Extracting MRS discriminant functional features of brain tumors

The current challenge in automatic brain tumor classification based on MRS is the improvement of the robustness of the classification models that explicitly account for the probable breach of the independent and identically distributed conditions in the MRS data points. To contribute to this purpose, a new algorithm for the extraction of discriminant MRS features of brain tumors based on a functional approach is presented. Functional data analysis based on region segmentation (RSFDA) is based on the functional data analysis formalism using nonuniformly distributed B splines according to spectral regions that are highly correlated. An exhaustive characterization of the method is presented in this work using controlled and real scenarios. The performance of RSFDA was compared with other widely used feature extraction methods. In all simulated conditions, RSFDA was proven to be stable with respect to the number of variables selected and with respect to the classification performance against noise and baseline artifacts. Furthermore, with real multicenter datasets classification, RSFDA and peak integration (PI) obtained better performance than the other feature extraction methods used for comparison. Other advantages of the method proposed are its usefulness in selecting the optimal number of features for classification and its simplified functional representation of the spectra, which contributes to highlight the discriminative regions of the MR spectrum for each classification task. Copyright © 2012 John Wiley & Sons, Ltd.     

基于MRI弥散成像的直方图纹理分析鉴别肝脏局灶性结节性增生和少脂型肝血管平滑肌脂肪瘤

肝局灶性结节性增生(focal nodular hyperplasia, FNH)是一种较少见的良性富血供肿瘤样病变，是肝细胞对局部血管异常产生的一种反应性增生，而非真正意义上的肿瘤[1]。肝脏血管平滑肌脂肪瘤是肝脏内少见的肿瘤，由增生的厚壁血管、平滑肌及成熟的脂肪组织构成，且3种成分构成比例、分布各不相同，且具有潜在的恶性转化和自发破裂的危险，应该积极手术治疗[2]。肝脏血管平滑肌脂肪瘤可分为4 种类型：脂瘤型（脂肪含量≥ 70%）、肌样型（脂肪含量≤ 10%，上皮样型及梭形细胞型）、血管型（以多发粗大、扭曲的畸形血管为主）及混合型（3 种组成成分比例相近）[3]。肌样型及血管型是含微量成熟脂肪的少脂型血管平滑肌脂肪瘤（Low-fat hepatic angiomyolipoma,LF-HAML)，与肝癌、肝腺瘤及FNH等肝脏富血供病变鉴别困难，术前FNH和LF-HAML在临床和影像表现存在较多的重叠[4]，目前国内外对此研究较少，因此准确诊断并鉴别对确定治疗方案和改善患者预后至关重要, 纹理分析是影像组学研究的基础，在肿瘤病灶提取、定性、疗效评估及预后预测方面具有较高的价值[5-6]。笔者旨在探讨基于直方图的MRI-DWI纹理特征方法鉴别两种病变的价值。     

Optimization of breast lesion segmentation in texture feature space approach

This paper develops a method for semi-automatic detection of breast lesion boundaries by combining the snake evolution techniques with statistical texture information of images. We propose an efficient image energy function in segmentation based on image features, first-order textural features and four n × n masks. The segmentation results were evaluated by using area error rate. The image features were evaluated qualitatively by using the contrast-to-noise ratio and fractal dimension analysis. In our study, standard deviation, skewness and entropy are indicated as being the most relevant image features.     

灼口综合征患者心理健康状况及相关因素分析

目的:探讨灼口综合征患者心理健康状况及相关因素。方法:采用抑郁自评量表(SDS)、焦虑自评量表(SAS)、艾森克人格问卷简式量表中国版(EPQ-RSC)以及医学应对方式问卷(MCMQ)对60例灼口综合征患者和对照组进行测评。结果:灼口综合征患者抑郁、焦虑情绪明显高于对照组,"回避"和"屈服"应对方式与抑郁情绪呈正相关;精神质、神经质和掩饰性人格与抑郁、焦虑情绪呈正相关。结论:灼口综合征患者并发较高程度的抑郁、焦虑症状,同时不同人格类型与应对方式对其焦虑、抑郁有较大影响。     

Discrimination between glioblastoma multiforme and solitary metastasis using morphological features derived from the p:q tensor decomposition of diffusion tensor imaging

The management and treatment of high‐grade glioblastoma multiforme (GBM) and solitary metastasis (MET) are very different and influence the prognosis and subsequent clinical outcomes. In the case of a solitary MET, diagnosis using conventional radiology can be equivocal. Currently, a definitive diagnosis is based on histopathological analysis on a biopsy sample. Here, we present a computerised decision support framework for discrimination between GBM and solitary MET using MRI, which includes: (i) a semi‐automatic segmentation method based on diffusion tensor imaging; (ii) two‐dimensional morphological feature extraction and selection; and (iii) a pattern recognition module for automated tumour classification. Ground truth was provided by histopathological analysis from pre‐treatment stereotactic biopsy or at surgical resection. Our two‐dimensional morphological analysis outperforms previous methods with high cross‐validation accuracy of 97.9% and area under the receiver operating characteristic curve of 0.975 using a neural networks‐based classifier. Copyright © 2014 John Wiley & Sons, Ltd.     

