Changes in brain structural network connection of children with attention deficit hyperactivity disorder / 中华实用儿科临床杂志

Objective@#To explore the changes in brain structure network connection in children with attention deficit hyperactivity disorder(ADHD), and to provide novel markers for early identification of ADHD in clinical practice.@*Methods@#Deterministic diffusion-tensor tractography and graph theory approaches were used to investigate the topologic organization of the brain structural connectome in 25 children with ADHD and 23 healthy control children from May 2017 to May 2018, at Children′s Hospital of Xuzhou Medical University.Individual white matter networks were constructed for each participant, then the global properties, nodal properties and edge-wise distributions were compared between the two groups.@*Results@#(1)The global efficiency of the ADHD group (0.30±0.13) was significantly lower than that of the healthy control group (0.38±0.11), but the clustering coefficient (0.35±0.28) and the characteristic path length (2.94±0.38) were significantly higher than those of the healthy control group (0.28±0.10, 2.65±0.37), and the differences were statistically significant (t=-2.41, 2.31, 2.62, all P<0.05). (2)In the ADHD group, the nodal efficiency of the left inferior frontal gyrus, triangular part (0.13±0.06), left supramarginal gyrus (0.30±0.10), left inferior parietal, angular gyri (0.29±0.10), left precuneus (0.26±0.12)were significantly lower than the healthy control group(0.17±0.07, 0.38±0.10, 0.40±0.12, 0.35±0.12), while the nodal efficiency of the right superior frontal gyrus, orbital part and right paracentral lobule were significantly higher than the healthy control group(0.49±0.17, 0.43±0.14), and the differences were statistically significant[t=-2.52, -2.62, -3.11, -2.77, 2.34, 2.79, all P<0.05, false discovery rate(FDR) corrected]. (3)A disrupted subnetwork was observed that consisted of left frontoparietal areas, basal ganglia, thalamus and insular network (P<0.05, FDR corrected), which has the potential to discriminate individuals with ADHD from healthy control children(area under receiver operating characteristic curve was 0.78). (4)Diminished strength of the subnet work connections was correlated with the attention defect in patients with ADHD(r=-0.607, P=0.003).@*Conclusions@#Using magnetic resonance diffusion tensor imaging, with the help of graph theory analysis technology, ADHD children can be observed changes in brain structure network at multiple levels.The distribution pattern of brain network structure connection changes is expected to become a new marker for identifying ADHD.

Brain structural network changes in Parkinson's disease with mild cognitive impairment:a diffusion tensor imaging study / 中华行为医学与脑科学杂志

Objective To explore the changes of brain structure network in patients with Parkinson's disease with mild cognitive impairment(PD-MCI),and to provide novel markers for the early recognition of PD-MCI. Methods Total 47 patients with primary PD were continuously enrolled at the De-partment of Neurology,Affiliated Hospital of Xuzhou Medical University from May 2017 to May 2018. Twenty-four healthy volunteers were selected as the healthy control (HC) group. General demographic data were col-lected from all subjects. The overall cognitive function and the five cognitive domains (attention and working memory,executive function,language,memory and visual spatial function) were comprehensively evaluated, then the patients with PD were further divided into PD-MCI group(n=22) and PD-NC group(n=25) based on their cognitive evaluation results. All subjects completed the diffusion tensor imaging( DTI) scan and the individual structural brain connection was obtained by deterministic diffusion-tensor tractography. By graph theory analysis technology,the network properties (global properties and node properties) and edge-wise dis- tributions were compared to assess structural connectivity differences among the three groups. Results Com-pared with the PD-NC and HC groups,the PD-MCI group had a larger characteristic path length(PD-NC:(8. 33±0. 95),HC:(8. 18±1. 35),PD-MCI:(9. 20±1. 52),F=4. 14,P<0. 05) and reduced global efficien-cy (PD-NC:(0. 13±0. 05),HC:(0. 13±0. 04),PD-MCI:(0. 10±0. 04),F=3. 73,P<0. 05) in addition to a lower nodal efficiency in frontoparietal areas,thalamus,cingulate gyrus,and insular(P=0 . 003-0. 040,FDR correction). Compared with the HC group,the PD-MCI group had a large frontotemporoparietal areas,basal ganglia,and insular network with decreased connection strength (P<0. 05,FDR correction). Compared with the PD-NC group,the PD-MCI group had a lower network connection strength in the frontoparietal areas (P<0. 05,FDR correction). Conclusion A disruption of structural connections that make up the brain network can lead to changes in information integration and delivery,leading to cognitive dysfunction in patients with PD. The distribution pattern of brain network structure connection changes is expected to become a new marker for identifying PD-MCI.

