Diffusion Tensor Imaging with Three-dimensional Fiber Tractography of Traumatic Axonal Shearing Injury: An Imaging Correlate for the Posterior Callosal “Disconnection” Syndrome: Case Report

Neurosurgery ◽  
2005 ◽  
Vol 56 (1) ◽  
pp. E195-E201 ◽  
Author(s):  
Tuong H. Le ◽  
Pratik Mukherjee ◽  
Roland G. Henry ◽  
Jeffrey I. Berman ◽  
Marcus Ware ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Fiber Tractography ◽  
Disconnection Syndrome ◽  
Apparent Diffusion

Abstract OBJECTIVE: To demonstrate that magnetic resonance diffusion tensor imaging (DTI) with three-dimensional (3-D) fiber tractography can visualize traumatic axonal shearing injury that results in posterior callosal disconnection syndrome. METHODS: A 22-year-old man underwent serial magnetic resonance imaging 3 days and 12 weeks after blunt head injury. The magnetic resonance images included whole-brain DTI acquired with a single-shot spin echo echoplanar sequence. 3-D DTI fiber tractography of the splenium of the corpus callosum was performed. Quantitative DTI parameters, including apparent diffusion coefficient and fractional anisotropy, from the site of splenial injury were compared with those of a normal adult male volunteer. RESULTS: Conventional magnetic resonance images revealed findings of diffuse axonal injury, including a lesion at the midline of the splenium of the corpus callosum. DTI performed 3 days posttrauma revealed that the splenial lesion had reduced apparent diffusion coefficient and fractional anisotropy, reflecting a large decrease in the magnitude of diffusion parallel to the white matter fibers, which had partially recovered as revealed by follow-up DTI 12 weeks postinjury. 3-D tractography revealed an interruption of the white matter fibers in the posteroinferior aspect of the splenium that correlated with the patient's left hemialexia, a functional deficit caused by disconnection of the right visual cortex from the language centers of the dominant left hemisphere. CONCLUSION: DTI with 3-D fiber tractography can visualize acute axonal shearing injury, which may have prognostic value for the cognitive and neurological sequelae of traumatic brain injury.

scholarly journals Diffusion Tensor Imaging to Predict Long-term Outcome after Cardiac Arrest

2012 ◽  
Vol 117 (6) ◽  
pp. 1311-1321 ◽  
Author(s):  
Charles-Edouard Luyt ◽  
Damien Galanaud ◽  
Vincent Perlbarg ◽  
Audrey Vanhaudenhuyse ◽  
Robert D. Stevens ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Diffusion Coefficient ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Tensor ◽  
Brain Magnetic Resonance Imaging ◽  
Unfavorable Outcome ◽  
Resonance Imaging ◽  
Apparent Diffusion

Background Prognostication in comatose survivors of cardiac arrest is a major clinical challenge. The authors' objective was to determine whether an assessment with diffusion tensor imaging, a brain magnetic resonance imaging sequence, increases the accuracy of 1 yr functional outcome prediction in cardiac arrest survivors. Methods Prospective, observational study in two intensive care units. Fifty-seven comatose survivors of cardiac arrest underwent brain magnetic resonance imaging. Fractional anisotropy (FA), a diffusion tensor imaging value, was measured in predefined white matter regions, and apparent diffusion coefficient was assessed in predefined grey matter regions. Prediction of unfavorable outcome at 1 yr was compared using four prognostic models: FA global, FA selected, apparent diffusion coefficient, and clinical classifiers. Results Of the 57 patients included in the study, 49 had an unfavorable outcome at 12 months. Areas under the receiver operating characteristic curve (95% CI) to predict unfavorable outcome for the FA global, FA selected, clinical, and apparent diffusion coefficient models were 0.92 (0.82-0.98), 0.96 (0.87-0.99), 0.78 (0.65-0.88), and 0.86 (0.74-0.94), respectively. The FA selected model had the best overall accuracy for predicting outcome, with a score above 0.44 having 94% (95% CI, 83-99%) sensitivity and 100% (95% CI, 63-100%) specificity for the prediction of unfavorable outcome. Conclusion Quantitative diffusion tensor imaging indicates that white matter damage is widespread after cardiac arrest. A prognostic model based on FA values in selected white matter tracts seems to predict accurately 1 yr functional outcome. These preliminary results need to be confirmed in a larger population.

