Probabilistic Tractography Between Nucleus Accumbens and Other Reward-related Brain Areas in Malay Female Adolescents

@#Introduction: Studies show that adolescents are more reward sensitive compared to other age groups. The nucleus accumbens (NAcc) has been identified as a key brain area involved in reward through its connectivity to other reward-related brain areas. Our study aimed to characterise the white matter structural connectivity of nucleus accumbens with brain areas that are most often associated with reward in female adolescents. Methods: Fifteen healthy female Malay adolescents were recruited and underwent diffusion-weighted brain scanning. Two behaviour scales were also given to verify typical reward responsiveness. Then, probabilistic tractography and NAcc segmentation were performed on the data using FMRIB Software Library (FSL). Probabilistic tractography was performed to determine the relative connection probability of nucleus accumbens (NAcc) to areas shown to be associated with reward, namely amygdala, anterior cingulate cortex (ACC), medial orbitofrontal cortex (mOFC), hippocampus, ventrolateral prefrontal cortex (vlPFC) and dorsolateral prefrontal cortex (dlPFC). Connectivity-based segmentation of NAcc was performed to determine the spatial distribution of its connectivity with the target brain areas according to the highest connection probability. Results: The highest relative connection probability was found between NAcc to mOFC, while the NAcc parcellation showed the widest distribution of connection to mOFC compared to the other five targets on both sides of the brain. Conclusion: Our findings demonstrated the strongest structural connectivity and widest distribution between NAcc and mOFC compared with other brain areas related to reward. This study’s findings could be used as baseline to compare with people with atypical reward circuit problems.

Applying a unified model of fiber dissection, tractography, microscopic anatomy and plastination techniques for basic neuroanatomy education: Hacettepe University experience / Aplicación de un modelo unificado de disección de fibras, tractografía, anatomía microscópica y técnicas de plastinación para la educación básica en neuroanatomía: experiencia de la Universidad Hacettepe

SUMMARY: Anatomy education has gathered together a great many of many new modalities and was modified from classical lecture-based and laboratory practice system to the blended modules. In the scope of the present study, we develop a new, practical, cost- effective and efficient three dimensional (3D) educational model, which aimed to be helpful for the detection and better understanding of basic neuroanatomy education. Tractographic imaging, fiber dissection, microscopic anatomy and plastination techniques were applied to the white matter regions of the two brains. After the photographs that were taken were converted to 3D images, the specimens were plastinated. By way of establishing an educational model as a whole, we applied it to 202 second-year medical students. The students were separated into two groups when they attended to the theoretical lecture. Group 1 took the classical laboratory education; on the other hand, Group 2 received the newly designed educational model. Pre and post-tests were introduced to each group before and after laboratory sessions, respectively. The success scores were put to comparison. The average achievement scores of each group showed increase significantly (p<0.05) after the laboratory sessions, besides the increase in the post-test results of Group 2 was more statistically significant (p<0.05). Consequently, this new educational model enriched by newly designed unified methods could be regarded as useful for grasping and improving the basic neuroanatomy knowledge.

La educación en anatomía ha reunido una gran cantidad de nuevas modalidades, modificándose el sistema clásico de la práctica del laboratorio y de las clases basadas en conferencias, hacia los módulos combinados. En el ámbito del presente estudio, desarrollamos un modelo educativo tridimensional (3D) nuevo, práctico, rentable y eficiente, que pretendía ser útil para la detección y una mejor comprensión de la educación básica en neuroanatomía. Se tomaron imágenes tractográficas, disección de fibras, anatomía microscópica y técnicas de plastinación en los cerebros. Después de convertir las fotografías que se tomaron en imágenes 3D, se plastinaron los especímenes. A modo de establecer un modelo educativo en su conjunto, lo aplicamos a 202 estudiantes de segundo año de medicina. Los estudiantes fueron separados en dos grupos cuando asistieron a la clase teórica. El Grupo 1 tomó la educación clásica de laboratorio; por su parte, el Grupo 2 recibió el nuevo modelo educativo diseñado para el estudio. Se introdujeron pruebas previas y posteriores a cada grupo, antes y después de las sesiones de laboratorio. Se compararon las puntuaciones. Los puntajes promedio de rendimiento de cada grupo mostraron un aumento significativo (p<0,05) después de las sesiones de laboratorio. Además, se obtuvo un aumento en los resultados positivos, posteriores a la prueba del Grupo 2, siendo estadísticamente significativo (p<0,05). En consecuencia, este modelo educativo, enriquecido por métodos unificados de nuevo diseño, podría considerarse útil para captar y mejorar los conocimientos básicos de neuroanatomía.

