Subject-specific regional measures of water diffusion are associated with impairment in chronic spinal cord injury

Choe, Ann S.; Sadowsky, Cristina L.; Smith, Seth A.; Zijl, Peter C.M. van; Pekar, James J.; Belegu, Visar

doi:10.1007/s00234-017-1860-9

Cited by 8 publications

(5 citation statements)

References 63 publications

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“…Several human and animal studies have shown the relative importance of the cord above and below the level of injury in SCI patients. [35][36][37] With that goal, we decided to investigate the differences between DTI and DTT measures of the following groups: 1) between normal and SCI group; 2) in cervical SCI, only the thoracic slices (which is the common region for all cervical SCI no matter where the level of injury is) was compared with the thoracic average of the normal population; and 3) in the thoracic SCI group, the cervical area (which is the common region for all thoracic SCI no matter where the level of injury is) was compared with the cervical average of the normal group. Although our group results showed that in the cord above (in thoracic injury patients) and below (in cervical injury patients) there were statistically significant changes compared to the normal healthy controls, our sample size was small to deduce the utility of these findings to a single subject's treatment and rehabilitation status.…”

Section: Figmentioning

confidence: 99%

Reduced Field of View Diffusion Tensor Imaging and Fiber Tractography of the Pediatric Cervical and Thoracic Spinal Cord Injury

Alizadeh

Fisher

Saksena

et al. 2018

Journal of Neurotrauma

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The aim of this study is to assess the utility and effectiveness of diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) of the entire pediatric cervical and thoracic spinal cord toward discrimination of typically developing (TD) controls and subjects with spinal cord injury (SCI). A total of 43 pediatric subjects, including 23 TD subjects ranging in age from 6 to 16 years old and 20 subjects with SCI ranging in age from 7 to 16 years, were recruited and scanned using a 3.0 Tesla magnetic resonance scanner. Reduced field of view diffusion tensor images were acquired axially to cover the entire spinal cord across two slabs. For DTI analysis, motion correction was performed by coregistration of the diffusion-weighted images to the reference image (b0). Streamline deterministic tractography results were generated from the preprocessed data. DTI and DTT parameters of the whole cord, including fractional anisotropy (FA), mean diffusivity (MD), tract length, and tract density, were calculated, averaged across the whole spinal cord, and compared between the TD and SCI groups. Statistically significant decreases have been shown in FA (TD = 0.46 ± 0.11; SCI = 0.37 ± 0.09; p < 0.0001) and tract density (TD = 405.93 ± 243.84; SCI = 268.90 ± 270.34; p < 0.0001). However, the mean length of tracts and MD did not show significant differences. When investigating differences in DTI and DTT parameters above and below the injury site, it was shown that the FA and tract density in patients with cervical SCI decreased significantly in the thoracic region. An identical trend was observed in the cervical region for patients with thoracic SCI as well. When comparing TD and SCI subjects, FA and tract density were the most sensitive parameters in detecting functional changes of the spinal cord in chronic pediatric SCI. The results show that both DTI and DTT have the potential to be imaging biomarkers in the diagnosis of SCI.

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Section: Figmentioning

confidence: 99%

Reduced Field of View Diffusion Tensor Imaging and Fiber Tractography of the Pediatric Cervical and Thoracic Spinal Cord Injury

Alizadeh

Fisher

Saksena

et al. 2018

Journal of Neurotrauma

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“…DWI stitching is difficult to perform and is sensitive to artifacts produced by respiratory and cardiac movements at the thoracic level of the spinal cord 9,57 . Nonetheless, several teams 14,58,59 have aimed to perform DWI and tractography of the entire spinal cord.…”

Section: Discussionmentioning

confidence: 99%

“…1 Performing spinal cord tractography, which requires extreme precision, is the last step of the DWI processing chain; it results in a long pipeline of data acquisition, processing, and modeling. 2 As several studies have reported, spinal cord tractography is of diagnostic interest for a wide range of pathologies (intramedullary tumor, 3,4 vascular malformations, 5,6 dysraphism, 7 spinal cord injury, 8,9 multiple sclerosis 10,11 ). To date, spinal cord tractography is not used in routine clinical practice because of difficulties in producing a rendering consistent with the anatomical truth.…”

Section: Introductionmentioning

confidence: 99%

Effect of distortion corrections on the tractography quality in spinal cord diffusion‐weighted imaging

