Clinical characteristics analysis of pediatric spinal cord injury without radiological abnormality in China: a retrospective study.

PURPOSE: This study aims to analyze the clinical characteristics of Chinese children with spinal cord injury (SCI) without radiographic abnormality (SCIWORA) and explore their contributing factors and mechanisms of occurrence. METHODS: A retrospective analysis was conducted on the clinical data of pediatric patients diagnosed with SCIWORA from January 2005 to May 2020. Epidemiological, etiological, mechanistic, therapeutic, and outcome aspects were analyzed. RESULTS: A total of 47 patients with SCIWORA were included in this study, comprising 16 males and 31 females. The age range was 4 to 12 years, with an average age of 7.49 ± 2.04 years, and 70% of the patients were below eight. Sports-related injuries constituted 66%, with 70% attributed to dance backbend practice. Thoracic segment injuries accounted for 77%. In the American Spinal Injury Association (ASIA) classification, the combined proportion of A and B grades accounted for 88%. Conservative treatment was chosen by 98% of the patients, with muscle atrophy, spinal scoliosis, hip joint abnormalities, and urinary system infections being the most common complications. CONCLUSION: SCIWORA in Chinese children is more prevalent in those under eight years old, with a higher incidence in females than males. Thoracic spinal cord injuries are predominant, dance backbend as a primary contributing factor, and the social environment of "neijuan" is a critical potential inducing factor. Furthermore, the initial severity of the injury plays a decisive role in determining the prognosis of SCIWORA.

SCIWORA. Una rara entidad clínica en la población pediátrica. Estudio ambispectivo / SCIWORA in children. A rare clinical entity: Ambispective study

Introducción: La lesión medular tipo SCIWORA es una entidad clínica con baja incidencia y alta repercusión funcional. El objetivo del estudio es la descripción epidemiológica de esta lesión y su evolución funcional con un seguimiento medio de 10 años. Material y métodos: Estudio analítico, longitudinal, de cohortes ambispectivo. Fueron evaluados 13 pacientes con el diagnóstico de SCIWORA en el periodo de estudio 2001-2022. Variables evaluadas: edad, sexo, días hasta la lesión medular, causa de lesión, imagen medular en la RM postraumatismo, nivel neurológico de lesión, ASIA ingreso/alta/5 años, SCIM III ingreso/alta/3 años, tipo de tratamiento empleado, empleo de terapia NASCIS III ingreso, tiempo de hospitalización, seguimiento medio. En octubre del 2022 fueron nuevamente evaluados en consultas externas mediante: cuestionario de discapacidad cervical (NDI)/Oswestry y cuestionario de calidad de vida validado en castellano para lesionados medulares (SV-QLI/SCI). Resultados: La mediana de edad fue de 4 años, 77% varones. El 54% de las lesiones corresponden a nivel cervical. El ASIA al ingreso fue del 31% A y del 31% C, nivel neurológico: C2 (22%) y T10 (15%), tráfico como causa de lesión (77%), SCIM III ingreso/alta: 28,5/42. La estancia media hospitalaria fue de 115 días. NDI: 11,6 y Oswestry: 15,3. Conclusión: El 77% de los SCIWORA se producen en menores de 8 años. Al año del alta hospitalaria un 31% de los pacientes fueron catalogados como ASIA D y a los 5 años el porcentaje se mantiene constante. No se encontraron diferencias significativas entre la causa de la lesión y tipo de alteración en RM (p = 0,872), ni entre la edad y el tipo de lesión medular objetivada en RM (p = 0,149).(AU)

