Hello, everyone. My name is Pete Montes and I'm a consultant radiologist at Big White Referrals. Thank you for inviting me to speak in the virtual congress.

And we're going to talk today about thoracic radiology. So, how do we go about making sense from those shadows we see? Specifically, we're going to talk about the normal radiographic anatomy of the thorax.

A reminder is always a good thing. Then we're going to See how we can go about reading the whole radiograph. I know the rule is read the whole radiograph.

But the problem is nobody tells you how to go about. So I will give you a few ideas of how you can do that and feel free to use them or not if they work for you or not. The rule is, look at the whole radio work.

We're going to talk about land patterns, the confusing topic, see how we can easily identify them and see what is their use and limitation. And then we will finish a little bit with a few mediastinal and plural abnormalities that we see commonly in practise. So you are familiar when you see them to be able to recognise them.

Why do we need to look at the whole radiograph? Always a question I come across. And the reality of the matter, and you know that from your experience is we cannot always predict the lesions based on the radiographic signs, on the, sorry, on the clinical signs.

So sometimes we have clinical science that too general, you know, my animal is not well enough. It falls a little bit down, his appetite is down or he's coughing a little bit. That does not necessarily tell you exactly where the lesion is.

Or sometimes we get some lesions from the history, but we find other lesions that we didn't expect. It would be embarrassing, for example, to see the chronic bronchitis. And miss a big mass in the vertebra simply because at this stage the animal does not show any signs.

And of course, we always have diseases like a trauma, for example, or traffic accident, but you really don't know exactly where the abnormalities are going to be. So it's always a good idea even if you have a clinically, you think the lesion in a specific organ or area, make sure you also check the other organs and areas there. I recommend to people to go systematically and I insist on actively looking at the organs.

You know, probably we all had our experience sometimes as students especially or some of us, maybe even as vets, looking at the radiograph, gazing around, not looking at anything, somebody walking across the corridor. Looking at the radiograph and pointing to a tumour saying that's a nice mass. And then we spent half an hour thinking why we didn't see the obvious.

And my answer to that is because we were not actively looking, we were gazing. We were looking at the radiograph expecting something. To drop out You know, and that's why I insist to people, make sure you actively look.

So when you think of an organ, look to that to see if it is normal or abnormal. When we find an abnormality, try to be as specific as possible, exactly where anatomically it is. That may be possible in some situations.

In others, it may be in one or two organs that happen to be in the area. Don't forget radiographs are flattographs. Sometimes you cannot just pinpoint, be comfortable with that, consider both options.

At the end, we have to arrive at an appropriate specific diagnosis. And contrary to our comfort zone, if you like, it may not be just one disease. Again, be comfortable with that.

You know, radiography doesn't have to be the last thing we're going to do on the animal, and we have to think what's the next step. Before I give you a way of going around the radiographs, I will give you two tips. Tip number 1, radiographic signs.

Whenever you find something on the radiograph that looks abnormal, or you think it may be abnormal, but you're not sure or you're not sure what it is, or you're not even sure. If it should be there or not, or whatever, something that you cannot categorically say it's normal. You just stop and describe it using the radiographic signs.

And they are number, size, shape, location, marination, radio positive. I repeat. Number?

Size, shape, location, marination, radio path. And you say, why? Because our brain, as I say half jokingly, does not see.

Our brain listens. So we have to be extremely specific to information we give into our brain to think logically. Or as my supervisor used to say, rub is in, rub is out.

So we try to avoid that at all costs. Think of this example. Somebody tells you there is an opacity in the cranial thorax.

How many things you can think with a description. Now let's be more specific. There is one.

2 centimetres in diameter. Around it Well marginated. Soft tissue opacity.

In the left cranial lung lobe. Suddenly, it's not just an opacity in the cranial and the thorax. That could be meistinal, it could be lung, it could be wall, could be bone, it could be many things, but here it can be many things.

It is in the left cranial and lobe. It is around it. It is soft tissue passing.

I'm pretty sure you all are thinking something far more specific than the general things you were thinking with an opacity in the cranial thorax. And that is why. You need to use radiographic signs.

Every time you find something that you cannot categorically call normal. Tip number 2. Be specific on to what radiographic capacities we are talking about.

OK. We only have 5, gas. Fat, soft tissue, bone, metal.

That's from most lucent. To most opaque. And we can see that in every radiograph.

So there is no excuse. And we can actually look and decide what opacity it is, and it's extremely important because of course if I told you that this nodule opacity was metal. Or was mineralized, you're going to think other things that you wouldn't think when I told you it's soft tissue.

So avoid just saying opacity. That's tip number 2. Say specifically what opacity.

And now that we know every time we find something that we don't. We can't for sure call it normal. We use a radiographic signs.

And when we come to radioplasty, we use a specific opacity, gas, fat, soft tissue, bone, or metal. I can show you what I usually recommend to my students. So, I always say to them, go organ.

By organ. That's what anatomical method means. So you have to look in a thorax or a book and say, OK, which organs do we normally see?

Which organs we may normally see and which organs we shouldn't normally see. Put them in whatever list you like. You can go from head to toe, top to bottom in circles, centre to periphery, periphery to centre.

Honestly, nobody cares how you're going to go as long as you examine the whole film. Then the whole exam, the whole study you have available if you have more than the films. So organ by organ in whichever.

Or you like to use. Number 2, when you find something that you cannot call normal, can be definitely abnormal, possibly abnormal, I really don't have a clue. Use the radiographic size.

We said number. Size Shape Location Margination And radio opacity. And when we come to radio opacity, we have to be specific gas, fat, soft tissue, bone, or metal.

Then we need to think what's the structural change. So what has happened, for example, in this land is not loosen anymore, it's soft tissue pass. And we, we need to see, think simply.

So for, in this example, lung doesn't have a loosen appearance, the soft tissueacity. It can be because air has left the building. It's not full with air anymore and that's why soft tissue plastic.

Otherwise it will be loosen. What can a place there? Keep it simple, fluid.

