• 【DKI和DTI的全肿瘤放射组学分析可能会改善星形细胞瘤基因型的预测:一项初步研究。】 复制标题 收藏 收藏
    DOI:10.1016/j.ejrad.2019.108785 复制DOI
    作者列表:Tan Y,Mu W,Wang XC,Yang GQ,Gillies RJ,Zhang H
    BACKGROUND & AIMS: PURPOSE:To test whether the whole-tumor radiomics analysis of DKI and DTI images could predict IDH and MGMTmet genotypes of astrocytomas. METHOD:Sixty-two astrocytomas were enrolled. 364 radiomics features of whole tumor were extracted from mean-kurtosis (MK), and mean-diffusivity (MD) images, respectively. The multivariable logistic regression was used to select the most meaningful radiomics features for predicting IDH and MGMTmet genotypes. A radiomics model was built by logistic linear regression. A combined model was established based on selected radiomic, radiological and clinical features. To assess the difference between the models, the Z-test was performed. RESULTS:The radiomics model built using the three most informative radiomics features for each genotype yielded an AUC of 0.831 ((95 % confidence interval [CI]: 0.721-0.918) for predicting IDH genotype, and 0.835 (95 %CI: 0.686-0.951) for MGMTmet genotype. A combined model for predicting IDH based on the radiomics score, age, and degree of edema reached an AUC of 0.885 (95 %CI: 0.802-0.955) and a combined model for predicting MGMTmet based on radiomics score and edema degree reached an AUC of 0.859 (95 %CI: 0.751-0.945) which was not significantly higher than the radiomics only model (P =  0.081). CONCLUSIONS:The radiomics models via an objective whole-tumor analysis of MK and MD maps were independent imaging biomarkers for predicting IDH and MGMTmet genotypes, and the combined model further improved the performance for IDH, but not for MGMTmet.
    背景与目标: 目的:检验DKI和DTI图像的全肿瘤放射组学分析是否可以预测星形细胞瘤的IDH和MGMTmet基因型。
    方法:纳入62例星形细胞瘤。分别从均值峰度(MK)和均值扩散率(MD)图像中提取了364个整个肿瘤的放射学特征。多变量logistic回归用于选择最有意义的放射学特征,以预测IDH和MGMTmet基因型。通过逻辑线性回归建立了放射学模型。基于选定的放射,放射和临床特征建立了一个组合模型。为了评估模型之间的差异,进行了Z检验。
    结果:针对每种基因型使用三种信息量最大的放射学特征建立的放射学模型产生的AUC预测IDH基因型为0.831((95%置信区间[CI]:0.721-0.918)),以及0.835(95%CI:0.686-0.951) MGMTmet基因型的组合模型,基于放射线学评分,年龄和水肿程度的IDH预测组合模型的AUC为0.885(95%CI:0.802-0.955),基于放射线学评分和水肿预测MGMTmet的组合模型AUC达到0.859(95%CI:0.751-0.945),这并不显着高于仅使用Radiomics的模型(P = 0.081)。
    结论:通过MK和MD图的客观全肿瘤分析,放射线学模型是预测IDH和MGMTmet基因型的独立成像生物标志物,组合模型进一步提高了IDH的性能,但没有改善MGMTmet的性能。
  • 【无症状性颈动脉斑块患者的微结构白质异常和认知障碍:使用TBSS分析的DTI研究。】 复制标题 收藏 收藏
    DOI:10.1016/j.clineuro.2020.106096 复制DOI
    作者列表:Liu L,Huang Q,Yang S,Wen Y,He W,Liu H,Meng L,Jiang H,Xia J,Liao W,Liu Y
    BACKGROUND & AIMS: BACKGROUND:It has been shown that symptomatic or severe carotid atherosclerosis is closely related to cognitive impairment and brain white matter damage. However, there is still a lack of effective and non-invasive imaging biomarkers to identify early high-risk cerebrovascular diseases. Therefore, the purpose of this study is to explore the integrity of brain white matter and cognitive impairment in patients with asymptomatic carotid plaques by using imaging technology. METHODS:All subjects were from a project of Stroke Risk Screening and Prevention and were defined as stroke high-risk patients (with three or more stroke risk factors). Tract-based spatial statistics (TBSS) based on diffusion tensor imaging (DTI) was used to analyze the whole brain white matter abnormalities in 61 patients with carotid artery plaque and in 40 healthy controls. At the same time, the general clinical data between the two groups were compared, such as age, gender, smoking, hypertension and cognitive function scores etc. Furthermore, the plaque group was divided into the have-hyperintensities group and the no-hyperintensities group to compare their microstructure of white matter injuries. RESULTS:The cognitive scores of plaque group were significantly lower than that of control group. We found that when plaque group and control group were compared, no white matter fiber tracts with difference was found in FA, MD, AD and RD. However, the decrease of FA and the increase of RD were found in some white matter regions (P < 0.05) when comparing the have-hyperintensities group and the no-hyperintensities group. These white matter regions included anterior thalamic radiation, corticospinal tract, cingulum (cingulate gyrus), forceps minor, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, uncinate fasciculus. What's more, there were significant differences in blood pressure between the two groups. CONCLUSION:The cognitive function of patients with early high-risk cerebrovascular diseases (asymptomatic carotid plaques) has a downward trend. TBSS based on DTI can help to find out the actual damage of brain white matter in patients with early carotid plaque, and reflect the early pathological changes from the micro level.