Introduction: SCIWORA has a low incidence but a high functional repercussion. The aim of the present study was to characterize the epidemiology of this clinical-radiological condition and evaluate functional outcome with a mean of 10-years follow-up. Material and methods: Observational, longitudinal ambispective cohort study. Thirteen SCIWORA patients were admitted in the study period. Demographics, mechanism of injury, spinal cord MRI findings, neurological level of injury, time to SCI, neurological status (AIS) at admission/discharge/5 years, spinal cord independence measure (SCIM III) scale at admission and discharge, hospital length of stay and mean follow-up were recorded. On October 2022 patients were re-evaluated using NDI, Oswestry, and SV-QLI/SCI. Results: Median age was 4 years. The study population for this investigation was mostly men (77%). 54% of level of injury correspond to cervical spine. AIS at admission was A (31%) and C (31%). Neurological level of injury was C2 (22%) and T10 (15%). Motor vehicle-related injury was the most prevalent mechanism of injury (77%), SCIM III scale at admission and discharge: 28.5/42, hospital length of stay was 115 days. The NDI was 11.6, Oswestry: 15.3 and SV-QLI/SCI: 17. Conclusions: Seventy-seven percent of SCIWORA patients was detected under 8 years-old. At 1 year follow-up after discharge 31% patients were AIS grade D and with 5 years follow-up the percentage remain constant. No statistically significant differences in the mechanism of injury and MRI findings (P = 0.872), age and MRI spinal cord findings (P = 0.149) were found in SCIWORA patients.(AU)

Clinical Reasoning: A 24-Year-Old Woman With Penetrating Neck Injury From a Needlefish.

Evaluating patients with a traumatic spinal cord injury can be complicated by other injuries. In this case, a 24-year-old woman injured by a needlefish presented with combined motor and sensory defects, cranial nerve deficits, and a blunt vascular injury. This case highlights the importance of neurologic and vascular localizations and an understanding of spinal cord injuries involving various ascending and descending tracts. Appreciation of these anatomical considerations through this case illustrates the diagnostic approach to neurologic evaluation. While we present a traumatic etiology for multiple neurologic syndromes, this case gives readers an opportunity to develop a comprehensive differential diagnosis and tailor investigations for other relevant etiologies. Readers walking through this stepwise process will ultimately arrive at several distinct but related diagnoses.

PET/CT Examination of Teratomas after Stem Cell Transplantation for a Spinal Cord Injury: A Case Report.

BACKGROUND: In clinical practice, stem cell transplantation has become an effective method for treating spinal cord nerve injury. Up to now, there has been no report on teratoma caused by transplanted stem cell's abnormal differentiation in the clinic, especially in the analysis of imaging manifestations. Therefore, this article aims to analyze the PET/CT imaging manifestations of teratoma caused by stem cell transplantation to improve the imaging diagnosing capability. CASE PRESENTATION: A patient with a spinal cord injury who had received a stem cell transplant was examined by PET/CT on September 10th, 2020. The PET/CT images of the lesion showed irregular mixed low density on the right side of the erector spinae muscle area at the level of the cervical 3-5 vertebral body, with a maximum cross-section of 9.1×3.9 cm. The 18F-FDG metabolism of the lesion was increased, and the maximum standard uptake value (SUVmax) was 10.7. The boundary was unclear with the third cervical vertebra and cervical 3 and 4-level vertebral plates. Based on the patient's medical history, the lesion was diagnosed as an abnormal proliferative tumor, which was consistent with the pathological examination results. CONCLUSION: To date, there have been no clinical reports on teratomas caused by stem cell transplantation for spinal cord injury at home or abroad. This case report enhances the knowledge of the diagnosis and treatment methods of this type of disease and confirms the diagnostic value of PET/CT examination.

Concurrently Occurring Spinal Cord Cross-Section and Aortic Injury After a Chalk-Stick Fracture and Dislocation in Patient with Ankylosing Spondylitis: Clinical Image.

A 74-year-old woman with ankylosing spondylitis presented with back pain and complete paraplegia after a fall. A radiologic finding of a bamboo spine, a characteristic feature of ankylosing spondylitis, was observed on computed tomography, along with a fracture-dislocation involving T10 and T11 (chalk-stick fracture) and compression of the descending thoracic aorta due to the caudal bony column. The patient underwent an open reduction and T8-L3 posterior fusion in the operating room. A complete cross-section of the spinal cord was observed during surgery. Post operation, a decrease in blood pressure led to a thoracotomy and thoracic endovascular aortic repair due to a crack in the descending aorta wall. Thoracolumbar fracture-dislocations, particularly in patients with ankylosing spondylitis, are characterized by instability and can be further complicated by concurrent vascular and spinal cord injuries. It is crucial therefore to recognize the potential for vascular and spinal cord injuries early on in such cases.