Cavernoma Paraventricular / Paraventricular Cavernoma

Introducción: Los cavernomas representan el 5 al 13% de las malformaciones cerebrales y suelen tener una localización supratentorial. Clínicamente pueden permanecer asintomáticos o presentar síntomas neurológicos progresivos. Para estos últimos, así como los que presentan hemorragia recurrente, la resección quirúrgica es el tratamiento de elección. Sin embargo, para aquellos que presentan una localización profunda es menester estudiar la relación que existe entre la lesión y las estructuras cerebrales adyacentes. La tractografía (DTI) y las técnicas de navegación intraoperatoria son herramientas fundamentales para planificar y guiar el abordaje a la lesión y realizar un mapeo de las vías de proyección, asociación y comisurales, permitiendo un acceso seguro mediante corticotomías pequeñas y mínima retracción del parénquima cerebral. Objetivo: Describir la técnica quirúrgica guiada por neuronavegación para la resección de un cavernoma frontal derecho profundo yuxtaventricular a través de una pequeña corticotomía. Caso: Paciente de sexo masculino de 20 años de edad, deportista profesional, con parestesias miembro superior izquierdo y cefalea severa. Resonancia magnética evidencia lesión heterogénea en T1 y T2 y presencia de un halo de hemosiderina, compatible con cavernoma a nivel del techo del cuerpo en el ventrículo lateral derecho. Mide 28 mm x 31 mm x 28 mm en sus diámetros transversal, dorso-ventral y rostro-caudal. Tractografía evidencia lesión en íntima relación con el tracto corticoespinal en su recorrido por la corona radiada. Resultados: Exéresis completa de la lesión. El paciente evolucionó sin déficit neurológico y fue dado de alta a las 72 horas del postoperatorio. Conclusión: El uso de la tractografía y de la navegación intraoperatorio, permite abordar lesiones profundas, en contacto con áreas elocuentes, mediante corticotomías pequeñas con mínima retracción cerebral

Introduction: Cavernous malformation represents among 5 to 13% of brain vascular malformations, most of them have a supratentorial location. Clinically they can remain asymptomatic or present with neurological symptoms. In cavernomas with recurrent hemorrhage, located in safe areas, surgical resection is the treatment of choice. However, for those which have a deep yuxta-ventricular localization it is necessary to know the relationship between the lesion and eloquent cerebral structures. Fiber tractography and intraoperative navigation systems are essentials tools to plan and guide the surgical approach and make a mapping of the projection, association and commissural fibers in order to have a safe access to the lesion. Objective: To describe the surgical technique using neuronavigation for the resection of a right frontal yuxta-ventricular cavernous malformation through a minimal approach. Case: A 20-year-old man, professional athlete with left arm paresthesia and severe headache. Magnetic resonance shows a heterogeneous lesion in T1 and T2 with a hemosiderin in the roof of the right lateral ventricle, compatible with a cavernous malformation. Its size was 28 mm x 31mm x 28 mm in the transversal, dorsoventral and rostrocaudal diameter. The fiber tractography shows an intimate relationship with the corticospinal tract on its path through the corona radiata. Results: Complete resection of the lesion. The patient evolved without a neurological deficit and was discharged 72 hours later. Conclusion: The fiber tractography and the intraoperative navigation system allow the deep lesions approach, especially for those who have an intimal relationship with eloquent ́s areas, using minimally corticotomy with less parenchymal retraction.

Effects of Acupuncture on Motor and Corticospinal Tract Impairment after Cerebral Infarction: Using Diffusion Tensor Imaging and Tractography / 中国康复理论与实践

Objective:To explore the effects of Tiaoren Tongdu Acupuncture on motor function and corticospinal tract (CST) remodeling after cerebral infarction. Methods:From February, 2017 to December, 2020, 54 patients with cerebral infarction were randomly divided into control group (n = 27) and acupuncture group (n = 27), each group was divided into subgroups 1, 2 and 3 according to the impairment of corticospinal tract, with nine cases for each subgroup. All the patients received routine medicine, while the acupuncture group received Tiaoren Tongdu Acupuncture, for four weeks. They were assessed with Fugl-Meyer Assessment (FMA) and modified Barthel Index (MBI) before and after treatment, and scanned with diffusion tensor imaging and diffusion tensor tractography, to obtain the fractional anisotropy (FA) and the bilateral FA ratio (rFA). Results:The scores of FMA and MBI, and FA and rFA increased in both groups (t > 2.841, P < 0.05) after treatment, and increased more in the acupuncture group than in the control group (t > 2.140, P < 0.05). Conclusion:Tiaoren Tongdu Acupuncture can promote the recovery of CST to improve motor function for patients with cerebral infarction.

Síntomas afectivos en pacientes con lesiones talámicas y su correlación con el patrón de conectividad talamocortical: revisión sistemática de la literatura / Affective symptoms in patients with thalamic lesions and their correlation with the thalamocortical connectivity pattern: a systematic review

RESUMEN Desde la década de 1970, la disponibilidad de neuroimágenes estructurales (tomografia computarizada y resonancia magnética) y funcionales como la tomografía computarizada por emisión de fotón único (SPECT), la tomografia por emisión de positrones (PET) o la resonancia magnética funcional (fMRI)), abrió una nueva via en el estudio de la relación bidireccional que existe entre los fenómenos comportamentales y la actividad neuronal. La introducción de estas técnicas condujo a una mejor comprensión del impacto de una lesión cerebral en la actividad cortical y en el desarrollo de síntomas psiquiátricos. Explicar la presencia de síntomas afectivos como una alteración en la función de una estructura cerebral es insuficiente, y se debe considerar siempre un compromiso de los circuitos cerebrales. Muchos trastornos del afecto se han asociado con lesiones en las conexiones talamolímbicas, incluyendo trastorno depresivo mayor, trastorno obsesivo-compulsivo, adicción a sustancias psicoactivas y trastorno de estrés postraumático, por lo que la identificación de los tractos de conectividad puede proporcionar nuevos medios para una intervención terapéutica eficaz.

