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Diffuse tensor imaging

Bertram J Wilm, Christoph Barmet, Simon Gross, Lars Kasper, S Johanna Vannesjo, Max Haeberlin, Benjamin E Dietrich, David O Brunner, Thomas Schmid, Klaas P Pruessmann
PURPOSE: The purpose of this work was to improve the quality of single-shot spiral MRI and demonstrate its application for diffusion-weighted imaging. METHODS: Image formation is based on an expanded encoding model that accounts for dynamic magnetic fields up to third order in space, nonuniform static B0 , and coil sensitivity encoding. The encoding model is determined by B0 mapping, sensitivity mapping, and concurrent field monitoring. Reconstruction is performed by iterative inversion of the expanded signal equations...
October 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Swarupa Kancherla, William J Kohler, Yolandi van der Merwe, Kevin C Chan
Visual function has been shown to deteriorate prior to the onset of retinopathy in some diabetic patients and experimental animal models. This suggests the involvement of the brain's visual system in the early stages of diabetes. In this study, we tested this hypothesis by examining the integrity of the visual pathway in a diabetic rat model using in vivo multi-modal magnetic resonance imaging (MRI). Ten-week-old Sprague-Dawley rats were divided into an experimental diabetic group by intraperitoneal injection of 65 mg/kg streptozotocin in 0...
2016: PloS One
Prashanthi Vemuri, David S Knopman, Clifford R Jack, Emily S Lundt, Stephen D Weigand, Samantha M Zuk, Kaely B Thostenson, Robert I Reid, Kejal Kantarci, Yelena Slinin, Kamakshi Lakshminarayan, Cynthia S Davey, Anne Murray
BACKGROUND: Chronic kidney disease (CKD) studies have reported variable prevalence of brain pathologies, in part due to low inclusion of participants with moderate to severe CKD. OBJECTIVE: To measure the association between kidney function biomarkers and brain MRI findings in CKD. METHODS: In the BRINK (BRain IN Kidney Disease) study, MRI was used to measure gray matter volumes, cerebrovascular pathologies (white matter hyperintensity (WMH), infarctions, microhemorrhages), and microstructural changes using diffusion tensor imaging (DTI)...
October 19, 2016: Journal of Alzheimer's Disease: JAD
Julie M Hall, Kaylena A Ehgoetz Martens, Courtney C Walton, Claire O'Callaghan, Peter E Keller, Simon J G Lewis, Ahmed A Moustafa
Parkinson's disease (PD) is a heterogeneous neurological disorder with a variety of motor and non-motor symptoms. The underlying mechanisms of these symptoms are not fully understood. An increased interest in structural connectivity analyses using diffusion tensor imaging (DTI) in PD has led to an expansion of our understanding of the impact of abnormalities in diffusivity on phenotype. This review outlines the contribution of these abnormalities to symptoms of PD including bradykinesia, tremor and non-tremor phenotypes, freezing of gait, cognitive impairment, mood, sleep disturbances, visual hallucinations and olfactory dysfunction...
September 28, 2016: Parkinsonism & related Disorders
Klaus Kopitzki, Andreas Oldag, Catherine M Sweeney-Reed, Judith Machts, Maria Veit, Jörn Kaufmann, Hermann Hinrichs, Hans-Jochen Heinze, Katja Kollewe, Susanne Petri, Bahram Mohammadi, Reinhard Dengler, Andreas R Kupsch, Stefan Vielhaber
PURPOSE: Aim of the present study was to investigate potential impairment of non-motor areas in amyotrophic lateral sclerosis (ALS) using near-infrared spectroscopy (NIRS) and diffusion tensor imaging (DTI). In particular, we evaluated whether homotopic resting-state functional connectivity (rs-FC) of non-motor associated cortical areas correlates with clinical parameters and disease-specific degeneration of the corpus callosum (CC) in ALS. MATERIAL AND METHODS: Interhemispheric homotopic rs-FC was assessed in 31 patients and 30 healthy controls (HCs) for 8 cortical sites, from prefrontal to occipital cortex, using NIRS...
2016: NeuroImage: Clinical
Xinghui Li, Ling Zhuang, Xiaoming Zhang, Jian Wang, Tianwu Chen, Liangjun Li, Emmanuel Ajedichiga Aduah, Jiani Hu
[This corrects the article DOI: 10.1371/journal.pone.0160115.].
2016: PloS One
Cailei Zhao, Yongxin Li, Weiguo Cao, Kui Xiang, Heye Zhang, Jian Yang, Yungen Gan
To explore the use of diffusion tensor imaging (DTI) parameters in the quantitative assessment of early brain microstructure changes before and after ventriculoperitoneal shunt in children with high intracranial pressure hydrocephalus.Ten patients with communicating hydrocephalus (age: 2-36 months) and 14 age-/gender-matched controls (age: 2-36 months) were enrolled in this study. All patients underwent the ventriculoperitoneal shunt procedure. The imaging data were collected before and 3 months after the operation...