    背景与目标: 背景:有症状或严重的颈动脉粥样硬化与认知障碍和脑白质损害密切相关。然而,仍然缺乏有效的和非侵入性的成像生物标记物来鉴定早期的高危脑血管疾病。因此,本研究的目的是通过影像技术探讨无症状性颈动脉斑块患者脑白质的完整性和认知障碍。
    方法:所有受试者均来自中风风险筛查和预防项目,被定义为中风高危患者(具有三个或更多中风风险因素)。基于扩散张量成像(DTI)的基于空间的空间统计(TBSS)被用于分析61例颈动脉斑块患者和40例健康对照者的全脑白质异常。同时比较两组患者的一般临床资料,如年龄,性别,吸烟,高血压和认知功能评分等。此外,斑块组分为高血脂组和无高血脂组。比较他们的白质损伤的微观结构。
    结果:斑块组的认知评分明显低于对照组。我们发现,当将斑块组和对照组进行比较时,在FA,MD,AD和RD中没有发现具有差异的白质纤维束。但是,与高血脂组和无高血脂组相比,在某些白质区域中,FA的减少和RD的增加(P <0.05)。这些白质区域包括丘脑前部放射线,皮质脊髓束,扣带回(扣带回),小镊子,额枕下筋膜,纵向上筋膜,束状筋膜。此外,两组之间的血压存在显着差异。
    结论:早期高危脑血管疾病(无症状性颈动脉斑块)患者的认知功能呈下降趋势。基于DTI的TBSS可以帮助找出早期颈动脉斑块患者脑白质的实际损害,并从微观水平反映出早期病理变化。
  • 【DTI在颅脑外伤中的十年:10年后100篇文章。】 复制标题 收藏 收藏
    DOI:10.3174/ajnr.A3395 复制DOI
    作者列表:Hulkower MB,Poliak DB,Rosenbaum SB,Zimmerman ME,Lipton ML
    BACKGROUND & AIMS: SUMMARY:The past decade has seen an increase in the number of articles reporting the use of DTI to detect brain abnormalities in patients with traumatic brain injury. DTI is well-suited to the interrogation of white matter microstructure, the most important location of pathology in TBI. Additionally, studies in animal models have demonstrated the correlation of DTI findings and TBI pathology. One hundred articles met the inclusion criteria for this quantitative literature review. Despite significant variability in sample characteristics, technical aspects of imaging, and analysis approaches, the consensus is that DTI effectively differentiates patients with TBI and controls, regardless of the severity and timeframe following injury. Furthermore, many have established a relationship between DTI measures and TBI outcomes. However, the heterogeneity of specific outcome measures used limits interpretation of the literature. Similarly, few longitudinal studies have been performed, limiting inferences regarding the long-term predictive utility of DTI. Larger longitudinal studies, using standardized imaging, analysis approaches, and outcome measures will help realize the promise of DTI as a prognostic tool in the care of patients with TBI.
    背景与目标: 摘要:过去十年来,报道使用DTI来检测颅脑外伤患者脑部异常的文章数量有所增加。 DTI非常适合询问白质微结构,这是TBI中病理学的最重要位置。此外,动物模型研究证明了DTI发现与TBI病理的相关性。一百篇文章符合此定量文献综述的纳入标准。尽管样本特征,成像技术和分析方法存在显着差异,但共识是DTI可以有效区分TBI和对照患者,而不论受伤后的严重程度和时限如何。此外,许多人在DTI措施和TBI结果之间建立了联系。但是,所使用的特定结果指标的异质性限制了文献的解释。同样,很少进行纵向研究,限制了对DTI长期预测效用的推论。使用标准化的影像学,分析方法和结果测量方法进行的较大的纵向研究将有助于实现DTI的前景,将其作为治疗TBI患者的预后工具。
  • 【特质焦虑的个体差异与穹and和束状束中的白质束完整性有关:基于DTI的束学研究的初步证据。】 复制标题 收藏 收藏
    DOI:10.1016/j.bbr.2012.10.007 复制DOI
    作者列表:Modi S,Trivedi R,Singh K,Kumar P,Rathore RK,Tripathi RP,Khushu S
    BACKGROUND & AIMS: :Trait anxiety, a personality dimension that measures an individual's higher disposition to anxiety, has been found to be associated with many functional consequences viz. increased distractibility, attentional bias in favor of threat-related information etc. Similarly, volumetric studies have reported morphological changes viz. a decrease in the volume of left uncinate fasciculus (fiber connecting anterior temporal areas including the amygdala with prefrontal-/orbitofrontal cortices) and an increase in the volume of the left amygdala and right hippocampus, to be associated with trait anxiety. The functional and morphological changes associated with trait anxiety might also be associated with the changes in the integrity of WM tracts in relation with the trait anxiety levels of the subjects. Therefore, in the present diffusion tensor tractography (DTT) study, we investigated the possible relationship between the diffusion tensor imaging (DTI) derived indices of a wide array of fiber tracts and the trait anxiety scores in our subject group. A positive correlation between trait anxiety scores and the mean fractional anisotropy (FA) value was obtained in fornix and left uncinate fasciculus. The study provides first account of a positive relation between sub-clinical anxiety levels of subjects and the FA of fornix thereby providing interesting insights into the biological foundation of sub-clinical anxiety.
