Hello everyone. This is a webinar that I'm presenting for you on avian radiology. My name is Andrew Cushing.
I'm a vet, a zoo vet over at the University of Tennessee. I graduated from Liverpool in 2007, and I've been primarily working in exotics and zoo medicine for, since that time. So what I'd like people to get out of this class is to determine the most suitable method of restraint for the study, so what you're looking for and the aims, so what you're looking for as well.
Know how to effectively position a bird for diagnostic radiographs, so whether that's lateral or DV or whether it's a bird that's awake, you know how to get the most out of your image protocols. And then really the main, the main facet of this is to be is to be able to know what is normal because if you know what's normal, you can then start to diagnose what's abnormal. So I'll go over some normal anatomical structures, both soft tissues and skeletal structures.
Be able to identify some positional problems which can certainly throw you off if a bird is not exactly straight or is not positioned correctly on the X-ray plate, and you can, you can misdiagnose issues. And then I'll do a few cases at the end showing radiological changes to specific clinical problems or at least to create a differential list to kind of narrow that down. And then as I kind of related to positional problems, there's obviously some pitfalls when diagnosing pathology on radiographs alone, so getting that whole clinical picture I think is useful.
What I'm not gonna go over is more localised studies, so skull or feet or contrast studies, it's kind of beyond the, the, the realms of this and other imaging modalities as well, so ultrasound, CT MRI are really beyond the, the scope of this talk. So the first question with any diagnostic tool is what can I gain from this procedure, oops. What can I gain from this?
And I, if you think you may gain something that is useful, then it's worth doing. But really think about what their positives, what their potential outcomes are. And does it change your treatment plan, does it change how you manage that patient, you know, and then following from that, does the risk of doing the procedure outweigh the benefits?
Some main methodologies, bid in a box is a, is a classic kind of picture. Perching or sedated are the two other facets to kind of get pictures. I would advise never do manual restraint.
So these radiographs are ones that were sent to us which obviously show, poor health and safety, I think is is what we'd all agree. So in the picture on the left, it's got someone's whole hand in, but also it's missed the bird, and the one on the right is somebody holding a bird and taking a radiograph through it, which is kind of non-diag diagnostic for numerous reasons, as well as radiograph in that person's hand. This is another manual restraint, I'll say this is a chameleon and not a bird, but these are people just holding the legs of this animal and stretching it apart.
Again, this is not acceptable. Bird in a Box is probably the, the easiest one to do, and it, with that it brings some limits, certainly diagnostically. Whereas if the bird is stood there, you can't position well, you can't take the wings out the way or move the legs, so you don't get a great view of all the bones or all the soft tissues, but it is the lowest stress, you know the bird is just placed in a shoebox, and radiographs could be taken either either a top down beam or a or a horizontal beam and could pick up certainly some major issues.
So this is great for if there's an obvious big fracture of a femur or or humerus and you can see it. I think really what bird in a box is used for is, does this, does this bird have an egg within it, so is it egg bound? And eggs are pretty easily noticed on radiographs, and, and you would pick that up nicely on a bird in a box.
So it's a lot of stress cos it's no handling and no anaesthesia, so it makes it safer from that perspective, but really limited to major issues. This is a little study looking at a comparison of inbox radiographs versus standard and CT and basically the conclusion of the discussion, the, the paragraph on the right of your screen. Suggest that inbox inbox conscious radiographs may have value you when you see caudal thoracic site lesions but are likely to miss the majority of other respiratory lesions.
And again, this is limited to respiratory pathology, so this is not an egg bound bird presentation, this is respiratory diseases. And you looked for, kind of, across all those imaging modalities, and clearly bird in a box is the least effective at picking up lesions, but it may have use if you've got a bird that is very sick, or you think may not survive anaesthesia. A perching bird is a bird, is kind of similar apart from the bird is not restren within a box.
So this is a bird that can sit there on, on a, on a branch or on a box. Horizontal beam is useful here. They tend to stand up a bit more when they're on a perch rather than slump down in a box, so you can see the bottom right picture that birds stood up a little more than the previous one.
But you do get a lot, still a lot of superimposition of, legs and the wings through these image modalities. And the picture just showing you a horizontal beam is obviously again. Not a bird, but a turtle, but it gives you the right idea.
It's it's how that beam's set up and then the the the plate's vertical here. And then sedated is really the best one regarding diagnostic images. And it definitely keeps radiology happy and keeps any radiologist that you may use happy.
You get the best quality images and diagnostic tools. Obviously it does require anaesthesia, which is an additional facet and an additional risk that you have to make the judgement call as a clinician, whether that's worthwhile or not. And really, I always take a VD rather than a DV and laterally I usually do 2nd.