Or cells. And this is the actual structural change that happens in this example. Then we have to think type of pathology.

You say pathology, wait a minute, I hope we qualified. We have, don't have to think pathology anymore. OK, I know sometimes it's tricky, but I'm not talking the detailed pathology.

All I'm saying is in our example, for example, is fluid. What fluid do we know, edoema? Haemorrhage But What cells do we know?

Inflammatory neoplastic? This is the type of pathology. Now that we have set that up, the first differential diagnosis.

The long one. It's already said, Why? If it is edoema, we're talking about pulmonary edoema.

If it is haemorrhage, we're talking about pulmonary haemorrhage. If it is pass, we're talking about abscess. Or pneumonia, or both.

If it is inflammatory cells, we're talking about pneumonia, neoplastic cells, we're talking about neoplasia. Now it's the time to combine this with what we know, what breed, what animal, what age, what signs we know, and narrow it down. Sometimes we can narrow it down to one.

But a lot of times it will be more than one differential diagnosis and that should be OK. We just put them in order of most likely to least likely. And we have more than one, next step, what are we going to do?

Which basically means what study will either give me the answer to what I'm thinking. Or will exclude the majority of my differentials. So What I recommend to you, and feel free to use it or if it doesn't work for you.

Don't, just make sure you check the whole radiograph is go organ by organ. Honestly, just by doing that, your radiographic interpretation will improve dramatically overnight. Find what you cannot categorically call normal and describe it using the radiographic signs.

Number, size, shape, location, multination radio positive. When you come to radioposity, be specific. Is it gas?

Is it fat? Is it soft tissue? Is it bone or is it metal?

Then think structural changes, simple stuff. What has replaced the air like fluid and cells, for example. Type of pathology.

It structural change will provide you effectively a cause, and that cause will give you a differential diagnosis. And now it's the time to combine with what you know. Arrive at the diagnosis, if it is one, well done, but many times it wouldn't be just one.

Just make sure you put it in most likely to least likely. And then think what am I going to do next? What's my next step but either will give me the answer or exclude the majority of my differentials.

Now that we've been through that, there are always some questions, for example, What if I do a clinical exam, I have a suspicion and I think it's a specific area or organ I need to check. Can I not start with that area? Absolutely.

Go ahead and do it. But don't forget when you finish there, either you found what you're looking for and that's very important, or you didn't, you check the whole radiograph. Just to make sure you have missed something else potentially even more important for the animal.

Now the question is, when we have some obvious lesions or something that is obviously abnormal. Do I just follow my system or start with the obviously abnormal and then follow my system? Whichever works for you.

If it was me, I usually start with the obvious and then examine the rest of the radiograph following my system. But if you are the very organised person and you can go your system without being having one eye on that lesion, by all means do it. I can't.

If something stands out, I'm dying to see it. So I usually start with that and then check the hell of the rest of the radiograph. If that doesn't work for you and you want to go always in the same order, by all means do it.

Then all you have to do is just check the whole radiograph, OK, and be clever about it. Here is an X-ray, right lateral view of a normal thorax from a dog. OK.

Quite inflated, you can see that. What I would have done in any radiograph like that, first of all, I will check each organ in all the available radiographs. So I'm not going to go right lateral this, left lateral this, with the, with this.

Why it's a three-dimensional world called. So make sure you check organ in each organ in each and every view you have available. Number 2, I know for myself from experience that if I don't start from the periphery outside the thorax, I will forget to do that.

So I tend to start from the periphery just to make sure I didn't forget to check these subcutaneous tissues, spine, ribs, sternum, cranial abdomen, diaphragm. I'm pretty sure I will check the inside, but I want to make sure I will check also the outside. So we start there and whatever I have something I can count like vertebrate ribs, I will.

So I will go 123, and you will say why. It's not before if I find, because if I find 14 ribs, you know, something exciting has happened. It's just that every time I count, I focus my eye, so I will see that particular vertebra.

OK. The same for sane. The same for the ribs.

Because that way I focus my eye on that. I will check the liver, the cranial abdomen, the stomach. Is there anything else that I can check?

I can check the diaphragm. And then I will go inside and say OK, let's see that right here. Carinami this this vein soft tissue pasty calleddavina cava.

Aorta cardiac silhouette. And I always use the term cardiacs. I like to remember that it's not just heart, it's also pericardium in the off chances speak.

Then I will see the lungs, OK, the lung fields, cranio ventral, middle, and called the lung fields and check also artery, bronchus vein, the triad. Arteries are cranial, arteries are lateral. One way to remember where the artery is.

So from the triad, the most cranial artery, the most lateral is artery. And I will check the area of the oesophagus. Can I see it?

Can I not see it? And at the end, I always ask myself, have I checked everything? And I will do each organ in every of the views.

Here is the left lateral again, a little bit different diaphragm. We're going to see the difference later on in the codavina cava, but I will check each organ moving from the one view to the left. Here we have a little bit of gas in the oesophagus, which is something we commonly see a little bit without particularly worrying.

And that's the DV. Here, we can actually see the cranial, middle, caudal, and accessory lung lobe. And then on the left, we only have a cranial with the cranial part and the caudal part and the caudal lung lobe.

So we can check each individual lung lobe clearly without the separate position we have on the lateral view. Here all three together again with the right lateral on the left, left. And dorsoventral on in the middle.

Now I told you about the radiographic opacity, so. How can I see them? Gass.

The black thing in the lung fat. Look at the falsiform fat below the liver soft tissue, liver. Cardiac silhouette, bone, any bone you like to pick from ribs.

If you have the humerus, use the humerus, steebra. And you will say, OK, now we got you. Where is the mineral?

Mineral. It's usually the market. Because it's the most white bits.

So if you have a right or a left mark in there, that's mineral opacity. So in each and every radiograph, you can see all five opacities gas, fat, soft tissue, bone, and mineral. And that's why you can look carefully at the lesion you have or the area you're looking and describe specifically what opacity you are looking at.

