MRI morphometry

  • 文章类型: Journal Article
    背景:人类小脑作为整合感觉运动神经网络的后脑结构出现,认知,和整个生命周期的情感处理。小脑解剖结构和功能的发展研究很少。我们检查了小脑前疣的年龄依赖性MRI形态学,小叶I-V和后新皮质小叶VI-VII及其与感觉运动和认知功能的关系。
    方法:通常发育中的儿童(TDC;n=38;9-15岁)和健康成人(HAC;n=31;18-40)参与高分辨率MRI。使用手动分割计算机辅助FreeSurfer图像分析程序[http://surfer。nmr.mgh.哈佛。edu].神经心理学评分(WASI-II)被标准化,并与前牙体积相关,后疣,TBV。
    结果:TBV与年龄无关。TDC中I-V和VI-VII的体积显著减少。VI-VII与I-V的比率(〜60%)在年龄组中是稳定的;I-V与视觉空间运动技能相关;VI-VII与口头,视觉抽象和FSIQ。
    结论:在TDC中,前I-V和后VI-VII疣均未达到成人体积。青春期灰质高峰的“倒U”发育轨迹并不能解释这一发现。少突胶质细胞/髓鞘形成的长期发育假说被认为是TDC小脑疣体积降低的一个原因。
    BACKGROUND: The human cerebellum emerges as a posterior brain structure integrating neural networks for sensorimotor, cognitive, and emotional processing across the lifespan. Developmental studies of the cerebellar anatomy and function are scant. We examine age-dependent MRI morphometry of the anterior cerebellar vermis, lobules I-V and posterior neocortical lobules VI-VII and their relationship to sensorimotor and cognitive functions.
    METHODS: Typically developing children (TDC; n=38; age 9-15) and healthy adults (HAC; n=31; 18-40) participated in high-resolution MRI. Rigorous anatomically informed morphometry of the vermis lobules I-V and VI-VII and total brain volume (TBV) employed manual segmentation computer-assisted FreeSurfer Image Analysis Program [http://surfer.nmr.mgh.harvard.edu]. The neuropsychological scores (WASI-II) were normalized and related to volumes of anterior, posterior vermis, and TBV.
    RESULTS: TBVs were age independent. Volumes of I-V and VI-VII were significantly reduced in TDC. The ratio of VI-VII to I-V (∼60%) was stable across age-groups; I-V correlated with visual-spatial-motor skills; VI-VII with verbal, visual-abstract and FSIQ.
    CONCLUSIONS: In TDC neither anterior I-V nor posterior VI-VII vermis attained adult volumes. The \"inverted U\" developmental trajectory of gray matter peaking in adolescence does not explain this finding. The hypothesis of protracted development of oligodendrocyte/myelination is suggested as a contributor to TDC\'s lower cerebellar vermis volumes.
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  • 文章类型: Journal Article
    脑白质疏松症(LA)与认知功能受损和痴呆风险增加密切相关。确定识别患有轻度认知障碍(LA-MCI)的LA患者的有效和可靠的方法对于临床干预和疾病监测很重要。在这项研究中,提出了一种结合多种磁共振成像(MRI)形态学特征的集成学习方法,用于区分LA-MCI患者和缺乏认知障碍(LA-nCI)的LA患者.多种综合形态学测量(包括灰质体积(GMV),皮质厚度(CT),表面积(SA),皮质体积(CV),沟深度(SD),分形维数(FD),从MRI中提取出和旋化指数(GI)),以丰富疾病表征信息的模型训练。然后,基于通用极值梯度提升(XGBoost)分类器,我们利用加权软投票集成框架来集成数据级重采样方法(FusionXGBoost)和算法级焦点损失(FL)改进的XGBoost模型(FL-XGBoost),以克服类不平衡学习问题并提供卓越的分类性能和稳定性。在原始不平衡数据集上训练的基线XGBoost模型具有78.20%的平衡准确度(Bacc)。单独的Fusion+XGBoost和FL-XGBoost模型获得了80.53和81.25%的Bacc分数,分别,哪些是明显的改进(即,2.33%和3.05%,分别)。融合模型区分LA-MCI和LA-nCI的总体准确率为84.82%。敏感性和特异性也得到了很好的提高(85.50%和84.14%,分别)。这种改进的模型具有促进LA-MCI临床诊断的潜力。
    Leukoaraiosis (LA) is strongly associated with impaired cognition and increased dementia risk. Determining effective and robust methods of identifying LA patients with mild cognitive impairment (LA-MCI) is important for clinical intervention and disease monitoring. In this study, an ensemble learning method that combines multiple magnetic resonance imaging (MRI) morphological features is proposed to distinguish LA-MCI patients from LA patients lacking cognitive impairment (LA-nCI). Multiple comprehensive morphological measures (including gray matter volume (GMV), cortical thickness (CT), surface area (SA), cortical volume (CV), sulcus depth (SD), fractal dimension (FD), and gyrification index (GI)) are extracted from MRI to enrich model training on disease characterization information. Then, based on the general extreme gradient boosting (XGBoost) classifier, we leverage a weighted soft-voting ensemble framework to ensemble a data-level