Research progress of magnetic resonance technology in investigating the role of cerebellar in the pathophysiology of obsessive-compulsive disorder / 上海交通大学学报（医学版）

Obsessive-compulsive disorder (OCD) is a chronic disabling mental illness with thecore symptoms of obsession and compulsion, while its pathological mechanism has not yet been fully understood. In recent years, magnetic resonance (MR) technology has been used in the study of mental illness, because of its nonradiative and non-invasive advantage, etc. Many MR studies have found that OCD patients havecerebellar changes in structure and function, and these changes have contact with the incidence of OCD. This paper reviews the cerebellar's role in the onset of OCDapplying MR technology.

Tract-based spatial statistical analysis of Alzheimer's disease and its correlation with cognition scores / 中华神经科杂志

Objective To observe microstructural changes of white matter in Alzheimer's disease (AD),and to find out the relationship between white matters lesion and declined cognition.Methods Twenty-four AD patients and 24 controls with normal cognition performed diffusion tensor imaging MR scan.Tract-based spatial statistical analysis (TBSS) was used to investigate microstructural change of white matter,and then its correlation with Mini-Mental State Examination (MMSE) scores was analyzed.Results Fractional anisotropy (FA) values were decreased in corpus callosum,fornix,left corticospinal tract,bilateral cerebral peduncle,superior cerebellar peduncle,internal capsule,corona radiata,posterior thalamic radiation,sagittal stratum including inferior longitidinal fasciculus and inferior fronto-occipital fasciculus,external capsule,cingulate gyrns,hippocampus,superior longitudinal fasciculus and uncinate fasciculus,while mean diffusivity (MD) values were increased in fornix,left hippocampus,bilateral internal capsule,corona radiata,posterior thalamic radiation,sagittal stratum including inferior longitidinal fasciculus and inferior fronto-occipital fasciculus,external capsule,cingulate gyrus,superior longitudinal fasciculus,superior fronto-occipital fasciculus and uncinate fasciculus (all P ＜ 0.05,threshold-free cluster enhancement corrected).MMSE scores had a positive correlation with decreased FA values of left sagittal stratum (r =0.535,P =0.007) and negative correlations with increased MD values of left sagittal stratum (r =-0.427,P =0.037),left superior longitudinal fasciculus (r =-0.424,P =0.039) and left uncinate fasciculus (r =-0.505,P =0.012).Conclusions There exist widespread white matter lesions in AD with impairment of white matter connections of intra-and inter-hemispheres.Impaired white matters in left hemisphere may have close relationships with cognition decline.

Control de calidad en imagen por resonancia magnética: evaluación de parámetros de calidad en protocolos de neuroimagen / Quality control in magnetic resonance imaging: evaluation of quality parameters in neuroimaging protocols

Magnetic resonance imaging (MRI) plays an important role in neuroimaging due to the development of sequences that provide insight into structural and functional aspects of the brain, such as DTI and functional magnetic resonance (fMRI). Analysis of the images in neuroimaging is of a quantitative nature, which requires that the images be of a high quality. To ensure delivery of this required high quality image, a quality control protocol designed exclusively for neuroimaging has been developed. This protocol covers the evaluation of 5 quality parameters: geometric accuracy, image uniformity, SNR, slice position and slice thickness. MRI images were acquired of 3 mannequins, analyzing the images according to the methodology proposed for each parameter. The results have been mixed, in some parameters results obtained have been satisfactory and in others not. It is recommended that this proposed protocol be carried out respecting the methodology and taking into account the considerations cited in this article.