October 2016: Medicine (Baltimore)
Fang Zhang, WenMing Hong, Yan Guo, QianYing Guo, XiaoPeng Hu
BACKGROUND: Microsurgery is a common treatment of brainstem tumors. However, misdirection, vascular damage, nerves injuries, paralysis, even death are all well-known complications, and the risk of adverse events is more likely in less experienced operators. This study was aimed to validate the accuracy of multimodal neuronavigation during microsurgery resection of brainstem tumors. METHODS: Ten patients with brainstem tumors underwent preoperative MRI, diffusion tensor imaging, computed tomography, three-dimensional print, and images loaded into the neuronavigation platform were used for its segmentation and preoperative planning...
October 14, 2016: Journal of Craniofacial Surgery
Archontis Giannakidis, Gerd Melkus, Guang Yang, Grant T Gullberg
Diffusion tensor magnetic resonance imaging (DT-MRI) allows a unique insight into the microstructure of highly-directional tissues. The selection of the most proper distance function for the space of diffusion tensors is crucial in enhancing the clinical application of this imaging modality. Both linear and nonlinear metrics have been proposed in the literature over the years. The debate on the most appropriate DT-MRI distance function is still ongoing. In this paper, we presented a framework to compare the Euclidean, affine-invariant Riemannian and log-Euclidean metrics using actual high-resolution DT-MRI rat heart data...
November 7, 2016: Physics in Medicine and Biology
Weifei Wu, Jie Liang, Ying Chen, Aihua Chen, Bin Wu, Zong Yang
To investigate the microstructural changes in compressed nerves using diffusion tensor imaging (DTI) of herniated disc treated with percutaneous transforaminal endoscopic discectomy.Diffusion tensor imaging has been widely used to visualize peripheral nerves, and the microstructure of compressed nerve roots can be assessed using DTI. However, the microstructural changes after surgery are not well-understood in patients with lumbar disc herniation.Thirty-four consecutive patients with foraminal disc herniation affecting unilateral sacral 1 (S1) nerve roots were enrolled in this study...
October 2016: Medicine (Baltimore)
Vani A Mathur, Massieh Moayedi, Michael L Keaser, Shariq A Khan, Catherine S Hubbard, Madhav Goyal, David A Seminowicz
Migraine is a pain disorder associated with abnormal brain structure and function, yet the effect of migraine on acute pain processing remains unclear. It also remains unclear whether altered pain-related brain responses and related structural changes are associated with clinical migraine characteristics. Using fMRI and three levels of thermal stimuli (non-painful, mildly painful, and moderately painful), we compared whole-brain activity between 14 migraine patients and 14 matched controls. Although, there were no significant differences in pain thresholds nor in pre-scan pain ratings to mildly painful thermal stimuli, patients did have aberrant suprathreshold nociceptive processing...
2016: Frontiers in Human Neuroscience
RaviK Shastri, GaurangV Shah, Page Wang, Patricia Cagnoli, Tobias Schmidt-Wilcke, Joseph McCune, Richard Harris, PiaC Sundgren
PURPOSE: Systemic lupus erythematosus (SLE) is a predominantly female autoimmune disease that can affect the central nervous system. Neuropsychiatric symptoms are found in 25-70% of SLE patients. Using diffusion tensor imaging, various studies have reported changes in white matter integrity in SLE patients with neuropsychiatric symptoms (NPSLE patients). The purpose of this study was to investigate if changes can be detected in the individual white matter tracts in SLE patients regardless if neuropsychiatric symptoms are present or not...
October 13, 2016: Academic Radiology
Yi-Bin Xi, Fan Guo, Hua Li, Xiao Chang, Jin-Bo Sun, Yuan-Qiang Zhu, Wen-Ming Liu, Long-Biao Cui, Gang Chen, Hua-Ning Wang, Hong Yin
Heterogeneous findings across studies of structural abnormality in schizophrenia (SZ) have impeded the development a unified theory of white matter pathology. As a cardinal symptom of SZ, auditory verbal hallucination (AVH) has been suspected to be associated with improper communication among several brain regions, which might indicated white matter pathology. Participants comprised 25 first-episode (FE) patients with AVH, 25 patients without AVH and 25 healthy subjects. Diffusion tensor imaging (DTI) measures were calculated using the TBSS of FSL...
September 28, 2016: Psychiatry Research
Tamara Ius, Luca Turella, Giada Pauletto, Miriam Isola, Marta Maieron, Giovanni Sciacca, Riccardo Budai, Serena D'Agostini, Roberto Eleopra, Miran Skrap
BACKGROUND: Pre-operative diffusion tensor tractography (DTT) has recently been utilized to aid in the mapping of functional pathways in order to limit damage associated with resection of low-grade gliomas. OBJECTIVE: To assess the predictive capacity of DTT as a biomarker of post-operative motor outcomes in patients with low-grade gliomas (LGGs) involving the corticospinal tract (CST). CST parameters obtained using a quantitative fiber-tracking approach were used to investigate the reliability of the DTT biomarker by comparing their values in the tumoral (Tcst) and healthy (Hcst) hemispheres...