    背景与目标: 特质焦虑是一种衡量人对焦虑的更高倾向的人格维度,已发现与许多功能性后果相关,即。注意力分散,注意力偏向偏向威胁相关信息等的增加。类似地,体积研究也报告了形态学上的变化。与特征性焦虑相关的左无束状筋膜的体积减少(连接包括杏仁核在内的前颞叶区域的纤维与前额-/眶额皮质)的纤维,左杏仁核和右海马的体积增加。与特质焦虑相关的功能和形态变化也可能与受试者的特质焦虑水平有关的WM道完整性的变化相关。因此,在本研究中,我们研究了一组广泛的纤维束的弥散张量成像(DTI)衍生指标与特质性焦虑评分之间的可能关系。性状焦虑评分与平均分数各向异性(FA)值在穹ni和左束状筋膜中均呈正相关。该研究首先说明了受试者的亚临床焦虑水平与穹隆FA之间存在正相关关系,从而为亚临床焦虑的生物学基础提供了有趣的见解。
  • 【临床孤立综合征患者的非病变小脑损害:DTI措施可预测早期转化为临床明确的多发性硬化症。】 复制标题 收藏 收藏
    DOI:10.1016/j.nicl.2018.04.028 复制DOI
    作者列表:Kugler AV,Deppe M
    BACKGROUND & AIMS: Background:Today, no specific test for the diagnosis of multiple sclerosis (MS) is available due to the lack of characteristic symptoms at beginning. This circumstance also complicates estimation of disease progression. Recent findings provided evidence for early, non-lesional cerebellar damage in patients with (clinically definite) relapsing-remitting MS. Objective:To investigate if microstructural cerebellar alterations can also serve as early structural biomarker for disease progression and conversion from clinically isolated syndrome (CIS) to MS. Methods:46 patients diagnosed with CIS and 26 age-matched healthy controls were admitted to high-resolution MRI including diffusion tensor imaging (DTI) to examine atrophy and microstructural integrity of the cerebellum. Microstructural integrity of cerebellar white matter was assessed by fractional anisotropy (FA) as derived from DTI. Results:Although all 46 patients of our CIS cohort showed no cerebellar lesions in structural MRI (T1w, T2w, FLAIR), their mean cerebellar FA was already reduced compared to healthy controls. Significant FA reduction at follow-up DTI 6 months after baseline examination was observed. In 16 patients that converted to MS, we found a correlation between initial cerebellar FA and conversion latency (R = 0.71, p < 0.002). Initial cerebellar FA under FAcrit = 0.352 predicted conversion into relapsing-remitting MS within 24 months (FAcrit: mean cerebellar FA of patients with early MS, determined in another study). Conclusion:DTI seems to reflect early tissue injury in beginning MS, when atrophy and lesions are not yet detectable. Decreased cerebellar FA in patients with CIS might indicate an active and unstable disease stage, resulting in a shorter conversion time into MS.
    背景与目标: 背景:由于一开始缺乏特征性症状,目前尚无用于诊断多发性硬化症(MS)的特异性测试。这种情况也使疾病进展的估计复杂化。最新发现为患有(临床上明确的)复发缓解型MS的患者早期,非病变性小脑损伤提供了证据。
    目的:探讨微结构小脑改变是否还可以作为疾病发展和从临床孤立综合征(CIS)转变为MS的早期结构生物标志物。
    方法:46例确诊为CIS的患者和26例年龄相匹配的健康对照者接受包括弥散张量成像(DTI)在内的高分辨率MRI检查,以检查小脑的萎缩和微结构完整性。小脑白质的微结构完整性通过衍生自DTI的分数各向异性(FA)进行评估。
    结果:尽管我们的CIS队列中的所有46例患者在结构MRI(T1w,T2w,FLAIR)中均未显示小脑病变,但与健康对照组相比,他们的平均小脑FA已有所减少。在基线检查后6个月的随访DTI中观察到了显着的FA减少。在16名转化为MS的患者中,我们发现初始小脑FA与转化潜伏期之间存在相关性(R = 0.71,p <0.002)。在FAcrit = 0.352以下的初始小脑FA预计在24个月内会转化为复发缓解型MS(FAcrit:早期MS患者的平均小脑FA,在另一项研究中确定)。
    结论:DTI似乎反映了MS早期的组织损伤,当时尚无法检测到萎缩和病变。 CIS患者的小脑FA降低可能表明疾病的活动期和不稳定期,从而缩短了MS的转化时间。
  • 【用胶质母细胞瘤治疗的患者周围增强的肿瘤脑组织的DTI和PWI分析。】 复制标题 收藏 收藏
    DOI:10.1007/s11060-010-0310-x 复制DOI
    作者列表:Stecco A,Pisani C,Quarta R,Brambilla M,Masini L,Beldì D,Zizzari S,Fossaceca R,Krengli M,Carriero A
    BACKGROUND & AIMS: :To analyse the role of MR diffusion-tensor imaging (DTI) and perfusion-weighted imaging (PWI) in characterising tumour boundaries in patients with glioblastoma multiforme. Seventeen patients with surgically treated WHO IV grade gliomas who were candidates for adjuvant chemo-radiotherapy were enrolled. Before (T0) and after radiation treatment (T1), they underwent DTI and PWI, and the apparent diffusion coefficient (ADC), fractional anisotropy (FA) and relative cerebral blood volume (rCBV) in the enhancing tumour, the hyperintense tissue adjacent to the enhancing tumour, and the normal-appearing white matter (NAWM) adjacent to the hyperintense areas were analysed. The enhancing tissue at T1 was retrospectively divided on the basis of whether or not it was also enhancing at T0. The controls were the corresponding contralateral areas, on which we normalized the rCBV values, calculating the rCBV ratio. In NAWM, we did not find any significant differences in FA, ADC or rCBV. In the hyperintense perilesional regions, FA was significantly lower and ADC significantly higher than in the unaffected contralateral tissue; there were no significant differences in the rCBV maps. The values of FA, ADC and rCBV in enhancing neoplastic tissue were all significantly different from those observed in the contralateral tissue. There was no significant difference in rCBV values between the areas enhancing at T0 and those not enhancing at T0 but enhancing at T1, which may indicate the neoplastic transformation of apparently normal brain tissue. DTI metrics identify ultrastructural changes in hyperintense perilesional areas, but these are not specific for neoplastic tissue. rCBV seemed to reflect an ultrastructural alteration that was not visible at T0, but became visible (as neoplastic progression) on conventional MR images at T1. These findings could help identify tissue at risk of tumour infiltration.
