Interpretation of the Adult Chest X-Ray | The Advanced EM Boot Camp Imaging Workshop

all right welcome everyone good afternoon and thank you guys for coming to talk about a subject that's really near and dear to my heart which is emergency radiology it's become my area of academic interest and full disclosure I am married to a radiologist so that may contribute to part of it I cleared all the radiology jokes through her so it's okay and it's like Rick said I think it is a valuable skill and it's really an integral skill to emergency medicine and we wouldn't dream of not interpreting our own EKGs and I don't see why we would dream of not interpreting our own x-rays so we're gonna do sort of a whirlwind tour of plain radiography with you guys and we're gonna start with the chest x-ray and at least my residents can't believe that we're still doing these old fashioned x-rays they're like why aren't we ultrasound and why aren't we cat scanning isn't it old-fashioned technology and in a way it is but it is still incredibly valuable and it's still plain radiography represents the majority of imaging that we get like we're excite it really is the bread and butter or the workhorse of the department and none I think more than a chest x-ray no matter what anyone comes in for it they get a chest x-ray right and part of the reason why I think this is still such a valuable skill is you may be the one who needs to make the read and if you think about what's inside the chest there are a lot of important parts in there right heart great vessels lungs you may have to make a diagnosis very quickly that is potentially life-saving and so as we go through this I want you to sort of put yourself in the radiologists spot there in a reading in a vacuum there in a dark room they don't know the patient you do and as we go through this I'm gonna emphasize over and over again that history and the physical exam can really influence how we interpret these films so our objectives today are pretty simple and I'm going to be the same for all of the plain film lectures we're going to talk about a systematic way to look at these and I drill my resonance on this over and over and over again you need to do it the same way every time because when you don't that's when mistakes happen and talked about some common abnormal findings for some pretty common disease entities that you guys are going to be seeing and I also want to talk about some of the pitfalls because it is sometimes challenging to look at these quick show of hands who here actually has seen plane radiographs like held an x-ray all right that makes me feel a little bit better if our residents have never actually held a film and when patient shows up transferred in they actually have plain films this is what they look like I have no idea what to do with them I don't even think we have a lightbox left in our department chest x-rays in particular even though there's black and white there really are shades of grey and like I said the history and physical exam really influenced how we interpret them and I like to call them the medical Rorschach drawing right so you can sort of squint your eyes and say yeah maybe there's a little pneumonia there yeah maybe they look a little wet whatever it takes to like get them admitted right but you really should be using that history and physical and again you need to be systematic and first things first when you look at it next right and I know this sounds very basic but make sure it's the right patient and I know that sounds silly but in this era of electronic imaging it's very easy to click the wrong patient or click the wrong x-ray so make sure it's the right patient and the right study the next thing you want to do is look at the film markers you want to make sure that left is really left our pack system had a glitch in it a few years ago and started flipping images and somebody almost got a wrong sided chest too because of it so you really would just take a quick look and make sure your left is really left the next thing is you want to evaluate the film technique and what I mean by that is how was that film taken was the patient upright was it a PA film or was the patient supine in an AP film because that alone can have dramatic impacts on how we interpret the film and I'll show you some examples of that the next thing with chest x-rays that you want to do is you want to assess the adequacy and there's four big things that go into it penetration is one inspiration rotation and then completeness are we seeing everything that we need to see on the film penetration x-rays are not a one-size-fits-all dose and so the x-ray tech will dial up or down the amount of radiation they use based on their judge at the patient's body habitus for an x-ray to be adequately penetrated to interpret you should be able to make out the lower thoracic vertebrae through the heart you don't want to see them in great detail like you would with a t spine film because that means the lungs are burnt out and you're not able to interpret it but you should be able to make out the outlines of it the next is inspiration typically we take an x-ray a chest x-ray in full inspiration and the way that we assess for that is we count the ribs so on the right side as you count down the ribs the 10th or 11th rib should be right at the intersection with that number ten is of the heart in the diaphragm of the cardio phrenic sulcus their films that are not adequately inspired make everything squished together it makes the heart look bigger than it is it makes the lungs look more congested than they are and can really influence how you interpret something rotation rotation is actually really important and something I don't think we think enough about in order to assess for rotation you want to look at bony landmarks you don't want to use something like the trachea because it's mobile and things can sort of shift it around you want to look at bony landmarks so you look at the clavicular heads which are here and then you find the tip of the spinous process behind it and it should be right in the middle of that space that means the patient was you know the plate was equal equally