Intro to POCUS Lecture

July 29, 2021

ID6850

To CiteDCA Citation Guide

00:00Hey there, thanks for your interest in doing
00:03a scanning ship with us in the pediatric Ed.
00:06We thought it likely be useful to
00:08have an introductory lecture provided
00:09before your shift so they can have a
00:12little bit of background information to
00:14use as a guide when you're doing your
00:16hands on scanning with us on shift.
00:19Maybe after they do their next slide.
00:23So this intro presentation hopefully
00:24will be able to view your scanning
00:27shift and then it'll give you a brief
00:29introduction to some key concepts
00:31that you're going to need to be
00:34clearly with most in order to be good
00:36at getting images and interpreting
00:38the images on the screen.
00:40So we'll have to delve into a little
00:42bit and some basic ultrasound physics.
00:45We're going to talk about scamming
00:47concepts that are related to the type
00:50of probe that you use with you forever.
00:52Transducer orientation.
00:53On the screen, some function apps
00:55and functionality such as color,
00:57Doppler depth gain,
00:58things like that and nobody is an idea
01:01of all these different functions as it
01:04pertains to your particular machine.
01:07So this is something that is
01:10often the rate limiting Step 4.
01:13Sonologist or positions were using
01:15Hope Sam to get comfortable at
01:18that doing winter care studies.
01:20And then you know,
01:21do the limited nature of trying
01:24to keep this short.
01:25Few guys,
01:26there's tons of other resources we
01:28can tap into focus at least 5 minutes,
01:31so no additional podcast picture,
01:33video based teaching materials and alien
01:35as well has some case based or person.
01:52So you know our goals for when we do this.
01:55Standing just together is just spend
01:57a little bit time to teach how to
01:59perform quality control, percent scans.
02:01And it's nice to have a dedicated time
02:03pressure that to do this so we don't have
02:06competing interests and other clinical care
02:08needs that are happening simultaneously.
02:10So we can really spend the time
02:13to go over the approach to.
02:15Patient how to integrate family members
02:18and some tricks to make things a little bit
02:21easier and smoother for for this games.
02:24And we talked a lot about what our role is
02:28in terms of binary yes or no questions.
02:31And then we're doing over summer the bedside.
02:35So for both of them accommodation, yes or no.
02:38Is there free fluid in the abdomen
02:40or patient they were concerned about
02:43undifferentiated chat, yes or no?
02:46The cardiac function preserved and
02:48so that really is, is a unique.
02:54Aspect of clinical percent,
02:55which differs from radiology over sample,
02:57tends to be a little more in depth and
03:00detail in terms of their scope and
03:03the questions out there in certain.
03:06So just to get on my orca sound,
03:09clip it here for a moment.
03:11There's multiple advantages over sounds,
03:12sort of relative to other
03:14diagnostic database like X rays,
03:16and you know we said CAT scans and even more,
03:19and so our furniture or
03:20sound is very dynamic study.
03:22So you're looking at objects and
03:24organs and two planes of everything
03:26we want to image and we have an
03:29object of interest you want to get.
03:31Get an image in perpendicular plane.
03:33So we say along Axis and the short axis.
03:37By the salesperson doesn't
03:38employ any radiation,
03:39so it's safe for patients and
03:41we could do it that seriously.
03:43So you can check the progression of
03:46illness with furniture or percent
03:48in two different points in time.
03:51It's fairly painless.
03:52There's been tons of studies on
03:54fracture literature with clinic
03:56programs in applied with paint,
03:58faces, scores,
03:59and and if you use enough gel
04:01and use appropriate techniques,
04:03we really should not be causing
04:06any additional pain,
04:07and certainly something that does
04:09not require sedation or should not
04:12require sedation and little to be
04:14performed and and then finally again sort of.
04:17It's repeatable.
04:18So if if repeatedly not only by a different.
04:22Later,
04:23or we say it's analogous,
04:24but it's easy to repeat at
04:26a different point in time,
04:28and having a machine at the
04:30radio for bedside.
04:31So it's really great and adds a
04:33lot of really important information
04:35to the clinical picture,
04:36and in many cases.
04:39So the questions we always are gonna ask
04:42yourself with where was an ultrasound done?