SUMMARY Since the 1970s, the availability of structural neuroimaging (computed tomography and magnetic resonance imaging) and functional neuroimaging (single photon emission computed tomography (SPECT), positron emission tomography (PET), functional magnetic resonance imaging (fMRI)), has opened a new way in the study of the bidirectional relationship between behavioral phenomena and neuronal activity. The introduction of these techniques led to a better understanding of the impact of a brain injury on cortical activity and on the development of psychiatric symptoms. It is difficult to explain affective symptoms as a consequence of a brain structure dysfunction and is important to consider a brain circuit impairment. Many affective disorders have been associated with lesions in thalamolymbic connections, including major depressive disorder, obsessive-compulsive disorder, addiction to psychoactive substances and post-traumatic stress disorder, and the identification of the connectivity tracts can provide new means for effective therapeutic intervention.

Volumetría de fascículos cerebrales en población sana / Brain fascicles volumetry in healthy population

Objetivo Desde la aparición de la tractografía, al tratarse de una técnica no invasiva y que usa la ampliamente conocida resonancia magnética (RM), el estudio de la sustancia blanca se ha facilitado. A partir de eso, se han logrado grandes descubrimientos en cuanto a fascículos cerebrales involucrados en funciones cognitivas. Sin embargo, su evaluación sigue siendo subjetiva y depende de la experiencia y entrenamiento del evaluador, razón por la cual se ha limitado su aplicabilidad en la práctica clínica. En ese sentido, es conveniente parametrizar volúmenes cerebrales de sustancia blanca en población sana a través de una herramienta electrónica que se pueda reproducir y así poderlo aplicar en enfermos. Materiales y métodos Se reportan 10 sujetos sanos desde el punto de vista neurológico. Para cada sujeto, se adquirieron imágenes ponderadas por difusión y los resultados se visualizaron mediante FiberNavigator (http://scilus.github.io/fibernavigator). Finalmente, esa misma herramienta fue utilizada para purificar los fascículos objeto de estudio y realizar el conteo de las fibras. Resultados Se obtuvieron valores de volumetría del fascículo longitudinal superior (FLS), fascículo longitudinal inferior (FLI), fascículo frontoccipital inferior (FFI), fascículo uncinado (FU) y fascículo del cíngulo (FC), identificando que no existen diferencias estadísticamente significativas entre el número de fibras que componen los fascículos cerebrales. Discusión Los resultados alcanzados de la anatomía y la direccionalidad de fibras de los fascículos cerebrales de este estudio coinciden con el resto de la evidencia publicada hasta el momento, sin encontrar diferencias en cuanto a su organización y recorrido. Conclusión Aunque esos resultados no sirven como valores de referencia para ser aplicados en pacientes con patología neurológica, brindamos información inexistente hasta el momento, con ese equipo en específico y la reproducción entre los distintos usuarios y el software.

Objective Since the appearance of tractography, as it is a non-invasive technique and uses the widely known magnetic resonance (MR), the study of white matter has been facilitated. After this, great discoveries have been made regarding the brain fascicles involved in cognitive functions. However, its evaluation continues to be subjective and depends on the evaluator's experience and training. That the reason why its applicability has been limited in clinical practice. Because of this, it is convenient to parametrize cerebral volumes of white matter in healthy population through an electronic, reproducible tool that could be applied in patients. Materials and Methods Ten neurologically healthy subjects are reported, for each subject we acquired images weighted by diffusion and the results were visualized by means of FiberNavigator (http://scilus.github.io/fibernavigator). Finally, this same tool was used to purify the fascicles under study and perform the fiber count. Results Volumetric values of the upper longitudinal fasciculus, inferior longitudinal fasciculus, inferior frontoccipital fasciculus, uncinated fasciculus and cingulate fasciculus were obtained, identifying that there are not statistically significant differences in the number of fibers that make up the cerebral fascicles. Discussion The results achieved of the anatomical and fiber directionality of the cerebral fascicles of this study, coincide with the rest of the evidence published up to now, without finding differences regarding its organization and route. Conclusion Although these results do not serve as reference values to be applied in patients with neurological pathology, do we provide nonexistent information so far, with this specific equipment and the reproducibility between the different users and the software.