La resonancia magnética juega un rol muy importante en neuroimagen debido al desarrollo de secuencias que permiten conocer aspectos estructurales y funcionales del cerebro, tales como la DTI y la resonancia magnética funcional. El análisis de las imágenes en neuroimagen es de carácter cuantitativo, esto requiere que las imágenes sean de una elevada calidad. Con el fin de asegurar la obtención de esta elevada calidad de imagen requerida se ha elaborado un protocolo de control de calidad exclusivamente diseñado para neuroimagen. Este protocolo abarca la evaluación de 5 parámetros de calidad: exactitud geométrica, uniformidad de imagen, SNR, posición del corte y espesor del corte. Se han adquirido las imágenes por resonancia magnética de 3 maniquíes, analizando las imágenes de acuerdo a la metodología propuesta para cada parámetro. Los resultados han sido variados, en algunos parámetros se han obtenido resultados satisfactorios y en otros no. Se recomienda llevar a cabo este protocolo propuesto respetando la metodología y tomando en cuenta las consideraciones que se citan en este trabajo.

Characteristics of Brains in Autism Spectrum Disorder: Structure, Function and Connectivity across the Lifespan

Autism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder characterized by impaired social communication and restricted and repetitive behaviors (RRBs). Over the past decade, neuroimaging studies have provided considerable insights underlying neurobiological mechanisms of ASD. In this review, we introduce recent findings from brain imaging studies to characterize the brains of ASD across the human lifespan. Results of structural Magnetic Resonance Imaging (MRI) studies dealing with total brain volume, regional brain structure and cortical area are summarized. Using task-based functional MRI (fMRI), many studies have shown dysfunctional activation in critical areas of social communication and RRBs. We also describe several data to show abnormal connectivity in the ASD brains. Finally, we suggest the possible strategies to study ASD brains in the future.

Application value of diffusion registration in diffusion tensor imaging / 重庆医学

Objective To evaluate the value of diffusion registration in diffusion tensor imaging (DTI) through comparing the diffusion tensor data to conduct the two kinds of post-processing methods for obtaining the ADC ,eADC and FA values and the vis-ual neural fiber length .Methods 20 cases of DTI data were analyzed retrospectively .The original data were adopted to directly process for obtaining the ADC ,eADC and FA values respectively ,after exerting diffusion registration the ADC ,eADC and FA val-ues were measured again ,at the same time the two different processing modes were performed the fiber trace imaging ,.The changes of ADC ,eADC and FA values in each case were compared before and after exerting the diffusion registration ,and at the same time the differences of fiber length in the same interest area in the fiber trace image were compared before and after exerting the diffusion registration .Results The difference of the ADC and eADC values obtained before and after exerting the diffusion registration in the normal group showed no statistical significance (P=0 .695 3 ,P=0 .632 1) and the FA value difference between before and after ex-erting the diffusion registration had statistical significance (P=0 .032 1);the difference of the ADC and eADC values obtained be-fore and after exerting the diffusion registration in the clinical patients group had no statistical significance ( P= 0 .203 9 ,P=0 .075 4) ,the FA value difference had statistical significance (P=0 .011 4) ,the visual neural fiber length was elongated after exer-ting the diffusion registration .Conclusion The diffusion registration processing can obtain better quality of ADC ,eADC ,FA images and the fiber trace image ,more reliable ADC ,eADC and FA values ,the visual fiber length is elongated ,which has large application value in MR DTI .