04:44Is it done by a clinician at
04:47the point of care Commission,
04:49who's likely taking care of the patient?
04:51Or is it a technician performed or
04:53radiology performed ultrasound done
04:55with diagnostic imaging street?
04:56Then who's doing it? Or ultrasounds?
04:59Unique is that it's it's.
05:00It's very operator dependent.
05:02So even if even within a certain application,
05:05so let's take the appendix for example.
05:07We can have two. And skilled.
05:12Ultrasound performers and one
05:14of the two has a higher on.
05:18Oh accuracy in terms of appendix
05:21identification and then ability to
05:23interpret surrounding structures
05:25from things like that.
05:27Saving amongst ourselves as an
05:29emergency medicine physicians
05:31and even in in the radiology and
05:34environment with the operator
05:35is gonna make a difference.
05:37So it's very different than putting
05:40a plate on somebody's back and
05:43shooting a picture like that they
05:46do for radiography for X rays so.
05:49So very important to be aware that
05:51is an operator dependent modality and
05:52then why is ultrasound being done so?
05:55Where is it done?
05:56Who's doing it?
05:57Are you doing this as a as
05:59a diagnostic and it should,
06:00and if so at the point of care should
06:03really be a yes or no question.
06:05And for the most part and then
06:07there's times where ultrasound
06:08is just a necessary part of
06:10clinical care because it's safer.
06:12It's safer when it comes to procedures
06:14and it has been shown time and time
06:16again to increase success rates.
06:18So for certain procedures.
06:22So let's get into what you're
06:23looking at on the screen.
06:25How are the images created by
06:27either a handheld device or a
06:30more standard for the ultrasound?
06:32Machine, So what happens is you have that
06:35everything starts with the transducer,
06:38so the machine sends an electrical signal.
06:41Some energy is transmitted to the
06:43probe to the transducer and these
06:46these probes are tightly packed with
06:49crystals and so that that electricity
06:52that that current what it does is
06:55it it causes vibration of these
06:57crystals at a very high frequency.
07:00Hence the name ultrasound.
07:03So the sound signal at that
07:05point is sent to a tissue.
07:07In this case, here you have.
07:11Cardiac structure.
07:12And depending on the tissue
07:15density and some properties,
07:18how fluid filled it is,
07:20there is an interaction between the tissue.
07:25And the pro.
07:26And there's two concepts that come into play,
07:30so there is a attenuation which is lost.
07:33Signal entry energy and there's
07:36impedance which is reflection of
07:39ultrasound back to the to the court.
07:42Yeah,
07:42in a combination of these two
07:45properties of ultrasound,
07:46the computer is going to generate an image.
07:49It's going to be a grayscale image
07:53and with knowledge of important.
07:55Uh, concepts of general concepts
07:57that we're going to go into.
07:59You will be able to say,
08:02OK,
08:02this image that is dark on the
08:05ultrasound screen is because it's
08:07a fluid filled structure because
08:09Doo Doo Doo Doo full attenuation.
08:12And lack of influence.
08:15And so let's look at these two properties,
08:19average of 10 transmission one at a time.
08:22The first is attenuation,
08:24so attenuation is essentially
08:25the loss of signal energy,
08:27as as ultrasound goes through
08:29a certain object or structure,
08:31it's going to lose the amount of signal
08:34that it can transmit deep to that structure.
08:38So you'll have a less define.
08:41The image on the screen that seems to happen.
08:45Now the amount of attenuation is going
08:48to be different depending on the make
08:50up the composition of the structure
08:53that the beam is going through,
08:55but you can almost always come. Man.
09:00Imagine that there's some degree of
09:02attenuation that's going to exist.
09:04That's why the images at the top half of
09:07the screen are always crisper and nicer
09:09than those at the bottom part of the screen.
09:12And then the other property,
09:14Loper Sound is impedance.
09:16Impedance has to do with tissue density
09:18and reflection of the ultrasound
09:20being back to their transducer.
09:23So in this case with bone which has
09:25high high impedance property that
09:27ultrasound reflects off the bone and
09:30back to the transducer and the machine
09:33cannot generate an image deep to the
09:36bone so everything goes dark behind
09:39tissues that have high impedance
09:42and we we do call that a certain.
09:45Artifact referred to his post here.
09:49Acoustic shadow.