placed on the patient in cases where they're rotated what that means is that one lung is in closer contact to the x-ray plate than the other and so that can influence the appearance of that lung field and in this case this patient is a supine trauma patient and when I look at those lungs the right lung looks more Lucent looks darker than the left the left looks hazy to me and in a supine trauma patient that concerns me for hemothorax because it's going to layer up this way this way all right so little things like rotation can actually have a big influence on how the film looks it can also make the mediastinum look much bigger than it is which again in a trauma patient is sort of a big deal and the last thing is completeness you're really going to be able to see everything on the film that you want so oftentimes the costophrenic angles get cut off you guys know this also a true complete extra chest x-ray series is an AP and or a PA and a lateral so you really if at all possible should be getting a lateral chest x-ray as well because a lot can hide behind the heart back there so how do we interpret it so we've gone through it's the right study we've assessed the technique we've assessed for adequacy how do we read these things and there's lots of methods out there that you'll see and that people use I think a common one that's taught is the geographic approach and by that I mean you start at the outside and work your way in or start on the inside and work your way out the problem I have with that approach is something I call the happy eyes phenomenon so all too often what happens as you're looking if you see something obvious you stop you get happy eyes and you don't look at the rest of the film and that's how things get missed the next approach is the targeted approach and this is what I think a lot of us do in practice you know somebody comes in with a fever in a coffee you want to rule out pneumonia you get a chest x-ray and you look at the lungs to look for pneumonia and you may miss the shoulder dislocation the clavicle fracture all the other stuff that could be on that film so the method that I like and that I try and drill my resonance on are the ABCs and you're going to see I use the ABCs a lot in radiology they work really well and the reason why I like this is because it provides you a systematic framework for you to read this to fill in the same way every single time this is a lot of all these cases actually are from my home shop a lot of them were my own screw-ups so I'm happy to share those with you today and this was a case that I had that really resonated with me early in my attending career and it was a really unfortunate 21 year old male he had pretty severe MRCP he had a known C your disorder and he seized and he aspirated right in front of us it was like clear as day he was tachycardic he was - Kip Nikki was hypoxic like he did a good job and we got an x-ray and sure enough when we look at it he's got a big mental consolidation alright so done we admitted him for his hypoxia and the mom kept coming out of the room and she's like something's wrong with my son he's not acting right I know him something's wrong and I was like yeah he's got this aspiration he's got this pneumonia he's he'll be fine shoo-shoo and finally the radiologist came out which you know is never a good sign right they come out they're bright lights are blinding them right he's so you know it's gotta be something serious for them to come out of their room he's like Bob what's going on this guy I said what do you mean he's got pneumonia he had an aspiration he's like yeah I haven't seen any post reductions come by and if you look on the left his shoulders dislocated just poor kid dislocated when he sees and I let him sit there for hours because I wasn't systematic and that really scared me this was like sort of an eye opening case like if I couldn't see this on an x-ray what else am I missing so it really started me sort of down this pathway trying to develop a system in doing it every time and the more you do it the more intuitive it becomes and you don't even have to think about it so the ABCs airway bones cardiac idea steinem diaphragms everything else and by that I mean line and to placement in foreign bodies air under the diaphragm air in the mediastinal space everything else and then f is for fields lung fields and that's why I like this method the most because it's human nature when you put a chest x-ray up in front of somebody they're gonna look at the lungs and particularly like that last case if there's a finding there they just stop and I've seen this over and over and over again if you do this method you look at the lungs last and that way you don't miss anything alright it's also good some cases so this guy comes in 40 year old male pretty healthy comes in with a couple days of fever in a cough and we get an x-ray and we go through our method it's actually pretty adequate diaphragms are a little flappy's a little hyper inflated but he has this big dense consolidation which is pretty consistent with an amount it's what we were expecting to see so now the question is where is it how do we localize these on a flat image and what you notice is there's no right heart border anymore it just merges with this consolidation and the lung and by that I know that the right middle lobe sets up against the right heart there and because I can't see that interface now I know that that pneumonia is in the right middle lobe x-rays I like to say are studying contrasts in order for you to see a border between one thing and another they have to be of different densities so normally you have air filled lung sitting up against dense heart you see a border there now you have pus-filled lung sitting up Ed's sitting up against dense heart and you lose that border and this is what's known as one of the silhouette signs in radiology and it's really a misnomer it's really the loss of silhouette but we use these silhouette signs in this concept of different densities to help localize things so like I said if you lose the right heart border it's typically in the right middle lobe if you lose the right hemidiaphragm it's typically