Application of a Machine Learning Algorithm for Structural Brain Images in Chronic Schizophrenia to Earlier Clinical Stages of Psychosis and Autism Spectrum Disorder: A Multiprotocol Imaging Dataset Study

Background and HypothesisMachine learning approaches using structural magnetic resonance imaging (MRI) can be informative for disease classification; however, their applicability to earlier clinical stages of psychosis and other disease spectra is unknown. We evaluated whether a model differentiating patients with chronic schizophrenia (ChSZ) from healthy controls (HCs) could be applied to earlier clinical stages such as first-episode psychosis (FEP), ultra-high risk for psychosis (UHR), and autism spectrum disorders (ASDs).Study DesignTotal 359 T1-weighted MRI scans, including 154 individuals with schizophrenia spectrum (UHR, n = 37; FEP, n = 24; and ChSZ, n = 93), 64 with ASD, and 141 HCs, were obtained using three acquisition protocols. Of these, data regarding ChSZ (n = 75) and HC (n = 101) from two protocols were used to build a classifier (training dataset). The remainder was used to evaluate the classifier (test, independent confirmatory, and independent group datasets). Scanner and protocol effects were diminished using ComBat.Study ResultsThe accuracy of the classifier for the test and independent confirmatory datasets were 75% and 76%, respectively. The bilateral pallidum and inferior frontal gyrus pars triangularis strongly contributed to classifying ChSZ. Schizophrenia spectrum individuals were more likely to be classified as ChSZ compared to ASD (classification rate to ChSZ: UHR, 41%; FEP, 54%; ChSZ, 70%; ASD, 19%; HC, 21%).ConclusionWe built a classifier from multiple protocol structural brain images applicable to independent samples from different clinical stages and spectra. The predictive information of the classifier could be useful for applying neuroimaging techniques to clinical differential diagnosis and predicting disease onset earlier.     

Multidimensional feature interactions in visual crowding: When configural cues eliminate the polarity advantage

Crowding occurs when surrounding objects (flankers) impair target perception. A key property of crowding is the weaker interference when target and flankers strongly differ on a given dimension. For instance, identification of a target letter is usually superior with flankers of opposite versus the same contrast polarity as the target (the “polarity advantage”). High performance when target-flanker similarity is low has been attributed to the ungrouping of target and flankers. Here, we show that configural cues can override the usual advantage of low target-flanker similarity, and strong target-flanker grouping can reduce – instead of exacerbate – crowding. In Experiment 1, observers were presented with line triplets in the periphery and reported the tilt (left or right) of the central line. Target and flankers had the same (uniform condition) or opposite contrast polarity (alternating condition). Flanker configurations were either upright (||), unidirectionally tilted (\\ or //), or bidirectionally tilted (\/ or /\). Upright flankers yielded stronger crowding than unidirectional flankers, and weaker crowding than bidirectional flankers. Importantly, our results revealed a clear interaction between contrast polarity and flanker configuration. Triplets with upright and bidirectional flankers, but not unidirectional flankers, showed the polarity advantage. In Experiments 2 and 3, we showed that emergent features and redundancy masking (i.e. the reduction of the number of perceived items in repeating configurations) made it easier to discriminate between uniform triplets when flanker tilts were unidirectional (but not when bidirectional). We propose that the spatial configurations of uniform triplets with unidirectional flankers provided sufficient task-relevant information to enable a similar performance as with alternating triplets: strong-target flanker grouping alleviated crowding. We suggest that features which modulate crowding strength can interact non-additively, limiting the validity of typical crowding rules to contexts where only single, independent dimensions determine the effects of target-flanker similarity.     

桥本氏病的影像表现分析

目的 探讨各种影像检查诊断桥本氏病的价值。方法回顾性分析61例桥本氏病的超声、核素扫描、CT、MRI检查结果，总结其特点。结果 桥本氏病在超声下特点为：弥漫性增大，网格样结构，血流异常丰富，可以有结节；^99mTcO4^-核素扫描显示甲状腺弥漫肿大，放射性分布不均。结节以凉结节和冷结节多见，^99mTc-MIBI可鉴别冷结节是否为恶性肿瘤，而CT、MRI也可鉴别合并恶性肿瘤，并可发现有无侵犯及颈淋巴结转移，为手术提供依据。结论 各种影像检查对桥本氏病的诊断有一定价值。     