09:53So in this slide,
09:54open sound is essentially the same
09:57as marine life with echolocation.
09:59I like to bring up this example to
10:02drive home the point that the water
10:05or fluid filled structures are
10:07excellent transmitters of ultrasound.
10:09So when a say in orca or corpus or a dolphin.
10:15Uh, send it over sound signals in in in the
10:18ocean through their application mechanism.
10:21That signal is going to continue
10:23to travel until it hits an object.
10:27And then based on the distance
10:29of that object and to the marine
10:33life and potentially the size of
10:35that object or multiple objects.
10:38The movie life mammal will get
10:42a sense of predator versus prey.
10:45And then how far did they would
10:47have to travel to reach that?
10:49That object that's in front of them?
10:52Or perhaps in some cases,
10:54but there how far the object would
10:56make they pose potential risks to
10:59their livelihood is so so that
11:01they can react in attending them.
11:04So it's it's a great example of how
11:06there is very little attenuation of
11:09ultrasound and fluid filled structures,
11:12and we we talked about this a lot.
11:16And when we're imaging, we want to see.
11:21Organs that are potentially deep in
11:23the pelvis or the common would be
11:26at work after ovarian pathology,
11:28ovarian torsion if we're doing
11:29transabdominal ultrasound,
11:30we want to have a nice, fluid filled bladder.
11:33So that the ultrasound beam can
11:36be well transmitted to the public
11:38structures to get a good look at the police.
11:45And here we had one last slide
11:47just to once again go over this
11:50idea of a person transmission.
11:52And when we talk about transmission,
11:54we're essentially asking yourself
11:56how well is my ultrasound being
11:59penetrated through the tissue.
12:01This has to do with the
12:03composition of that issue.
12:04So if you have a fluid filled structure,
12:07we have excellent transmission
12:08and nice fluid filled nicely.
12:10Nicely filled bladder is going
12:12to act as an acoustic window
12:14so that the ultrasound can
12:15visualize structures deep to it,
12:17such as the older is worried about
12:19a very enclosure morphologic
12:20sester ordering biology.
12:24When you have a.
12:26Structure with high impedance.
12:28There is a very very poor
12:32transmission behind that.
12:34Get or sometimes in fact,
12:36no transition.
12:37And then you have air.
12:40Air is actually the enemy for ultrasound.
12:43So in terms of the appearance of ultrasound
12:46as it crosses above an airfield structure,
12:50you really cannot delineate any
12:53Christmas on the screen at all.
12:56I put air essentially does is it
12:59causes scattered over something?
13:02Air can cause a very bright or
13:05hyperechoic appearance to the image,
13:07and it can and what it will do is.
13:11It will give you a very poorly defined.
13:15Me.
13:16Picture on the screen.
13:22Alright, so let's apply this.
13:23These concepts of ultrasound
13:25transmission to an actual still image.
13:27In this case, I will let you know this
13:30is a long access London Olympics in
13:32the midline of a pregnant patients,
13:35and you can see that come over the bladder
13:38because it's a nice fulfilled structure.
13:41There is no attenuation to alter sound,
13:44so you can actually see.
13:47Structures deep to it.
13:48In this case, there's a bag and a
13:51strike which is a landline that lets
13:53us know that we're at the midline.
13:56I am very sad.
13:58Transit transported here.
13:59And then you can think about the uterus.
14:02Look at how the the fundis portion is sort
14:05of well delineated with the gestational SAC.
14:08And also you can get a sense
14:10here of a fetal pole right there.
14:13And so the ultrasound transmission here
14:15maybe a slight little bit different,
14:17so more attenuation deep to the
14:19structures so you don't see as crisp
14:22of the margin of the posterior border.
14:24The uterus, like you do anteriorly.
14:27And guess what's behind the uterus well?
14:30It's mostly bad,
14:31and it's probably bow that's filled with
14:34air because we're not seeing anything.
14:37Everything looks very indistinct
14:38and that makes sense based on the
14:41ultrasound interaction with her,
14:43so that here,
14:44even though there is intestines
14:46and there's actual anatomy,
14:48we're not seeing anything on the screen
14:51because bowel gas causes ultrasound beam
14:54to scatter and just had a lot of white,
14:57right?