Here is a cut and basically that's the right lateral in a cut again, same system in a way, again, I will start from the periphery. Of course, checking every organ in its you count the vertebrae, count the ribs, count the ertebrae, check the shoulder if it is in and the scapula. See the cranial abdomen with the stomach, the liver, and intestines, if we can see a little bit of kidneys.

I will check the diaphragm. Then I will go inside and they will see the trachea, the carina got the exil ran this kind of area ordavina cava aorta lung. And I can see artery bronchus vein, the vessels inside the lung.

Don't be surprised, identities are quite common, especially in the United Kingdom, so we may see them over there and I will see each organ in, in every view. The important thing though, you have to pay attention in cats is that the lung comes normally a little bit away from the spine in the cordo dorsal a. That's normal appearance for cats, not for dogs.

In dogs it goes all the way up. And here we see a little bit of an upward bending of the sternum, very commonly seen cuts. It's called pectus excavatum, can be very mild like here, can be more severe, and it can be incidental.

Now, let's see its individual area. Chess wall, basically it has multiplayers. It's soft tissue, bone and fat.

It's superimposed on the cardiac silating lung structures on the lateral view and some parts we may see them tangentially and don't if you like. So look carefully. Here I have a dorsal ventral view, sorry, a ventral dorsal view.

Let's delete that ventral dorsal here, dorsoventral there. You can see the angle of the ribs is not the same. One thing you can immediately notice and get an idea.

Another very important bit about the ribs is the cartilage. It gets mineralized and especially Jondro dystrophhoic dogs. It can be very early, even before a year.

Now that is commonly seen and it's incidental. And you'll say, why do you mention it? Because when the rib cartilage gets mineralized, most people, they have the idea it starts on the one end, let's say that's the rib, and then continue to get mineralized all the way down.

Which is not actually what happens. What happens is we have islands of mineralization. So we may have mineralization then an area not mineralized and then an area that's mineralized, and then again an area not mineralized and then more mineralization.

And people who don't know that, they see the gaps and they are wondering who do I have? A fracture of the cartilage. So if that's your worry, I will say always look if the areas are aligned.

If they are, it's likely mineralization. If they are not. Then You know there is a fracture in that area.

So because the reefs get mineralized from islands of mineralization, you may end up having in between areas, not mineralized, make sure you actually check the alignment before you conclude that they are fractured. And always check for fractured ribs. You'll say, how am I going to do that?

It's always tricky and all of us have been in the unpleasant situation to miss a very faint one. So what would be a good way of going? There are two things I employ.

One, you already know. It's actually counting the ribs. I will do that on a lateral, I will do that on a DV from both sides because really they are quite tricky to spot even when they are quite displaced.

Another thing that I, and you can see here, for example, I count the ribs. And when I come to the 7th, where is the rib? So eventually just checking the ribs doesn't only allow me to see fractures, it allows me to say, OK, this extra plural mass is most likely originating from the rib.

Why? Because it's missing. So something has destroyed it.

Another suggestion I do to people for some words, some, they don't find any benefit, feel free to use it, is put the radiograph in an orientation you are not used to look at. For example, usually we put the radiographs with the head pointing to the left and the right side pointing to the left. Now, if we're used to see it like that, the ribs bent with the background, so we may not see them clearly.

So what I say is Flip it. Suddenly, because your eyes not used to see it that way, the ribs stand out more and you can evaluate them easier. It may work for you, it may not.

All you have to do is flip the radiograph in an orientation. You are not accustomed. To look at.

OK. And that is Why it's helpful for your eye to look at the its more clearly. Some people, they find that useful.

That's another trick and you say, how can I do that digitally. Digitally, you just press the reverse button and it will flip the image on your screen like it would have been flipping the radiograph with your hand. Diaphragm, how does it look differently?

On the right, I have a right lateral and on the left, I have a left lateral as you can see from the indicators. And my advice is always put indicators, especially on a ventral dorsal or dorsoventral. And not because you may forget which is the right and what's the left, but there is one condition that the only way you can diagnose it is if you know truly which is the right and left side on the animal.

And that is called CIOsus. Which means animals that all the organs are the other way around. They're totally normal.

But of course, the only way to diagnose that is if you have a market. Otherwise, you just say, oh, somebody put a radiograph the other way around, you just flick it. So left lateral crust of the diaphragm creates a corner Codavina cava enters the second one and the gas in the stomach, if you have a little bit will be in the pylorus at the bottom.

Right lateral crush of the diaphragm parallel to each other. Codovina cava enters the first one, gas in the stomach will be at the fundus and body. Remember, gas always goes up.

This works for thorax. Don't try to use it in the abdomen. The angle of projection is different.

Also, it will work in most normal radiographs, but if it is abnormal, maybe you have displacement of the diaphragm, so you can't use it there. Now Remember, the crust that is dependent always goes cranially and that's why here the cranial crust is the right. That's why you see the Codavina cava entering that while here the cranial crust is the left and that's why the Coda vena cava passes the left and goes into the right to pass through into the abdomen.

So this is a quick way to distinguish which one is the left and which one is the right. Don't forget CITES investors. So always put markers on the radio.

Ventro dorsal and dorsoventral. In the ventro dorsal, you have what we like to call the Mickey Mouse appearance. I suppose they assume here are the ears, and that's the head.

So you have the three bulges, the 3 or stooges as I like to call it, and usually you have a gap between the apex of the heart and the diaphragm and that will make it the ventro dorsal. Also, the gas in the abdo in the stomach is going to be in the area of the pylorus mainly. In the dorsoventral, you have the diaphragm having a uniform outline.

What we like to call a policeman's hat, but that's in the United Kingdom, but the policeman's hat are quite tall and curvy. And the cardiac silhouette seems to overlay the diaphragm. And if you have a little bit of gas in the stomach, it's usually on the left.

Which is the founders of the stop. So you can clearly distinguish the the from a DV view. Except only also the ribs that you already know the angle of the ribs.

