability values for detecting different sedation levels were 0.847, 0.841, and 0.844 in BIS, 95% spectral edge frequency, and dexmedetomidine Ce, respectively. As the depth of sedation increased, δ power increased, but high β and γ power decreased significantly (P <0.001). α and spindle power increased significantly under light and moderate sedation (P <0.001 in light vs baseline and deep sedation; P = 0.002 and P <0.001 in moderate sedation vs baseline and deep sedation, respectively). The bicoherence peaks of the δ and α-spindle regions along the diagonal line of the bicoherence matrix emerged during moderate and deep sedation. Peak bicoherence in the δ area showed sedation-dependent increases (29.93%±7.38%, 36.72%±9.70%, 44.88%±12.90%; light, moderate, and deep sedation; P = 0.008 and P <0.001 in light sedation vs moderate and deep sedation, respectively; P = 0.007 in moderate sedation vs deep sedation), whereas peak bicoherence in the α-spindle area did not change (22.92%±4.90%, 24.72%±4.96%, and 26.96%±8.42%, respectively; P=0.053).Conclusions: The increase of δ power and the decrease of high-frequency power were associated with the gradual deepening of dexmedetomidine sedation. The δ bicoherence peak increased with increasing sedation level and can serve as an indicator reflecting dexmedetomidine sedation levels.     

Practical uses of contrast‐enhanced spectral mammography in daily work: A pictorial review

Contrast‐enhanced spectral mammography (CESM) has a number of uses including the work‐up of inconclusive findings on mammography, assessment of breast symptoms, cancer staging, evaluation of response to neoadjuvant chemotherapy and recently as an alternative to magnetic resonance imaging (MRI) in high‐risk screening. CESM can be swiftly incorporated into the workflow of busy breast clinics. We share our experiences with CESM at a large breast assessment centre in Western Australia.     

GE宝石能谱CT故障分析

简要介绍了GE宝石能谱CT(Discovery CT750 HD)的技术特点,详细阐述了日常使用中出现的间歇性停机、无法进行Fastcal(快速空气校正)以及扫描中断和gantry(扫描架)自动复位3例故障的维修过程,为医院维修人员维修类似故障提供了参考。最后总结了医疗设备常见故障及主要故障原因,提出了快速排查CT故障的方法,并建议在日常使用中及时保养维护以降低设备故障率。     

能谱CT多参数成像评估胆结石成分的应用价值

目的 探究能谱CT多参数成像评估胆固醇结石和非胆固醇结石的应用价值。方法 收集125枚胆结石置入猪肝模型中行CT能谱模式扫描,并重建普通螺旋CT图像,测量所有胆结石单能量40 keV、100 keV时的CT值（HU_{40 keV}、HU_{100 keV}）、有效原子序数（Eff-Z）和普通螺旋CT值（HU_{120 kVp like}）,并计算40～100 keV区间能谱衰减斜率（K）,根据红外光谱分析结果分为胆固醇结石组56枚和非胆固醇结石组69枚。采用秩和检验比较两组各参数差异,利用多因素Logistic回归分析判断胆结石成分的独立影响参数,绘制受试者工作特征（ROC）曲线,分析评估影响效能及截断值。招募胆结石患者80例,术前行CT能谱模式扫描并重建普通螺旋CT图像,分别预测术前胆结石成分,术后取出86枚胆结石行红外光谱分析,分析各参数预测结果的准确性。结果 体外非胆固醇结石组HU_{40 keV}、HU_{100 keV}、Eff-Z、K值及HU_{120 kVp like}与胆固醇结石组比较,差异有统计学意义（P <0.05）,非胆固醇结石组高于胆固醇结石组。多因素Logistic回归分析结果显示仅Eff-Z［R=12.57（95% CI：5.38,29.35）］是胆固醇和非胆固醇结石的影响因素,其ROC曲线下面积为0.962（95% CI：0.928,0.997）,对应截断值为7.27。体内验证结果显示,以术后红外光谱分析为参照,能谱CT预测胆结石成分的总准确率为91.86%（95% CI：0.831,0.967）,而普通螺旋CT预测的总准确率仅为77.9%（95% CI：0.690,0.872）,能谱CT与红外光谱分析结果具有较高的一致性（κ =0.832,P <0.05）。而普通螺旋CT值预测胆结石成分结果与红外光谱分析结果一致性一般（κ =0.561,P <0.05）。结论 能谱CT多参数成像可较准确地评估胆结石成分,尤其以Eff-Z参考价值为佳,优于普通螺旋CT扫描。     

Representation and classification of breath sounds recorded in an intensive care setting using neural networks

Objective.Develop and test methods for representing and classifying breath sounds in an intensive care setting. Methods.Breath sounds were recorded over the bronchial regions of the chest. The breath sounds were represented by their averaged power spectral density, summed into feature vectors across the frequency spectrum from 0 to 800 Hertz. The sounds were segmented by individual breath and each breath was divided into inspiratory and expiratory segments. Sounds were classified as normal or abnormal. Different back-propagation neural network configurations were evaluated. The number of input features, hidden units, and hidden layers were varied.Results.2127 individual breath sounds from the ICU patients and 321breaths from training tapes were obtained. Best overall classification rate for the ICU breath sounds was 73% with 62% sensitivity and 85% specificity. Best overall classification rate for the training tapes was 91% with 87%sensitivity and 95% specificity. Conclusions.Long term monitoring of lung sounds is not feasible unless several barriers can be overcome. Several choices in signal representation and neural network design greatly improved the classification rates of breath sounds. The analysis of transmitted sounds from the trachea to the lung is suggested as an area for future study. This revised version was published online in July 2006 with corrections to the Cover Date.