Quantitative assessment of spinal cord perfusion by using contrast-enhanced ultrasound in a porcine model with acute spinal cord contusion

Abstract

Objectives: To quantify spinal cord perfusion by using contrast-enhanced ultrasound (CEUS) in a porcine model with acute spinal cord injury. Methods: Microcirculatory changes of acute spinal cord injury were shown by CEUS in a porcine model with spinal cord contusion at three selected time points, coupling with conventional ultrasound (US) and Color Doppler US (CDFI). Time-intensity curves and perfusion parameters were also obtained by autotracking contrast quantification (ACQ) software in the epicenter of contusion site, adjacent region and distant region, respectively. Neurologic and histologic examinations were used to confirm the severity of injury. Results: Conventional US revealed the spinal cord was hypoechoic and homogeneous, whereas the dura mater, pia mater and cerebral aqueduct were hyperechoic. On CDFI intramedullary blood vessels were displayed as segmental and columnar. It was homogeneous on CEUS. After spinal cord contusion, the injured region on gray scale US was hyperechoic. CDFI demonstrated intramedullary blood vessels of adjacent region had increased and dilated during the observation period. On CEUS the epicenter of contusion site was hypoperfusion, whereas its adjacent region was hyperperfusion compared with the distant region. Quantitative analysis showed that peak intensity decreased in epicenters of contusion but increased in adjacent regions significantly at all time points (Po0.05). Evaluation of neurological function for post-contusion demonstrated significantly deterioration in comparison before injury (Po0.05). Conclusions: CEUS is a practical technique that provides overall views for evaluating microcirculatory pattern in spinal cord injury. Quantitative analysis shows the efficacy in assessment of perfusion changes after spinal cord injury.

Very High Resolution Ultrasound Imaging for Real-Time Quantitative Visualization of Vascular Disruption after Spinal Cord Injury

“…1 Various studies in clinical and experimental settings have shown that ultrasound (US) imaging can be used to visualize the PH subsequent to SCI. [15][16][17][18][19][20][21] In experimental studies, the highest frequencies used were 10-12 MHz, [18][19][20][21] but the small diameter of the rat spinal cord (3-4 mm) limited the resolution of imaging. More recent US devices using very high frequencies (40-55 MHz) have been specifically designed to image small animals with spatial resolutions as low as 30 microns per pixel.…”

Porcine Model of Spinal Cord Injury: A Systematic Review

“…Huang and colleagues used the modified Tarlov score, which is a shorter, 4-point scale with 0 representing no locomotion and 4 indicating normal gait. 52 , 53 …”

“…Hematoxylin and eosin (H&E) is the most common stain and can depict general morphology and the degree of tissue damage. 27 , 33 , 34 , 43 , 53 , 54 Eriochrome cyanine R, commonly used in conjunction with the counterstain cresyl violet or Neutral Red, can help delineate and measure areas of white and gray matter, allowing for analysis of lesion size and neuronal degeneration. 11 , 25 , 37 , 38 , 42 , 45 , 47 , 48 , 55–57 Luxol fast blue can also be used with cresyl violet counterstain to identify myelinated fibers in white matter and the residual preserved tissue.…”

“…Contrast-enhanced ultrasound and color Doppler have shown hypoperfusion at the injury epicenter with concomitant hyperperfusion in the adjacent regions, demonstrating the ischemia that occurs at the injury site. 9 , 53 Jones and colleagues used B-mode ultrasound to demonstrate the gradual and immediate swelling that occurs after moderate and severe SCI, respectively, suggesting the need for decompression after injury. 29 Kim and colleagues and Santamaria and colleagues used B-mode ultrasound to show that the thickness of the CSF layer is a major determinant of injury severity.…”

How to generate graded spinal cord injuries in swine – tools and procedures

“…dexterity and locomotion), the similarities in anatomy of the vertebral column and spinal cord represent a good compromise ( Lee et al, 2013 ; Schomberg et al, 2017 ). This explains the increased number of pig studies over the past decades ( Benavides et al, 2017 ; Bernards and Akers, 2006 ; Hachmann et al, 2013 ; Hong et al, 2016 ; Huang et al, 2013 ; Jones et al, 2012 , 2013 ; Kowalski et al, 2016 ; Kuluz et al, 2010 ; Kwon et al, 2015 ; Lee et al, 2013 ; Martirosyan et al, 2015 ; Navarro et al, 2012 ; Okon et al, 2013 ; Santamaria et al, 2018 ; Streijger et al, 2015 , 2016 , 2017 ; Tigchelaar et al, 2017 ; Zahra et al, 2010 ; Zurita et al, 2008 , 2012 ). Despite this growing interest in the pig model, utilizing it requires a specific infrastructure, a substantial budget and several types of expertise that can be challenging to gather.…”