    背景与目标: :分析MR扩散张量成像(DTI)和灌注加权成像(PWI)在表征多形性胶质母细胞瘤患者肿瘤边界中的作用。纳入了17例经手术治疗的WHO IV级神经胶质瘤患者,这些患者为辅助化学放疗的候选人。在(T0)之前和在放射治疗(T1)之后,他们经历了DTI和PWI,并且在增强肿瘤(毗邻的高强度组织)中出现了表观扩散系数(ADC),分数各向异性(FA)和相对脑血容量(rCBV)。分析肿瘤的增强情况,并分析与高信号区相邻的正常出现的白质(NAWM)。根据T1处的增强组织是否在T0处也进行增强进行回顾性划分。对照是相应的对侧区域,我们在其上标准化了rCBV值,计算了rCBV比率。在NAWM中,我们没有发现FA,ADC或rCBV有任何显着差异。在高强度病灶周围区域,FA明显低于ADC,而ADC明显高于未受影响的对侧组织。 rCBV图没有显着差异。增强肿瘤组织中的FA,ADC和rCBV值均与对侧组织中观察到的值显着不同。在T0增强的区域和在T0不增强但在T1增强的区域之间,rCBV值没有显着差异,这可能表明表面正常的脑组织发生了肿瘤性转化。 DTI指标可确定高强度病灶周围区域的超微结构变化,但这些变化并非专门针对赘生性组织。 rCBV似乎反映了一种超微结构改变,该改变在T0时不可见,但在T1时的常规MR图像上变得可见(随着肿瘤的进展)。这些发现可能有助于确定有肿瘤浸润风险的组织。
  • 【DTI与患有痉挛型二肢瘫痪性脑瘫的足月儿童的认知能力相关。】 复制标题 收藏 收藏
    DOI:10.1016/j.ejpn.2012.11.005 复制DOI
    作者列表:Rai Y,Chaturvedi S,Paliwal VK,Goyal P,Chourasia A,Singh Rathore RK,Yadav A,Pandey CM,Lalla RS,Garg RK,Gupta RK
    BACKGROUND & AIMS: BACKGROUND AND AIMS:Presently, there is no published study that shows association between cognition and white matter injury in spastic cerebral palsy. We aimed to correlate cognitive functions with diffusion tensor imaging derived metrics in spastic diplegic children. METHODS:Twenty-two term children with spastic diplegia and 22 healthy controls were recruited. All patients were graded on the basis of gross motor function. The Indian children intelligence Test was used to quantify cognition and diffusion tensor imaging was used to quantify microstructural changes in various white matter regions. Diffusion tensor imaging metrics were quantified by placing regions of interests in different white matter regions like corona radiata, anterior limb of internal capsule, posterior limb of internal capsule, mid brain, pons, medulla, genu, splenium, temporal white matter, parietal white matter, frontal white matter and occipital white matter. RESULTS:Spastic diplegic children showed significantly lower neuropsychological test scores as compared to controls. A significantly decreased fractional anisotropy values were observed in corona radiata, anterior limb of internal capsule, posterior limb of internal capsule, mid brain, pons, medulla, genu, splenium and occipital white matter; however significantly increased mean diffusivity values were observed in corona radiata, anterior limb of internal capsule, posterior limb of internal capsule, mid brain, pons and genu in spastic diplegic as compared to controls. A significant positive correlation in fractional anisotropy and negative correlation in mean diffusivity was observed with neuropsychological test scores. CONCLUSION:These results suggest that these imaging metrics may be used as a biomarker of cognitive functions in term children with spastic diplegia.
    背景与目标: 背景与目的:目前,尚无发表的研究表明痉挛性脑瘫的认知与白质损伤之间存在关联。我们旨在将痉挛性双盲儿童的认知功能与扩散张量成像导出的指标相关联。
    方法:招募了22名足月痉挛性瘫痪患儿和22名健康对照者。所有患者均根据总体运动功能进行分级。印度儿童智力测验用于量化认知,扩散张量成像用于量化各种白质区域的微结构变化。通过将感兴趣区域放置在不同的白质区域(例如电晕放射线,内囊的前肢,内囊的后肢,中脑,脑桥,脑桥,髓质,属,脾,颞白质,顶叶白质)来量化扩散张量成像指标,额叶白质和枕叶白质。
    结果:痉挛性双腿抽搐儿童的神经心理测验得分明显低于对照组。在电晕放射线,内囊的前肢,内囊的后肢,中脑,脑桥,延髓,膝,脾和枕叶白质中观察到分数各向异性值显着降低;然而,与对照组相比,痉挛性腿瘫的电晕放射线,内囊前肢,内囊后肢,中脑,脑桥和下肢的平均扩散率值显着增加。神经心理学测验分数观察到分数各向异性的显着正相关和平均扩散率的负相关。
    结论:这些结果表明,这些影像学指标可以用作足月痉挛性双足瘫痪儿童认知功能的生物标记。
  • 【前交叉韧带重建患者的皮质脊髓束结构和兴奋性:DTI和TMS研究。】 复制标题 收藏 收藏
    DOI:10.1016/j.nicl.2019.102157 复制DOI
    作者列表:Lepley AS,Ly MT,Grooms DR,Kinsella-Shaw JM,Lepley LK
    BACKGROUND & AIMS: BACKGROUND:Underlying neural factors contribute to poor outcomes following anterior cruciate ligament reconstruction (ACLR). Neurophysiological adaptations have been identified in corticospinal tract excitability, however limited evidence exists on neurostructural changes that may influence motor recovery in ACLR patients. OBJECTIVE:To 1) quantify hemispheric differences in structural properties of the corticospinal tract in patients with a history of ACLR, and 2) assess the relationship between excitability and corticospinal tract structure. METHODS:Ten participants with ACLR (age: 22.6 ± 1.9 yrs; height: 166.3 ± 7.5 cm; mass: 65.4 ± 12.6 kg, months from surgery: 70.0 ± 23.6) volunteered for this cross-sectional study. Corticospinal tract structure (volume; fractional anisotropy [FA]; axial diffusivity [AD]; radial diffusivity [RD]; mean diffusivity [MD]) was assessed using diffusion tensor imaging, and excitability was assessed using transcranial magnetic stimulation (motor evoked potentials normalized to maximal muscle response [MEP]) for each hemisphere. Hemispheric differences were evaluated using paired samples t-tests. Correlational analyses were conducted on structural and excitability outcomes. RESULTS:The hemisphere of the ACLR injured limb (i.e. hemisphere contralateral to the ACLR injured limb) demonstrated lower volume, lower FA, higher MD, and smaller MEPs compared to the hemisphere of the non-injured limb, indicating disrupted white matter structure and a reduction in excitability of the corticospinal tract. Greater corticospinal tract excitability was associated with larger corticospinal tract volume. CONCLUSIONS:ACLR patients demonstrated asymmetry in structural properties of the corticospinal tract that may influence the recovery of motor function following surgical reconstruction. More research is warranted to establish the influence of neurostructural measures on patient outcomes and response to treatment in ACLR populations.
