Dynamic diffusion tensor imaging of spinal cord contusion: A canine model.

This study aimed to explore the dynamic diffusion tensor imaging (DTI) of changes in spinal cord contusion using a canine model of injury involving rostral and caudal levels. In this study, a spinal cord contusion model was established in female dogs using a custom-made weight-drop lesion device. DTI was performed on dogs with injured spinal cords (n=7) using a Siemens 3.0T MRI scanner at pre-contusion and at 3 h, 24 h, 6 weeks and 12 weeks post-injury. The tissue sections were stained for immunohistochemical analysis. Canine models of spinal cord contusion were created successfully using the weight-drop lesion device. The fractional anisotropy (FA) value of lesion epicenter decreased, while the apparent diffusion coefficient (ADC), mean diffusivity (MD), and radial diffusivity (RD) values increased, and the extent of the curve was apparent gradually. The site and time affected the DTI parameters significantly in the whole spinal cord, ADC (site, P < 0.001 and time, P = 0.077, respectively); FA (site, P < 0.001 and time, P = 0.002, respectively). Immunohistological analysis of GFAP and NF revealed the pathologic changes of reactive astrocytes and axons, as well as the cavity and glial scars occurring during chronic SCI. DTI is a sensitive and noninvasive imaging tool useful to assess edema, hemorrhage, cavity formation, structural damage and reconstruction of axon, and myelin in dogs. The DTI parameters after contusion vary. However, the curves of ADC, MD, and RD were nearly similar and the FA curve was distinct. All the DTI parameters were affected by distance and time.

Risk factors for venous thromboembolism in patients with spinal cord injury: A systematic review and meta-analysis.

CONTEXT: Patients with spinal cord injury (SCI) are at high risk for venous thromboembolism (VTE). The risk factors for VTE in patients with SCI are complex. OBJECTIVE: This meta-analysis was conducted to clarify the risk factors for VTE in patients with SCI. METHODS: The Cochrane Library, PubMed, EBSCO, Web of Science, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), Wanfang Med Data Database, and VIP Database were searched to identify studies reporting on risk factors for VTE in patients with SCI. RESULTS: The meta-analysis included 25 studies. Findings showed that risk of VTE in patients with SCI was significantly associated with middle- and old-age (OR = 2.08, 95%CI, 1.47, 2.95), male sex (OR = 1.41, 95%CI, 1.26, 1.59), complete paralysis (OR = 3.69, 95%CI, 2.60, 5.24), personal/family history of venous thrombosis (OR = 1.95, 95%CI, 1.35, 2.81), history of smoking (OR = 2.67, 95%CI, 1.79, 3.98), lack of compression therapy (OR = 2.44, 95%CI, 1.59, 3.73), presence of lower limb/pelvic fracture (OR = 3.47, 95%CI, 1.79, 6.75), paraplegia (OR = 1.81, 95%CI, 1.49, 2.19), and diabetes (OR = 4.24, 95%CI, 2.75, 6.52). CONCLUSION: The meta-analysis identified 9 risk factors for VTE in patients with SCI. Healthcare providers should be aware of the risk factors for VTE when rehabilitating patients with SCI.

An unprecedented hexagonal double perovskite organic-inorganic hybrid ferroelastic material: (piperidinium)2[KBiCl6].

An unprecedented A2MIMIIIX6-type double perovskite adopting a fully hexagonal BaNiO3-type structure, (piperidinium)2[KBiCl6], undergoes a 2/mF1[combining macron] ferroelastic phase transition at 285 K with a spontaneous strain of 0.0615, arising from the order-disorder transition of organic cations together with the synchronous displacement of inorganic chains.

Switching hydrogen bonds to readily interconvert two room-temperature long-term stable crystalline polymorphs in chiral molecular perovskites.

It is challenging to endow polymorphs with both long-term stability and easy interconvertibility. We demonstrate an interesting example that two room-temperature polymorphs could be long-term stable yet easily interconvertible, at a pressure of ∼4.8 MPa and a temperature of 120 °C, by switching hydrogen bonds via collective reorientation of organic cations in chiral molecular perovskites.

Dynamic correlation of diffusion tensor imaging and neurological function scores in beagles with spinal cord injury.

Exploring the relationship between different structure of the spinal cord and functional assessment after spinal cord injury is important. Quantitative diffusion tensor imaging can provide information about the microstructure of nerve tissue and can quantify the pathological damage of spinal cord white matter and gray matter. In this study, a custom-designed spinal cord contusion-impactor was used to damage the T10 spinal cord of beagles. Diffusion tensor imaging was used to observe changes in the whole spinal cord, white matter, and gray matter, and the Texas Spinal Cord Injury Score was used to assess changes in neurological function at 3 hours, 24 hours, 6 weeks, and 12 weeks after injury. With time, fractional anisotropy values after spinal cord injury showed a downward trend, and the apparent diffusion coefficient, mean diffusivity, and radial diffusivity first decreased and then increased. The apparent diffusion-coefficient value was highly associated with the Texas Spinal Cord Injury Score for the whole spinal cord (R = 0.919, P = 0.027), white matter (R = 0.932, P = 0.021), and gray matter (R = 0.882, P = 0.048). Additionally, the other parameters had almost no correlation with the score (P > 0.05). In conclusion, the highest and most significant correlation between diffusion parameters and neurological function was the apparent diffusion-coefficient value for white matter, indicating that it could be used to predict the recovery of neurological function accurately after spinal cord injury.