Non-contrast ultrasound image analysis for spatial and temporal distribution of blood flow after spinal cord injury.

Ultrasound technology can provide high-resolution imaging of blood flow following spinal cord injury (SCI). Blood flow imaging may improve critical care management of SCI, yet its duration is limited clinically by the amount of contrast agent injection required for high-resolution, continuous monitoring. In this study, we aim to establish non-contrast ultrasound as a clinically translatable imaging technique for spinal cord blood flow via comparison to contrast-based methods and by measuring the spatial distribution of blood flow after SCI. A rodent model of contusion SCI at the T12 spinal level was carried out using three different impact forces. We compared images of spinal cord blood flow taken using both non-contrast and contrast-enhanced ultrasound. Subsequently, we processed the images as a function of distance from injury, yielding the distribution of blood flow through space after SCI, and found the following. (1) Both non-contrast and contrast-enhanced imaging methods resulted in similar blood flow distributions (Spearman's ρ = 0.55, p < 0.0001). (2) We found an area of decreased flow at the injury epicenter, or umbra (p < 0.0001). Unexpectedly, we found increased flow at the periphery, or penumbra (rostral, p < 0.05; caudal, p < 0.01), following SCI. However, distal flow remained unchanged, in what is presumably unaffected tissue. (3) Finally, tracking blood flow in the injury zones over time revealed interesting dynamic changes. After an initial decrease, blood flow in the penumbra increased during the first 10 min after injury, while blood flow in the umbra and distal tissue remained constant over time. These results demonstrate the viability of non-contrast ultrasound as a clinical monitoring tool. Furthermore, our surprising observations of increased flow in the injury periphery pose interesting new questions about how the spinal cord vasculature reacts to SCI, with potentially increased significance of the penumbra.

Urologic surveillance of persons with spinal cord injuries - a scoping review.

STUDY DESIGN: Scoping review - standardized according to the Equator-network and the Prisma-Statement guidelines with PRISMA-ScR. OBJECTIVES: Review the literature concerning surveillance of the urinary- and renal systems in persons with spinal cord injuries (SCI). Specifically, to assess: #1 the usability of non-invasive and non-ultrasound methods, #2 the usage of systematic ultrasound surveillance #3 patient characteristics which predispose to urinary tract abnormalities (UTA) or renal function deterioration. METHODS: The literature assessed was collected from PubMed by creating a search string comprised of three main phrases: #1 persons with SCI, #2 kidney function and #3 surveillance program. The final search resulted in 685 studies. Eligibility criteria were defined prior to the search to assess the studies systematically. RESULTS: Four studies found serum cystatin C (s-cysC) to be accurate in estimating the glomerular filtration rate in persons with SCI. One study found no difference in UTA between surveillance adherent and surveillance non-adherent persons up to 30 years post injury. UTA and especially renal function deterioration seems rare the first 15 years post-injury. Non-traumatic SCI, time since injury, high detrusor pressure, upper urinary tract dilation, vesicourethral reflux, trabeculated bladder, history of calculi removal are significant risk factors for developing UTA or renal function deterioration. CONCLUSION: Measurements of S-cysC should be considered to replace serum creatinine in most cases. Surveillance non-adherent persons are not at higher risk of developing UTA. A selective surveillance based on a baseline risk profile may be beneficial for patients and caretakers.

Comparison of the prevalence of osteoporosis in people with spinal cord injury according to bone mineral density reference values for the diagnosis of osteoporosis: a retrospective, cross-sectional study.