in the right lower lobe and if you lose the left upper heart border it's typically in the lingula so it just helps us localize where these lesions are this guy comes in very similar story and at first glance the radiograph looks very similar right he's got this big dense consolidation on the right but if you look carefully at it you can actually see make out his right heart border pretty well if you follow his hemidiaphragm over towards the heart though you start to lose it and you lose it right about in there and that tells me this is most likely right lower lobe process going on if we take a closer look at it and I know this is hard to project well if we take an even closer look you see this sort of dark branching structure right there so everyone see that that is what we call an heir Branca Graham normally you don't see the smaller bronchi because they're air filled to against air filled alveoli no difference in density there but now what you have is air filled bronchi surrounded by pus filled consolidated alveoli different densities so now you're able to see it and it just really supports the diagnosis that this is most likely pneumonia all right this woman comes in I'll never forget can even picture the room that she was in 65 year old lady fairly healthy she was obese she had the usual hypertension and high cholesterol stuff and she came in with pretty rapid onset of pretty severe left-sided pleuritic chest pain she was short of breath and you look at her vitals she was tachy to the 120s she was hypoxic too like 90% with no prior lung history and this really just sort of came on out of the blue so what are you guys thinking with that sort of story like PE right so we get an x-ray and I took a quick look at it and it does look a little hazy that's mostly due to her body habitus if you actually do go through it is adequately penetrated nothing really serious jumped out at me certainly nothing to explain her clinical picture here's her lateral and again I know nothing at the time really jumped out at me however when you look at her prior from a year ago there are differences there and so if you look at her prior you can trace out her left hemidiaphragm behind the heart here you can't do that today we've lost that left hemidiaphragm behind the heart when you look at her lateral from a year ago you noticed that as you go down the spine it becomes darker it becomes more loosened that's normal today however it becomes brighter it becomes more opaque and that tells me that there's consolidated long sitting back there or fluid or something but given that I can see the angles of her diaphragm pretty well it's most likely consolidated long so this lady has a retro cardiac pneumonia radiology called it to be fair and I didn't believe him because I'm like it just doesn't fit clinically you know the time chorus how she looks that looks pretty subtle to me on plain film so I did go ahead and scan her and again pretty formative case because on her scan you can see this big dense socked in consolidated pneumonia sitting right there with that chest x-ray so it was a great sort of illustrative case for me of just how much x-rays can underestimate the extent of pathology and also how much you need to respect those sort of subtle signs they do actually mean something and by the way it showed it as you go down that's called the spine sign when it becomes more opaque or brighter as you go down the spine that's a spine sign and you got to look for that and respect it when you see it this woman comes in so a 45 year old woman had a couple of weeks a low-grade fever cough and she just didn't look good she looked pretty sick she was hypoxic she was too kipnuk her lungs sounded awful and we got an x-ray and as I look at it it just there's no obvious lobar consolidation and it seems like an obvious huge pneumonia but just everything looks busy there there's increased interstitial markings there everything's sort of hazy now if I were to tell you that this was a 65 year old guy with a history of CHF who went out for Chinese food and didn't take his lasix I could sort of buy that this is pulmonary edema but that story is not what we had we had a young woman with infectious symptoms so that launches you down a whole different pathway as I look I looked at the read and it was your classic you know hedge and so you know absolutely no help but then you have to start to think of a differential what causes diffuse interstitial pattern in an infectious sort of setting and those are atypical pneumonia and the things that we worry about are thing like you know Michael plasmon can do it chlamydia can do it herpetic pneumonias can do this but also PCP and that's in fact what this woman had so this was a new diagnosis of AIDS for her so again clinical picture really matters she didn't present like CHF or pulmonary oedema she presented more with infectious type symptoms and with this pattern you got to start to think atypical they talked about having a reticular or reticular nodular appearance to a particular meaning lace-like or net-like and that just reflects those increased interstitial markings and they tend to be pretty diffuse this was a guy who came in the following month exact same story and again didn't look very good and this is his x-ray and his looks different his on the right you see these sort of patchy white areas the left actually looks pretty good when I see that in an infectious setting you still think a typical pneumonias but you also start to think of some other things like endocarditis with septic emboli can look just like this they these little cottony patches so we did end up going down that route we look for endocarditis but we also sent an HIV in arm and this is another example of PCP pneumonia this is more than nodular appearance that they talked about again in the right clinical scenario if this was you know a woman with ovarian cancer or young guy with testicular cancer these could easily be Mets right so the the historical context really matters so pneumonia we look for things like consolidation for these lobar pneumonia as we look for the silhouette signs so we can help localize them look for the spine