BLOOD FLOW CHANGES ASSOCIATED WITH SPINAL CORD INJURY ASSESSED BY NON-LINEAR DOPPLER CONTRAST-ENHANCED ULTRASOUND

Contrast-enhanced ultrasound (CEUS) is clinically used to image the microcirculation at lower imag-ing frequencies (<2 MHz). Recently, plane-wave acquisitions and Doppler processing have revealed improved microbubble sensitivity, enabling CEUS use at higher frequencies (15 MHz) and the ability to image simulta-neously blood flow in the micro-and macrocirculations. We used this approach to assess acute and chronic blood flow changes within contused spinal cord in a rodent spinal cord injury model. Immediately after spinal cord injury, we found significant differences in perfusion deficit between moderate and severe injuries (1.73 +/- 0.1 mm2 vs. 3.2 +/- 0.3 mm2, respectively), as well as a delay in microbubble arrival time in tissue adjacent to the injury site (0.97 +/- 0.1 s vs. 1.54 +/- 0.1 s, respectively). Acutely, morphological changes to central sulcal arteries were observed where vessels rostral to the contusion were displaced 4.8 +/- 2.2 degrees and 8.2 +/- 3.1 degrees anteriorly, and ves-sels caudal to the contusion 17.8 +/- 3.9 degrees and 24.2 +/- 4.1 degrees posteriorly, respectively, for moderate and severe injuries. Significant correlation of the acute perfusion deficit and arrival time were found with the chronic assessment of locomotive function and histological estimate of spared spinal cord tissue. (E-mail: mbruce@uw.edu)(c) 2022 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

Automated summary

Contrast-enhanced ultrasound (CEUS) is a valuable tool for assessing blood flow changes in spinal cord injury. This study utilized new imaging techniques to reveal significant differences in perfusion deficit and delayed microbubble arrival time in the injured tissue. These findings have implications for understanding acute and chronic blood flow changes in spinal cord injury.