So for 95% of bird anaesthesia, I would just use isoflurane alone without any injectables. And. You can go pretty fast to get some radiographs if that's all you're gonna do.
So the VD. The bird can be relatively asleep, but certainly a, a lighter plane of anaesthesia than for a lateral. So usually I do a VD first, the bird lies on its back.
And then the lateral, I do 2 because they often respond to those wings being cranked over and above their back, so they need to be in a deeper plane of anaesthesia. So you can get that first shot while they're still almost going down, and the lateral shot when they're deeper. So some anatomy things, obviously these are not.
You know, radiographs, but they give you kind of a 3D image of what normal anatomy is, and I think it's important to have a good idea in your mind of what a normal anatomical variant is, so you can see this skeletal structure here on the right, which I'm not gonna go through on a 3D picture, but I'll point out to the the radiographic sites. So some some things to think about when you, when you're looking into these. This is obviously a big part of the, the skeletal structure, so this is the pectoral girdle.
The sternum or the keel is number 1, that's this huge bone here. The carraoid, 2, the clavicles, which combine to form the circular, is number 3, this V shape, and then the scapular point backwards, number 4. It's important to be aware of what that looks like, it's pretty important, especially if you're dealing with wildlife, and birds that could potentially fracture these bones.
The respiratory anatomy is obviously different to mammals, so red here is lungs and blue there is air sacs or potential air sacs and having an idea of where those are in relation to the rest of the anatomy of your patient really gives you a good idea of working out what's going on at a radiograph. And obviously this is a very simplified view of the gastrointestinal tracts of birds, but you can see oesophagus crop into proventriculous gizzard and intestines, kind of see where those lie. The kidneys are hidden way up here in the syn sacrum, this big bone is like the pelvic box which is called the syn sacrum, and the kidneys hide in there, so you often don't see those unless they've got pathology and are enlarged.
The reproductive organs, either the, the, the, the gonads or the on the cranial kidney, so they can sometimes peep out on the sing sacrum and, and, you can see those on a lateral view. So this is a sedated VD view. So this bird's anaesthetized, and it's great to see symmetry of organs, the symmetry of the pectoral and the pelvic girdles, both the heart and liver silhouettes and the cordalized sacks.
And I've shown you two different ways to do it here. So, one is a grey parrot, laying on its back, and you can see it's got ropes around its legs and the legs are pulled backwards and the wings are just left there. Now what I normally do is take both shoulders in my hands and just gently arrange them, and they, if a bird does not have pathology of the shoulders or the back, it will generally lie straight without pulling the wings out with tape.
I think you, if you're really interested in the wing bones, you can pull the wings either way and stretch that bird out. One problem I do see with that is if you if you slightly pull one side more than the other, you can very easily rotate that animal that leads to some frustrations and poor radiographs. So if you're more interested in the, the, salomic cavity and the shoulder symmetry, things like that, just gently hold those shoulders and and kind of gently bounce it up and down, and it should just relax to a straight shot.
The picture on the right is a restraint device so you can see that bird has its head stuck in there. The wings are both stretched out, you know, as I just talked about, as a potential way to get better imaging of the wing bones, and the legs are pulled cordially as well. So really straight is the key.
So the keel should overlie the spine, so the keel is a straight line down here, which is that big bone we saw previously, this is kind of end on, and that it should overlie the spine. The shoulders should be symmetrical and level, and the same with the pelvis should be symmetrical here as well. So if it's not straight, it's really easy to misdiagnose things, especially fractures up in the clavicle carochod region.
And each kind of rotation can throw you off and look like a fracture when it's actually not, or fractures can be hidden when they're actually there. So it's really important to get this BD view straight, which is why if you're looking for this region rather than anything else, I would consider not taping those wings down. And I think knowing how identified the following bones is useful, so I just made them yellow here for you, so you can see tibial tarsus is number 7, which is the the tibia in the tarsal bones fused essentially.
The humerus, we'll know is number 1. The clavicle is the smaller of these bones here, the most cranial one, and that's number 3. Again, the two clavicles form the ercua.
The caricoids are these large bones here, which is number 2. Pigger style is all the way down here, that's like the coal vertebrae, which is 11, femur we know, scapula points backwards, so that's number 4, points backwards here, and the fibula is number 8, which is here. And you can put all that together to get a normal skeletal anatomy.
And then from there you can get soft tissues as well. So you can see intestines, which is this green kind of area number 19. The liver lies just caudal to the heart, so this is the cardiac hepatic silhouette, so 16 and 17 right now.
