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Diffusion Tensor MRI

Jianfei Yang, Dirk H J Poot, Matthan W A Caan, Tanja Su, Charles B L M Majoie, Lucas J van Vliet, Frans M Vos
PURPOSE: This paper presents and studies a framework for reliable modeling of diffusion MRI using a data-acquisition adaptive prior. METHODS: Automated relevance determination estimates the mean of the posterior distribution of a rank-2 dual tensor model exploiting Jeffreys prior (JARD). This data-acquisition prior is based on the Fisher information matrix and enables the assessment whether two tensors are mandatory to describe the data. The method is compared to Maximum Likelihood Estimation (MLE) of the dual tensor model and to FSL's ball-and-stick approach...
2016: PloS One
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
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
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
Mirza A Baig, Joshua P Klein, Laszlo L Mechtler
PURPOSE OF REVIEW: Neuroimaging is an essential tool for the diagnosis and management of brain tumors. RECENT FINDINGS: Advances in neuroimaging have allowed for noninvasive visualization of tumors and have changed how brain tumors are diagnosed and treated. Presurgical planning with the use of functional MRI (fMRI) and diffusion tensor MRI helps to preserve eloquent regions of the brain and fiber tracts, thereby decreasing patients' postsurgical morbidity. With the use of susceptibility-weighted imaging (SWI) filtered phase images, diffusion-weighted studies, and perfusion imaging techniques, deciphering posttreatment effects versus tumor progression can be facilitated...
October 2016: Continuum: Lifelong Learning in Neurology
Michele R Colonna, Giuseppe Tallarida, Francesco Stagno d'Alcontres, Salvatore Noto, Aurora Parodi, Alberto Tagliafico
Five years after both right ulnar and median nerve decompression for paraesthesias and palsy, a patient, coming from Nigeria but living in Italy, came to our unit claiming to have persistent pain and combined median and ulnar palsy. Under suspicion of leprosy, skin and left sural nerve biopsy were performed. Skin tests were negative, but Schwann cells resulted as positive for acid-fast bacilli (AFB), leading to the diagnosis of Pure Neuritic Leprosy (PNL). The patient was given PB multidrug therapy and recovered from pain in two months...
2016: Case Reports in Neurological Medicine
Volker Ressel, Ruth O'Gorman Tuura, Ianina Scheer, Hubertus J A van Hedel
BACKGROUND: Rehabilitation in children with acquired brain injury is a challenging endeavour. There is a large variability in motor recovery between patients, and a need to optimize therapies by exploiting cerebral plasticity and recovery mechanisms. This retrospective study aims to identify tract-based markers that could serve as predictors of functional outcome following rehabilitation. METHODS: Twenty-nine children with traumatic brain injury (n = 14) or stroke (n = 15) underwent a 3 T Magnetic Resonance Imaging (MRI) measurement, including Diffusion Tensor Imaging (DTI) between admission to the Hospital and onset of rehabilitation therapy at the Rehabilitation Centre...
October 12, 2016: Brain Imaging and Behavior
B F Kjølby, A R Khan, A Chuhutin, L Pedersen, J B Jensen, S Jakobsen, D Zeidler, R Sangill, J R Nyengaard, S N Jespersen, B Hansen
Diffusion kurtosis imaging (DKI) is sensitive to tissue microstructure and may therefore be useful in the diagnosis and monitoring of disease in brain and body organs. Generally, diffusion magnetic resonance imaging (dMRI) in the body is challenging because of the heterogeneous body composition, which can cause image artefacts as a result of chemical shifts and susceptibility differences. In addition, the abdomen possesses physiological factors (e.g. breathing, heartbeat, blood flow) which may severely reduce image quality, especially when echo planar imaging is employed, as is typical in dMRI...
October 12, 2016: NMR in Biomedicine
Maria A Rocca, Silvia Fumagalli, Elisabetta Pagani, Roberto Gatti, Gianna C Riccitelli, Paolo Preziosa, Giancarlo Comi, Andrea Falini, Massimo Filippi
Action observation training (AOT) is thought to facilitate motor system function. We applied voxelwise methods to assess the regional modifications of brain gray matter (GM) volumes and white matter (WM) architecture in healthy subjects following AOT and their correlations with improvements at motor and cognitive functional scales. Forty-two righ-handed healthy subjects were randomized into an experimental (AOT-G, n = 20) and a control (C-G, n = 22) group. The training lasted 2 weeks and consisted of 10 sessions of 45 min each during which subjects watched videos of daily-life actions (AOT-G) or landscapes (C-G), alternated by the execution with the right hand of actions presented in the AOT-G videos...
October 11, 2016: Brain Imaging and Behavior
Freddy J Alfaro, Vasileios-Arsenios Lioutas, Daniela A Pimentel, Chen-Chih Chung, Francisco Bedoya, Woo-Kyoung Yoo, Vera Novak
Subjects with metabolic syndrome (MetS) often show worse cognitive performance compared with the healthy population. We investigated whether microstructural white matter abnormalities are associated with cognitive performance in adults with MetS using diffusion tensor MR imaging. A total of 32 subjects with MetS (age 64.8 ± 7.8, 56.25 % female) and 23 age-, gender-, and education-matched healthy controls completed a battery of neuropsychological tests and diffusion tensor imaging (DTI) at 3-T MRI. Brain global and regional volumes, white matter fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (LD) were calculated...