    背景与目标: 背景:潜在的神经因素导致前十字韧带重建(ACLR)后的不良预后。在皮质脊髓束兴奋性中已经确定了神经生理适应性,但是关于神经结构变化的有限证据可能会影响ACLR患者的运动恢复。
    目的:1)对有ACLR病史的皮质脊髓束结构特性的半球差异进行量化; 2)评估兴奋性与皮质脊髓束结构之间的关系。
    方法:十名ACLR参与者(年龄:22.6±1.9岁;身高:166.3±7.5 cm;体重:65.4±12.6 kg,手术后数月:70.0±23.6)自愿参加了这项横断面研究。使用扩散张量成像评估皮质脊髓束结构(体积;分数各向异性[FA];轴向扩散率[AD];径向扩散​​率[RD];平均扩散率[MD]),并使用经颅磁刺激评估兴奋性(将运动诱发电位标准化)每个半球的最大肌肉反应[MEP])。使用配对样本t检验评估半球差异。对结构和兴奋性结果进行了相关分析。
    结果:与未受伤肢体的半球相比,ACLR肢体的半球(即与ACLR肢体对侧的半球)显示出较低的体积,较低的FA,较高的MD和较小的MEP,这表明白质结构受到破坏,并且皮质脊髓束兴奋性降低。更大的皮质脊髓束兴奋性与更大的皮质脊髓束体积有关。
    结论:ACLR患者表现出皮质脊髓束结构特性的不对称性,这可能影响手术重建后运动功能的恢复。有必要进行更多的研究来确定神经结构措施对ACLR人群患者预后和治疗反应的影响。
  • 【DTI-CDF:一种基于混合特征的级联深林模型,用于预测药物-靶标相互作用。】 复制标题 收藏 收藏
    DOI:10.1093/bib/bbz152 复制DOI
    作者列表:Chu Y,Kaushik AC,Wang X,Wang W,Zhang Y,Shan X,Salahub DR,Xiong Y,Wei DQ
    BACKGROUND & AIMS: :Drug-target interactions (DTIs) play a crucial role in target-based drug discovery and development. Computational prediction of DTIs can effectively complement experimental wet-lab techniques for the identification of DTIs, which are typically time- and resource-consuming. However, the performances of the current DTI prediction approaches suffer from a problem of low precision and high false-positive rate. In this study, we aim to develop a novel DTI prediction method for improving the prediction performance based on a cascade deep forest (CDF) model, named DTI-CDF, with multiple similarity-based features between drugs and the similarity-based features between target proteins extracted from the heterogeneous graph, which contains known DTIs. In the experiments, we built five replicates of 10-fold cross-validation under three different experimental settings of data sets, namely, corresponding DTI values of certain drugs (SD), targets (ST), or drug-target pairs (SP) in the training sets are missed but existed in the test sets. The experimental results demonstrate that our proposed approach DTI-CDF achieves a significantly higher performance than that of the traditional ensemble learning-based methods such as random forest and XGBoost, deep neural network, and the state-of-the-art methods such as DDR. Furthermore, there are 1352 newly predicted DTIs which are proved to be correct by KEGG and DrugBank databases. The data sets and source code are freely available at https://github.com//a96123155/DTI-CDF.