Inspiration usually we manage to get a diaphragm. Below the 12. Thoracic vertebrae, then we know that the earth is most likely an inspiration.

Another thing to notice is that we see only the cranial part of the diaphragm. We do not see the caudal because caudalli, the diaphragm which is soft tissue, silhouettes with a soft tissue lever. Plural cavity, it's a potential space.

We don't normally see it. Sometimes when we see lines between the lobes of the land. Because we happen to hit them 90 degrees that.

Otherwise, unless they are thickened or there is some fluid in there or there is a lot of fat in that animal, we will not normally see them. Medsinum is formed by a reflection of the parietal pleura and contains many, many organs. Some that we see right here.

Heart, cardiac silt, aorta, and some of the major branches. Some we don't normally see like oesophagus, thoracic duct, lymph node, and nerve. Oesophagus we see more often than the rest.

Because it may have a little bit of gas, especially sedated or anaesthetized animal or this sneak animal that they swallow air, but we don't normally see any of the other smaller vessels in their lymph node nerves. So what part of the middle time we do see? Not really much.

We see this kind this time, which is the opacity below the track here and we can see it here between the land. We can see the cranioventralmisinal reflection. And we see the code of ventermidisinal reflection.

That's all, really. One good rule of the thumb we employ unless the animal is really, really fat, is that the width of the cranium mestinum should be less than twice the width of a vertebra on a dorsoventral or ventil dorsal view. That's a good way, a good rule of the thumb to use unless you have something like a bulldog, a very, very fat animal that it can have wider because of a lot of fat in there.

Lang patterns. The Taj Mahal or if you like the tricky part of the land. Most people, they get really confused at recognising land patterns.

So let's simplify it. We have 4. 45.

Bear with me. We have bronchial where it affects the bronchi. We have vascular where it affects the vessels, and we have interstitial.

Or alveolar when it affects the pareheim of the lung beyond the bronchi. OK. And some people, if I have interstitial and alveolar, they call it mixed.

That's why the 4 can become 5. Now, it's quick, quick way to learn buttons. If it affects the bronchi, which means the bronchi are thick, dilated, more visible like when they get mineralized in age-related changes, then that's bronchi.

If the vessels Artery or vein are big, small. Then it's vascular. When we have opacity in the lung, it can be interstitial or alveolar.

In this situation, we have to look carefully in the affected area. If we can see the vessels in the affected area, it's initial. If we cannot see the vessels, it is alveolar.

OK. Of course, some people will say that is wrong because in early alveolar, we can see the vessels. It's a small error I'm happy to make if it simplifies things.

Why? Because no matter what disease affects the lung, it will start as bronchial. Or peri bronchi, for example, edoema.

Then it will become interstitial. And at the end it will become alveola. So the progression of the disease is in the top to bottom direction.

And when we treat it and hopefully it works, it goes from bottom to top. So if I treat pneumonia and it was alveolar and that becomes intesticialura, we're doing better. If it becomes bronchial perirronchial, even better and then it turns to normal lung.

While if it gets worse, it will start from bronchial or perirronchial. Go to intesticial then to alveolar. So the beauty with the patterns is it tells me how bad it is.

It gives me a sense of progression. What is not So good it's not specific. So because the land will always, no matter what's the aetiology is on the same way.

We cannot say for sure that it's only one thing. So they are not specific as far as the diagnosis is concerned. And you, and that's the other thing confusing about the patterns is that sometimes you go into a radiograph and you find a little bit of bronchi mildeesthesia and inicia and a lot of alveolar or you have one pattern that stands out much more than the others and that's the usual pattern we describe unless we have more or less equal measure of interstitial alveolar, in which case we can say mixed or we can say mixed intersicialentalveolar pattern.

So, if it affects the bronchi, it's bronchi. If it affects the vessels, it's vascular. If it affects the land parenchyma beyond the bronchi's interstitial or alveolar, then we look carefully if we can.

See the vessels we call it intesticia would still be a little bit of early alveolar, live with it. If we cannot see the vessels in the affected land, it's alveola. Now, let's talk a little bit more specifically.

Here is a small drawing to show you normal land. Mineralized bronchy so we can see the walls, but they're still quite thin. Thick bronchy, so the walls are quite thick and dilated bronchi.

The, the bronchi do not appear to taper or become smaller towards the periphery. They stay either parallel or widened in circular or cylindrical bronchitais. All of this indicates bronchi pattern.

Let's see how they look in real life. That's the mineralized broncos. We can see the world, it is opaque, but it is still quite thin.

Here is the thick bronchial wall. I have the lumen in the middle and you can see the wall being quite thick in the periphery. And on the right, I have a malveolar pattern just to show you the bronchi and see how bronchiectasis makes the bronchi not to taper or become smaller towards the periphery.

It looks like it doesn't become any narrower as we go down the road. Bronchiectasis is not really A disease in its own right. It's the end result of any lung disease that is untreated or the treatment doesn't work.

So hopefully when it's treated it will reverse, but how much we don't really know. Here is a cat with a feline asthma and you can see all these little thick bronchy throughout the landfills. Very, very typical.

Bronchial pattern is as simple as they come. Basically, if they're not thick, we have to think mineralization, which is an age-related change, so don't lose your sleep over that. It can be bronchitis, allergic or chronic.

And some books, they include peribronchial cuffing. What is that? That is truly institial pattern that is around the bronchi.

So you have the bronchus and then you have a little bit of opacity around it in the early stages of the disease. And that may, may make it look as bronchial pattern. That's why they include it in the differential of the bronchial pattern.

So bronchi pattern as far as differential is concerned, comes as simple as they can. I test alviola, we said if that's the normal land. Institial, I can see the vessel alveolar I cannot.

And in alveola I have two stages, the early, where the bronchos still contains air, and they call that air bronchogram. But if nothing happens then it gets worse, the bronchi will be flooded also or filled with cells and the whole land globe will become opaque. OK.