resampling method (Fusion + XGBoost) and an algorithm-level focal loss (FL)-improved XGBoost model (FL-XGBoost) to overcome class-imbalance learning problems and provide superior classification performance and stability. The baseline XGBoost model trained on an original imbalanced dataset had a balanced accuracy (Bacc) of 78.20%. The separate Fusion + XGBoost and FL-XGBoost models achieved Bacc scores of 80.53 and 81.25%, respectively, which are clear improvements (i.e., 2.33% and 3.05%, respectively). The fused model distinguishes LA-MCI from LA-nCI with an overall accuracy of 84.82%. Sensitivity and specificity were also well improved (85.50 and 84.14%, respectively). This improved model has the potential to facilitate the clinical diagnosis of LA-MCI.
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  • 文章类型: Journal Article
    To detect brain morphological alterations in patients with early Parkinson\'s disease (PD) by using magnetic resonance imaging (MRI) morphometry under radiological diagnostic conditions.
    T1-weighted brain images of 18 early PD patients and 18 age-sex-matched healthy controls (HCs) were analyzed with free software Computational Anatomy Toolbox (CAT12). Regional cortical thickness (rCTh) in 68 atlas-defined regions-of-interest (ROIs) and subcortical gray matter volume (SGMV) in 14 atlas-defined ROIs were determined and compared between patients and HCs by paired comparison using both ROI-wise and voxel-wise analyses. False-discovery rate (FDR) was used multiple comparison correction. Possible correlations between brain morphological changes in patients and clinical observations were also analyzed.
    Comparing to the HCs, the ROI-wise analysis revealed rCTh thinning significantly in left medial orbitofrontal (P = .001), by trend (P < .05 but not significant after FDR correction) in four other ROIs located in frontal and temporal lobes, and a volume decreasing trend in left pallidum of the PD patients, while the voxel-wise analysis revealed one cluster with rCTh thinning trend located between left insula and superior temporal region of the patients. In addition, the patients showed more distinct rCTh thinning in ipsilateral hemisphere and SGMV deceasing trends in contralateral hemisphere in respect of the symptom-onset body side.
    Brain morphological alterations in early PD patients are evident despite of their inconspicuous findings in standard MRI. Quantitative morphological measurements with CAT12 may be an applicable add-on tool for clinical diagnosis of early PD. These results have to be verified in future studies with larger patient samples.
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  • 文章类型: Journal Article
    Cortical and subcortical grey matter (GM) morphometric changes have been demonstrated Temporal Lobe Epilepsy (TLE) or Idiopathic Generalized Epilepsies (IGE). Hot Water Epilepsy (HWE) has not hitherto been studied in these perspectives.
    To investigate the cortical and subcortical grey matter in subjects with HWE in terms of thickness, volume, and surface area using Surface-Based Morphometry (SBM). To assess relationships of SBM-derived metrics with clinical variables.
    Ninety-nine people with HWE and 50 age-matched healthy controls underwent high resolution volumetric MRI brain. These were processed with FreeSurfer to obtain SBM parameters i:e cortical thickness, cortical volume, and Cortical surface area. Volumes of seven subcortical GM structures (hippocampus, globus pallidus, nucleus ambiguous(NA), caudate nucleus, putamen, thalamus, and amygdala) were computed. Intergroup morphometric differences and their correlation with epilepsy-specific clinical variables were calculated.
