# Lung Ultrasound Assessment of Lung Injury Following Acute Spinal Cord Injury in Rats

## TL;DR

This study shows that lung ultrasound can track lung injury in rats after spinal cord injury, matching up with other tests.

## Contribution

The study introduces lung ultrasound as a non-invasive method to monitor lung injury progression after acute spinal cord injury in rats.

## Key findings

- Lung ultrasound findings correlated with histopathological changes and pulmonary function decline after spinal cord injury.
- Modified B-line scores from lung ultrasound showed strong correlations with lung edema and inflammation markers.
- Ultrasound detected progressive lung injury, including pleural abnormalities and confluent B-lines, over time.

## Abstract

Background/Objectives: Acute spinal cord injury (ASCI) often leads to pulmonary complications, yet reliable, non-invasive assessment tools are limited. This study aimed to evaluate the utility of lung ultrasound (LUS) in assessing lung injury following ASCI in a rat model. Methods: Fifty-four female Sprague Dawley rats were randomized into sham (n = 27) or ASCI (n = 27) groups. LUS was performed at 12 h, 48 h, and 1 week post-injury, with lung injury quantified using a modified B-line score (BLS). Pulmonary function was assessed non-invasively, and histopathological evaluation and wet-to-dry (W/D) weight ratios were conducted post-mortem. Correlations between BLS and functional and pathological parameters were analyzed. Results: Histological analysis revealed progressive pulmonary hemorrhage, edema, and inflammatory infiltration peaking at 48 h post-injury, with residual hemorrhage and fibroplasia at 1 week. LUS findings evolved from narrow-based B-lines at 12 h to confluent B-lines with pleural abnormalities by 1 week. ASCI rats showed significant reductions in respiratory frequency, peak inspiratory and expiratory flow, and EF50 at all time points (p < 0.05). Tidal volume and minute volume decreased initially, with partial recovery at 1 week. BLS negatively correlated with all pulmonary function parameters and positively with the histological score and W/D ratio (p < 0.001). Conclusions: LUS reliably detects and tracks lung injury after ASCI, correlating well with physiological and pathological indicators. These findings support its potential as a non-invasive monitoring tool. Future refinement of ultrasound scoring may improve clinical applicability in ASCI-related pulmonary assessment.