We said it's not 100% because in aerial dealer we can still see the vessels but live with it. The error is minor and to avoid confusion, I'm quite happy to have a cutoff distinction. Here is interstitial pattern in a dog.

You know, We can see it and if we look carefully, we can see the vessels. We can see the zoom in appearance and we can see the various vessels inside the increased capacity land. That will make it easier.

Nodular, let's make it simple. Whenever you see lung nodules, it's interstitial pattern. So if you want to be funky, you can call it nodular interstitial pattern and you will sound very scientific.

It can be micro nodular like here, a lot of nodules throughout that may give you the impression in areas that you may have alveolar because they are one on top of the other and make the whole lung look very, very opaque. So what do we think with interstitial pattern? First time I saw the differential for interstitial pattern, I really, really got scared.

I'm thinking if you go into the books, you will see hay interstitial pattern, unstructured interstitial pattern, reticular interstitial pattern. They have various description. Keep in mind the hazy reticular is more of a description of the appearance.

It's still interstitial pattern. So, first time I saw them, I was like, oh God, I'm not going to remember that ever. But after looking more carefully, I noticed that if I exclude artefacts, for example, expiratory reviews.

You know, and exposed radiographs. Then I can narrow it down to pneumonia, edoema, haemorrhage, neoplasia of any cause. So I thought, OK, that is something I can remember, I can live with.

So whenever I see in the pattern, my four main differences is pneumonia, edoema, haemorrhage, neoplasia. Now, what if I tell you that in the dog and only in the dog, cats are not small dogs, so only in the dog. Edoema and haemorrhage are usually called the dorsally.

Pneumonia is usually cranioventral or ventral if you like. Neoplasia can be anywhere. So for the dog, based on the distribution of where the pattern is, I can put some differentials more than others.

Furthermore, pneumonia will take a while to be treated. To show radiographic changes, it can take 3 to 4 days. You may give antibiotics, they may work.

The animal is fine, happy, jumping here and there, but if you take a radiograph 24 hours later, I doubt you will see any changes and that will be confusing. Pneumonia will take 3 to 4 days to see the geographic changes. On the other hand, edoema and haemorrhage can change within hours.

You can have edoema because of heart failure, give diuretics, and literally within 4 to 8 hours, it has improved. Maybe within 24, it's totally disappeared. So, edoema haemorrhages, they change quickly.

Pneumonia will take place. That's another factor you can use to decide whether, you know, something is most likely pneumonia or edoema or haemorrhage. Keep in mind the distribution is only for dog.

Alveolar pattern, alveolar pattern, we can see like in this dog with pneumonia. Increased opacity in the lung and in the affected area, we can't see vessels, but in the early stages like here, we can see air bronchograms, air within the bronchi. At a later stage, this will totally fill up and you may have areas with no bronchograms and give it time, if it gets worse, these bronchograms here will also disappear.

Now, differential of alveolar pattern will be like the intesthesia. So it could be pneumonia, edoema, haemorrhage, or neoplasia or whatever cause. And for the dog, distribution will be similar.

Pneumonia will be usually cranio ventrally or ventrally, edoema haemorrhage called the dorsally. Again, edoema haemorrhage resolved much faster within hours. Pneumonia needs 3 to 4 days.

And you will say, wait a minute. Here it looks much bigger. Not really, because let's take the localised pneumonia, edoema, haemorrhage, no pleasure.

Sounds familiar. Now, of course, when the lung is collapsed, of course it will be more opaque. You wouldn't see any vessels, so it looks alveolar.

Cases of drofilariasis or pulmonary infects, we have to think of with alveolar pattern. If we get diffused alveolar patterns, we take an X-ray and it's the nightmare of every vet, a very dismayed dog with very white lines that they look very alveolar. Again, pneumonia, edoema, haemorrhage is in the game.

You can even put further neoplasia if you like, but of course, you also have to think to other conditions that they include there, near drowning and smoke inhalation. So when you see a general change in the land, think to ask the owner. Was it near the river or maybe his animal dropped in and then came out, maybe we had the drowning experience or it was in a fire and that will help you and that's why I include them here in the differential.

But the basic differential has not really changed. And of course, it hasn't because we said patterns, basically, they follow the same order no matter what is the cause that affects the land and that's the drawback, they are not specific. Here I have a dog, very, very distinct.

It came one day. You can see this almost generalised alveolar pattern. It also has its min of pneumothorax.

We'll see that later. This dog was given frosemide diuretics, and look at that 16 hours later. Cleared almost totally.

If that was pneumonia. I wouldn't expect such a quick response. 16 hours later it will be more or less the same, while here it has cleaned, including a little bit of the humans we saw before.

So basically, keep in mind hemorrhas, edoema, they will change quickly. Pneumonia will take a few days. Vascular pattern.

Here I have an X-ray. We can see the artery and we can see the vein. Remember, arteries are lateral, arteries are cranial.

We assume the in between is the bronchus. And you will say, how do I know these are big? Why they are not normal.

The rule of the thumb on a dorsoventral or a ventral dorsal view is going to the 9th rib, let's say that this is the 9th rib, since this is a close up. We measure the weight of that rib. And we compare it to the width of the vessel as it crosses that rib.

So we will measure the artery here as it crosses the rib. It should be the same or less. In this example, of course, they are humongous.

So I don't think anybody has any doubts that they are much wider than the width of the rib. And you will say, what about the lateral view? So, here is the lateral view.

How am I going to measure the vessel? We go to the proximal 3rd. Of the 4th rib.

And that width will be, as a rule of the thumb, the cutoff point for the width of the vessels we see in that view. They should be equal or less to the approximate 3 of the 4th rib. So what do we think if only the arteries are enlarged, this part, the lateral or the cranial.

Then we think pulmonary hypertension. We can get that with the right to left chanting PDA filariasis. If it's only the veins large, so from the triad, the most medial or caudal part on the lateral view, then we think congestion due to mitral insufficiency because basically they finish in the left atrium.