BACKGROUND: Spinal cord injury (SCI) is a complex cause of rapid low bone mass that easily predisposes the affected individuals to osteoporosis-induced fractures. Several studies have investigated osteoporosis pathophysiology in SCI; however, those associated with its diagnosis in SCI are limited. Additionally, errors in osteoporosis diagnosis and its prevalence vary based on the bone mineral density (BMD) reference values (BMDRV), and no studies have reported BMDRV application for osteoporosis diagnosis in individuals with SCI. Therefore, this study aimed to compare the prevalence of osteoporosis among Korean adults aged ≥ 50 years with SCI according to BMDRV for diagnosing osteoporosis. METHODS: Overall, 855 patients with SCI who underwent BMD tests of the lumbar spine, femoral neck, and total hip at the National Rehabilitation Center (NRC) in Korea between 2010 and 2020 were included in this retrospective cross-sectional study. Osteoporosis was diagnosed in patients with SCI by comparing the differences in prevalence, diagnostic consistency, and risk factors according to the region-based BMDRV of the dual-energy x-ray absorptiometry (DXA) manufacturer and international BMDRV based on the Third National Health and Nutrition Examination Survey (NHANES III) data of females aged 20-29 years. RESULTS: The prevalence of osteoporosis according to the T-score provided by a single reference population of the NHANES III (TNHA) (PONHA) (males: 26.69%; females: 69.35%) was significantly higher in females and males than that according to the T-scores provided by the DXA manufacturer (TDXA) (PODXA) (males: 15.32%; females: 43.15%). The lumbar spine and femoral neck were major osteoporosis diagnosis sites for the PODXA and PONHA, respectively. Risk factors for osteoporosis differed based on the probability of osteoporosis (also known as the OZ ratio) according to the BMD criteria; however, the risk factors were similar according to old age, female sex, low body mass index (BMI), and long SCI period. No significant relationship was noted between the different SCI-related clinical factors (p > 0.05). CONCLUSIONS: The osteoporosis diagnostic site and prevalence in SCI differed according to the regional-based TDXA and international standards of the TNHA. Therefore, further studies on BMDRV are warranted to establish accurate diagnostic criteria for osteoporosis prevention in patients with SCI.

Structural and functional changes in the brain after chronic complete thoracic spinal cord injury.

This study aimed to investigate whether brain anatomical structures and functional network connectivity are altered after chronic complete thoracic spinal cord injury (cctSCI) and to determine how these changes impact clinical outcomes. Structural and resting-state functional MRI was performed for 19 cctSCI patients (18 for final statistics) and 19 healthy controls. Voxel-based morphometry (VBM) was used to assess gray matter volume (GMV) with differences between cctSCI patients and controls. VBM results were used as seeds for whole-brain functional connectivity (FC) analysis. The relationship between brain changes and clinical variables was investigated. Compared with those of the control group, the left triangular inferior frontal gyrus, middle frontal gyrus, orbital inferior frontal gyrus, precuneus and parietal superior gyrus volumes of SCI patients decreased, while the left superior frontal gyrus and supplementary motor area volumes increased. Additionally, when the regions with increased GMV were used as seeds, the FC of the parahippocampus and thalamus increased. Subsequent partial correlation analysis showed a positive correlation between FC and total sensorimotor score based on the ASIA criteria (p = 0.001, r = 0.746). Overall, the structural and functional changes in the brain after cctSCI occurred in some visual and cognitive areas and sensory or motor control areas. These findings aid in improving our understanding of the underlying brain injury mechanisms and the subsequent structural and functional reorganization to reveal potential therapeutic targets and track treatment outcomes.

Model-based parcellation of diffusion MRI of injured spinal cord predicts hand use impairment and recovery in squirrel monkeys.

A mathematical model-based parcellation of magnetic resonance diffusion tensor images (DTI) has been developed to quantify progressive changes in three types of tissues - grey (GM), white matter (WM), and damaged spinal cord tissue, along with behavioral assessments over a 6 month period following targeted spinal cord injuries (SCI) in monkeys. Sigmoid Gompertz function based fittings of DTI metrics provide early indicators that correlate with, and predict, recovery of hand grasping behavior. Our three tissue pool model provided unbiased, data-driven segmentation of spinal cord images and identified DTI metrics that can serve as reliable biomarkers of severity of spinal cord injuries and predictors of behavioral outcomes.