Nuevos conceptos en neuromodulación cerebral: rol de DTI y estimulación de tractos / New concepts in brain neuromodulation: role of DTI and tract stimulation

Introducción: La estimulación cerebral profunda es una técnica difundida y validada para eltratamiento de múltiples dolencias neurológicas y psiquiátricas, entre ellas el temblor esencial. Objetivo: Evaluar si existe un correlato clínico-anatómico, para un paciente con TE, entre la mejor estimulación lograda y los tractos involucrados. Para esto se realiza una descripción de la técnica utilizada, incluyendo el procesamiento de imágenes necesario. Material y métodos: Se presenta el caso de un paciente de 53 años de edad, con una historia de 23 años de temblor esencial progresivo e incapacitante. Se realizó un implante de DBS bilateral en Vim. Se realizó un post procesamiento de imágenes con un método desarrollado por nuestro equipo a través del cual se permitió evaluar gráficamente el área de estimulación cerebral y sus relaciones con los tractos implicados en la patología (dento-rubro-talámico, haz piramidal y haz lemniscal). Resultados: El paciente presentó una mejoría del 55% medido por escala de temblor de Tolosa. Se obtuvo una correlación anatómica y funcional de lo esperado según imágenes y la respuesta clínica del paciente. Se constataron efectos adversos cuando la estimulación implicaba fibras del haz piramidal y lemniscal, presentando los mejores efectos clínicos cuando el haz dento-rubro-talámico era influenciado por el área de acción del campo eléctrico. Conclusiones: En este reporte mostramos la aplicabilidad de DTI y tractografía para explicar los efectos de la programación de los pacientes con estimulación cerebral profunda.

Introduction: Deep brain stimulation is a widespread and validated technique for the treatment of multiple neurological and psychiatric disorders, including essential tremor. Objective: To evaluate if there is a clinical-anatomical correlate, for a patient with essential tremor, between the best stimulation achieved and the tracts involved. For this, a description of the technique used is made, including the necessary image processing. Methods: We present the case of a 53-year-old patient with a 23-year history of progressive and disabling essential tremor. A bilateral DBS implant was performed on Vim. We performed a post-processing of images with a method developed by our team through which we were able to graphically evaluate the area of brain stimulation and its relationships with the tracts involved in the pathology (dento-rubro-thalamic tract, pyramidal tract and lemniscal tract). Conclusions: In this report we showed the applicability of DTI and tractography to explain the clinical effects of the programming features in patients with deep brain stimulation.

Mini-Review of Studies Reporting the Repeatability and Reproducibility of Diffusion Tensor Imaging

PURPOSE: Diffusion tensor imaging (DTI) data must be analyzed by an analyzer after data processing. Hence, the analyzed data of DTI might depend on the analyzer, making it a major limitation. This paper reviewed previous DTI studies reporting the repeatability and reproducibility of data from the corticospinal tract (CST), one of the most actively researched neural tracts on this topic. MATERIALS AND METHODS: Relevant studies published between January 1990 and December 2018 were identified by searching PubMed, Google Scholar, and MEDLINE electronic databases using the following keywords: DTI, diffusion tensor tractography, reliability, repeatability, reproducibility, and CST. As a result, 15 studies were selected. RESULTS: Measurements of the CSTs using region of interest methods on 2-dimensional DTI images generally showed excellent repeatability and reproducibility of more than 0.8 but high variability (0.29 to 1.00) between studies. In contrast, measurements of the CST using the 3-dimensional DTT method not only revealed excellent repeatability and reproducibility of more than 0.9 but also low variability (repeatability, 0.88 to 1.00; reproducibility, 0.82 to 0.99) between studies. CONCLUSION: Both 2-dimensional DTI and 3-dimensional DTT methods appeared to be reliable for measuring the CST but the 3-dimensional DTT method appeared to be more reliable.

Generation of Mouse Basal Ganglia Diffusion Tractography Using 9.4T MRI

Over the years, diffusion tractography has seen increasing use for comparing minute differences in connectivity of brain structures in neurodegenerative diseases and treatments. Studies on connectivity between basal ganglia has been a focal point for studying the effects of diseases such as Parkinson's and Alzheimer's, as well as the effects of treatments such as deep brain stimulation. Additionally, in previous studies, diffusion tractography was utilized in disease mouse models to identify white matter alterations, as well as biomarkers that occur in the progression of disease. However, despite the extensive use of mouse models to study model diseases, the structural connectivity of the mouse basal ganglia has been inadequately explored. In this study, we present the methodology of segmenting the basal ganglia of a mouse brain, then generating diffusion tractography between the segmented basal ganglia structures. Additionally, we compare the relative levels of connectivity of connecting fibers between each basal ganglia structure, as well as visualize the shapes of each connection. We believe that our results and future studies utilizing diffusion tractography will be beneficial for properly assessing some of the connectivity changes that are found in the basal ganglia of various mouse models.

Progress of obsessive-compulsive disorder in diffusion tensor imaging / 中华行为医学与脑科学杂志

Diffusion tensor imaging (DTI),a noninvasive MRI technique for measuring the integrity and direction of white matter in the brain,is a promising method to explore the pathogenesis of obsessive compulsive disorder (OCD).At present,the etiological research of OCD suggests that,in addition to the classical cortical-striatum-thalamus-cortical (CSTC) circuit,the parietal lobe,temporal lobe,occipital lobe and other regions of the brain are also involved in the pathogenesis of OCD.White matter fibers are important structure of material information communication in various brain regions and affected by individual neurodevelopment.Therefore,it is very important to explore the characteristics of white matter fiber in the brain of patients with OCD by using diffusion tensor imaging technology clarifying its role in the occurrence of OCD.This paper reviews the studies on uncinate fasciculus,superior longitudinal fasciculus,corpus callosum in adult DTI studies and the progress of DTI studies on children and adolescents.