14:59Enhancement other than that
15:00computer scheme and we never really
15:02seen anything other than that.
15:08OK, so here we have a quiz named that phone.
15:15So how do we know what we're looking from?
15:18So one of the things we always want to keep
15:21an eye out when we're reviewing clips,
15:23and also when you're performing
15:25order sound scans is the settings.
15:27So here's a bit of a clue,
15:30and this happens to be more
15:33for sound of lung tissue.
15:35So in terms of meaning of bone,
15:38what bone would be seen in front of?
15:43One that would be a question groups so.
15:46Here you see the top of the rib in
15:51short access. And as you can see.
15:55Focus and cannot penetrate deep to the red.
15:58So everything here is dark. Dark.
16:01And so that is his artifact that we have
16:04alluded to as posterior acoustic enhancement.
16:07So we know that this is a ribbed here.
16:11Interesting story finding is
16:13that we typically will see.
16:16Flora here very bright line
16:19in between the rooms faces.
16:21So in this case,
16:23come not only do you sort of see
16:26separation or look for a right here.
16:29Looks like there's one line another one.
16:34Do this mother fluid collection device
16:36model period fusion, but this is
16:38actually a patient who has pneumonia
16:41by one 8% in the breakfast area field.
16:45We said briefly, then air gives no image,
16:49so just a sensually artifact. And dumb.
16:56We can spend an attack now we're
16:59talking about wonderful sound,
17:00but essentially this jaggedness here.
17:02Of the. That issue of this lung
17:07tissue is an appearance that you would
17:10see with a subfloor consolidation.
17:13And just some other findings.
17:15And in addition to that shred sign
17:17you had these little bright echogenic
17:20appearance is come in within a
17:22tissue that we shouldn't be seeing.
17:25We shouldn't be seeing a distinct
17:27sort of organ appearing tissue up
17:30there under the pleura because lung
17:32because since it's when it's health
17:34healthy as airfield does not give
17:37up any appearance on their person.
17:39We just see the regulation artifact.
17:42Which weakened spectrum little bit ahead of.
17:47Where we are right now in
17:50terms of this lecture,
17:51but I'm hoping you can get
17:54a good sense of ribbon here.
17:56Open sound hitting the red bone.
17:59It looks bright and echogenic.
18:02There's high impedance,
18:03there's no transmission,
18:04so you get this complete acoustic
18:06shadowing deep to that structure.
18:11Right, so when we're talking
18:13about what transducer to choose,
18:15the transducer sort of the
18:18film return for a person probe.
18:21There's essentially three choices.
18:22You have a linear probe which
18:26has a nice flat footprint here,
18:28great for superficial structures.
18:30You have a curvilinear Rd.
18:33There's a curved footprint which is
18:35better to look for deeper structures
18:37and you have a type of trouble linear
18:40code for the phased array probe,
18:43which is a cardiac together between
18:45rib spaces and get a nice view of
18:49the heart structures when you're
18:51doing a focus projector person.
18:53So when we talk about post
18:55election or cancer selection,
18:57you're gonna pick a a probe.
19:00Which is going to fit your needs.
19:03So the tradeoff between a
19:05curvilinear low frequency and a.
19:08Linear high frequency is resolution
19:10to depth or depth is how.
19:12How much penetration can the
19:14older sound being achieved?
19:16So the linear probe.
19:18The higher frequency pros are able to.
19:21It should be greater resolution and
19:24higher level of detail for superficial
19:27structures at the trade off.
19:30ML penetrate to deeper structures and
19:32vice versa with the curvilinear probes
19:35and the phased array publicly linear code.
19:38So with these probes you're going to
19:41sacrifice resolution for your ability
19:43to penetrate to deeper structures,
19:45so intrabdominal.
19:47Examinations,
19:47the classical being trauma
19:49focused assessment.
19:50Sonography comma.
19:51So the first exam you're going
19:54to perform with curvilinear
19:55or low frequency plates.
20:00So there's two scanning planes
20:01to be familiar with, and then
20:03it's important because we have
20:05convention in terms of how we image.
20:10Patience. Better pattern recognition
20:14can be consistent across patients.
20:16So we will use in the long axis of the
20:19sagittal or longitudinal axis on the plane.
20:22We will use the Convention of having
20:25the indicator, which is usually like a
20:28little non shoreline on the probe itself.