October 12, 2016: World Neurosurgery
Farid Ahmed Sid, Karim Abed-Meraim, Rachid Harba, Fatima Oulebsir-Boumghar
PURPOSE: To examine the effects of MR acquisition parameters on brain white matter fiber orientation estimation and parameter of clinical interest in crossing fiber areas based on the Multi-Tensor Model (MTM). MATERIAL AND METHODS: We compute the Cramér-Rao Bound (CRB) for the MTM and the parameter of clinical interest such as the Fractional Anisotropy (FA) and the dominant fiber orientations, assuming that the diffusion MRI data are recorded by a multi-coil, multi-shell acquisition system...
October 12, 2016: Magnetic Resonance Imaging
Gianluca Coppola, Antonio Di Renzo, Emanuele Tinelli, Cherubino Di Lorenzo, Giorgio Di Lorenzo, Vincenzo Parisi, Mariano Serrao, Jean Schoenen, Francesco Pierelli
OBJECTIVE: We used MRI to search for changes in thalamo-cortical networks and thalamic microstructure during spontaneous migraine attacks by studying at the same time structure with diffusion tensor imaging and resting state function in interconnected brain networks with independent component analysis. METHODS: Thirteen patients with untreated migraine without aura (MI) underwent 3T MRI scans during an attack and were compared to a group of 19 healthy controls (HC)...
October 14, 2016: Neurology
Karol Borkowski, Krzysztof Kłodowski, Henryk Figiel, Artur Tadeusz Krzyżak
The recently presented B-matrix Spatial Distribution (BSD) approach is a calibration technique which derives the actual distribution of the B-matrix in space. It is claimed that taking into account the spatial variability of the B-matrix improves the accuracy of diffusion tensor imaging (DTI). The purpose of this study is to verify this approach theoretically through computer simulations. Assuming three different spatial distributions of the B-matrix, diffusion weighted signals were calculated for the six orientations of a model anisotropic phantom...
October 11, 2016: Magnetic Resonance Imaging
Robert J Young, Ek T Tan, Kyung K Peck, Mehrnaz Jenabi, Sasan Karimi, Nicole Brennan, Jennifer Rubel, John Lyo, Weiji Shi, Zhigang Zhang, Marcel Prastawa, Xiaofeng Liu, Jonathan I Sperl, Robin Fatovic, Luca Marinelli, Andrei I Holodny
PURPOSE: To compare compressed diffusion spectrum imaging (CS-DSI) with diffusion tensor imaging (DTI) in patients with intracranial masses. We hypothesized that CS-DSI would provide superior visualization of the motor and language tracts. MATERIALS AND METHODS: We retrospectively analyzed 25 consecutive patients with intracranial masses who underwent DTI and CS-DSI for preoperative planning. Directionally-encoded anisotropy maps, and streamline hand corticospinal motor tracts and arcuate fasciculus language tracts were graded according to a 3-point scale...
October 11, 2016: Magnetic Resonance Imaging
Samata Kakkad, Jiangyang Zhang, Alireza Akhbardeh, Desmond Jacob, Balaji Krishnamachary, Meiyappan Solaiyappan, Michael A Jacobs, Venu Raman, Dieter Leibfritz, Kristine Glunde, Zaver M Bhujwalla
Collagen 1 (Col1) fibers play an important role in tumor interstitial macromolecular transport and cancer cell dissemination. Our goal was to understand the influence of Col1 fibers on water diffusion, and to examine the potential of using noninvasive diffusion tensor imaging (DTI) to indirectly detect Col1 fibers in breast lesions. We previously observed, in human MDA-MB-231 breast cancer xenografts engineered to fluoresce under hypoxia, relatively low amounts of Col1 fibers in fluorescent hypoxic regions...
October 2016: Neoplasia: An International Journal for Oncology Research
Martin T Freitag, Klaus H Maier-Hein, Francisczek Binczyk, Frederik B Laun, Christian Weber, David Bonekamp, Rafal Tarnawski, Barbara Bobek-Billewicz, Joanna Polanska, Henryk Majchrzak, Bram Stieltjes
OBJECTIVE: Here, we retrospectively investigate the value of voxel-wisely plotted diffusion tensor-derived (DTI) axial, radial and mean diffusivity for the early detection of malignant transformation (MT) in WHO II glioma compared to contrast-enhanced images. MATERIALS AND METHODS: Forty-seven patients underwent brain magnetic resonance imaging follow-up between 2006-2014 after gross-tumor resection of intra-axial WHO II glioma. Axial/Mean/Radial diffusivity maps (AD/MD/RD) were generated from DTI data...
2016: PloS One
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