"This artifact was first detected in 2015, and described in 2016 by two separate groups (one in Scotland, the other in the US) in two different case-series, each seemingly unaware of the other 1,2. It has now been reported by multiple centres. It remains unknown why this artifact was not reported previously, even allowing for its subtle nature."
Expected headings
"Cause"
"Formation of air bubbles"
"Detecting the artifact"
"Removing the artifact"