High-resolution Micro-CT Myelography to Assess Spinal Subarachnoid Space Changes After Spinal Cord Injury in Rats

Comprehensive phenotyping of cutaneous afferents reveals early-onset alterations in nociceptor response properties, release of CGRP, and hindpaw edema following spinal cord injury

Spinal cord injury (SCI) is a complex syndrome that has profound effects on patient well-being, including the development of medically-resistant chronic pain. The mechanisms underlying SCI pain have been the subject of thorough investigation but remain poorly understood. While the majority of the research has focused on changes occurring within and surrounding the site of injury in the spinal cord, there is now a consensus that alterations within the peripheral nervous system, namely sensitization of nociceptors, contribute to the development and maintenance of chronic SCI pain. Using an ex vivo skin/nerve/DRG/spinal cord preparation to characterize afferent response properties following SCI, we found that SCI increased mechanical and thermal responding, as well as the incidence of spontaneous activity (SA) and afterdischarge (AD), in below-level C-fiber nociceptors 24 hr following injury relative to naïve controls. Interestingly, the distribution of nociceptors that exhibit SA and AD are not identical, and the development of SA was observed more frequently in nociceptors with low heat thresholds, while AD was found more frequently in nociceptors with high heat thresholds. We also found that SCI resulted in hindpaw edema and elevated cutaneous calcitonin gene-related peptide (CGRP) concentration that were not observed in naïve mice. These results suggest that SCI causes a rapidly developing nociceptor sensitization and peripheral inflammation that may contribute to the early emergence and persistence of chronic SCI pain.

Diagnostic Value of Magnetic Resonance Imaging Scan, Multislice Spiral Computed Tomography Three-Dimensional Reconstruction Combined with Plain Film X-Ray in Spinal Injuries

Objective

The main objective is to explore the diagnostic value of magnetic resonance imaging (MRI) scan, multislice spiral computed tomography (MSCT) three-dimensional reconstruction combined with plain film X-ray in spiral injuries.

Methods

By means of retrospective study, the data of 100 patients with spiral injury treated in our hospital from January 2020 to December 2021 were retrospectively analyzed, and all patients received MRI scan, MSCT three-dimensional reconstruction, and plain film X-ray examination, and by taking the operation results as the reference, the diagnostic results of different diagnostic modalities were analyzed, and the accordance rates (diagnostic result/surgical result × 100%) of the three diagnostic modalities and their combination were calculated, respectively.

Results

Among the 100 patients, 52 cases (52%) had a fracture at the anterior column of the spine, 28 cases (28%) had a fracture at the middle column of the spine, and 20 cases (20%) had a fracture at the posterior column of spine; 24 cases (24%) had simple flexion compression fracture, 60 cases (60%) had burst fracture, 6 cases (6%) had seat belt fracture, and 10 cases (10%) had fracture dislocation. The accordance rate of combined diagnosis for fracture site was 100%, and that for fracture type was 98.0%; MRI could visualize bone marrow injuries, ligamentous injuries, soft tissue injuries, and nerve root injuries that could not be visualized on X-ray plain films, and 3D reconstruction with MSCT could clearly demonstrate the 3D relationship of spinal fracture displacement, fracture line orientation, and spinal injury.

Conclusion

Plain film X-ray is the basic method for diagnosing spinal injuries, while MRI and MSCT have their unique advantages in this regard, and patients with a negative result of X-ray plain film can be examined by MRI and MSCT to observe the spinal injury comprehensively.

In vivo imaging in experimental spinal cord injury – Techniques and trends

Introduction

Traumatic Spinal Cord Injury (SCI) is one of the leading causes of disability in the world. Treatment is limited to supportive care and no curative therapy exists. Experimental research to understand the complex pathophysiology and potential mediators of spinal cord regeneration is essential to develop innovative translational therapies. A multitude of experimental imaging methods to monitor spinal cord regeneration in vivo have developed over the last years. However, little literature exists to deal with advanced imaging methods specifically available in SCI research.

Research Question

This systematic literature review examines the current standards in experimental imaging in SCI allowing for in vivo imaging of spinal cord regeneration on a neuronal, vascular, and cellular basis.

Material and Methods

Articles were included meeting the following criteria: experimental research, original studies, rodent subjects, and intravital imaging. Reviewed in detail are microstructural and functional Magnetic Resonance Imaging, Micro-Computed Tomography, Laser Speckle Imaging, Very High Resolution Ultrasound, and in vivo microscopy techniques.

Results

Following the PRISMA guidelines for systematic reviews, 689 articles were identified for review, of which 492 were sorted out after screening and an additional 104 after detailed review. For qualitative synthesis 93 articles were included in this publication.

Discussion and Conclusion

With this study we give an up-to-date overview about modern experimental imaging techniques with the potential to advance the knowledge on spinal cord regeneration following SCI. A thorough knowledge of the strengths and limitations of the reviewed techniques will help to optimally exploit our current experimental armamentarium in the field.

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In vivo imaging is essential to enhance the understanding of SCI pathophysiology.

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Multiple experimental imaging methods have evolved over the past years.

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Detailed review of in vivo (f)MRI, μCT, VHRUS, and Microcopy in experimental SCI.

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Experimental imaging allows for longitudinal examination to the cellular level.

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Knowledge of the strengths and limitations is essential for future research.