You can see the air sacs, which are number 14. These are the darker areas, thoracic and abdominal air sacs. The heart is 16, we just said, clavicular air sacs are 15, so they're all the way up here.
Cloaca, obviously way down there. The lung is number 13, so that's this more honeycomby region to the left and right of the heart before it goes into the air sacs, and the ventricular or the gizad is number 18, that's often got a grip or stones within it. A few numbers that might help you determine if there's problems, so the heart silhouette we said is #1, and the liver silhouette is #2.
There's a couple of papers out there that look at, measurement of cardiac width to thoracic width, so that's 4 to 5. So here's the maximal width of the cardiac silhouette, the maximum width of the thoracic silhouette, so 4 and 5, about 50 to 60% is normal, with the caveat that that is in medium sized parrots, so it certainly doesn't go for every bird species you may come across, but it gives you some idea of what is totally normal. Obviously that's on inspiration, so .
Ventilation is useful or capturing that radiograph right as the bird inspires. For a sedated lateral view, this is great to look down the spine, the heart and blood vessels show up nicely here as well as the lung structure. You can see spleen and kidneys usually gonads often, and GI system is obviously picked up better here as well.
And again, there's a couple of ways to do this, so you can see the top picture, this is bird is restrained in a, in a, its head is restrained here, the legs are pulled backwards, and this is actually a lead glove which is used to to pull the wings back. As I said before, this is when the bird's gonna react when you pull those wings very cordially. Sorry, very dorsally, and that's, that's when a bird that's under light anaesthesia will respond.
So usually get them deeper to a deeper plane before you do that. And then pulling the legs back. If you're more interested in the GI tract and the sloma cavity, pull both legs back, so that will lead to legs overlying each other, so it's difficult to diagnose, say a tibiotarsal fracture.
But it's, it exposes the GI tract a lot more. Whereas this picture on the right. Again, this bird is in a mask, the wings are taped up, and these legs are separated, so if you're worried about legs more than GI track, you can separate those legs out and really get a left and right leg.
And there's nothing to stop you doing two views, so you could do the legs and then pull them both back and go for GI system as well if you're more interested in, if you weren't sure what you were looking for. So here's what a lateral view radiograph looks like. Normally do it in right lateral.
And what we're looking for is superimposed coxofemoral joints, which are, almost superimposed here and superimposed shoulder joints which are pretty good here. And that would be a relatively straight lateral view. And then what is normal, so we see vertebrae.
Or 78, 1011, so 7 all the way up here, 8 in the middle, 10 and 11, those are the vertebrae you can see, where you can pick up femurs, which is number 5. The keel we can see is this big bone here, so it's not end on anymore. Now it's a, now it's an ortho orthogonal view and so the keel appears a lot bigger, so that's number 1.
Since sacrum is that big pelvic box we talked about before, which is number 9. Tibio Tarsus, you see a 6, so the lower leg bone. Now clavicle is 3, again this is the most cranial one of the pectoral girdle of bones and it's the smallest, so number 3 is here.
The chorioid is 2, just just caudal to that, so number 2 here, and then the scapula is number 4 which go backwards almost kind of next to the spine along there. So knowing what this girdle looks like normally is a really useful tip. And in terms of soft tissues, we can see the lung, it's 15, that was that kind of honeycomby area and it kind of gets lost in the vertebrae, but you can see it nicely here.
The proventriculus is number 18 and that's this green, so green is GI so you can see it come through the oesophagus. Proventriculus is 18 and into gizzard 19, and then intestines which is 20. The liver's 21, that kind of lives down here and again windpipe, you can, the liver's next to the heart, so 21 and 16 overlie each other a little bit.
Again on the VD view they make the cardioopathic silhouette. Figure of 8 kind of look alike. The kidney hides up in the sin sacrum, but you can see it peeking out sometimes.
That's 23, and the gonads are 2 number 24, which live just cranial to the kidneys up here. So whether that's ovaries or testicles, you can see those there. The spleen is important, that's 22.
Normly sits just above the proventriculus. I, as I said, the giz of the ventriculus is number 19. So that's a normal soft tissue view.
The additional view you may want to look at if you're particularly interested in the pectoral garden is called the H view. And what happens is you take a 45 degree shot, . Through this pectoral girdle, so this is a normal VD of that, and this is the H view and you can see the 45 degree view is done here.
And as you can see the caricoid and the clavicle are much more separated. So if you're worried about fractures and you're not quite sure whether there is one in there because there's a lot of tissue, there's a lot of stuff overlying it, this really separates it out unless you pick up the H view. And that's a useful extra diagnostic tool that you can use if you're suspicious of some kind of fracture formation in there.