sign and respect it for what it is look for air Branca Graham's but realize that the whole other spectrum of atypical organisms has a very different appearance and it's much more diffuse sort of increased interstitial pattern alright this woman comes in sudden onset severe shortness of breath she did not look good and this was her x-ray she there's a lot going on in this x-ray and we're gonna sort of break it down but just general first impressions there was a lot of increased interstitial marking she's got a big heart that automatically with her story makes me start to think is this pulmonary edema things that sort of support that diagnosis are if you look at those vessels in the upper lung fields they're too big in an upright patient gravity pulls the blood down and so the vessels in the upper lung field should be smaller when you start to see them approaching the size of the ones in the lower lung fields that's called cephalization and what's happening is there's just so much back pressure that everything is backing up you're not getting adequate venous return so everything is sort of backing up you see a thickened inter low bar fissure that's a horizontal fissure that's too thick and too noticeable that's a demet assets' full of fluid you see this or to call this peri hilar fullness or fluffiness you're not seeing nice distinct pulmonary vasculature it's just all sort of hazy and this is along the spectrum of imaging findings in pulmonary edema as it gets worse everything starts to weep and become more indistinct other things that support the diagnosis if we take an even closer look if you look out at the periphery you see all these horizontal lines coming off the pleura these are what are known as curly B lines most people have heard that term and what they represent are engorged in demet us inter lobular septa which again is just reflective of increased back pressure and is pretty consistent with pulmonary edema from congestive heart failure so a lot of these things sort of suggest that diagnosis I will tell you this case was particularly interesting to me because I always teach my residents congestive heart failure is really a symptom it's not a disease in and of itself it's a symptom of something something put that patient into congestive heart failure and then this lady she had no history of it she did have hypertension high cholesterol and diabetes the usual and she flashed like at and in her if you look at her aortic arch it's pretty heavily calcified but that ring is not continuous this is actually the most specific plain film finding for aortic dissection is this displaced intimal calcification here that's actually the dissection flap and she dissected down and tori or de Groote and developed acute aortic incompetency and that's what put her into pulmonary edema so this guy comes in sudden onset respiratory distress and as we go through our method airway he's going to endotracheal tube in go down cardio mediastinum that heart is enormous right he has huge huge heart efore everything else he's got piece or pads on him right defibrillator pads somebody was really worried about this guy he's sick so you automatically get some clues just by going through our method that this guy is in pretty rough shape and then when we get to his lungs they're a mess he has a lot of this Perry hilar consolidation if we take a close look at it he's got civilizations he's got an engorged fissure and he actually has curly B lines down at the base he's got those nice horizontal lines coming off which really supports the diagnosis of pulmonary edema it's cases like this where the radiologist really start to hedge and they're like well could be multifocal pneumonia versus you know pulmonary edema and that's again where the historical context comes in all right so pulmonary edema and you notice I'm not saying congestive heart failure because there's a lot of things that can cause pulmonary edema so we can see cardiomegaly but recognize that you can have pulmonary edema without it you look for those increased interstitial markings that's one of the first things that you're going to see sometimes you see a fusion sometimes you don't look for those curly B lines the more you look for him the more you're gonna see him and that should really raise your suspicions for CHF and look for cephalization on that very film all right this gentleman comes in son onset pleuritic chest and back pain right-sided he's a smoker kind of thin dude and you get this x-ray and he's a little hyper inflated which goes along with the smoking history and I know it's hard to see on this so I blew it up a little bit I was worried about a pneumothorax on this guy sort of the poster child for who has a spontaneous pneumo and sure enough when you look up in the apex there's a line there that doesn't really line up with any rib right there and beyond that up in the apex I'm not seeing any other lung markings it's very loosened up there so this is the plural reflection this is the edge of the lung and a pneumothorax the key with this is the guy was upright it was an upright film air rises up it's very different so this one hopefully everyone can see from the back of the room his entire left lung is down and everything is starting to get shifted over this one's pretty obvious but sometimes it's not and plain film we'll talk about in a second actually is not that great for diagnosing this but there are some tips and tricks that we can use to try and if we're really suspicious we can try and see it one of them is getting expert ory films and so I said normally we take x-rays in full inspiration this is one time when you can take them in full expiration and it condenses everything down so it pulls that lung down and it will accentuate a pneumothorax if it's there and again there's a plural reflection right there that we could not see on the inspiratory view another trick that you can use and for those of you who actually have looked at playing films you know that we used to use something called a hot light which was basically a spotlight that you would backlight the film with and you'd look around the edge of the thorax looking for plural