    SBM revealed a global reduction in bihemispheric cortical thickness and left hemispheric cortical volume. Besides, a regional difference in the morphometric measures was noted in temporo-limbic, parietal, pre-cuneus, and the cingulate region. Reduced volume of thalami and left caudate alongside an increased volume of the bilateral amygdala, bilateral nucleus ambiguous (NA), right caudate, and putamen was the other cardinal observation.
    HWE subjects show alterations in the morphometry of the cortical ribbon and the subcortical grey matter. The temporal semiology, \'reflex nature\' pathophysiology correlates involvement of temporo-limbic structures/somatosensory cortex, while the involvement of structures like pre-cuneus, posterior cingulate, and frontal regions are in agreement with functional networks related loss of awareness. That bilateral amygdala swelling occurs in HWE is a novel observation and may signal that it could be a distinct variant of Mesial TLE.
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  • 文章类型: Journal Article
    There are serious clinical gaps in our understanding of chronic lung disease that require novel, sensitive, and noninvasive in vivo measurements of the lung parenchyma to measure disease pathogenesis and progressive changes over time as well as response to treatment. Until recently, our knowledge and appreciation of the tissue changes that accompany lung disease has depended on ex vivo biopsy and concomitant histological and stereological measurements. These measurements have revealed the underlying pathologies that drive lung disease and have provided important observations about airway occlusion, obliteration of the terminal bronchioles and airspace enlargement, or fibrosis and their roles in disease initiation and progression. ex vivo tissue stereology and histology are the established gold standards and, more recently, micro-computed tomography (CT) measurements of ex vivo tissue samples has also been employed to reveal new mechanistic findings about the progression of obstructive lung disease in patients. While these approaches have provided important understandings using ex vivo analysis of excised samples, recently developed hyperpolarized noble gas MRI methods provide an opportunity to noninvasively measure acinar duct and terminal airway dimensions and geometry in vivo, and, without radiation burden. Therefore, in this review we summarize emerging pulmonary MRI morphometry methods that provide noninvasive in vivo measurements of the lung in patients with bronchopulmonary dysplasia and chronic obstructive pulmonary disease, among others. We discuss new findings, future research directions, as well as clinical opportunities to address current gaps in patient care and for testing of new therapies. Level of Evidence: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:28-40.
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  • 文章类型: Journal Article
    Psychiatric complications after subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson\'s disease patients are common. The aim of this study was to evaluate a possible role of cortical thickness, cortical and subcortical volume for neuropsychiatric complications after STN-DBS implantation surgery. Twenty-two Parkinson\'s disease patients underwent STN-DBS. Control group consisted of 18 healthy volunteers who were matched by age and gender. All Parkinson\'s disease patients and control subjects underwent neuropsychological assessment and brain MRI. Control group subjects had normal MRI and neurocognitive testing results. Seven (31.8%) Parkinson\'s disease patients developed neuropsychiatric complications (psychosis and delirium) after STN-DBS implantation surgery with full recovery in short follow up. Two Parkinson\'s disease patients were excluded from further analysis, because they did not match image processing and analysis quality control. Volumetric analysis showed significant differences in cortical thickness between STN-DBS patients with and without postoperative neuropsychiatric complications in 13 gyruses on the right hemisphere (superior frontal, caudal middle frontal, pars triangularis and opercularis, temporal lobe, superior and inferior parietal, supramarginal) and in 7 gyruses on the left hemisphere (caudal middle frontal, inferior and middle temporal, pre and postcentral, superior parietal and supramarginal). White matter volume analysis showed also its reduction in the left caudal middle frontal area. Moreover, white matter volume and surface area reduction implicating that this area can be the most important for postoperative neuropsychiatric complication risk. Study results suggest that neuropsychiatric complications are common in Parkinson\'s disease patients after STN-DBS implantation and can be associated with excitation of frontal-striatum-thalamus and temporal-parietal circuits.
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  • 文章类型: Journal Article
    BACKGROUND: Sleep disturbances are common in patients with advanced Parkinson disease (PD). The aim of this study was to evaluate a possible association of cortical thickness, cortical and subcortical volume with sleep disturbances in PD patients.
    METHODS: Twenty-eight PD patients (14 men and 14 women, median age 58 years) were evaluated for sleep disturbances with PDSS and underwent brain MRI. Control group consisted of 28 healthy volunteers who were matched by age and gender. Automated voxel based image analysis was performed with the FreeSurfer software.