    背景与目标: :药物-靶标相互作用(DTI)在基于靶标的药物发现和开发中起着至关重要的作用。 DTI的计算预测可以有效地补充用于确定DTI的实验性湿实验室技术,这通常是耗时和资源消耗的。但是,当前的DTI预测方法的性能存在精度低和假阳性率高的问题。在这项研究中,我们旨在开发一种新的DTI预测方法,以基于称为DTI-CDF的级联深林(CDF)模型来提高预测性能,该模型具有多个药物之间基于相似性的特征以及目标之间基于相似性的特征从异构图中提取的蛋白质,其中包含已知的DTI。在实验中,我们在三种不同的数据集实验设置下建立了10倍交叉验证的五个重复样本,分别是某些药物(SD),靶标(ST)或药物靶标对(SP)的相应DTI值。缺少训练集,但存在于测试集中。实验结果表明,与传统的基于集合学习的方法(例如,随机森林和XGBoost),深度神经网络以及最新的方法(例如,DDR)相比,我们提出的方法DTI-CDF的性能要高得多。此外,还有KEGG和DrugBank数据库证明是正确的1352个新预测的DTI。数据集和源代码可从https://github.com//a96123155/DTI-CDF免费获得。
  • 【皮质脊髓束和弓状筋膜的可靠性用基于DTI的束线照相术重建:对临床实践的影响。】 复制标题 收藏 收藏
    DOI:10.1007/s00330-012-2589-9 复制DOI
    作者列表:Kristo G,Leemans A,de Gelder B,Raemaekers M,Rutten GJ,Ramsey N
    BACKGROUND & AIMS: OBJECTIVES:To assess the reliability of diffusion tensor imaging (DTI)-based fibre tractography (FT), which is a prerequisite for clinical applications of this technique. Here we assess the test-retest reproducibility of the architectural and microstructural features of two clinically relevant tracts reconstructed with DTI-FT. METHODS:The corticospinal tract (CST), arcuate fasciculus (AF) and its long segment (AFl) were reconstructed in 17 healthy subjects imaged twice using a deterministic approach. Coefficients of variation (CVs) of diffusion-derived tract values were used to assess the microstructural reproducibility. Spatial correlation and fibre overlap were used to assess the architectural reproducibility. RESULTS:Spatial correlation was 68 % for the CST and AF, and 69 % for the AFl. Overlap was 69 % for the CST, 61 % for the AF, and 59 % for the AFl. This was comparable to 2-mm tract shift variability. CVs of diffusion-derived tract values were at most 3.4 %. CONCLUSIONS:The results showed low architectural and microstructural variability for the reconstruction of the tracts. The architectural reproducibility results encourage the further investigation of the use of DTI-FT for neurosurgical planning. The high microstructural reproducibility results are promising for using DTI-FT in neurology to assess or predict functional recovery.
    背景与目标: 目的:评估基于弥散张量成像(DTI)的纤维束成像(FT)的可靠性,这是该技术临床应用的先决条件。在这里,我们评估了用DTI-FT重建的两个临床相关道的结构和微结构特征的重测重现性。
    方法:采用确定性方法,对17例健康受试者进行了两次成像,分别重建了皮质脊髓束(CST),弓形筋膜(AF)及其长节(AF1)。扩散衍生管道值的变异系数(CV)用于评估微观结构的可重复性。空间相关性和纤维重叠被用来评估建筑的可重复性。
    结果:CST和AF的空间相关性为68%,AF1的空间相关性为69%。 CST的重叠率为69%,AF的重叠为61%,AF1的重叠为59%。这相当于2毫米的道偏移变化。扩散源的CV值最多为3.4%。
    结论:结果表明,重建道的建筑和微观结构变异性较低。结构的可重复性结果鼓励进一步研究DTI-FT在神经外科计划中的应用。在神经病学中使用DTI-FT评估或预测功能恢复具有很高的微结构可再现性结果。
  • 【扩散张量成像(DTI)及其在探索正常或病理性脑发育中的重要性。】 复制标题 收藏 收藏
    DOI:10.1055/s-2005-870948 复制DOI
    作者列表:Stegemann T,Heimann M,Düsterhus P,Schulte-Markwort M
    BACKGROUND & AIMS: :Diffusion tensor MR imaging (DTI) can provide in vivo unique information on integrity of white matter structures (anisotropy) and connectivity (fiber tracking) in the human brain. This is made possible by means of non-invasive MR-based technique. The purpose of this article is to review the method and the current applications of diffusion tensor MR imaging. Studies of the past decade featuring relevant neuropsychiatric disorders as well as disorders in child psychiatry are reviewed. Furthermore, this report offers a summary of DTI-studies in children and adolescents showing alterations in brain or CNS structures including neurological, traumatological and oncological investigations. In particular, it focuses on the importance of this method with respect to exploration of normal and pathological brain development.
    背景与目标: :扩散张量MR成像(DTI)可以在人脑中提供有关白质结构完整性(各向异性)和连通性(纤维跟踪)的体内独特信息。借助于基于MR的非侵入性技术,这成为可能。本文的目的是回顾扩散张量MR成像的方法和当前应用。回顾了过去十年中有关神经精神疾病以及儿童精神病疾病的研究。此外,本报告提供了儿童和青少年DTI研究的摘要,这些研究表明大脑或CNS结构发生了变化,包括神经,创伤和肿瘤学研究。特别是,它着重于此方法在探索正常和病理性大脑发育方面的重要性。
  • 【具有脑震荡史的运动员中的白质微观结构:比较弥散张量成像(DTI)和神经突取向弥散和密度成像(NODDI)。】 复制标题 收藏 收藏
    DOI:10.1002/hbm.23658 复制DOI
    作者列表:Churchill NW,Caverzasi E,Graham SJ,Hutchison MG,Schweizer TA
    BACKGROUND & AIMS: :Sport concussion is associated with disturbances in brain function in the absence of gross anatomical lesions, and may have long-term health consequences. Diffusion-weighted magnetic resonance imaging (MRI) methods provide a powerful tool for investigating alterations in white matter microstructure reflecting the long-term effects of concussion. In a previous study, diffusion tensor imaging (DTI) showed that athletes with a history of concussion had elevated fractional anisotropy (FA) and reduced mean diffusivity (MD) parameters. To better understand these effects, this study compared DTI results to neurite orientation dispersion and density imaging (NODDI), which was used to estimate the intracellular volume fraction (VIC ) and orientation dispersion index (ODI). Sixty-eight (68) varsity athletes were recruited, including 37 without a history of concussion and 31 with concussion >6 months prior to imaging. Univariate analyses showed elevated FA and decreased MD for concussed athletes, along with increased VIC and reduced ODI, indicating greater neurite density and coherence of neurite orientation within white matter. Multivariate analyses also showed that for athletes with a history of concussion, white matter regions with increased FA had increased VIC and decreased ODI, with greater effects among athletes who were imaged a longer time since their last concussion. These findings enhance our understanding of the relationship between the biophysics of water diffusion and concussion neurobiology for young, healthy adults. Hum Brain Mapp 38:4201-4211, 2017. © 2017 Wiley Periodicals, Inc.