If like in our example here, both artery and vein are enlarged. Then we think over circulation could be over hydration commonly seen sometimes we give too much fluid to the animal, but we also think left to right shunt. And you will say when it's small arteries and veins, what are we thinking of?

And probably you were thinking, wait a minute, mate, you told us about big. You didn't say a thing about small. I'm afraid I don't know of any rule of the thumb of how small it should be, but when the arteries and veins are small, They are almost like a line.

So the whole lung looks very, very loosen. So you have, when you have small arteries and veins, you look at the X-ray and you think, wow, this is burned, this is overexposed. But then if you look carefully, you will see except the lungs, everything else looks proper for a thoracic.

So that's how you realise that these arteries and veins, they look like lines. You realise they are small. You can see that with hypovolemia shock or unfortunately for the dog with the trilogy of Falo.

So here are some ideas of how to interpret the vascular pattern. Just quickly to recoup on the patterns because a lot of people get confused. By the way, you don't have to use patterns, you know, you can just say it's an opaque land.

That's fine. I like to use patterns. Why?

It tells me how advanced we are in the disease. Plus, using the distribution, remember, especially in the dog called the dorsal cranio ventral. Unfortunately, that it can be anywhere.

It gives me kind of an idea of what to put first in my different and what to put second. So if the bron here affected, think brown here. If The vessels are affected, think vascular.

The confusion lies to when the land beyond the bronchi is affected because it can be interstitial or alveolar, and they both look increase of tissue acity. So look at it. Can you see the vessels?

If the answer is yes. Call it inesthesia. If the answer is no, you cannot see the presence in the affected area, call it alveolum.

And you will say Eli alveolar, as we said before, shows the vessels, live with it, smaller to make than to look at it like oh God. And don't get confused if you call it Algeria and you say, but it has also grown here, it would. Because every lung condition will go that from bronchial peribronchial and will expand to alveolar and when you treat it, it will go the other way around.

So don't lose your sleep because yes, you have alveolar and you have a few bronchitic you should. Because not all land globes have the same advancement within the disease. I hope that is clear.

And let's go to the opposite now. The land looks loosened. If it is focal, we have to think bulla.

Loar emphysema, pulmonary embolism, because the vessels will be small with embolism. If it is the whole land before you jump the bandwagon, that is something really, really bad, think overexposure, weight loss, overinflation. So yes, we gave the correct exposure if the dog had the full weight, for example, but so lost so much weight that for this dog is basically overexposed.

Could be, of course, hypovolemia because the vessels will be smaller. Air trapping or emphysema. Here how bule looked like.

Thin walled gas field. And here we have 3. That we can see.

They can be congenital or they can be acquired. The fact that we saw them means nothing. This dog can actually breathe normally, but we make a note of them because if they rupture, we go to pneumothorax, and it's good to know that the dog that developed pneumothorax had pulmonary Ebola because we would be faster at reacting and thinking ruptial bullet than if we didn't know that.

Calcified lesions. So we see bone lesions in the lung. It could be focal, multifocal or it could be also the whole lung.

When we see a lot of mineralizations throughout the land, it can be the bronchial walls. Can be pulmonary heterotopic bone formation. They used to call these guys osteomas.

So basically, yeah, it's kind of mineralization bone within the lung incidental. We avoid the thermostoma, it confuses sometimes people think tumour. Could be granulomas, could be metastatis, metastastromostosarcoma, or a primary lung tumour, if you like, or quite commonly could be aspirated barium sulphate.

They try to do for example upper gastrointestinal study, or esophagram, and it went the wrong tube. If it is throughout the land. We have to think hyperadrenal cortices.

Hyperparathyroidism. Chronic uremia? Or we don't have a clue, also known as idiopathic, which translates to it causes itself.

It's a useful term basically to say that we don't really know the cause. Here is bio master given by a friend of mine to remain anonymous. The good news is the dogs survive, but you can see how you get this alveolar pattern with mineralization throughout the lungs because barium sulphate gives you this capacity.

Now, if you wait a while, the macrophages will take all this barium into the tracheobronchial lymph nodes and maybe you will see some in the lung. It will take a few months. So if you see mineralization and tracheobronchial lymph nodes and it comes later on, don't lose your sleep.

OK. Basically It can be before because the macrophages, they take the contrast into the lymph nodes there. So now that you know that can happen, next time you see it, you're not going to get on that.

Sometimes we see these little bones that they are, if you look carefully, quite angular, this boneopas is usually in the periphery of the lungs. This is what we call pulmonary heterotopic bone formation. They have been called pulmonary osteomas and now they even call them idiopathic pulmonary hyperstosis.

So these are all terms have been used for this thing, effectively an incidental finding in the lungs, but because of the They look, they may be confused with metastasis. So you have to be careful. If they look kind of angular when you look carefully and they're mineralized, you know, don't jump to the conclusion they are metastasis because it could be heterotopic bone formation, which is incidental.

Pneumothorax Basically, with pneumothorax, we need to be able to recognise it immediately and we have a space between the sternum and the cardiac silhouette on the lateral view. We see the lung away from the wall with loosens in in the periphery and we have increased lung capacity because effectively it collapses. It has less air, less volume.

We have to be careful with tension pneumothorax, especially when the diaphragm is flat, because then we don't care what's causing pneumothorax. Job #1, drain the chest. Job #2, look what possibly has caused this pneumothorax.

And here we can see the air, you can see this tension in the diaphragm and you can see that the pneumothorax is mainly on the left side, not so much on the right. Everything is actually shifted to the right. And now the question is how do you know this is air and not a lung?

And that would be a very important question because in lung, I have vessels and I have bronchi. In air, I just have the lucency. There are no vessels and there are no bronchi.

So if we see lucent area, gas lucency. Without Vessels Or bronchi, it's not lung, it's air free in the plural space. Usually, you like to drain it, like in this case it's quite significant and then repeat the radiograph as soon as you drain it because it's your best chance to get the line as expanded as possible to look for causes.

