in this video we're going to introduce the 10 basic signs of lung ultrasound
now Liechtenstein breaks us down into ten basic signs and we will look at each
of these signs in detail in subsequent videos so the point of this video is
just to introduce them and get you to start recognizing these ten basic signs
so the first sign is called the bat sign and I'll be honest I don't know that I
can appreciate it as a bat as Liechtenstein does but I do appreciate
the importance of the bat sign and the importance is to accurately identify the
pleural line because if you don't accurately identify the pleural line you
can misinterpret things in lung ultrasound so this is going to serve as
a key landmark for us the way I like to think of it is layers from the outside
in as we've previously discussed so we have the skin layer the subcutaneous
layer we have the muscular layer here then we have the cortex of the rib with
shadowing shadowing and the cortex of the rib here with shadowing and
shadowing we have the intercostal area between the ribs and then and only then
can I identify this hyper echoic line below the ribs an intercostal area as
the pleural line now Lichtenstein sees this as a bat where the curved ribs are
like the wings of the bat it's like the bats flying towards you and then below
those wings you can call the pleural line again I don't know if I can
identify it that way but this will serve as a core landmark for us identifying
this hyper echoic pleural line the bat sign now the second sign is the seashore
sign in the seashore sign is identifying what normal lung sliding looks like in
both 2d and M mode so if we look at this 2d picture on the left we see here that
we have rib and rib shadow rib and rib shadow so we know this is the pleural
line as we've talked about before and for now just a pre
she ate that there's a movement along the pleural line if we take an m-mode
slice through the pleural line and then depicted over time that's what gives us
this seashore appearance on M mode on the right and if we notice in the
picture here that everything above the pleural line is relatively static I mean
there's a little bit movement in the intercostal and muscular segments but
it's mostly straight lines because it's relatively static where everything below
the pleural line is relatively dynamic you see all of this sparkling and
movement in this artifact that is created that is the appearance of normal
lung sliding and this is said to look like a seashore a sandy beach where you
have up here the horizon the waves coming in you hit the seashore and then
you have this sandy beach appearance of everything below it the next sign is the
a line and again if we identify that this is the pleural line what a lines
are is horizontal lines that are reverberation artifact of the original
pleural line so we see the original pleural line here and then we'll notice
that equidistant from the skin to the original pleural line we have a second
horizontal line and then equidistant again we have a third horizontal line
and again these horizontal lines are reverberation artifact identified as an
a-line the next two signs are the quad sign in the sinusoidal pleural effusions
so we're going to look at them together now if we look at the image on the
bottom left we see our normal anatomy that we're used to with the rib and
shadow and then below the ribs we see the parietal pleura and then between the
parietal in the visceral pleura we see that there's fluid in this fluid takes
this quadrangle misshape because we have the ribbon
shadows serving as the side borders and then the parietal and the visceral
pleura serving as the top and bottom border and if we were to take an M mode
right down through the middle of this pleural effusion and watch it out over
time what we would see is the parietal pleura here and then with inspiration
exploration we'd see the visceral pleura moving in and out which gives us
sinusoidal in between the two pleural layers and that's the sinusoidal are
going to look at together are the Shred side which is depicted here as well as
the tissue like sign which is depicted here in both of these are signs of
consolidation now if we look at this video down here we see that here we have
the diaphragm below the diaphragm is liver and above the diaphragm we see a
little bit of pleural fluid but we see this tissue like area which is an area
of consolidated lung it almost looks like liver tissue and that's why some
call it hepatis ation of the lung because here's the liver but the liver
has black blood vessels in it where this has white areas in it and those white
areas are air Branca Graham's so the first sign that we're talking about is
this tissue like sign and it's tissue like appearance of consolidated lung
with white air Branca Graham's inside of it the second is the Shred sign in the
Shred sign is where the consolidated lung meets normal aerated lung it
creates the shredded like pleural line it's not the pleural line it's where the
interface between the consolidation of the lung and the aerated lung meet
it doesn't create a straight line like the lung line or the pleural line but
this irregular shredded like line so the Shred sign in the tissue lake sign are
both signs of consolidation the eighth sign that we're going to talk about our
lung Rockets now long rockets by definition are greater than or equal to
three B lines per interspace and B lines are an artifact that we're going to
identify here now C rib rib with shadow and shadow that should be familiar to
you now with the pleural line then seen just below that but notice how off of
the pleural line there's coming a bright white vertical artifact I imagined it as
a bright white almost flashlight beam beaming off of the pleural line off of
the screen notice that it comes from the pleural line it's vertical it's bright
white it moves with the pleural line and it obliterates this a line so B lines
when they're present obliterate the a line and if there's greater than two or
equal three B lines we call that lung Rockets and lung Rockets are a sign of
interstitial syndrome the next sign is called the stratosphere sign or some
call it the barcode sign and this is the m-mode equivalent of lack of lung
sliding so if we look at this 2d video clip here we see rib shadowing rib a
little bit of shadowing so we know below that is this hyper coline that we've
identified as the pleural line but notice looking at this pleural line that
there's no movement along it there's movement of the chest wall but there's
not movement of the pleural line back and forth in opposition to each other so
if we contrast that to the seashore sign we've seen before we can identify that
everything above the pleural line is still relatively static I mean again we
see the movement in the intercostal and muscular layers from time to time
that's movement of respiration but below it we don't see that Sandy Beach in fact
above in below the pleural line are now mirrored they look exactly the same and
this is what Lichtenstein refers to as the stratosphere sign are almost like
the smoke jets coming from a jet plane in the stratosphere or others have
identified as a barcode or straight lines all the way across so the key to
identifying this sign is when everything above the pleural line in below the
pleural line are identical that's the stratosphere sign and it
equals lack of lung sliding the last sign we're going to talk about is the
lung point in the lung point is the transition between a pneumothorax or air
in the pleural space in normal lung sliding and if we look on this video on
the Left we see rib shadow rib shadow and so we know this is the pleural line
but we see movement along the pleural line on this part and so that is lung
sliding and on the other side we see no lung sliding so this transition point
between the two is the lung point and if we were to place m-mode on this we would
see that above the pleural line we have the static area so no significant
movement below the pleural line on this side we see the sandy beach sign with
lung sliding and then that lung sliding goes away here where we have the
stratosphere sign all in the same intercostal segment this is
pathognomonic for pneumothorax so burn this in your memory the lung point
all right let's review real quickly then the ten basic signs of lung ultrasound
number one the bat sign identifying the pleural line number two the sea shore
sign or the m-mode equivalent of normal lung sliding now
number three a lines reverberation artifact horizontal lines equidistant
from the pleural line number four the quad sign or fluid between the visceral
and parietal pleura indicative of pleural effusion
number five the sinusoidal inspiration and expiration the visceral pleura
coming towards and away from the prado pleura with fluid in between creating
this sinusoidal indicative of a pleural effusion number six the Shred sign or
the uneven lung line below the area of consolidation the shredded lung sign
indicative of consolidation number seven the tissue like sign or tissue with air
Branca Graham's in it inside the lung which is indicative of consolidation as
well number eight lung Rockets these vertical flashlight like beams coming
off of the pleural line moving with the pleural line obliterating the a line
these are indicative of interstitial syndrome number nine the stratosphere
sign or the barcode sign which is indicative of lack of lung sliding and
then number ten the lung point which is indicative of pneumothorax and that's
where you have lung sliding and lack of lung sliding in the same intercostal
segment
you