October 11, 2016: Journal of Neurology
Alexander Frizell Santillo, Karl Lundblad, Markus Nilsson, Maria Landqvist Waldö, Danielle van Westen, Jimmy Lätt, Erik Blennow Nordström, Susanna Vestberg, Olof Lindberg, Christer Nilsson
Disinhibition is an important symptom in neurodegenerative diseases. However, the clinico-anatomical underpinnings remain controversial. We explored the anatomical correlates of disinhibition in neurodegenerative disease using the perspective of grey and white matter imaging. Disinhibition was assessed with a neuropsychological test and a caregiver information-based clinical rating scale in 21 patients with prefrontal syndromes due to behavioural variant frontotemporal dementia (n = 12) or progressive supranuclear palsy (n = 9), and healthy controls (n = 25)...
2016: PloS One
Leah H Suttner, Amanda Mejia, Blake Dewey, Pascal Sati, Daniel S Reich, Russell T Shinohara
Diffusion tensor imaging (DTI) has become the predominant modality for studying white matter integrity in multiple sclerosis (MS) and other neurological disorders. Unfortunately, the use of DTI-based biomarkers in large multi-center studies is hindered by systematic biases that confound the study of disease-related changes. Furthermore, the site-to-site variability in multi-center studies is significantly higher for DTI than that for conventional MRI-based markers. In our study, we apply the Quantitative MR Estimation Employing Normalization (QuEEN) model to estimate the four DTI measures: MD, FA, RD, and AD...
2016: NeuroImage: Clinical
Els Fieremans, Gregory Lemberskiy, Jelle Veraart, Eric E Sigmund, Soterios Gyftopoulos, Dmitry S Novikov
The time dependence of the diffusion coefficient is a hallmark of tissue complexity at the micrometer level. Here we demonstrate how biophysical modeling, combined with a specifically tailored diffusion MRI acquisition performing diffusion tensor imaging (DTI) for varying diffusion times, can be used to determine fiber size and membrane permeability of muscle fibers in vivo. We describe the random permeable barrier model (RPBM) and its assumptions, as well as the details of stimulated echo DTI acquisition, signal processing steps, and potential pitfalls...
October 7, 2016: NMR in Biomedicine
Ulysse Gimenez, Adriana-T Perles-Barbacaru, Arnaud Millet, Florence Appaix, Michele El-Atifi, Karin Pernet-Gallay, Boudewijn van der Sanden, François Berger, Hana Lahrech
Monitoring glioma cell infiltration in the brain is critical for diagnosis and therapy. Using a new glioma Glio6 mouse model derived from human stem cells we show how diffusion tensor imaging (DTI) may predict glioma cell migration/invasion. In vivo multiparametric MRI was performed at one, two and three months of Glio6 glioma growth (Glio6 (n = 6), sham (n = 3)). This longitudinal study reveals the existence of a time window to study glioma cell/migration/invasion selectively. Indeed, at two months only Glio6 cell invasion was detected, while tumor mass formation, edema, blood-brain barrier leakage and tumor angiogenesis were detected later, at three months...
September 15, 2016: NMR in Biomedicine
P Porcari, M E Hegi, H Lei, M-F Hamou, I Vassallo, S Capuani, R Gruetter, V Mlynarik
Glioma models have provided important insights into human brain cancers. Among the investigative tools, MRI has allowed their characterization and diagnosis. In this study, we investigated whether diffusion MRI might be a useful technique for early detection and characterization of slow-growing and diffuse infiltrative gliomas, such as the proposed new models, LN-2669GS and LN-2540GS glioma sphere xenografts. Tumours grown in these models are not visible in conventional T2 -weighted or contrast-enhanced T1 -weighted MRI at 14...
September 15, 2016: NMR in Biomedicine
Cenan Hepdurgun, Özgün Özalay, Seda Eroğlu, Irmak Polat Nazlı, Ömer Kitiş, Ali Saffet Gönül
The majority of the research studying the prefrontal region has focused on gray matter injury. However, recent studies show that damage to white matter also contributes to the development of cognitive impairment after traumatic brain injury (TBI). Through the use of diffusion tensor imaging (DTI), it is now possible to assess the white matter fiber pathways between brain regions. With Diffusion Tensor Tractography (DTT), fibers of interest can be three dimensionally reconstructed and associated measurements can be performed...
2016: Türk Psikiyatri Dergisi, Turkish Journal of Psychiatry
Andrea Polli, Luca Weis, Roberta Biundo, Michael Thacker, Andrea Turolla, Kostantinos Koutsikos, K Ray Chaudhuri, Angelo Antonini
BACKGROUND: The pathophysiology of pain in Parkinson's disease (PD) is still poorly understood, although it is conceivable that supraspinal mechanisms may be responsible for pain generation and maintenance. METHODS: We examined brain functional and anatomical changes associated with persistent pain in 40 PD patients, 20 with persistent pain and 20 without pain. We also examined 15 pain-free healthy participants of similar age, gender, and cognitive state as a control group...
October 5, 2016: Movement Disorders: Official Journal of the Movement Disorder Society
Jiafeng Chen, Lijun Zhu, He Li, Ziwen Lu, Xin Chen, Shaokuan Fang
Multiple sclerosis (MS) is easily detected by routine magnetic resonance imaging (MRI). However, it is not possible to detect early or occult lesions in MS by routine MRI, and this may explain the inconsistency between the severity of the lesions found by MRI and the degree of clinical disability of patients with MS. The present study included 10 patients with relapsing-remitting MS and 10 healthy volunteers. Each patient underwent routine 3.0 T MRI, diffusion tensor imaging (DTI), and diffusion tensor tractography (DTT)...
October 2016: Experimental and Therapeutic Medicine
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