Why the cardiac silhouette is looking elevated by the air. Believe me, it has nothing to do with the air pushing the cardiac silhouette up. If anything, it pushes it down.

And here in this diaphragm, I have the spine here, the sternum down there. I have the heart or cardiac lung, lung, and air. Air always goes up.

That will push everything down that includes the lung and the heart. That will create a gap. Between the cardiac apex and the sternum.

And that's why we get this gap on the X-ray and it looks like the cardiac silhouette has actually gone up. Pleural effusion is the exact opposite. So again, lung is away from the thoracic wall, but now we have increased soft tissue opacity because fluid is soft tissueacity and because it goes between the land globes, we see, we see widen plural fissures, basically the margins between the land globes.

And here we have pleural effusion. You can see the lung away because of the fluid. We can see visual lines between the lung lobes, and we can see here also the lung being away from the wall, maybe a little bit more fluid on the right than on the left.

We don't see the cardiac silhouette. Because basically it's silhouettes with the fluid. And of course some people may say, OK, but on the lateral, I can see the cranial edge.

Can you see this line here, I will put it, I will put my drawing next to that line. And you will say why? And the answer lies to what opacity this line is, and this line is fat opacity.

It's the fat around the heart. So that helps highlight that margin of the heart. OK.

So with pleural effusion, lung is away from the thoracic wall with increase of tissue opacity, we lose the diaphragmatic outline, we lose the cardiac outline. Here is a cut with pleural effusion again just to make the point that actually also cats get it. Again, the lung is a way we can see the fissure lines between the land lobes and to make also a point, if you see these land globes, they have kind of a rounded margin.

When the land globe changed this nice pointy margin, it usually has. OK. We are thinking adhesions.

So when you see a more round declined globe, think the possibility of adhesions of helping change the shape radiographically. Medstinum, we can have the mediastinum shifted left or right. And how do we know if it's left or right?

We look where are the mediastinal structures we can see like the trachea, cardiacil, oesophagus. You know, we see if they shifted in one direction or the other. Of course, to see that we need a VD or a DV view.

We can't say that on the la. Like here, try here, should have been at this stage, has moved to the left. Cardiac silhouette has moved to the left.

So you can see the Minum has shifted or we have a mideastinal shift towards the left. Why? In this case, clearly because of this big land mass.

Unfortunately, this dog has also nodules or if you want to be fancy nodular interstitial pattern that indicates metastasis. Masses we see in the in this time, no, plenty. And I have put here in this drawing kind of the virus positionings we can get with these masses and we have the position one here, cranio ventrally.

That can be any mass tumour like thymoma, lymphoma, and angiosarcoma, could be meinal lymphadenopathy. Ectopic thyroid or parathyroid tumour, median spinal abscess or cyst, could be a hematoma, could be sternal lymphadenopathy. Though for sternal lymphadenopathy, we look dorsal to the 2nd and 3rd tenebra because that's where the sternal lymph node usually lies.

So we see an opacity there. Then we have the cranio dorsal location too. Which we can see for example, a dilated oesophagus or vascular ring and normally a neurogenic tumour, we can see a hematoma.

Position 3, again, we can have tracheal bronchial lymphadenopathy that's the higher position heart base mass if we can see, it can be a foreign body in the oesophagus. Position 4 at the top and we may see like the dia from kind of bulges forward. For this one, it could be Hayat alheni, which is the first thing we have to think of.

Could be a foreign body or a mass in the caudal oesophagus in that location. And then we have position 5, which is the cordo ventral position. That can be stinal diaphragmatic hernia, midstinal abscess of granuloma is kind of less likely.

Just to recall, position one, we're thinking tumour, thymoma lymphoma, heangiosarcoma oppi thyroid or bihyroid tumours, lymphadenopathy, abscess metinal hematoma, or we can think external lymphadenopathy, but we said that is usually dorsal to the 2nd and 3rd sten. Cranial dorsal position 2, we can have pusular anomaly with a dilated oesophagus cranial to the heart base we have a, a tumour neurogenic tumour can be a hematoma in position 3, which is the high perihia region, when you have tracheal bronchial lymphadenopathy or a heart-based mass or esophageal foreign body in position 4. That looks like a soft tissue bulge, usually the diaphragm.

We have to think hiatal hernia. We have to think esophageal mass or esophageal foreign body or even diverticulum. And position 5, which is the code of ventral, we're going to think about diaphragmatic hernia, the spinal 1, you know, we can think of an abscess or a cyst less likely than a hernia in that location.

So based on the positions, we can think that. And here's an example. You can see this indistinct cranial mediastinal mass.

You will see white cranial mediastinal because it's in the middle, pushing the lung at the back. Not only pushing the lung at the back, pushing the trachea towards the left. What we're going to think here, of course, we're going to think tumour.

The most common are lymphoma, thymoyangiosarcoma. It could be an abscess, it could be a hematoma, or it could be even lymphadenopathy. We need to do further to find out exactly what this is.

Pneumoidstinum has a characteristic appearance. You can see the cranium mediastinal vessels. You can see the oesophagus.

You can see how much more clear margination the a and the Codovina cava has. For pneumoidtinum. We may think trachalence ofageal rupture, but before we jump into that conclusion and try to look for it, the most common by far is usually veny puncture coming from the facial planes of the neck.

OK, sometimes we take blood, you know, we create a valve effect, more air comes down through the accial planes into the mediastin. And then from the in this time, we can go to the retroperitoneum. So we may have pneumo retroperitoneium also with a pneumomidin.

Here is a tracheal mass and we can see the trachea coming and actually narrowing down by a soft tissue opacity mass that causes this narrowing. My rule states if the trachea is narrowed in the lumen. It's the mass is either originating or invading the tracheal wall.

There is always the argument that it could be dorsal to the trachea, pushing the membrane down. And that may make it narrow, but I'm still to see one case like that. Diaphragm, whenever we don't see clearly the diaphragm, we always have to consider diaphragmatic rupture.