20:31Who is the head of the patient?
20:33So the indicator always
20:35faces the head when we're.
20:38Doing a logical access.
20:40Scan this is going to correlate
20:42with the monitor.
20:44This way you're gonna have head.
20:46Here you're going to have
20:47the top part of the patient.
20:49You can have the bottom part of the patient,
20:51and you're going to have to keep working.
20:54And when we're doing the transverse, UM?
21:00Orientation at the Convention is always going
21:02to be for that indicator to be too low,
21:06right?
21:08So indicated to them right?
21:10Again, it's going to be a little
21:12notch or some sort of mark on
21:15the right side of the patient,
21:17and these are almost like a cross section.
21:19Your CT scan cross sections where
21:22you have indicated to the right.
21:24You have the right kidney here and on
21:26the screen the right kidney is going to
21:29appear as you're looking at the screen.
21:32It's actually the left side of the screen,
21:35but it's the right side of the patient.
21:39So.
21:40Once you get this down,
21:43visually spatially and you're in your brain.
21:47Two times it's a very easy concept to tackle.
21:52And then we will use some scanning
21:55lingo so we will slide rock sweep
21:58and fanned the Pro sliding means.
22:00You're just bringing the transducer
22:03back and forth along the Y axis
22:06or the long axis of a object.
22:09And when you walk along this waxes line,
22:12you would essentially keep the hand
22:15still and just sort of swivel.
22:17But probe back and forth.
22:20Because remember the image that
22:22you're going to generate is
22:24going to have to do with how.
22:26Perpendicular how straight that ultrasound
22:28beam is to a certain structure,
22:30so you may have a gallbladder for example.
22:33Just picking the example,
22:34you may have a gallbladder here,
22:36but if you don't rock the probe just
22:38right to have it for particular,
22:41you're not going to see it.
22:43It's not that it's unfair,
22:44it's right there nearby hiding out
22:47but something some small motions or
22:49their hand with with these maneuvers
22:51is what we need to do in order to
22:54get a good image on the screen.
22:56So we have the sliding and and the
22:59rocking which is essentially along
23:01the Y axis plane or London tunnel
23:04access plane and then sweeping
23:06would be in short access.
23:08So so you have a say you have a
23:11blood vessel here and it's you're
23:13sort of forcing the code.
23:15You're sleeping over it up and
23:18down the vessel.
23:20To see it entirely and on the screen
23:22rather than see it as a circle when
23:25you're when you're imaging the vessel.
23:28That location is critical in this way
23:30and you're gonna see Circle Circle,
23:32circle in the stream.
23:34I just sweep up and down and then fanning.
23:37We do a lot of planning with our fast exam,
23:41so again,
23:42it's a swivel motion in this
23:45short access cut with.
23:47Essentially,
23:47your hand isn't moving up or
23:49down in the patient's body.
23:51You have to stand still,
23:53but you're sort of fanning or rotating
23:55like this, rotating the pole.
23:58Me.
24:00Down to get a good look at the
24:02structure that you interested in.
24:07Alright, so let's look at this another way,
24:09so you have indicators which have a notch
24:12or at our probes have a team match and
24:15when we image and individual and the
24:17transverse plane or the short axis pointing,
24:20the indicator is going to point
24:22towards the right of the patient
24:24which is here on this gingerbread man.
24:27The right of the patient and you're
24:30going to actually see the indicator.
24:33Appear on the left side of the screen
24:35as you're looking at this thing,
24:37so this is a convention for transverse
24:40you have a fluid filled structure with a.
24:43Balloon catheter inside of it.
24:45This is a child with hearing the tension
24:47that happened with a Foley catheter
24:49placed and mess with the latter would
24:51look like in and transfers orientation
24:54with the indicated participation right.
24:55And if we're getting image it and
24:57longitudinal access lunchroom orientation,
24:59the indicator is going to
25:01go to the patients head.
25:02So the indicator the notch is going to
25:06point towards the head of the patient.
25:09On the screen it's gonna appear a little
25:12circle on the left side of the screen.
25:14If you're looking at the screen
25:17and the image itself,
25:18you're gonna have bladder.
25:20And then pour le balloon catheter
25:22right there.