    背景与目标: 在没有严重的解剖病变的情况下,脑震荡与脑功能紊乱有关,并且可能对健康产生长期影响。扩散加权磁共振成像(MRI)方法为研究反映脑震荡的长期影响的白质微观结构变化提供了强大的工具。在先前的研究中,扩散张量成像(DTI)表明具有脑震荡史的运动员分数各向异性(FA)升高,平均扩散系数(MD)参数降低。为了更好地理解这些效应,本研究将DTI结果与神经突取向分散和密度成像(NODDI)进行了比较,后者用于估算细胞内体积分数(VIC)和取向分散指数(ODI)。招募了六十八(68)名大学运动员,其中包括37名无脑震荡史的运动员和31名脑震荡≥6个月的运动员。单因素分析显示,脑震荡运动员的FA升高,MD降低,VIC升高,ODI降低,表明白质内神经突密度更高,神经突取向连贯。多变量分析还显示,对于有脑震荡史的运动员,FA升高的白质区的VIC升高,ODI降低,自上次脑震荡起成像时间较长的运动员中,其影响更大。这些发现增强了我们对年轻健康成年人水扩散生物物理学与脑震荡神经生物学之间关系的理解。嗡嗡声大脑Mapp 38:4201-4211,2017.©2017 Wiley Periodicals,Inc.
  • 【无症状病毒携带者和患有人类T型淋巴病毒1型(HTLV-1)相关性脊髓病/热带痉挛性轻瘫(HAM /】 复制标题 收藏 收藏
    DOI:10.1007/s13365-014-0282-2 复制DOI
    作者列表:Vilchez C,Gonzalez-Reinoso M,Cubbison C,Perez-Then E,Roa P,Martínez A,Foerster B,Oviedo J,Stoeter P
    BACKGROUND & AIMS: :In tropical spastic paraparesis, spinal cord atrophy is a well-known finding in magnetic resonance imaging. But in contrast to histological reports, focal lesions of the spinal cord have only been described in imaging reports in exceptional acute cases. Here, we looked for such focal lesions and for alterations of diffusion tensor imaging parameters of the long fibre tracts in the usual case of a long-standing and slowly progressive disease. We examined 10 symptomatic patients, 11 seropositive, but asymptomatic human T-lymphotrophic virus type 1 carriers and 18 seronegative volunteers as controls. Sagittal and transversal T2-weighted images were visually assessed for atrophy and focal cord lesions. The spinal cord cross-sectional areas and the segmental cord volumes were measured at all levels. High-resolution diffusion tensor imaging was performed in sagittal planes from the bregma down to the cervical spine. For tractography and calculation of fractional anisotropy and mean diffusivity, we used manufacturer-provided software. Two-thirds of patients showed focal lesions affecting the antero-lateral columns and in two cases also the dorsal columns. Compared to carriers and volunteers, patients presented a significant spinal cord atrophy and a reduction of fractional anisotropy (p < 0.05), correlating more to duration of symptoms than to clinical impairment. Because our carriers did not show a significant atrophy, focal lesions or a change of diffusion tensor imaging parameters, we need further long-term studies to see if these parameters at some stage may be used as early indicators of spinal cord affection in virus carriers.
    背景与目标: :在热带痉挛性截瘫中,脊髓萎缩是磁共振成像中的众所周知的发现。但是与组织学报告相反,仅在特殊急性病例的影像学报告中描述了脊髓的局灶性病变。在这里,我们寻找这种局灶性病变,以及在长期且缓慢进展的疾病的通常情况下,长纤维束的弥散张量成像参数的变化。我们检查了10例有症状的患者,11例血清阳性但无症状的人类1型T淋巴细胞营养性病毒携带者和18例血清阴性志愿者作为对照。视觉评估矢状和横断T2加权图像的萎缩和灶性脊髓损伤。在所有水平上测量脊髓的横截面积和节段的体积。在从前reg到颈椎的矢状面进行高分辨率扩散张量成像。对于束线照相法和分数各向异性和平均扩散率的计算,我们使用了制造商提供的软件。三分之二的患者表现出局灶性病变,影响前外侧柱,在两个病例中也影响到背侧柱。与携带者和志愿者相比,患者表现出明显的脊髓萎缩和分数各向异性的降低(p <0.05),与症状持续时间的相关性大于与临床损害的相关性。因为我们的携带者没有显示出明显的萎缩,局灶性病变或弥散张量成像参数的变化,所以我们需要进一步的长期研究,以查看这些参数在某个阶段是否可以用作病毒携带者脊髓感染的早期指标。
  • 【DTI用于评估肾小球肾炎患者的疾病分期-与肾脏组织学的相关性。】 复制标题 收藏 收藏
    DOI:10.1007/s00330-014-3336-1 复制DOI
    作者列表:Feng Q,Ma Z,Wu J,Fang W
    BACKGROUND & AIMS: OBJECTIVES:To investigate whether DTI allows assessment of renal impairment and pathology in patients with chronic glomerulonephritis. MATERIALS AND METHODS:Seventy-five patients and 20 healthy volunteers were enrolled in this study. Renal function and kidney biopsies were evaluated. For DTI, a respiratory-triggered coronal EPI sequence was performed (TR, 1400 ms; TE, 76 ms; diffusion direction, 6; NEX, 4; b values, 0 and 600 s/mm2; slices thickness, 6 mm, with no intersection gap). Renal ADC and FA values were calculated and compared between the groups. Correlations between ADC/FA and histopathology were evaluated. RESULTS:ADC values decreased with increased stages. ADC differences in renal parenchyma at different disease stages were found, with the exception of the control group compared with stage 1 patients; similar results were obtained for FA. ADC values in the cortex and medulla in stage 1-3 patients were both statistically different, similar to the FA values. A significant negative correlation was found between the percentage of glomerulosclerosis and FA in the renal cortex (r =  -0.74), similar to the degree of tubulointerstitial fibrosis with FA in the medulla (r = -0.76). CONCLUSIONS:ADC and FA values are correlated with the degree of renal impairment, the percentage of glomerulosclerosis, and area of interstitial fibrosis. KEY POINTS:• DTI can be used to assess renal function impairment in patients with chronic glomerulonephritis. • ADC and FA values were correlated with tubulointerstitial fibrosis and glomerulosclerosis. • Identification of renal impairment is helpful for timely treatment. • DTI can be used for non-invasive assessment of renal pathology.