Of course, in a case like in this card with all these loops of intestine, being inside, we can suspect diaphragmatic hernia with intestine and other organs, for example, the liver is not in position, stomach doesn't look in position. So everything has moved forward. And of course, in this case, we can suspect that it was a trauma, clearly probably an old one because we had new bone formation.

So because we see the hernia, especially in cats, keep in mind it doesn't have to to mean it happened this morning or yesterday, could be quite an old hernia. And I will finish off this lecture with some prompts. I provide my students and what do I mean by proms.

Sometimes we finish with something on the list of the left. OK. So we have kind of a diagnosis, but we haven't found any reason for it.

Then it would be a good idea to go a 2nd time. And check on the radiograph that second time whether any of the prompts on the right exist on the radiograph and you will say, why do you think that will work if it didn't work the first look. It works with a lot of people, including me, and sometimes the second time we see something we haven't seen the first time, because the first time we're looking at this, the whole radiograph.

So we are not concentrated on only one thing. While the second time around, we go and we look specifically for that one thing in a particular location also. So that is a double whammy that gives us much more chance to see it than in the first look.

So don't be afraid. If you finish with anything on the left of the list, to go back and check for the right of ther. Let's see what that is.

We finished with diagnosed pneumothorax, but we haven't found any reason, you know, we're still there and it may not be any reason visible, but go a second time and look, do you have any signs of trauma, soft tissue swelling, fractured ribs, or fractured bones, you know. Do we see the urinary bladder, which is always very important when suspect trauma. We finished with pleural effusion.

Go back a second time and see, is there anything that tells us there is a mass in there. We may not see exactly the mass because we have the pleural fluid, but we will see any lobe displaced. The trachea being displaced left, right, or more dorsal.

Do we have any abdominal organs moved more cranially? Is the liver in position, you know, in case of diaphragmatic hernia, you know, with organs more cranially and the liver not visible or the the stomach. Then, Check for is the heart big?

If we think it's the heart enlarged, and of course, radiology is not actually the most sensitive, but you remember the vertebral hearts score if you want to use it and if you have it particularly with specific breed. Or in the dog which can be 3 intercostal spaces or in the car 2 intercostal spaces on the lateral view, you know, there are indications that are all of the thumbs we can use to give us an idea. But let's say we said, we conclude that the heart is big, the cardiac silhouette, as I like to call it, looks larger than it should be.

We haven't seen anything else. Go back a second time and look, are there any signs of cardiac failure? For example, pulmonary edoema.

And we said in the dog, pulmonary edoema is usually called the dorsally or in the perihalala region. In the cat, it can be anywhere. So, and many times I've seen cats with edoema ventrally and vets diagnose that as pneumonia because they think cats are small dogs and cats, keep in mind can be anywhere.

We have a pathomegaly because it can be congested or even ascitis with the right-sided failure. We found dilated oesophagus. We haven't found anything else.

Go back a second time and look for signs of aspiration pneumonia, usually ventrally. Because commonly we have megaesophagus with aspiration pneumonia and don't be at all surprised if you just see it the second time. That's fine.

It happens to many of us, happens to me all the time. And that's why we have to go back a second time if something is very common and see it again. We see consolidation of the ventral lung.

Check the opposite. Could it be megaesophagus? You may have not seen it the first time because it may have not been too big.

Go back and check it. You see minimal pulmonary lesions in an animal that's still coughing. OK, look for tracheal lesions, but don't forget, it can be also upper respiratory problem.

It doesn't necessarily have to be in the chest. You end up with a puzzling on unexpected lesion and you're still thinking, oh my God, what is this? I can't guarantee you if you don't have a single clue, probably you cut corners in some area.

Go back, exam. Mean the whole film, organ by organ, use the radiographic signs. Remember number, size, shape, location, margination, radioplay, be specific on the radioathy.

Is it gas? Is it fat? Is it soft tissue?

Is it bone or is it metal? If you follow, there is no way you will allow yourself to come at the end and not have a single clue. If that happens, it means, and it has happened to me that somewhere you cut cornering because you're too much in a hurry or you didn't pay attention or you expected one thing irrelevant.

Go back and check it again. So that's the whole idea of this table and feel free, you know, to record and keep it for your record to look back. Here is a typical example.

Let's say you had this dog that was really coughing and had fever and had vomiting, actually regurgitation, but the owner sometimes cannot see the difference and you spotted that the oesophagus is generally dilated and just filled. You can't possibly miss it. But you haven't spotted anything else.

If you go back to the prom, it says dilated oesophagus, go back and look for aspiration pneumonia. So go back to the radiograph. You don't look at everything anymore.

You don't care about the rest. All you care is, do I have aspiration pneumonia? Do I see interstitial or alveolar pattern or both ventrally?

And then you look there and suddenly you notice oh, there are some bronchograms on the cardiac sil so there is some alveolar pattern ventrally which is consistent with aspiration pneumonia. And honestly, don't be surprised that that happened. The second time around.

That's a given. Thank you for being here, listening to me. I would like to thank the webinar vet for inviting me to be speaking in this virtual congress.

And Before I leave you, I will quickly recoup what we said. So make a system however it works for you. Go organ by organ, use the radiographic signs, be specific on the opacity.

When you use patterns, remember, if it affects the bronchi, it's bronchial. It affects the vessels, it's muscular. If it affects the rest of the lung, the parenchchi makes interstitial or alveolar.

If it is opaque soft tissue pasty, remember, always say whatasty and you don't see the vessels, it's interstitial. And so, and you do see the vessels, it's interstitial, you know, if you do not see the vessels, it's alveolar. Every disease will go from bronchial, peribronchial to alveolar when it gets worse and backwards when it gets better.

We talk about pneumothorax, pleural effusion, how to recognise them and especially how to distinguish between lung and free air in the pleural. And we also talk about diaphragmatic hernia. And how to recognise it.

Any questions you have, feel free to email the office at the webinarve and they will forward it to me and I will be happy to answer them since this is going to be a recording and not a live lecture. Thanks again for your time and looking forward to your questions or comments.