Ultrasonic Detection of Venous Gas Emboli and Tissue Gas in Rodents: Toward Imaging Biomarkers for Decompression Stress

Peak venous gas embolus grades in rats increased with estimated decompression sickness risk, rising from grade 1 at pDCS 0.1% to grade 2 at pDCS 13% after decompression.

• Why it matters: Rodent decompression studies lack an established link between ultrasound imaging findings and decompression outcomes, limiting imaging biomarkers for decompression stress.
• What they did: Rats underwent dry saturation at 700 KPA breathing heliox (pDCS = 0.1%) or air (pDCS = 13%), then received serial cardiac and renal ultrasound; VGE was scored ordinally and renal grayscale intensity (a.u.) was quantified in a region of interest.
• The result: Renal echogenicity decreased during higher VGE, with mean grayscale intensities of 67.0 a.u. for VGE grades 0–1 versus 60.7 a.u. for grades 2–4, and renal histopathology showed round voids consistent with pre-mortem gas emboli.