Pulmonary function and sarcopenia as predictors of dysphagia in cervical spinal cord injury.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine the risk factors associated with dysphagia in individuals with cervical spinal cord injury (CSCI) and analyze the differences between individuals with improved penetration-aspiration (PA) and persistent PA on follow-up. SETTING: Tertiary inpatient rehabilitation facilities. METHODS: Medical records of individuals with CSCI admitted between December 2009 and February 2023 who underwent a videofluoroscopic swallowing study (VFSS) were retrospectively reviewed. Multivariate logistic regression analysis was performed to assess risk factors for dysphagia. Differences between individuals with improved PA and persistent PA were analyzed using an independent t-test. RESULTS: In total, 149 participants were enrolled. Age (odds ratio (OR) 1.08, 95% confidence interval (CI) 1.04-1.12), percentage of forced vital capacity to predicted normal (FVC (% predicted)) (OR 0.90, 95% CI 0.85-0.94), and skeletal muscle index (OR 0.89, 95% CI, 0.79-0.99) were significant factors associated with the risk of PA. Based on the receiver operating characteristic curve analysis, the cut-off values for age, FVC (% predicted), and skeletal muscle index were determined as 56.0, 45.7, and 41.0, respectively. A secondary analysis of the follow-up VFSS was conducted on 38 participants. The follow-up FVC (% predicted) and degree of weight loss differed significantly between the improved PA and persistent PA groups. CONCLUSIONS: Older age, low FVC (% predicted), and low skeletal muscle index can be predictors of dysphagia in patients with CSCI. On follow-up VFSS, individuals with improved PA demonstrated greater improvement in FVC (% predicted).

Association between swallowing disorder and prevertebral hyperintensity on magnetic resonance imaging in patients after cervical cord injury without major fracture.

This study aimed to clarify the association between swallowing disorder and prevertebral hyperintensity on magnetic resonance imaging (MRI) in patients with cervical spinal cord injury (CSCI) without a major fracture. This retrospective observational study included 30 patients who were diagnosed with acute CSCI without a major fracture (mean age: 69.3 years, 27 men). Swallowing disorder was defined as tube-dependent nutrition because of obvious aspiration 28 days after injury. The high-intensity area (HIA) and anteroposterior width (HIW) of the prevertebral space at C1-7 levels were measured using MRI short-TI inversion recovery midsagittal images. Receiver operating characteristic curve analysis was used to determine the optimal cutoff values of the HIA for predicting swallowing disorder. The incidence of swallowing disorder after CSCI was 16.7%. The HIA was significantly higher in the swallowing disorder group (median, 409.0 mm2) than in the non- swallowing disorder group (median, 159.1 mm2) (P = .04). There was no significant difference in HIW between the two groups. The optimal cutoff point of the HIA was measured at 203.2 mm2 with 80.0% and 20.0% sensitivity and specificity, respectively, with an area under the curve of 0.848 (95% confidence interval, 0.657-1.000, P = .01). The prevertebral hyperintensity area on MRI for swallowing disorder in patients after cervical cord injury without skeletal injury is associated with swallowing disorder. The optimal cutoff point of the area was determined to be 203.2 mm2.

Schiff-Sherrington phenomenon in a cat with complete spinal cord transection from traumatic dorsocranial luxation of the second lumbar vertebra.

A young stray entire female domestic shorthair cat was presented with symmetrical forelimb extensor rigidity, neck hyperextension and hindlimb paraplegia, characteristic of Schiff-Sherrington phenomenon (SSP), within 30 min of a motor vehicle accident. Radiographic and post-mortem studies disclosed complete transection of the spinal cord from traumatic dorsocranial luxation of the second lumbar vertebra, displacement of the sacrum from the ilium, seventh lumbar and first caudal vertebrae and multiple pelvic fractures. Other causes of forelimb extensor rigidity and neck hyperextension such as decerebrate and decerebellate rigidity were excluded by a lack of neurological signs consistent with these entities and unremarkable findings on post-mortem examination of the cranial cavity and brain and histological examination of the cerebrum, brainstem and cerebellum. To the best of the author's knowledge, this is the first report of SSP in the cat outside the experimental arena of decerebrate or non-decerebrate preparations following post-brachial spinal cord transection/cold block.

