Per Wikipedia, it "is a colorless, odorless, non-flammable, and non-toxic gas."
When used as a contrast agent for ultrasound, it "has been used to examine the vascularity of tumours" -- which would be similar to its use in the OP. Then
"[i]t remains visible in the blood for 3 to 8 minutes, and is exhaled by the lungs."
So -- not collected and excreted by the liver, as I at first thought.
When used as a contrast agent for ultrasound, it "has been used to examine the vascularity of tumours" -- which would be similar to its use in the OP. Then "[i]t remains visible in the blood for 3 to 8 minutes, and is exhaled by the lungs."
So -- not collected and excreted by the liver, as I at first thought.