Dynesys治疗退行性腰椎疾病初期疗效分析

目的探讨后路中和固定系统（Dynesys）治疗退行性腰椎疾病初期疗效。方法选择2012年4月～2012年10月浙江省人民医院骨科因腰腿痛行腰椎后路减压Dynesys内固定术患者17例。应用视觉模拟评分（VAS）进行疼痛改善评估;应用Oswestry功能障碍指数进行临床疗效评价。结果术后随访6～13个月,平均10个月。VAS疼痛评分术前（8.4±1.5）分;术后（2.7±2.1）分,术后与术前比较差异有统计学意义（P〈0.05）。Oswestry功能障碍指数术前为（67±23）%,术后为（29±19）%,术后与术前比较差异有统计学意义（P〈0.05）。所有病例均无椎根螺钉松动断裂,无套管及绳索的松动滑脱。结论 Dynesys既能在临床上明显改善腰椎退行性疾病,又较好保留了固定节段间的活动度,是目前治疗腰椎退行性疾病的有效非融合性内固定技术。     

肺结核病的医学影像诊断现状与发展趋势

肺结核病仍然是中国较常见的慢性传染病。在临床的诊断与治疗过程中,现代医学影像技术的应用与价值日显突出。尽管常规X线胸片被视为肺结核病首选和主要检查手段,但其应用价值逐渐显露弊端;而多层螺旋CT检查在肺结核病的诊断、活动性判定和治疗随访中发挥越来越重要的作用,将成为未来肺结核病筛查和诊断的首选影像学方法。基于MRI多参数成像和组织分辨率高等优点,其在特殊肺结核病及非典型肺结核球与周围型肺癌的鉴别诊断中具有重要价值。正电子发射体层（ PET）-CT可显示病变的病理生理改变与代谢状况,在肺结核病成分判定与鉴别诊断等方面亦有潜在的应用价值。     

A risk prediction model for contrast-induced nephropathy associated with gadolinium-based contrast agents

ObjectiveThis is the first study to explore the risk factors for nephropathy caused by gadolinium-based contrast agents and establish a prediction model to identify high-risk patients.MethodsA total of 1404 patients who received gadolinium-based contrast agents in our hospital were included. The participants were randomly assigned in a 7:3 ratio to the modeling and validation groups. The modeling group was divided into a contrast-induced nephropathy group and a non-contrast-induced nephropathy group. The clinical characteristics before the use of contrast agents were compared between the two groups. The risk factors for contrast-induced nephropathy were analyzed by logistic regression. A nomogram that could predict the incidence of contrast-induced nephropathy was plotted. The validation group was used to verify the predictive model.ResultsThe incidence of contrast-induced nephropathy caused by gadolinium-based contrast agents was 3.92% (55/1404). The logistic stepwise regression analysis showed that sex, systolic pressure (SBP), absolute neutrophil count, albumin, fasting blood glucose level, and furosemide use were significant predictors of contrast-induced nephropathy caused by gadolinium-based contrast agents. The above predictors were then included in the nomogram construction. The area under the receiver operating characteristic (ROC) curve was 0.82 (p < 0.001). The specificity and sensitivity corresponding to the optimal cutoff point (0.039) based on the area under the ROC curve were 71.9% and 80.5%, respectively.ConclusionSex, SBP, absolute neutrophil count, albumin, fasting blood glucose levels, and furosemide use are significant predictors of contrast-induced nephropathy caused by gadolinium-based contrast agents. Therefore, the incidence of contrast-induced nephropathy may be estimated by the prediction model established in this study before the use of contrast agents.     

Differential temporal neural responses of pain-related regions by acupuncture at acupoint ST36: a magnetoencephalography study

Background  Previous neuroimaging studies primarily focused on the spatial distribution of acupuncture needling stimulation. However, a salient feature of acupuncture was its long-lasting effect. This study attempted to detect the spatial-temporal neural responses evoked by acupuncture at an analgesia acupoint ST36 by using magnetoencephalography. To further verify its functional specificity, we also adopted acupuncture at Pericardium 6 and nonacupoint as separated controls.

Methods  Forty-two college students, all right-handed and acupuncture naïve, participated in this study. Every participant received only one acupoint stimulation, resulting in 14 subjects in one group. Both magnetoencephalography data (151-channel whole-head system) and structural functional magnetic resonance imaging data (3D sequence with a voxel size of 1 mm³ for anatomical localization) were collected for each subject. All processing procedures were performed in BrainStorm Toolbox.

Results  Acupuncture at ST36 showed a significantly time-varied brain activities with different onset time. Our results presented that acupuncture at different acupoints (or comparing with nonacupoint) can specifically induce neural responses in different brain areas—acupuncture at ST36 can specifically induce the neural responses of pain-inhibition areas, while acupuncture at PC6 can specifically induce the activities of the insula and amygdala.