Histologic basis of diffusion tensor tractography for prostate disease / 实用放射学杂志

Objective To explore the histological basis of diffusion tensor tractography (DTT)fiber tracer images of benign prostatic hyperplasia (BPH)and prostate cancer (PCa).Methods Sixty-eight patients with PCa and sixty patients with BPH confirmed by pathology were recruited for this study.Conventional MRI and DTI examinations were performed.The original DTI data were processed at the AW4.5 workstation.After pos-t processed,FA and ADC values were recorded,DTT was plotted.Fiber bundle travel was observed and scored by two senior radiologists.The BPH and PCa specimens were stained with Masson fibers,and the diameter and angle of the fiber bundles were recorded.Results The FA values of BPH and PCa were 0.22±0.05 and 0.47±0.01 ,respectively.ADC values of BPH and PCa were (1.31 ±0.27)×10－3 mm2/s and (0.6 1 ±0.09)× 10－3 mm2/s,respectively.The differences in ADC and FA values among BPH and PCa were statistically significant (P＜0.05).DTT showeded that the fibers of BPH were dense and long,while the fibers of PCa were messy and short.The diameter and angle of collagen fibers and smooth muscle fibers for BPH were both larger than those for PCa,but only the difference between the diameter of smooth muscle fibers was statistically significant (P＜0.05).Conclusion There are significant differences between BPH and PCa in DTT images,which is consistent with the characteristics of fiber structure.DTI fiber bundle can reflect the differences of fiber structure between BPH and PCa.

Application of three-dimensional true fast imaging with steady-state precession sequence combined with diffusion tensor tractography for lumbar disc herniation / 中国介入影像与治疗学

Objective: To explore the value of three-dimensional true fast imaging with steady-state precession (3D-Ture FISP) sequence combined with diffusion tensor tractography (DTT) in determining the responsible nerve root of sciatica caused by lumbar disc herniation (LDH). Methods: MR examinations of lumbosacral region were performed on 40 LDH patients with unilateral sciatica (lesion group) and 40 healthy volunteers (control group). FA and ADC values of bilateral nerve roots were measured at L4-S1 vertebral level based on 3D-Ture FISP sequence and DTT fusing images. The responsible nerve roots of LDH patients with sciatica were detected combining with morphologic findings, course and FA and ADC values of the nerve roots shown on the fusing images. And statistical analysis was carried out. Results: All 3D-True FISP sequence and DTT fusing images could clearly show the morphology and course of nerve roots. In lesion group (51 involved nerve roots and 189 uninvolved nerve roots), 37 cases were found to be in accordance with the clinical symptoms whereas 3 cases were not. In control group (240 nerve roots), there was no statistical difference of FA and ADC values between the left and the right nerve roots (both P>0.05). The mean FA value of bilateral nerve roots was 0.346±0.042, and the mean ADC value was (1.296±0.080)mm2/s. The mean FA and ADC values of involved nerve roots in lesion group was 0.253±0.021 and (1.743±0.089)mm2/s, respectively. And the mean FA and ADC values of contralateral uninvolved nerve roots was 0.339±0.013 and (1.297±0.075)mm2/s, respectively. FA value of involved nerve roots in lesion group was significantly lower than that of contralateral uninvolved nerve roots in lesion group (t=0.806, P=0.038) and the mean FA value of control group (t=0.963, P=0.043), respectively,while ADC value significantly increased compared with contralateral uninvolved nerve roots (t=0.866, P=0.040) and control group (t=0.921, P=0.042). There was no statistical difference of the mean FA and ADC values between contralateral nerve roots in lesion group and control group (both P>0.05). Conclusion: 3D-Ture FLSP sequence combined with DTT technique can not only clearly show the anatomical morphology and course of nerve root, but also quantitatively detect the responsible nerve roots of sciatica in LDH patients, so as to provide information for clinical diagnosis and treatment.

Alteration of White Matter Integrity in Dyslexic Children: Case-Control Study / 신경정신의학

OBJECTIVES: To compare the white matter microstructure of dyslexic children with normal children using diffusion tensor imaging. METHODS: Twenty one dyslexic children and 24 normal control children were recruited in the second and third grade of elementary school students. The fractional anisotropy (FA) values of 20 representative white matter tracts were estimated from the diffusion tensor imaging data of each subject using the Johns Hopkins University-white matter tractography atlas to determine the difference in white matter integrity between the dyslexic children and normal children. RESULTS: Compared to the normal control group, the FA values of the left inferior longitudinal fasciculus [F(1,39)=5.908, p<0.05] and temporal part of the right superior longitudinal fasciculus [F(1,39)=7.328, p=0.010] were significantly higher in the dyslexic group and there was no significant difference in the other tracts. CONCLUSION: In dyslexic children, compensatory pathways develop in the left inferior longitudinal fasciculus and in the temporal part of the right superior longitudinal fasciculus.