Other extra views, you might, if you've got a tiny bird, you might want a magnification view. Obviously this is not the bird, this is Eeyore, but the patient's elevated from the cassette some way. So what happens is it's a divergent beam that comes out of the X-ray camera.
So if you lift this animal away from the plate, the beam is diverged even further when it hits the plate and the bird is magnified onto the film. You do lose some detail, because it's, you know, further away from it, so you, you may struggle to pick up, you know, small things, but it does magnify it, so it helps you pick things up. So if you're worried that the bird is too small and you can't see anything, try and magnify you and see if that helps you make some diagnostic tools.
Here again, just a quick refresher, normal VD and normal lateral, these are really important to take home and think about. So these are, these are what you need to do to diagnose abnormal stuff. Some odd normals you might see.
So if you spotted it, great. If you didn't, here it is. So this kind of section in here just between the clavicle and the carryoid.
This is what we see in a lot of waterfowl, and this is a syringeal bulla, and if you x-ray ducts, you'll see this fairly commonly and it's totally normal. And we see it in waterfowl species. Don't worry about it.
It's not something horrible stuck in there. There it is again. Just a point just with some arrows to highlight it for you.
Some more odd normals you might see. So this is intriguing in the fact that this bird has something in its crop, which is the out pouch and food storage chamber. This is a lizard or a snake, I think this bird's eating is probably a raptor.
It's probably eating that animal. So again, this is, this looks like a lot of bones going on in here, a lot of bones going on here, but this is actually food within his crop. This is a redgiraffe from a penguin.
It's not the zip, that's not the abnormal bit, it's actually, they actually have two windpipes, so you can see, the windpipes bifurcate really high up, really proximately in penguins, a few other species as well, but for birds, it's primarily penguins, so they have 2 windpipes, and again that's totally normal. If you have an extra penguin, how you know. Some positional problems we might see, so this is obviously a poor radiograph.
It's not straight, so the shoulders are not lined up, the pelvis is not lined up and both legs are way, way up over the slo cavity. So this is not diagnostic for almost anything, I wouldn't say. It's a massively rotated, poorly positioned patient.
So for the first bits we've been through the most suitable method of restraint, so whether that's bird in a box or a perching animal or a sedated creature. We know how to effectively position them, whether you do that with tape, without tape, pull the legs back, separate the legs, use the, use the rack system. And then obviously the normal anatomy is probably something you have to take some time and look over, but over those images will help you pick that up over time.
Because once you get that, you can start to pick up abnormals and then obviously positional problems jumps off from that. So I thought I'd do a few cases. So some classic signs you might see, some classic pathologies, you might see a loss of a cardiohepatic waste it might disappear.
Look for bone consistency and bone regularity and symmetry or lack thereof. Oops. So this is loss of cardioopathic waste, so you can see the cardiac, you just lost that kind of figure of 8 that normally lives between the heart and the liver.
And you may see this with either hepatomegaly, so the liver's too big, cardiomegaly so the heart's too big, or even splenomegaly. Enlargement of some of the GI tract can cause, can cause this kind of look alike. And it's basically some kind of mass mass effect within the salloic cavity.
And it can be hard to distinguish what's cause, what's causing that based just on the VD view. So you can see there's there's too much going on in here in the salloic cavity of this bird. So the latter of you can help differentiate it somewhat.
So this is a splenomegaly and this is an enlarged spleen here. This is bigger than 1.5 times the femur.
And so that's a splenomegaly that will cause that that that that could cause that effect. Again, just to go over some normal steroid here, this honeycomby area is the lung, and that's that's the end of the lung before you go into air sac. You can see the heart and proventriculars come down here.
Here's the spleen, there's the liver. Hot down here. Liver, spleen and proventriculars coming in here.
This is a hepatomegaly, so this is not the world's best radiograph, but you see the heart in here and this is, see the spleen's being pushed all the way up here. It's like very dorsal and this is all liver that's caused this, there's an increase in liver size which has pushed that spleen up and pushed those intestines backwards this way. So that's a hepatomega you've seen in this bird.
This you may see as well, a dilated proventriculus. So just to point out, here's the heart, you can see through here and you can follow this GI tract coming in here and imagine this line here, this is all proventricular. So this is a, this is something you might see with proventricular dilatation disease or some other GI issue.
And this clues you into a GI rather than a liver or a cardiac problem. So looking at bone regularity, you can see bone lysis here in the middle of the femur, an obvious fracture on that middle picture. And the picture on the right is bowed bone, so the tibiotalysis on the femurs are all bent, and that's a, that's a metabolic bone disease bird.