scholarly journals Exercise-induced muscle damage: multi-parametric MRI quantitative assessment

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaohong Lyu ◽  
Yue Gao ◽  
Qiang Liu ◽  
Heng Zhao ◽  
Huadong Zhou ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Tensor Imaging ◽  
Magnetic Resonance ◽  
Muscle Damage ◽  
Eccentric Exercise ◽  
Diffusion Tensor ◽  
T2 Mapping ◽  
Exercise Group ◽  
Fatigue Exercise ◽  
Apparent Diffusion

Abstract Background To explore the value of magnetic resonance quantitative analysis using diffusion tensor imaging, T2 mapping, and intravoxel incoherent motion in the evaluation of eccentric exercise-induced muscle damage and to compare the effects of various eccentric exercise modes at different time points in rats. Methods A total of 174 Sprague-Dawley male rats were randomly divided into five groups: control, once-only exercise, continuous exercise, intermittent exercise, and once-fatigue exercise groups. Each experimental group was divided into seven time-subgroups: 0.5 h, 24 h, 48 h, 72 h, 96 h, 120 h and 168 h after exercise. The quadriceps femoris muscles were then scanned using magnetic resonance imaging. The apparent diffusion coefficient and fractional anisotropy values of diffusion tensor imaging, T2 values of T2 mapping, D and D* values of intravoxel incoherent motion and optical density values of desmin were measured. Associations among different eccentric exercise programmes, magnetic resonance imaging findings, and histopathological results were evaluated. Dunnett’s test, two-way repeated measures analysis of variance, and Pearson correlation analysis were used for statistical analysis. Results Diffusion tensor imaging showed that the number of muscle fibre bundles decreased to varying degrees with different time points and eccentric exercises. Apparent diffusion coefficient values of the exercise groups showed a trend that first increased and then decreased, the opposite of fractional anisotropy. The specimens in all eccentric exercise programmes showed high signal T2 values after exercise, the highest among which was in the once-fatigue exercise group. D and D* in the experimental groups were significantly higher than those in the control group at 0.5–48 h after exercise. The apparent diffusion coefficient, fractional anisotropy, T2, D and D* values correlated with the optical density values of desmin. Conclusions Diffusion tensor imaging, T2 mapping, and intravoxel incoherent motion technology accurately reflect the degree of skeletal muscle damage and recovery associated with eccentric exercise. The degree of muscle damage was the lowest in the continuous exercise group and the highest in the once-fatigue exercise group, which may provide more information and guidance for the formulation of physical and athletic training programmes.

Two and Three-dimensional Analyses of Brain White Matter Architecture Using Diffusion Imaging

CNS Spectrums ◽  
2002 ◽  
Vol 7 (7) ◽  
pp. 529-534 ◽  
Author(s):  
Susumu Mori
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Fiber Orientation ◽  
Diffusion Tensor ◽  
Three Dimensional ◽  
Imaging Data ◽  
Brain White Matter ◽  
Orientation Information ◽  
Diffusion Tensor Imaging Data

ABSTRACTThe raw diffusion tensor imaging data obtained after tensor calculations contain six tensor elements in each pixel. This unique data structure poses difficulties in visualizing and analyzing diffusion tensor imaging data. One of the most commonly used visualization techniques is the use of color-coded maps. This presents fiber orientation information as a mixture of three principal colors. These maps can reveal white matter substructures that may not be visible in conventional magnetic resonance imaging. By extending the fiber-orientation information into three-dimensional space, three-dimensional trajectories of white matter tracts can then be estimated. Once locations and trajectories of tracts of interest are identified, this technique allows for the utilization of tract-specific magnetic resonance analyses and/or macroscopic characterization of white matter anatomy. As an example, anatomical deformation of the white matter resultant of brain tumor is demonstrated. The potentials and limitations of the three-dimensional tract reconstruction techniques are also highlighted.

