A-lines vs B-lines in lung ultrasound

Increasingly over the last few years, ultrasound has been used to assess the lung.  In this capacity, two artifacts have been seen to be very useful.  In lung ultrasound these artifacts are called A-lines and B-lines.  The proponents of lung ultrasound often describe A-lines and B-lines as if they are unique to lung ultrasound.  However, A-lines and B-lines are simply different terms for very common air artifacts, namely reverberation and ring-down.

A-lines are simply long range reveberation artifact.

B-lines are simply ring-down artifact.

When these artifacts are seen emanating from gas in the abdomen we would just refer to them as reverberation and ring-down.  

However, when seen emanating from air in the lung, they are called A-lines and B-lines.      See below.  I also describe this in part 1 of the Artifacts video which you can access here.