Dauleac

Bannier

Cotton

et al. 2021

Magnetic Resonance in Med

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Purpose To assess the impact of a different distortion correction (DC) method and patient geometry (sagittal balance) on the quality of spinal cord tractography rendering according to different tractography approaches. Methods Forty‐four adults free of spinal cord diseases underwent cervical diffusion‐weighted imaging. The phase‐encoding direction was head→foot. Sequence with opposed polarities (foot→head) was acquired to perform DC. Eddy‐current, motion effects, and susceptibility artifact correction methods were used for DC, and two deterministic and one probabilistic tractography approaches were evaluated using MRtrix and DSI Studio tractography software. Fiber length and number of fibers were extracted to evaluate the quality of the tractography rendering. For each subject, cervical lordosis was measured to assess patient geometry. The angle between the main direction of the spinal cord and the orientation of the acquisition box were computed at each spine level to assess acquisition geometry and define an angle threshold for which a tractography of good quality is no longer possible. Results There was a significant improvement in tractography quality after performing DC with susceptibility artifact correction using a deterministic approach based on tensor. Before DC, the angle threshold was defined at C6 (15.2°) compared with C7 (21.9°) after corrections, demonstrating the importance of spinal cord angulation for DC. Conclusion The impact of DC on tractography quality is greatly impacted by acquisition geometry. To obtain a good‐quality tractography, we propose as a future perspective to adapt the acquisition geometry to that of the patient by automatically adjusting the acquisition box.

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“… 153 , 154 Diffusion tensor imaging quantifies axonal pathway disruption, while magnetization transfer imaging signal changes have been associated with neurological function and outcomes. 155 , 156 Currently, MRI is primarily used as a structural as opposed to mechanistic molecular biomarker but functional MRI, connectomics, spectroscopy, and integration with neurophysiology may reveal mechanistic changes related to the evolution of post-SCI phenotypic states such as neuropathic pain. 157 Projects such as Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) correlate brain structure changes to regional gene expression.…”

Section: Biomarker Modeling In Sci Prediction and Prognosticationmentioning

confidence: 99%

Development of a Systems Medicine Approach to Spinal Cord Injury

Guest

Kelly-Hedrick

Williamson

et al. 2023

Journal of Neurotrauma

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Traumatic spinal cord injury (SCI) causes a sudden onset multi-system disease, permanently altering homeostasis with multiple complications. Consequences include aberrant neuronal circuits, multiple organ system dysfunctions, and chronic phenotypes such as neuropathic pain and metabolic syndrome. Reductionist approaches are used to classify SCI patients based on residual neurological function. Still, recovery varies due to interacting variables, including individual biology, comorbidities, complications, therapeutic side effects, and socioeconomic influences for which data integration methods are lacking. Infections, pressure sores, and heterotopic ossification are known recovery modifiers. However, the molecular pathobiology of the disease-modifying factors altering the neurological recovery-chronic syndrome trajectory is mainly unknown, with significant data gaps between intensive early treatment and chronic phases. Changes in organ function such as gut dysbiosis, adrenal dysregulation, fatty liver, muscle loss, and autonomic dysregulation disrupt homeostasis, generating progression-driving allostatic load. Interactions between interdependent systems produce emergent effects, such as resilience, that preclude single mechanism interpretations. Due to many interacting variables in individuals, substantiating the effects of treatments to improve neurological outcomes is difficult. Acute injury outcome predictors, including blood and cerebrospinal fluid biomarkers, neuroimaging signal changes, and autonomic system abnormalities, often do not predict chronic SCI syndrome phenotypes. In systems medicine, network analysis of bioinformatics data is used to derive molecular control modules. To better understand the evolution from acute SCI to chronic SCI multi-system states, we propose a topological phenotype framework integrating bioinformatics, physiological data, and allostatic load tested against accepted established recovery metrics. This form of correlational phenotyping may reveal critical nodal points for intervention to improve recovery trajectories. This study examines the limitations of current classifications of SCI and how these can evolve through systems medicine.

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Subject-specific regional measures of water diffusion are associated with impairment in chronic spinal cord injury

Cited by 8 publications

References 63 publications

Reduced Field of View Diffusion Tensor Imaging and Fiber Tractography of the Pediatric Cervical and Thoracic Spinal Cord Injury

Reduced Field of View Diffusion Tensor Imaging and Fiber Tractography of the Pediatric Cervical and Thoracic Spinal Cord Injury

Effect of distortion corrections on the tractography quality in spinal cord diffusion‐weighted imaging

Development of a Systems Medicine Approach to Spinal Cord Injury

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