7T MRI of spinal cord injury

Spinal cord injury is a devastating trauma resulting in variable degree of neurological deficits, depending upon the severity of cord damage. Neurological outcome depends not only upon the extent of initial cord injury but also on the superimposed chronic sequel and wallerian degeneration. Spinal cord injury has variable appearance on imaging in acute and chronic phase, recognition of which is important not only for adequate and timely treatment but also for prognostication. Recognition of wallerian degeneration is also important as it is another independent cause of delayed neurological deterioration. We report a case of young child with spinal cord injury presenting in chronic phase with neurological deterioration due to development of extreme degree of spinal cord atrophy distal to the site of injury which is very rare and can be attributed to severe degree of distal wallerian degeneration. We also review the literature for chronic spinal cord injuries and wallerian degeneration with emphasis on various causes of delayed neurological deterioration and consequent importance of recognizing them by imaging.

Clinical Neurology and Neurosurgery, 2013

NeuroImage, 2011

One goal of in vivo neuroimaging is the detection of neurodegenerative processes and anatomical reorganizations after spinal cord (SC) injury. Non-invasive examination of white matter fibers in the living SC can be conducted using magnetic resonance diffusion-weighted imaging. However, this technique is challenging at the spinal level due to the small cross-sectional size of the cord and the presence of physiological motion and susceptibility artifacts. In this study, we acquired in vivo high angular resolution diffusion imaging (HARDI) data at 3T in cats submitted to partial SC injury. Cats were imaged before, 3 and 21 days after injury. Spatial resolution was enhanced to 1.5 × 1.5 × 1 mm 3 using super-resolution technique and distortions were corrected using the reversed gradient method. Tractography-derived regions of interest were generated in the dorsal, ventral, right and left quadrants, to evaluate diffusion tensor imaging (DTI) and Q-Ball imaging metrics with regards to their sensitivity in detecting primary and secondary lesions. A threeway ANOVA tested the effect of session (intact, D3, D21), cross-sectional region (left, right, dorsal and ventral) and rostrocaudal location. Significant effect of session was found for FA (P b 0.001), GFA (P b 0.05) and radial diffusivity (P b 0.001). Post-hoc paired T-test corrected for multiple comparisons showed significant changes at the lesion epicenter (P b 0.005). More interestingly, significant changes were also found several centimeters from the lesion epicenter at both 3 and 21 days. This decrease was specific to the type of fibers, i.e., rostrally to the lesion on the dorsal aspect of the cord and caudally to the lesion ipsilaterally, suggesting the detection of Wallerian degeneration.

1986

5 The thoracic spinal cords of five mongrel dogs were imaged with a 1.5 T MR scanner before and after trauma induced by a well-established method of spinal cord impaction that produces central cord hemorrhagic necrosis. The anesthetized dogs were studied acutely with a 5-in. circular surface coil, 12-cm field of view, sagittal and axial partial-saturation (TR = 600, TE = 25 msec) and spin-echo (TR = 2000, TE = 25-100 msec) techniques. One normal dog was used as a control. The cords were surgically removed and histologically examined. Direct correlation of the pathologic findings and imaging data showed that at the level of trauma there was obliteration of epidural fat and CSF spaces secondary to central cord hemorrhage and edema. The traumatized cords expanded to fill the bony canal, and there was loss of visualization of the internal anatomy of the cord (gray- and white-matter structures). We conclude that MR can accurately identify cord hemorrhage and edema within a few hours of s...

Journal of The Neurological Sciences, 1997

Dynamic signal intensity changes of Wallerian degeneration (WD) are well documented in cases of stroke. These changes have been . staged I-IV, depending on time-specific signal intensity changes in corticospinal tract with magnetic resonance imaging (MRI). We performed both prospective and retrospective evaluation of various intracranial lesions to look for evidence of WD and to assess its prognostic implications. Eighteen patients of acute stroke were studied prospectively. Their functional disability was evaluated by using a modified Barthel index of activity of daily living (ADL) at presentation, at 1 month and at 4 months, and was correlated with presence or absence of WD on MRI. 10/18 patients showed signal intensity changes of WD on MRI and their mean ADL score changed from 9.1 at 1 month to 11.4 at 4 months duration suggestive of moderate to severe disability after 4 months of stroke. The rest of the eight patients, ' where MN did not reveal signal intensity changes of WD, the mean ADL score improved from 10.37 at 1 month to 17.5 at 4 months, suggesting significant improvement in their clinical disability. 520 patients were studied retrospectively, out of whom 31 showed signal intensity changes of WD in various intracranial lesions, i.e. infarcts (14/220), intracranial haematoma (4/ 147), arterio-venous malformation (1/20), tumour (6/98), multiple sclerosis (5/20) and encephalitis (1/15). Presence of WD in these intracranial lesions correlated well with persistent clinical disability. This observation has immense prognostic value, particularly in relapsing and remitting disease like multiple sclerosis. We conclude that WD can be seen secondary to any CNS insult with MRI and its presence correlates well with persistent functional disability. It thus has prognostic value.