DTI analysis on white matter changes in children with ametropic amblyopia / 眼科新进展

Objective To evaluate white matter nerve fiber changes of children with binocular ametropic amblyopia by applying the technology of diffusion tensor imaging and the whole brain analysis method of deterministic tractography,and analyze its correlation with visual acuity.Methods Fourteen binocular ametropic amblyopia children was collected from the Second Xiangya Hospital of Central South University as study subject of experimental group,14 cases of normal sight children as the control group.All children were scanned by MRI system,conventional MRI examination,3DTlWI scan were made,then echo-planar sequence scanning was used to obtain diffusion tensor imaging.Quantitative analysis was made to all diffusion tensor imaging using deterministic tractography.Using the experimental group tracts with statistic changes of FA value,volume and tract count as the region of interest(ROI),the correlation analysis with vision for each ROI was performed.Results Isoametropic amblyopia children demonstrated low FA values in the right ventral and dorsal pathway,right optic radiation and corpus callosum compared to control group.There was low volume of fibers in the bilateral ventral and dorsal pathway,the left optic radiation and body of corpus callosum compared to control group.The tract count of right dorsal pathway had reduced compared to control group.Among FA value,tract count and volume,FA value had the maximum regression coefficient with visual acuity,the regression coefficient of tract count and volume was small.The relative correlation coefficient of FA value at right optic radiation,right ventral pathway and body of corpus callosum with vision acuity were 0.486,0.534 and 0.456,respectively,the right ventral pathway had the maximum correlation with visual acuity.Conclusion Isoametropic amblyopia patients shows abnormal structure on bilateral optic radiation,bilateral ventral and dorsal pathway and body of corpus cailosum,these may cause the capability loss of object recognition and spatial position recognition.The FA value of right ventral pathway has the maximum influence on visual acuity.

Diffusion tensor imaging tractography in assessing damage of limbic system pathways of relapsing-remitting multiple sclerosis patients / 中国医学影像技术

Objective To assess the damage of limbic system pathways in relapsing-remitting multiple sclerosis (RRMS) by diffusion tensor imaging (DTI) tractography.Methods DTI tractography was used to acquire fiber numbers,fractional anisotropy (FA),mean diffusivity (MD) of cingulum,fornix,and uncinate fasciculus (UF) in 20 RRMS patients (MS group) and 20 healthy volunteers (control group),and statistical analysis was performed.Results Compared with control group,lower FA value (P＜0.01) and higher MD value (P＜0.05) were found in cingulum,fornix and UF of MS group,and the fiber numbers of fornix decreased in MS group (P＜0.001).There were significant differences between the left and the right UF in fiber numbers and FA value of control group and the fiber numbers of MS group.Negative correlations were found between FA value of cingulum and UF and EDSS scores in MS group (r=-0.572,-0.665,both P＜0.05),and positive correlations were found between MD value and EDSS scores (r=0.627,0.603,both P＜0.05).Conclusion DTI tractography is valuable in assessing MS associated limbic system damage and in monitoring the clinical progression of the disease.

Brain Micro-structural Alterations of Cough Syrup Abuse Addiction Patients Containing Codeine Under Resting State / 中山大学学报(医学科学版)

[Objective]To investigate the micro-structural alterations within whole brain white matter(WM) in cough syrup abuse addiction patients containing codeine,and to explore the correlation between aberrant WH and abuse time of cough medicine abuse patients.[Methods]Thirty cough syrup abuse addiction patients containing codeine and 30 controls participated in the study. Structural changes in FA and(mean diffusivity)MD were examined in cough syrup abuse addiction patients containing codeine which derived from DTI tractography. Pearson correlation analysis was performed to compare the mean FA value and duration of cough syrup abuse addiction in patients.[Results]Cough syrup abuse addiction patients containing codeine had lower FA value in bilateral anterior limb of internal capsule(ALIC)and higher MD in the bilateral hippocampus and insula,right anterior cingulate cortex(ACC)and superior temporal gyrus,compared to the controls. Cough syrup abuse addiction group also had positive correlation between mean FAvalues and duration of cough syrup abuse addiction in patients.[Conclusion]Micro-structural alterations within whole brain white matter(WM)are found in cough syrup abuse addiction patients containing codeine. This disturbance progresses as duration increases of cough syrup abuse addiction in patients.

Role of magnetic resonance diffusion tensor imaging on prognostic evaluation of term neonates with asphyxia / 中华实用儿科临床杂志