Diffusion tensor imaging reveals microstructural differences between subtypes of trigeminal neuralgia

2020 ◽  
Vol 133 (2) ◽  
pp. 573-579 ◽  
Author(s):  
Matthew S. Willsey ◽  
Kelly L. Collins ◽  
Erin C. Conrad ◽  
Heather A. Chubb ◽  
Parag G. Patil
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Tensor Imaging ◽  
Trigeminal Neuralgia ◽  
Apparent Diffusion Coefficient ◽  
Diffusion Tensor ◽  
Statistical Significance ◽  
Region Of Interest ◽  
Pain Syndrome ◽  
Radial Diffusivity ◽  
Apparent Diffusion

OBJECTIVETrigeminal neuralgia (TN) is an uncommon idiopathic facial pain syndrome. To assist in diagnosis, treatment, and research, TN is often classified as type 1 (TN1) when pain is primarily paroxysmal and episodic or type 2 (TN2) when pain is primarily constant in character. Recently, diffusion tensor imaging (DTI) has revealed microstructural changes in the symptomatic trigeminal root and root entry zone of patients with unilateral TN. In this study, the authors explored the differences in DTI parameters between subcategories of TN, specifically TN1 and TN2, in the pontine segment of the trigeminal tract.METHODSThe authors enrolled 8 patients with unilateral TN1, 7 patients with unilateral TN2, and 23 asymptomatic controls. Patients underwent DTI with parameter measurements in a region of interest within the pontine segment of the trigeminal tract. DTI parameters were compared between groups.RESULTSIn the pontine segment, the radial diffusivity (p = 0.0049) and apparent diffusion coefficient (p = 0.023) values in TN1 patients were increased compared to the values in TN2 patients and controls. The DTI measures in TN2 were not statistically significant from those in controls. When comparing the symptomatic to asymptomatic sides in TN1 patients, radial diffusivity was increased (p = 0.025) and fractional anisotropy was decreased (p = 0.044) in the symptomatic sides. The apparent diffusion coefficient was increased, with a trend toward statistical significance (p = 0.066).CONCLUSIONSNoninvasive DTI analysis of patients with TN may lead to improved diagnosis of TN subtypes (e.g., TN1 and TN2) and improve patient selection for surgical intervention. DTI measurements may also provide insights into prognosis after intervention, as TN1 patients are known to have better surgical outcomes than TN2 patients.

Human Brain Diffusion Tensor Imaging Visualization With Virtual Reality

2010 ◽  
Author(s):  
Bin Chen ◽  
John Moreland
Keyword(s):  
Virtual Reality ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Biological Tissues ◽  
Head Tracking ◽  
Fiber Tractography ◽  
Brain White Matter ◽  
Diffusion Tensors ◽  
Visualization Techniques

Magnetic resonance diffusion tensor imaging (DTI) is sensitive to the anisotropic diffusion of water exerted by its macromolecular environment and has been shown useful in characterizing structures of ordered tissues such as the brain white matter, myocardium, and cartilage. The water diffusivity inside of biological tissues is characterized by the diffusion tensor, a rank-2 symmetrical 3×3 matrix, which consists of six independent variables. The diffusion tensor contains much information of diffusion anisotropy. However, it is difficult to perceive the characteristics of diffusion tensors by looking at the tensor elements even with the aid of traditional three dimensional visualization techniques. There is a need to fully explore the important characteristics of diffusion tensors in a straightforward and quantitative way. In this study, a virtual reality (VR) based MR DTI visualization with high resolution anatomical image segmentation and registration, ROI definition and neuronal white matter fiber tractography visualization and fMRI activation map integration is proposed. The VR application will utilize brain image visualization techniques including surface, volume, streamline and streamtube rendering, and use head tracking and wand for navigation and interaction, the application will allow the user to switch between different modalities and visualization techniques, as well making point and choose queries. The main purpose of the application is for basic research and clinical applications with quantitative and accurate measurements to depict the diffusivity or the degree of anisotropy derived from the diffusion tensor.

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