25:23So that's just the Convention,
25:25and that's how you're going to keep
25:28this little mark on the screen.
25:31This general sense of awareness so that you
25:34know that if things were converted you,
25:36it's likely that your crew is turn
25:39180 degrees by accident.
25:41Now in terms of positioning,
25:43this is a pretty easy concept to understand
25:46structures that are closer to the probe
25:49are going to appear higher on the screen.
25:52So in in this case we have liver.
25:56Here in front of kidney and
25:58here's your liver on this view,
26:00and that's closer to the top of the screen,
26:03whereas he had a kidney that's
26:06more posterior and the kidney is.
26:08Yeah there.
26:14You can read that handwriting,
26:15so a position on the monitor has to do
26:18with how close an object is to the probe
26:21top of the screen closer to the port.
26:24Alright, so the game is going to be
26:26an important function that you're
26:29gonna familiarize yourself with,
26:30so you can become comfortable with
26:33how to adjust it when you're doing
26:35scans and how to interpret images.
26:38So think about gamers, the volume of UM.
26:42Uh, electric sound, I guess globally,
26:43so if it gain if the volume is turned
26:46up to five, everything is going to
26:49appear very bright on the screen,
26:51whereas if the game is too low,
26:53if the volume is turned down,
26:55everything is going to appear to duck,
26:57and this is going to affect your image
27:00quality and it's going to affect
27:02your way to interpret images so.
27:04On the first one,
27:05the game is a little high.
27:07In that clip there with the UM.
27:10Kidney over here,
27:12and this is actually it's a screen
27:14over here and this entire area
27:16here is is fairly bright,
27:18so in terms of assessing for
27:20fluid collecting in that space.
27:21And sometimes we look for or not.
27:24Sometimes we we want to look for
27:27pleural effusions when we do these
27:29fast exams you you're going to want
27:31to have a just a slight adjustment
27:33of the game here just to avoid all
27:36this bright artifact down here.
27:38And conversely,
27:39we have a a child here patient
27:41with concern for likely a hit.
27:43The fusion of fluid collection.
27:45And if you're just looking at this area here,
27:48it looks kind of dark,
27:50and that's where we would teach
27:52to look for fluid to collect.
27:54But this is actually an operator error,
27:56not even operator error machine error.
27:58However, you want to call a false error.
28:01It would be a false positive.
28:04This this is a case where the
28:06game is just too low.
28:07You have to increase the game to be
28:09able to distinguish that that that
28:11issue here is actually normal appearing
28:13relative to the hip flexor muscles.
28:15Over here this is the.
28:19So this is learning for another day,
28:22but gained too high is not
28:24helpful and gain too low.
28:26Also is a potential problem.
28:29Yeah, death also is another big one,
28:32so here's a patient with the Halo
28:35colic intussusception on the first
28:37image with a linear linear probe.
28:40You have a debt set at 9 centimeters.
28:43So how do I know it's 9
28:46centimeters for every hash?
28:48Mark is a centimeter, so 123456,
28:50and it comes down here tonight.
28:53So you have a very end
28:55instinct structure there.
28:57Just look like there's something random.
28:59And it's really hard to
29:01make a judgement call.
29:03As to what that could be.
29:06And the depth is adjusted
29:08here to 4 centimeters.
29:09You have a much more crisp appearing
29:12target sign or this is illion here and
29:15this is the outer wall of the cecum.
29:18Here is their target,
29:19more than two and a half centimeters
29:22in terms of the 80 diameter.
29:24So this is really a pilot intussusception,
29:27which could easily be missed
29:30if you're looking at an image.
29:33Not the appropriate depth setting.
29:37Writing color Doppler is a really
29:41important function that we're going to
29:44use all the time when we're doing scans.
29:47So essentially you have a application
29:50where the ultrasound can detect flow. Uhm?
29:54So the the the important thing to remember
29:59is that here in in this first image.
30:04Right here we have a pulsating vessel, right?
30:07So the reason it appears blue is because
30:10the appearance of blue and ultrasound
30:12is flow away from the transducer,
30:15whereas flow to the transducer
30:17is going to appear as you read.
30:19So even this is an arterial structure,
30:22it's regal artery in this case.
30:26The the appearance of the.
30:31Building of that lumen is blue because
30:34the probe is slightly twisted away, so.