Objective To discuss the prognostic evaluation of magnetic resonance diffusion tensor imaging (DTI) in term neonates with mild and severe asphyxia.Methods Eleven neonates with mild asphyxia,14 neonates with severe asphyxia and 10 control neonates were studied.All the neonates were examined by conventional magnetic resonance imaging(MRI) and DTI.Fraction anisotropy (FA) values,apparent diffusion coefficient (ADC) values,voxel numbers and fiber numbers were calculated in seven regions of interest(ROI) and compared among the 3 groups.The correlation between FA values and neonatal behavioral neurological assessment (NBNA) scores were analyzed.Results (1) FA values in the left and the right thalamus were 0.54 ± 0.08 and 0.56 ± 0.15 in control group,0.45 ±0.03 and 0.44 ± 0.10 in mild group,and 0.21 ± 0.11 and 0.25 ± 0.13,respectively in severe group.FA values in posterior limbs of internal capsule were 0.49 ± 0.09 and 0.48 ± 0.08 in control group,0.37 ± 0.08 and 0.38 ± 0.03 in mild group,and 0.20 ± 0.04,0.19 ± 0.13 in severe group;FA values in thalamus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =9.12,9.11,8.18,8.55,all P ＜ 0.05).Voxel numbers in the left and the right superior longitudinal fasciculus were 1 094 ± 112 and 1 123 ± 113 in control group,986 ± 111 and 1 009 ± 144 in mild group,450 ± 116 and 671 ± 126 in severe group.Voxel numbers in anterior limbs of internal capsule were 947 ± 104 and 1 237 ± 184 in control group,854 ± 118 and 799 ± 114 in mild group,324 ± 110 and 311 ± 126 in severe group.Voxel numbers in posterior limbs of internal capsule were 2 047 ± 129 and 2 137 ± 238 in control group,1 843 ± 233 and 1 753 ± 247 in mild group,867 ± 118 and 999 ± 167 in severe group.Voxel numbers in superior longitudinal fasciculus,anterior and posterior limbs of internal capsule had statistical differences among the 3 groups (F =10.11,9.45,7.33,8.45,12.65,11.23,all P ＜ 0.05);Fiber numbers in the left and the right cingulate gyrus were 245 ±72 and 405 ±94 in control group,225 ±52 and 365 ± 114 in mild group,145 ±62 and 185 ±84 in severe group.Fiber numbers in inferior front-occipital fasciculus were 56 ± 19 and 212 ± 33 in control group,49 ±22 and 197 ± 33 in mild group,33 ± 12 and 156 ± 39 in severe group.Fiber numbers in posterior limbs of internal capsule were 284 ± 112 and 988 ± 233 in control group,234 ± 67 and 678 ± 234 in mild group,114 ± 67 and 188 ± 84 in severe group.Fiber numbers in cingulate gyrus,inferior front-occipital fasciculus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =3.11,3.45,9.88,9.12,7.45,8.88,all P ＜ 0.05).(2) The correlation between FA value and NBNA scores was analyzed:the correlation coefficient in posterior limbs of internal capsule was 0.666 which was higher than those of the other areas.The area under the ROC curve of FA values in anterior limbs of internal capsule was 0.816 (P =0.005),used NBNA scores ≥ 35 as a good outcome.FA values (≥ 0.375) in the posterior limbs of the internal capsules predicted a good outcome and the corresponding sensitivity and specificity was 73.1％ and 77.8％,respectively.Conclusion In some ROIs,FA values,voxel numbers,and fiber numbers can quantitatively reflect the degree of white matter injury in neonates with asphyxia.Furthermore,the FA values in the posterior limbs of the internal capsules are closely correlated with NBNA scores,so it has more important clinical significance,and can accurately and objectively assess the prognosis in neonates with asphyxia.

Role of magnetic resonance diffusion tensor imaging on prognostic evaluation of term neonates with asphyxia / 中华实用儿科临床杂志