Clinical Use of Diffusion Tensor Image-Merged Functional Neuronavigation for Brain Tumor Surgeries: Review of Preoperative, Intraoperative, and Postoperative Data for 123 Cases

PURPOSE: To achieve maximal safe resection during brain tumor surgery, functional image-merged neuronavigation is widely used. We retrospectively reviewed our cases in which diffusion tensor image (DTI)-merged functional neuronavigation was performed during surgery. MATERIALS AND METHODS: Between November 2008 and May 2010, 123 patients underwent surgery utilizing DTI-merged neuronavigation. Anatomical magnetic resonance images (MRI) were obtained preoperatively and fused with DTI of major white matter tracts, such as the corticospinal tract, optic radiation, or arcuate fasciculus. We used this fused image for functional neuronavigation during brain tumor surgery of eloquent areas. We checked the DTI images together with postoperative MRI images and evaluated the integrity of white matter tracts. RESULTS: A single white matter tract was inspected in 78 patients, and two or more white matter tracts were checked in 45 patients. Among the 123 patients, a grossly total resection was achieved in 90 patients (73.2%), subtotal resection in 29 patients (23.6%), and partial resection in 4 patients (3.3%). Postoperative neurologic outcomes, compared with preoperative function, included the following: 100 patients (81.3%) displayed improvement of neurologic symptoms or no change, 7 patients (5.7%) experienced postoperative permanent neurologic deterioration (additional or aggravated neurologic symptoms), and 16 patients (13.0%) demonstrated transient worsening. CONCLUSION: DTI-merged functional neuronavigation could be a useful tool in brain tumor surgery for maximal safe resection. However, there are still limitations, including white matter tract shift, during surgery and in DTI itself. Further studies should be conducted to overcome these limitations.

Diffusion Tensor Imaging Findings in Two Cases of Internal Capsular Genu Infarction

Internal capsular genu infarcts infrequently cause cognitive impairment and behavioral changes, and little is known about the underlying mechanism. Using diffusion-tensor imaging (DTI) and the fractional anisotropy (FA) index in the region of interest (ROI) and ipsilesional frontal cortex, we evaluated two patients with internal capsular genu infarction who presented with frontal dysfunction and cognitive impairment. The reported findings help to elucidate the mechanism underlying cognitive deterioration in internal capsular genu infarction.

Transcallosal Fibers from Corticospinal Tract in Patients with Cerebral Hemorrage

OBJECTIVE: To investigate the relationship between the transcallosal fibers (TCFs) from the corticospinal tract (CST) and the motor function of the affected extremities in patients with cerebral hemorrhage, using diffusion tensor image tractography (DTT). METHOD: 49 patients with cerebral hemorrhage and 38 controls were recruited. DTT was performed using 1.5 T magnetic resonance imaging. The DTT findings were classified into 3 groups according to targeting location: no TCF from the CST (type A), TCF ended in the corpus callosum or connected to the cortex of the opposite hemisphere (type B), and TCF that descending toward the lesion after passing through the corpus callosum (type C). RESULTS: The TCF originated from the CST of the unaffected hemisphere, and the presence of fiber descending toward the lesion after passing through the corpus callosum were significantly more prevalent in the patients who showed the worse motor function. CONCLUSION: The TCF originated from the unaffected CST toward the lesion in patients with cerebral hemorrhage might play a relevant role in compensating motor deficits in the major corticospinal disruption.

Global Aphasia without Hemiparesis: A case report

Aphasia, result from damage of language-dominant area of the brain, usually accompanied hemiparesis due to proximity of language centers and motor control areas. So, global aphasia without hemiparesis is a rare stroke syndrome. We report a case of right handed man with language disturbance after stroke. He showed global aphasia without hemiparesis. We use diffusion tensor image tractography (DTT) for evaluation of global aphasia without hemiparesis. DTT demonstrated that preservation of the corticospinal tract. After speech therapy, he showed improvement of language profile on K-WAB.

Clinical Usefulness of Diffusion Tensor Image Tractography in Stroke Patients: Report of two cases

We report the clinical usefulness of elucidating the state of the corticospinal tract (CST) by the use of diffusion tensor image tractography (DTT) in hemiparetic stroke patients. DTT was performed using 1.5 T magnetic resonance imaging. DTT demonstrated that the CST of the affected hemisphere was preserved in the medial portion of the hematoma in patient 1, but was interrupted by a hematoma in patient 2. DTT seems to be useful for elucidating the status of the CST in hemiparetic stroke patients.