30:37If I have a vessel here and I'm
30:42looking at it. With micro this way.
30:46They found tilted.
30:47That way you may have a blue appearance,
30:50whereas if I'm twisting this way and
30:53the the arteries coming from my wrist
30:56to positive is coming from my wrist is
30:59then it's going to appear red. Blue red,
31:04but it's essentially the same vessel.
31:08And so, so that's an important
31:11concept to be aware of,
31:13and we also use color Doppler
31:16flow for inflammation.
31:17So hyperemia is a common finding when there's
31:21inflammatory to tissues and anthology.
31:23This is an example of hyperemia around
31:27a somewhat ill defined appendix
31:29actually on this one clip here,
31:32but this is the partial wall of
31:35independence set within a patient.
31:38Thank you, defend the silence.
31:40So detection of inflammation and
31:43also detect detection of flow 2.
31:47Or away from the train station.
31:51OK, we're gonna do some quick hits
31:53to finish off here for shadowing,
31:55so we have.
31:56And acoustic shadowing,
31:58which is an artifact that's caused by.
32:02Failure of the Soundbeam to pass
32:04through certain tissue.
32:05So in still clip number one we have
32:09acoustic shadowing because there's
32:11gallstones in the global order.
32:13So you have hope sound coming here.
32:16Political structure falls
32:17down stairs and then this.
32:20Dark defect behind the gallstone.
32:22Here is an acoustic shadowing phenomenon.
32:24UM not to be concerned with.
32:26Not to be confused.
32:28Sorry with Edge Artifact,
32:29which is seen right next
32:32to the battery there.
32:34Uh,
32:34and probably a little slightly better,
32:36more clear example would be a heel
32:39foreign body so you have a splinter here.
32:42It looks a little bit right and then you
32:45give off this complete shadow artifact.
32:48So that's some acoustic shadowing
32:50which is an important artifact that
32:52we use to interpret our images.
32:56The next important artifact to talk
32:59about is mirror imaging artifact,
33:01which isn't a normal finding.
33:03Most of the time so.
33:07This artifact is created when
33:10you have a curved structure,
33:12which is a stronger reflector of
33:15ultrasound relative to the object.
33:18It's informative, so on the fast exam
33:22you have typically spleen or liver.
33:25Here you're stronger reflector curved
33:28object distance diagram there and
33:31given the difference in the tissue
33:33interface you have the appearance of.
33:37Liver. That mean the other thing,
33:40but it's really just a mirror
33:42imaging artifact that's created,
33:44which is useful to know because if you
33:46have a pleural effusion or human thorax,
33:49and this is all going dark over here.
33:53So instead of the mirror imaging,
33:55and that you're likely to see is complete.
33:59And collect technical through a collection
34:03there in and pushing his appointment so uhm.
34:07New imaging artifact and another
34:10example potentially would be,
34:12say, a scalp chemo Thomas.
34:15So here we have bone.
34:19It's a strong reflector.
34:21It's curved with the skulls, the scalp,
34:25and this is your scalp hematoma.
34:29In attainment, so that's just Dad is on.
34:32Injuries appreciated over time,
34:34so this appearance here is not in epidural
34:38subdural or a subcranial entertainer bleed,
34:40but it's rather a reflection of this
34:44material behind the bone mirror imaging
34:47artifact that you will need to get dressed.
34:51When you do this skins.
34:53We have posterior up to stick enhancement,
34:56which is a bright or hypoechoic appearance.
34:59At the posterior or far side of a
35:02cystic foods to structure due to the
35:05lack of attenuation of ultrasound beam.
35:07So we have a bladder here and the
35:10posterior wall appears very bright
35:12due to posterior acoustic enhancement.
35:14It's not any different consistency in
35:16terms of the wall there relative to
35:19the lateral side or the anterior side,
35:22but it just looks so much brighter because
35:25of the ocean transmission through that.
35:29And it's important again because of
35:31the possibility for Miss Pathology.
35:34So if you're doing a fast exam
35:37and everything looks very,
35:38very bright behind the bladder, you may miss.
35:42We flew in from the customer period.
35:45He may miss briefly behind the bladder,
35:47so just be cognizant of this artifact
35:51and adjust your game for quoting him.