    RESULTS: PD patients when compared to controls had larger ventricles, smaller volumes of hippocampus and superior cerebellar peduncle, smaller grey matter thickness in the left fusiform, parahipocampal and precentral gyruses, and right caudal anterior cingulate, parahipocampal and precentral hemisphere gyruses, as well as smaller volume of left rostral middle frontal and frontal pole areas, and right entorhinal and transverse temporal areas. According to the Parkinson\'s disease Sleep Scale (PDSS), 15 (53.58%) patients had severely disturbed sleep. The most frequent complaints were difficulties staying asleep during the night and nocturia. The least frequent sleep disturbances were distressing hallucinations and urine incontinence due to off symptoms. Patients who fidgeted during the night had thicker white matter in the left caudal middle frontal area and lesser global left hemisphere cortical surface, especially in the lateral orbitofrontal and lateral occipital area, and right hemisphere medial orbitofrontal area. Patients with frequent distressful dreams had white matter reduction in cingulate area, and cortical surface reduction in left paracentral area, inferior frontal gyrus and right postcentral and superior frontal areas. Nocturnal hallucinations were associated with volume reduction in the basal ganglia, nucleus accumbens and putamen bilaterally. Patients with disturbing nocturia had reduction of cortical surface on the left pre- and postcentral areas, total white matter volume decrease bilaterally as well in the pons.
    CONCLUSIONS: PD patients with nocturnal hallucinations had prominent basal ganglia volume reduction. Distressful dreams were associated with limbic system and frontal white matter changes, meanwhile nocturia was mostly associated with global white matter reduction and surface reduction of cortical surface on the left hemisphere pre- and postcentral areas.
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  • 文章类型: Journal Article
    Adult cerebral cortical structure is thought to be statically maintained over short intervals. This view is based on group average findings but has never been studied at the individual level. This issue was examined with an unconventional longitudinal magnetic resonance imaging design which measured hemispheric mean cortical thickness of an adult man repeatedly at week intervals over 6 months. These measures were compared with measurement error estimates to test the current prediction that thickness measures would be statically maintained within measurement error variation. The results did not support this prediction. Thickness underwent incremental and decremental fluctuations which ranged up to 0.12 mm and 5.83% over week and multiweek intervals and which differed from measurement error variation. These exploratory analyses suggest a working hypothesis that short-interval cortical structural maintenance in an individual can involve fluctuations in thickness. If confirmed, this hypothesis has potential implications for cortical maintenance mechanisms and precision medicine approaches.
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  • 文章类型: Journal Article
    BACKGROUND: The paucity of morphometric markers for hemispheric asymmetries and gender variations in hippocampi and amygdalae in temporal lobe epilepsy (TLE) calls for better characterization of TLE by finding more useful prognostic MRI parameter(s).
    METHODS: T1-weighted MRI (3 T) morphometry using multiple parameters of hippocampus-parahippocampus (angular and linear measures, volumetry) and amygdalae (volumetry) including their hemispheric asymmetry indices (AI) were evaluated in both genders. The cutoff values of parameters were statistically estimated from measurements of healthy subjects to characterize TLE (57 patients, 55% male) alterations.
    RESULTS: TLE had differential categories with hippocampal atrophy, parahippocampal angle (PHA) acuteness, and several other parametric changes. Bilateral TLE categories were much more prevalent compared to unilateral TLE categories. Female patients were considerably more disposed to bilateral TLE categories than male patients. Male patients displayed diverse categories of unilateral abnormalities. Few patients (both genders) had combined bilateral appearances of hippocampal atrophy, amygdala atrophy, PHA acuteness, and increase in hippocampal angle (HA) where medial distance ratio (MDR) varied among genders. TLE had gender-specific and hemispheric dominant alterations in AI of parameters. Maximum magnitude of parametric changes in TLE includes (a) AI increase in HA of both genders, (b) HA increase (bilateral) in female patients, and (c) increase in ratio of amygdale/hippocampal volume (unilateral, right hemispheric), and AI decrease in MDR, in male patients.
    CONCLUSIONS: Multiparametric MRI studies of hippocampus and amygdalae, including their hemispheric asymmetry, underscore better characterization of TLE. Rapidly measurable single-slice parameters (HA, PHA, MDR) can readily delineate TLE in a time-constrained clinical setting, which contrasts with customary three-dimensional hippocampal volumetry that requires many slice computation.
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