Delayed presentation of spinal cord injury without radiographic abnormality (SCIWORA): a case report.

Spinal Cord Injury without Radiographic Abnormality (SCIWORA) is an unprecedented event to occur in adults but may lead to serious complications including permanent neurological impairments and death. In this article, we report a case of a 60-year-old male presenting to the emergency for a head and neck trauma after a motorbike accident, who reported only a neck ache and a normal primary neurological exam. The evolution was marked by the occurrence of paraplegia with a diminished sphincter tone and hypoesthesia beneath the T12 dermatome level after six hours, confirmed by the Magnetic Resonance Imaging (MRI). He underwent a deferred laminectomy within 30 days after receiving methylprednisolone, with partial neurological improvement after two months. An early recognition of the diagnosis was challenge for the emergency physician, given the wide variability of clinical presentations. Magnetic resonance imaging (MRI) is a key examination to guide the diagnosis and the management of these patients.

The gray matter atrophy and related network changes occur in the higher cognitive region rather than the primary sensorimotor cortex after spinal cord injury.

Objective: This study used functional magnetic resonance imaging (fMRI) to explore brain structural and related network changes in patients with spinal cord injury (SCI). Methods: Thirty-one right-handed SCI patients and 31 gender- and age-matched healthy controls (HC) were included. The gray matter volume (GMV) changes in SCI patients were observed using voxel-based morphometry (VBM). Then, these altered gray matter clusters were used as the regions of interest (ROIs) for whole-brain functional connectivity (FC) analysis to detect related functional changes. The potential association between GMV and FC values with the visual analog scale (VAS), the American Spinal Injury Association (ASIA) score, and the course of injuries was investigated through partial correlation analysis. Results: GMV of the frontal, temporal, and insular cortices was lower in the SCI group than in the HC group. No GMV changes were found in the primary sensorimotor area in the SCI group. Besides, the altered FC regions were not in the primary sensorimotor area but in the cingulate gyrus, supplementary motor area, precuneus, frontal lobe, and insular. Additionally, some of these altered GMV and FC regions were correlated with ASIA motor scores, indicating that higher cognitive regions can affect motor function in SCI patients. Conclusions: This study demonstrated that gray matter and related network reorganization in patients with SCI occurred in higher cognitive regions. Future rehabilitation strategies should focus more on cognitive functions.

Sensitivity Analysis of CMAP Scan Step Index to Different Stimulation Parameters and Examination of Muscles Affected by Spinal Cord Injury.

Step index (STEPIX) is a recently developed compound muscle action potential (CMAP) scan method for evaluating motor unit loss and remodeling changes. This study investigates the influence of different stimulation parameters during CMAP scan on STEPIX and its examination of muscles affected by spinal cord injury (SCI). CMAP scan of the first dorsal interosseous (FDI) muscle was performed using different stimulus pulse widths (0.1 ms, 0.2 ms) and different numbers of stimuli (500, 1000) in 12 neurologically intact subjects. STEPIX was derived from each CMAP scan of all subjects. A significantly higher STEPIX was obtained using 1000 stimuli than 500 stimuli, while no significant difference in STEPIX was observed using 0.1 and 0.2 ms stimulus pulse widths. STEPIX was further applied to process CMAP scans of the FDI muscle from 13 tetraplegia and 13 healthy control subjects using the same stimulation parameter setting (0.1 ms, 500 stimuli), along with other methods including MScanFit motor unit number estimation (MUNE) and D50. STEPIX was significantly lower for the SCI subjects compared with the healthy control subjects. STEPIX was significantly correlated with MscanFit MUNE and D50, but had a smaller relative width of the overlapping zone (WOZ%) between tetraplegic and healthy control groups compared with MScanFit MUNE and D50. The findings of the study highlight the importance of maintaining a consistent stimulation parameter setting in CMAP scan studies and confirm the usefulness of STEPIX as a convenient CMAP scan parameter for examination of motor unit number changes.