Conclusions  In the present study, we attempted to detect the temporal neural responses underlying the functional specificity of acupuncture at ST36, using acupoint belonging to different meridians and non-acupoint with efficacy-irreverent as separate controls. The specific neural substrates involving acupuncture at different acupoints may be related to its functional specificity in clinical settings.

     

腰椎间盘突出症翻修患者的MRI表现

目的探讨腰椎间盘突出症再手术患者的MRI表现。方法回顾性分析1998年1月至2007年12月174例腰椎间箍突出症翻修患者的MRI资料。结果本组174例,男102例,女72例;年龄28～81岁,平均46．8岁。距初次手术时间7d～6年。所有患者均在手术前行MRI检查。其中61例同时行Gd增强扫描。结论MRI对腰椎间盘突出症翻修的原因大多能很好的做出诊断,但对椎弓根螺钉位置不当引起的神经根刺激却不如CT。     

多模态功能MRI在糖尿病脑病中的应用研究

【摘要】目的 探讨多模态功能MRI用于早期诊断2型糖尿病（T2DM）脑病及其病情严重程度评估。方法 纳入2016年3月～2017年5月我院收治的49例T2DM合并脑病患者,按照病程长短分为A组（23例）（＜10年）与B组（26例）（＞10年）,同时招募健康志愿者21名为志愿者组。采用磁敏感加权成像（susceptibility weighted imaging,SWI）与MR波谱成像(magnetic resonance spectroscopy,MRS)对受试者左侧海马部位进行扫描,计算各组受试者相位值与蒙特利尔认知（Montreal of Cognitive Assessment,MOCA）评分之间是否存在相关关系。结果 3组MoCA评分差异无统计学意义（P＞005）;B组的SWI相位值、Ins/Cr值、Cho/Cr值均高于A组（P＜005）,A组高于志愿者组（P＜005）;A组NAA/Cr值高于B组（P＜005）,但显著低于志愿者（P＜005）;MoCA评分与A组、B组受试者SWI相位值成正相关关系,与A组、B组受试者的Ins/Cr、Cho/Cr、NAA/Cr均具有负相关关系。 结论 多模态功能MRI有助于早期诊断并评价T2DM糖尿病脑病(diabetic encephalopathy,DE)病情严重程度。     

Prediction of early recurrence of hepatocellular carcinoma after resection based on Gd-EOB-DTPA enhanced magnetic resonance imaging: a preliminary study

BackgroundEarly recurrence (ER) after radical resection of hepatocellular carcinoma (HCC) affects the prognosis of patients. Gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) can improve the detection rate of small HCC. This study innovatively introduces a new quantitative index combined with qualitative index to compare the differences in clinical and imaging characteristics between ER and non-ER groups and evaluate the feasibility of Gd-EOB-DTPA-enhanced MRI in predicting ER.MethodsA total of 68 patients with HCC confirmed by operation and pathology in the Shandong Cancer Hospital and Institute were included retrospectively. All participants were examined by Gd-EOB-DTPA-enhanced MRI within 3 weeks before surgery. Regular follow-up was performed every 2 months within 1 year after operation. Among them, 18 cases with new lesions were in ER group, and 50 cases without new lesions were in non-ER group. The clinical and imaging data of the 2 groups were collected, and the differences of clinical data and preoperative MRI signs between the ER group and non-ER group were compared. The predictive factors of ER after HCC were analyzed by multivariate logistic regression.ResultsThe quantitative parameter lesion-to-liver contrast enhancement ratio (LLCER) can predict the pathological grade of HCC (P=0.023). The results of univariate analysis between the ER group and non-ER group showed that there were significant differences in pathological grade (P=0.008), lesion morphology (P=0.011), peritumoral low signal intensity in hepatobiliary phase (HBP) (P<0.001), satellite nodules (P<0.001), and LLCER (P<0.001) between the 2 groups. Multivariate logistic regression analysis showed that HBP peritumoral low signal intensity [odds ratio (OR) =7.214, 95% confidence interval (CI): 1.230–42.312, P=0.029], satellite nodules (OR =9.198, 95% CI: 1.402–60.339, P=0.021), and parameter LLCER value (OR =0.906, 95% CI: 0.826–0.995, P=0.039) were independent predictors of ER of HCC after resection.ConclusionsPreoperative Gd-EOB-DTPA enhanced MRI has important predictive value for early recurrence after radical resection of hepatocellular carcinoma.