35:54OK, and two more quick ones,
35:57so reverberation artifact very important.
35:58Windows coming along.
36:00Very important.
36:00We looking at Kirkland bodies.
36:02These are equidistant horizontal lines that
36:05tend to decrease in intensity on the monitor.
36:08It has to do with reflection or
36:11regulation of echoes too and.
36:14From the pros so.
36:16In this case we have the probe here.
36:21And we're looking at a lung tissue.
36:23This is the pleura.
36:25So this isn't a line here and this
36:28is a really great thing here and you
36:32can see the distance between this.
36:35Uh.
36:35And this is the same which is also
36:39similar to the distance between right.
36:42Exactly precisely the distance from
36:44the probe to when the ultrasound
36:46beam hits the floor.
36:48So normal filled air airlines are good day.
36:51OK, this is the type of reverberation
36:54artifact that we assume or that we should
36:57be seeing when there is healthy lung
36:59tissue without any problems reported.
37:05OK, and here's another example
37:07of reverberation artifact,
37:08sometimes called ringdown
37:09artifact or comma tail artifact,
37:11and this has to do with.
37:15And essentially the interface of the
37:18object where the sunbeams were stuck,
37:21reverberating back and forth,
37:23and which creates a deep dive
37:26vertically on the screen.
37:28So here is an image in terms of jugular vein,
37:33and then you have a.
37:36Presumably a needle here that's
37:39coming towards self alumina that
37:41thing so the the needle itself has
37:44two metallic portions right as the
37:46anterior portion and the post here
37:48portion so it ends up happening is
37:51that ultrasound beam gets trapped
37:54between the two parts of that needle
37:57in italic tip and it's going to
38:00create these sort of repetitive.
38:02Verdict never will be racing dates,
38:05so it's going to be down to the machine.
38:09So I'm unlike just the airlines
38:12that are separated by the distance
38:15of the probe to the flora.
38:18This is more of a persistent ping pong
38:21effect within the lumen of that needle,
38:25causing a vertical dive and
38:28you would expect to see.
38:31Bring down the appearance on the screen.
38:35Alright,
38:35so we've made it to the end and I thank
38:40you for sticking through the lecture.
38:44Recap how you can get good images.
38:46A lot of it is going to be practice.
38:49Practice,
38:49practice and more practice.
38:52But you're gonna and impose some
38:54of the important concepts and
38:57understanding of physics that dumb.
38:59Now we can throw in some of these slides.
39:02You're going to pick a good Pro is
39:05choosing the right probe is sometimes
39:07half the battle for for the the
39:09application that you're trying to achieve,
39:12use good windows.
39:13Use fluid filled structures to
39:15see objects that are behind them.
39:17Identify landmarks,
39:18a lot of what we do with pattern recognition.
39:21So if you don't start with
39:24good landmark identification,
39:25you're sort of going on a fishing
39:27expedition to some extent
39:29and adjust the depth.
39:30We don't want any wasted space on the screen,
39:34so we want to maximize your object
39:37of interest and make it as big as
39:40possible without losing any of
39:42the important detail behind it.
39:44Get to know your machine,
39:46you different settings.
39:48Even within a single hospital are
39:51going to have different machines with
39:53different knobs and so part of being
39:56able to be a good cynologist or or
39:59good clinician who include ultrasound
40:01to help care for your patient is dumb.
40:05Getting really comfortable and not
40:07having to sort of fiddle with the
40:10machine is here there in vivo.
40:13Caring for kids and their families.
40:15And and and that's it.
40:19Your friendly pimp Focusin consists of
40:22myself and lichen and Julie Lavender and
40:25will be doing the scanning shift sessions
40:28together and we're excited for this
40:31opportunity to augment your experience.
40:33We do realize this is an optional
40:36commitment on your behalf.
40:38So with that in mind,
40:40we're going to provide an extra
40:42fruitful experience. We hope.
40:46When we when we spend time
40:49together on his gaming ships,
40:51so the the same sheet will be
40:55updated quarterly and dumb right now.
40:58With COVID we're only limiting to 1.
41:01Maybe two rotators on today.
41:05But there's no limit you can do.
41:08Certainly if you're interested,
41:10multiple scanning ships with us
41:12throughout the academic year.
41:14And so solution.
41:16And thanks for listening.