Objective To discuss the prognostic evaluation of magnetic resonance diffusion tensor imaging (DTI) in term neonates with mild and severe asphyxia.Methods Eleven neonates with mild asphyxia,14 neonates with severe asphyxia and 10 control neonates were studied.All the neonates were examined by conventional magnetic resonance imaging(MRI) and DTI.Fraction anisotropy (FA) values,apparent diffusion coefficient (ADC) values,voxel numbers and fiber numbers were calculated in seven regions of interest(ROI) and compared among the 3 groups.The correlation between FA values and neonatal behavioral neurological assessment (NBNA) scores were analyzed.Results (1) FA values in the left and the right thalamus were 0.54 ± 0.08 and 0.56 ± 0.15 in control group,0.45 ±0.03 and 0.44 ± 0.10 in mild group,and 0.21 ± 0.11 and 0.25 ± 0.13,respectively in severe group.FA values in posterior limbs of internal capsule were 0.49 ± 0.09 and 0.48 ± 0.08 in control group,0.37 ± 0.08 and 0.38 ± 0.03 in mild group,and 0.20 ± 0.04,0.19 ± 0.13 in severe group;FA values in thalamus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =9.12,9.11,8.18,8.55,all P ＜ 0.05).Voxel numbers in the left and the right superior longitudinal fasciculus were 1 094 ± 112 and 1 123 ± 113 in control group,986 ± 111 and 1 009 ± 144 in mild group,450 ± 116 and 671 ± 126 in severe group.Voxel numbers in anterior limbs of internal capsule were 947 ± 104 and 1 237 ± 184 in control group,854 ± 118 and 799 ± 114 in mild group,324 ± 110 and 311 ± 126 in severe group.Voxel numbers in posterior limbs of internal capsule were 2 047 ± 129 and 2 137 ± 238 in control group,1 843 ± 233 and 1 753 ± 247 in mild group,867 ± 118 and 999 ± 167 in severe group.Voxel numbers in superior longitudinal fasciculus,anterior and posterior limbs of internal capsule had statistical differences among the 3 groups (F =10.11,9.45,7.33,8.45,12.65,11.23,all P ＜ 0.05);Fiber numbers in the left and the right cingulate gyrus were 245 ±72 and 405 ±94 in control group,225 ±52 and 365 ± 114 in mild group,145 ±62 and 185 ±84 in severe group.Fiber numbers in inferior front-occipital fasciculus were 56 ± 19 and 212 ± 33 in control group,49 ±22 and 197 ± 33 in mild group,33 ± 12 and 156 ± 39 in severe group.Fiber numbers in posterior limbs of internal capsule were 284 ± 112 and 988 ± 233 in control group,234 ± 67 and 678 ± 234 in mild group,114 ± 67 and 188 ± 84 in severe group.Fiber numbers in cingulate gyrus,inferior front-occipital fasciculus and posterior limbs of internal capsule had statistical differences among the 3 groups (F =3.11,3.45,9.88,9.12,7.45,8.88,all P ＜ 0.05).(2) The correlation between FA value and NBNA scores was analyzed:the correlation coefficient in posterior limbs of internal capsule was 0.666 which was higher than those of the other areas.The area under the ROC curve of FA values in anterior limbs of internal capsule was 0.816 (P =0.005),used NBNA scores ≥ 35 as a good outcome.FA values (≥ 0.375) in the posterior limbs of the internal capsules predicted a good outcome and the corresponding sensitivity and specificity was 73.1％ and 77.8％,respectively.Conclusion In some ROIs,FA values,voxel numbers,and fiber numbers can quantitatively reflect the degree of white matter injury in neonates with asphyxia.Furthermore,the FA values in the posterior limbs of the internal capsules are closely correlated with NBNA scores,so it has more important clinical significance,and can accurately and objectively assess the prognosis in neonates with asphyxia.

Resting-State Metabolism of Hand Knob Area on ¹⁸F-FDG PET-CT According to Hand Function and Tractography of Corticospinal Tract After Stroke

OBJECTIVE: To correlate the resting metabolism of hand knob and hand function after stroke, diffuse tensor tractography (DTT) and ¹⁸F-fluorodeoxyglucose position emission tomography (¹⁸F-FDG PET) were used to evaluate constructible state of white matter tract and metabolic state of gray matter, respectively. METHODS: A total of 17 patients were included in the study, who had suffered a stroke with hand weakness, after a stroke. They underwent diffusion tensor analysis and FDG PET in the subacute period. The ratio of both hemisphere parameters in voxel number of fibers, fractional anisotropy (FA) and apparent diffusion coefficient obtained by corticospinal tract as constructed by DTT, and the metabolism of hand knob area on cerebral cortex obtained from ¹⁸F-FDG PET were calculated. Hand movement scale was evaluated on the day of FDG PET or tractography, and at 6 months after onset. RESULTS: Difference of FA in DTT between both hemispheres and hand knob metabolism in FDG PET significantly correlated with the hand movement scale at the subacute stage and 6 months after onset. However, the difference of both hemispheres in DTT and metabolism of hand knob area was not significant. CONCLUSION: Resting metabolism on hand knob in FDG PET correlated with hand function after stroke.

Síndrome de Melas: correlación clínica con hallazgos imagenológicos en espectroscopia y tractografía, reporte de caso / Melas syndrome: clinical correlation with imaging findings in spectroscopy and tractography, case report

El síndrome de Melas es una enfermedad de herencia mitocondrial caracterizada por encefalopatía mitocondrial, acidosis láctica y eventos similares a ataque cerebrovascular, secundaria a una mutación en los genes que codifican las proteínas transportadoras de electrones, limitando la producción energética y generando disfunción multiorgánica, que afecta principalmente el sistema músculo esquelético y el sistema nervioso, lo que está en correlación con las características clínicas que presentan los pacientes. El diagnostico se basa en la sospecha clínica, los hallazgos paraclínicos e imagenológicos y la confirmación de la mutación a través del estudio genético. No existe tratamiento específico, se basa únicamente en el manejo sintomático y requiere apoyo multidisciplinario. Presentamos el caso de un paciente con antecedente de Melas, que ingresó por evento cerebrovascular isquémico bioccipital y correlación con hallazgos en neuroimágenes (espectroscopia y tractografía).

Melas syndrome is a disease characterized by mitochondrial inheritance of mitochondrial encephalopathy, lactic acidosis and events like stroke secondary to a mutation in the gene encoding the electron transport proteins limiting energy production and generating multiorgan dysfunction being affected mainly musculoskeletal system and the nervous system which correlates with the clinical characteristics presented by patients. The diagnosis is based on clinical suspicion, laboratory, and imaging findings and confirmation of the mutation through genetic study. No specific treatment is Is available, but symptomatic treatment is needed and requires multidisciplinary support. We report a patient with a history of Melas who who had bioccipital cerebral ischemic event and correlation with findings in neuroimaging (spectroscopy and tractography).