    背景与目标: 目的:探讨DTI是否可以评估慢性肾小球肾炎患者的肾功能损害和病理。
    材料与方法:该研究纳入了75名患者和20名健康志愿者。评估肾功能和肾脏活检。对于DTI,执行呼吸触发的冠状EPI序列(TR,1400毫秒; TE,76毫秒;扩散方向,6; NEX,4; b值,0和600 s / mm2;切片厚度,6 mm,无相交间隙)。计算肾ADC和FA值,并在各组之间进行比较。评估了ADC / FA与组织病理学之间的相关性。
    结果:ADC值随阶段增加而降低。发现在不同疾病阶段的肾实质中ADC的差异,对照组与1期患者相比有所不同。 FA的结果相似。 1-3期患者皮质和髓质中的ADC值均在统计学上不同,类似于FA值。在肾皮质中的肾小球硬化百分比与FA之间存在显着的负相关性(r = 0.7 -0.74),类似于髓质中FA引起的肾小管间质纤维化程度(r = -0.76)。
    结论:ADC和FA值与肾功能不全的程度,肾小球硬化的百分比和间质纤维化的面积有关。
    要点:•DTI可用于评估慢性肾小球肾炎患者的肾功能损害。 •ADC和FA值与肾小管间质纤维化和肾小球硬化相关。 •识别肾功能不全有助于及时治疗。 •DTI可用于肾脏病理的非侵入性评估。
  • 【通过DTI和神经元跟踪数据的联合评估,优化大型小鼠大脑连接体。】 复制标题 收藏 收藏
    DOI:10.1016/j.neuroimage.2015.04.050 复制DOI
    作者列表:Chen H,Liu T,Zhao Y,Zhang T,Li Y,Li M,Zhang H,Kuang H,Guo L,Tsien JZ,Liu T
    BACKGROUND & AIMS: :Tractography based on diffusion tensor imaging (DTI) data has been used as a tool by a large number of recent studies to investigate structural connectome. Despite its great success in offering unique 3D neuroanatomy information, DTI is an indirect observation with limited resolution and accuracy and its reliability is still unclear. Thus, it is essential to answer this fundamental question: how reliable is DTI tractography in constructing large-scale connectome? To answer this question, we employed neuron tracing data of 1772 experiments on the mouse brain released by the Allen Mouse Brain Connectivity Atlas (AMCA) as the ground-truth to assess the performance of DTI tractography in inferring white matter fiber pathways and inter-regional connections. For the first time in the neuroimaging field, the performance of whole brain DTI tractography in constructing a large-scale connectome has been evaluated by comparison with tracing data. Our results suggested that only with the optimized tractography parameters and the appropriate scale of brain parcellation scheme, can DTI produce relatively reliable fiber pathways and a large-scale connectome. Meanwhile, a considerable amount of errors were also identified in optimized DTI tractography results, which we believe could be potentially alleviated by efforts in developing better DTI tractography approaches. In this scenario, our framework could serve as a reliable and quantitative test bed to identify errors in tractography results which will facilitate the development of such novel tractography algorithms and the selection of optimal parameters.
    背景与目标: :最近,大量研究已将基于扩散张量成像(DTI)数据的牵引术作为一种工具来研究结构连接体。尽管DTI在提供独特的3D神经解剖学信息方面取得了巨大的成功,但它是一种间接的观察方法,其分辨率和准确性有限,其可靠性仍不清楚。因此,必须回答这个基本问题:DTI体层摄影术在构建大规模连接体中的可靠性如何?为了回答这个问题,我们以艾伦小鼠脑部连接图集(AMCA)发布的1772年小鼠大脑神经元追踪数据为基础,来评估DTI显像在推断白质纤维通路和区域间性能方面的表现。连接。通过与跟踪数据进行比较,已经首次在神经影像学领域中评估了全脑DTI描记法在构建大型连接体中的性能。我们的研究结果表明,只有优化的束线照相参数和适当的脑部碎裂方案规模,DTI才能产生相对可靠的纤维通路和大规模的连接组。同时,在优化的DTI影像学检查结果中也发现了相当多的错误,我们认为通过开发更好的DTI影像学检查方法可以潜在地减轻这种错误。在这种情况下,我们的框架可以用作可靠且定量的测试平台,以识别出物镜检查结果中的错误,这将有助于这种新颖的物镜检查算法的开发和最佳参数的选择。

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