Spinal Cord Injury Without Radiographic Abnormalities Caused By Rotation Stretching Injury Manifesting As Brown- Sequard Syndrome: A Case Report.

Spinal cord injury without radiographic abnormality (SCIWORA) is a term that denotes clinical symptoms of traumatic myelopathy without radiographic or computed tomographic features of vertebral fracture or instability. However, SCIWORA in adults is very rare, especially that involving the thoracic spine. We describe the case of a 38-year-old man who complained of weakness in the right lower extremity for two hours. The injury occurred due to rapid spinal cord rotation-stretching. The patient was diagnosed with SCIWORA at the T4 level, manifesting as Brown-Sequard syndrome (BBS). Finally, he was able to walk independently without assistance after two-month treatment. SCIWORA due to spinal cord rotation-stretching injury, manifesting as BSS, is a very rare mechanism of injury. When X-ray and CT scans rule out the diagnosis of spinal fractures, SCIWORA should be suspected. We recommend that clinicians should have a comprehensive and systematic understanding of this disease to greatly reduce misdiagnosis and improve the level of treatment.

Assessment of spinal cord injury using ultrasound elastography in a rabbit model in vivo.

The effect of the mechanical micro-environment on spinal cord injury (SCI) and treatment effectiveness remains unclear. Currently, there are limited imaging methods that can directly assess the localized mechanical behavior of spinal cords in vivo. In this study, we apply new ultrasound elastography (USE) techniques to assess SCI in vivo at the site of the injury and at the time of one week post injury, in a rabbit animal model. Eleven rabbits underwent laminectomy procedures. Among them, spinal cords of five rabbits were injured during the procedure. The other six rabbits were used as control. Two neurological statuses were achieved: non-paralysis and paralysis. Ultrasound data were collected one week post-surgery and processed to compute strain ratios. Histologic analysis, mechanical testing, magnetic resonance imaging (MRI), computerized tomography and MRI diffusion tensor imaging (DTI) were performed to validate USE results. Strain ratios computed via USE were found to be significantly different in paralyzed versus non-paralyzed rabbits. The myelomalacia histologic score and spinal cord Young's modulus evaluated in selected animals were in good qualitative agreement with USE assessment. It is feasible to use USE to assess changes in the spinal cord of the presented animal model. In the future, with more experimental data available, USE may provide new quantitative tools for improving SCI diagnosis and prognosis.

Attention-gated U-Net networks for simultaneous axial/sagittal planes segmentation of injured spinal cords.

Magnetic resonance imaging is currently the gold standard for the evaluation of spinal cord injuries. Automatic analysis of these injuries is however challenging, as MRI resolutions vary for different planes of analysis and physiological features are often distorted around these injuries. This study proposes a new CNN-based segmentation method in which information is exchanged between two networks analyzing the scans from different planes. Our aim was to develop a robust method for automatic segmentation of the spinal cord in patients having suffered traumatic injuries. The database consisted of 106 sagittal MRI scans from 94 patients with traumatic spinal cord injuries. Our method used an innovative approach where the scans were analyzed in series under the axial and sagittal plane by two different convolutional networks. The results were compared with those of Deepseg 2D from the Spinal Cord Toolbox (SCT), which was taken as state-of-the-art. Comparisons were evaluated using K-Fold cross-validation combined with statistical t-test results on separate test data. Our method achieved significantly better results than Deepseg 2D, with an average Dice coefficient of 0.95 against 0.88 for Deepseg 2D (p <0.001). Other metrics were also used to compare the segmentations, all of which showed significantly better results for our approach. In this study, we introduce a robust method for spinal cord segmentation which is capable of adequately segmenting spinal cords affected by traumatic injuries, improving upon the methods contained in SCT.