reflections and that backlight would make the lines look darker it would make the the lung markings darker so you could see them nowadays with digital imaging if you invert the image and most of your pax viewers are going to have a setting to do that it inverts the image and it will make lines jump out at you in here it makes that plural reflection a little bit more obvious it's also a neat trick too if you're worried about like subtle fractures invert it and sometimes you'll see the fracture line sort of jump out at you so how good is chest x-ray it's sort of the gold the gold standard but it's sort of like the first step when we go to diagnosis well it turns out it's not very good the best is a lateral decubitus film but nobody does that you're not certainly not going to do that on a trauma patient our upright chest x-ray which is sort of our go-to only 59 percent sensitive all right that's pretty poor and then a supine AP film which again most of our trauma patients get it drops to 37 percent which is terrible this is where as Rick allude to ultrasound is really starting to become much more useful but if you don't have that you left with playing phone so that's terrible sensitivities and part of the reason is they look different so this was a bad MVA that came in person was in respiratory distress and when you look at this film you can't see the left hemidiaphragm at all right it's plunging and hazy and indistinct this is what a big normal thorax will look like on a supine film because the air rises anteriorly it rises up in the chest not up to the apex because he's supine and the effect that has is it pushes down on the diaphragm and gives it that deep plunging look to it so this is what's known as a deep sulcus sign the other thing when I look at this patient again it's a little subtle but if you look at his lung fields the left is hazy ER than the right and he's not rotated this guy had a hemopneumothorax it's blood layering up this way that we're seeing the lung through so pneumothorax in an upright patient you're gonna look up at the apex all right in a supine patient look for that deep sulcus sign realize it may not be there a lot of the time now I'm not saying you need to diagnose every single pneumothorax I don't want people taking that message that we need to cat scan everyone because frankly we don't know what to do with some of the small ones anyway but if you suspect it there are some tricks that you can try to look for it this gentleman comes in it's a Saturday night like two o'clock in the morning and he comes in he's complaining of the sudden onset chest pain it's pleuritic he's a little short of breath with it no other medical history and we get is x-ray and as we go through our method we start at the airway as I looking at his cardio mediastinum I noticed that there are some extra lines and up in his neck there are some loosen seized up there that don't really belong there this is pneumomediastinum this is air in the mediastinal space and the lines around the heart are actually pleural reflections being lifted off the heart this film has one of the classic findings for it which is normally the dense heart is fused to the left hemidiaphragm anteriorly so again dense heart dense diaphragm you should not be able to see a border all the way across in this case we do that diaphragm is running all the way across on a single line and what that tells me is that now there's air in between the heart and the diaphragm and the two things that cause that are pneumomediastinum and much less commonly pneumopericardium this was a case of pneumomediastinum so then the question is what was this guy doing and it turns out he was smoking crack which is a very common reason for this on the lateral this is sort of the corollary to that continuous diaphragm sign here you're able to trace that left hemidiaphragm all the way over because there's air in it normally you're not able to do that other things that can cause it it can happen spontaneously it's typically from a forced exhalation against a closed glottis so it happens in inhalational drug use it happens in athletes particularly weight lifters as they're straining I've seen that happens in asthmatics it happens in cases of severe coughing so there are case reports of this and pertussis the one take-home that I want you to take away from this though is if you see pneumomediastinum and there's any hint of vomiting anywhere in the history you want to start to think about Borja syndrome which nowadays is termed effort related esophageal rupture because untreated that causes meatus tinnitus and it's almost universally fatal so if you see new one when you sign them and there's any history of vomiting you got to start to worry and this guy came in he was retching and develops really bad substernal chest pain when I look at him I can't trace his left hemidiaphragm over it's hidden behind the heart and he's got a little bit of bubbly looking things down at the right base there which I don't have a great explanation for so we ended up scanning him and he in fact had esophageal rupture you can see there's the esophagus outlined in air which doesn't belong so summary evaluate for adequacy re for things penetration inspiration rotation and completeness remember to be systematic please please please do it the same way every time train yourself to do that and over time you won't even have to think about it because then you won't miss stuff remember that the technique has a huge implications on how we interpret these is it upright is it's supine and then look for those silhouette signs we can up localize these things look for retro cardiac infiltrates because they can be subtle pulmonary edema is a spectrum of appearance but we now know some of the findings that support that diagnosis and that chest x-rays really are not that great for pneumothorax so with that I'm going to turn it over I'm going to hold questions to the NGS we stay on time but I'll be in the back of the room if you guys have any questions

Channel: The Center for Medical Education

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Length: 32min 16sec (1936 seconds)

Published: Thu Feb 07 2019