2020

Overall studies using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) provide strong evidence that these are important imaging tools in the diagnosis, prognosis, and evaluation of injuries associated with SCI. MRI was shown to have high sensitivity and specificity in the detection of microstructural abnormalities related to SCI, and that these observations can be used to predict motor score and classification. There is limited evidence to suggest that MRI may be useful in the diagnosis and prognosis of motor classification in individuals with SCI without radiographic abnormalities. With respect to DTI, there is strong evidence to support its use as a diagnostic tool, however the evidence surrounding its use as a prognostic indicator are mixed. In general, there are fewer studies reporting the use of DTI in relation to SCI management compared to the use of MRI. 2.0 Methods A key word literature search for scientific articles published between January 1, 2015 to August 31, 2018 investigating the use of imaging tools in the diagnosis and management of SCI was conducted using the following online databases: MEDLINE, CINAHL, Scopus, EMBASE and Cochrane Library. Population key words (i.e., spinal cord injury, quadriplegia, hemiplegia, and tetraplegia) and imaging key words (i.e., magnetic resonance imaging, CT, computed tomography, radiograph, x-ray, and imaging) were used. The search was limited to journal articles, reviews, or systematic reviews (excluding case reports) which were published in English, had a minimum sample of three adults (≥18 years) with an SCI. The SCI population within each study must have comprised of at least 50% of the total study population, unless results were stratified. A total of 4762 studies were found that satisfied the search criteria, after the removal of duplicates, animal and pediatric studies, and case reports 34 studies remained. Studies were considered appropriate for inclusion in this chapter if the majority of participants were within 3 months post-SCI. Articles were then further subdivided into groups based on the imaging technique used.

Neurology, 2000

2000

BACKGROUND AND PURPOSE: MR imaging is the most comprehensive noninvasive means to assess structural changes in injured central nervous system (CNS) tissue in humans over time. The few published in vivo MR imaging studies of spinal cord injury in rodent models by using field strengths Յ7T suffer from low spatial resolution, flow, and motion artifacts. The aim of this study was to assess the capacity of a 17.6T imaging system to detect pathologic changes occurring in a rat spinal cord contusion injury model ex vivo and in vivo. METHODS: Seven adult female Fischer 344 rats received contusion injuries at thoracic level T10, which caused severe and reproducible lesions of the injured spinal cord parenchyma. Two to 58 days postinjury, high-resolution MR imaging was performed ex vivo (2) or in vivo in anesthetized rats (5 spinal cord injured ϩ one intact control animal) by using 2D multisection spin-and gradient-echo imaging sequences, respectively, combined with electrocardiogram triggering and respiratory gating. RESULTS: The acquired images provided excellent resolution and gray/white matter differentiation without significant artifacts. Signal intensity changes, which were detected with ex vivo and in vivo MR imaging following spinal cord injury, could be correlated with histologically defined structural changes such as edema, fibroglial scar, and hemorrhage. CONCLUSIONS: These results demonstrate that MR imaging at 17.6T allows high-resolution structural analysis of spinal cord pathology after injury.

Surgical Neurology, 1996

AJNR. American journal of neuroradiology, 1998

Some cases of hemichorea-hemiballism (HCHB) are associated with a hyperintense putamen on T1-weighted MR images, the cause of which remains unclear. Our purpose was to determine the cause and significance of these MR signal changes. We analyzed the clinical and neuroimaging findings in 10 patients with HCHB, focusing on locations of the hyperintense lesions on T1-weighted images, comparing them with those on CT scans, and evaluating their changes after years of follow-up. A biopsy was performed in one patient. Seven patients had hyperglycemia and two had cortical infarcts. HCHB recurred in four patients. A hyperintense putamen preceded the occurrence of HCHB in two patients. T1-weighted MR images revealed hyperintense lesions limited to the ventral striatum in six patients. Hyperintense lesions extended to the level of the midbrain in one patient and persisted for as long as 6 years in another patient. T2-weighted MR images revealed slit-shaped cystic lesions in the lateral part of ...