老年人高血压临床特征及其防治方法分析

目的探讨分析老年高血压患者的临床特征,并提出相应的防治方法。方法选取2011年5月到2014年5月来我院就诊的老年高血压患者128例作为研究对象,对其临床表现进行观察分析。结果 128例患者临床表现主要是头晕、头痛、心悸且伴有耳鸣等症状;其中61例患者为ISH,32例患者为IDH,而其余患者则为二者的合并症;高血压I期、II期、III期所占比例分别为12.5%、71.88%、15.62%%;高血压患者易导致多种并发症的发生,在128例患者中合并脑溢血、冠心病、脑梗塞的比例为11.72%、74.22%、26.56%,其中合并冠心病、脑溢血的患者男女之间并无明显差异(P0.05),而脑梗阻患者的男女发病率具有较大的差异。结论老年患者的主要临床特征为单纯性的收缩压增高,且具有较多的并发症和合并症。     

重复住院呼吸道病毒感染患儿病因及临床特征

目的探讨重复住院呼吸道病毒感染患儿的临床特征,以更好地指导呼吸道病毒感染的诊断和治疗。方法通过对重复住院患儿(观察组)和一次住院患儿临床资料、发病特征、病毒感染等进行统计学分析,总结重复住院患儿的主要临床特征。结果观察组和对照组在临床基本资料和病毒检出方面并无统计学差异(P>0.05)。在主要临床症状上,观察组和对照组在发热、流涕、咳嗽、咳痰和呼吸困难等方面无统计学差异(P>0.05),但是在喘息和腹泻方面有统计学差异(P<0.05)。结论喘息和腹泻是呼吸道病毒感染患儿重复住院的主要参考症状。如患儿存在上述症状,要采取更有针对性的治疗,以提升治疗效果。     

Echocardiography and Cardiac Magnetic Resonance‐Based Feature Tracking in the Assessment of Myocardial Mechanics in Tetralogy of Fallot: An Intermodality Comparison

We investigated intermodality agreements of strains from two‐dimensional echocardiography (2DE) and cardiac magnetic resonance (CMR) feature tracking (FT) in the assessment of right (RV) and left ventricular (LV) mechanics in tetralogy of Fallot (TOF). Patients were prospectively studied with 2DE and CMR performed contiguously. LV and RV strains were computed separately using 2DE and CMR‐FT. Segmental and global longitudinal strains (GLS) for the LV and RV were measured from four‐chamber views; LV radial (global radial strain [GRS]) and circumferential strains (GCS) measured from short‐axis views. Intermodality and interobserver agreements were examined. In 40 patients (20 TOF, mean age 23 years and 20 adult controls), LV, GCS showed narrowest intermodality limits of agreement (mean percentage error 9.5%), followed by GLS (16.4%). RV GLS had mean intermodality difference of 25.7%. GLS and GCS had acceptable interobserver agreement for the LV and RV with both 2DE and CMR‐FT, whereas GRS had high interobserver and intermodality variability. In conclusion, myocardial strains for the RV and LV derived using currently available 2DE and CMR‐FT software are subject to considerable intermodality variability. For both modalities, LV GCS, LV GLS, and RV GLS are reproducible enough to warrant further investigation of incremental clinical merit.     

用谐波小波包变换法提取GIS局部放电信号多尺度特征参数

超高频(UHF)法在GIS局部放电(PD)检测中已得到了广泛应用，UHF PD信号的特征提取对准确识别GIS内部绝缘缺陷类型和指导检修工作具有重要意义，但目前仍然缺乏有效的特征提取方法。为此，本文利用谐波小波具有严格盒形频谱的优点，提出一种提取UHF PD特征信息的谐波小波包变换(HWPT)方法，对实验室获取的4种典型放电模型产生的UHF PD信号，采用HWPT进行多尺度分解，以克服实小波包分解子带间存在频谱混叠和能量泄漏的缺陷，利用UHF PD信号在不同尺度能量和复杂度的差异，提取多尺度能量和多尺度样本熵参数作为模式识别的特征量，更加精确地描述了UHF PD信号的时频域信息。最后利用支持向量机分类识别的结果表明，该方法可以取得比实小波包更好的识别效果，多尺度能量和多尺度样本熵特征参数均能有效识别4种绝缘缺陷。