The bottom left picture it's got increased calcification of the femur. You can see a lack of corticomadiary distinction between those two bones. So all those things go together to bone regularity.
The top left, the osteomyelitis could be something like AV and TB or an old healing fracture or something like that, but you know, Avian TB would always be on your list if you've got lysis of bones. Looking for symmetry, so primarily the shoulders, and you can see this is not symmetrical, and if you pick up there's a carraoid fracture in that picture on the left, and you can see the the crane down there on the left side where the arrow is, and that carraoid is broken, and that's an obvious fracture and leading to shoulder asymmetry. And we're also looking for the femoral head of the pelvis symmetry through here as well.
It So I've thought a few cases, for example, real life cases. This is a turkey you might see with open mouth breeding that we saw this was a female turkey, came in. And radiographs show this, which everyone always tells me is poor exposure, but actually that's not true.
This is ascites and this is generally a bad sign for avian species. So this saloic cavity is full of fluid. We can just on the lateral view, you can just see some honeycomb lung up here, that's probably the only, you know, free lung without the fluid.
You can see some stuff in the crop, which is normal. But this salomic cavity is just full of white out fluid. And after draining the fluid, this was post.
You can see that spurs a lot more lung in the air sac here, you can see some more tissues and actually here is incredible, you can see the difference, so now you can see the heart. And you can see this here, so growing down from here, and this is a classic reproductive tumour. On a female bird, and generally they produce a lot of SITs, salomic fluid, and it's a matter of management or, you know, dealing with that case, as, as you best see fit, but you can see the difference in draining off, you know, a significant amount of fluid before and after on this turkey, and that's a neoplasia.
So a penguin with increased respiratory effort. Obviously all these cases go to radiographs, and this is an obviously an egg bound bird, and you can see a huge egg if you could, yeah, you can pick that up, on a VD and a lateral view of this penguin. In terms of wildlife, we used to see a lot of wildlife, both here and in the in America.
A red tailed hawk is a, is the buzzard of America. It's the pigeon of the raptor world, but this one, you know, let's say it was found down in the road. In terms of wildlife, you can tell often whether the problem is acute or chronic based on the body condition score.
So a bird that has recently been hit will usually be in good body condition, whereas if it's been down for a while and barely survived, it will often be thin. And really trauma's the most common cause for wildlife presentation. Whether this bird has hit a car window, whether it's hit power lines, whether it's been attacked by a cat, something else like that, trauma's really the most common cause.
So this one presented down, which means it's not flying, so there's some reason for the breakup of that flight mechanism. And often when we, when we get that, we see a droopy wing, and that usually points to some fracture in the pectoral girdle, whether that's clavicles, caricoids, scapula or a combination of the above. And actually this bird has got a clavicle fracture which you can pick up if you look closely on the picture on the left, you can see a clavicle fracture in there.
It'd be nice to get hit with this animal. Often these birds usually just love to rest. In this one we opted to surgically repair it, so this is a plate within a, a red-tailed hawk.
Fix it's caricoid and that one was released. A great blue heron that came in, you know, just presented it's quiet, and this is a real, really incredible radiograph have to pick up the soft tissues. So this bird is just massively emaciated, but you can see, you can see this is a great.
X-ray to see everything that's within there so you can see the cardiac structures very easily. You see the GI tract which is all empty. You can see the liver hiding down here, kidneys are even, you can see peeping out.
So this is such a, this is such a nice film to pick up normal soft tissue structures, and this is purely emaciation. This is a marshall eagle which came to our zoo as a recent import presented with weight loss. It's quiet and anorexic.
And on radiographs we saw this, which if you can pick this up, great. If not, I'll point it out to you, but you can see within the lungs and the air sacs on both views you've got white splodges, white circular lesions in here. If this was a dog, you might think lung cancer because it's a bird and because of the history.
You're immediately thinking of aspergillosis, which is a fungal disease of birds, and for sure that was aspergillosis and that was a horribly progressive chronic disease. And if you see it that easily on radiographs, it's normally. You know, in really bad shape, so in this case it was fatal, it was a chronic progressive disease, and really treatment options were limited once it was that advanced and that bit passed away.
It's a tiny little bird, a little songbird, this one hit a window and actually this one had a fracture here. In the ulna, so you can see on the left wing, there's a fractured ulna and it's just such a tiny bird. We just use a 23 gauge or a 25 gauge needle to to pin that on that they did fine, but just to show you different things we can use even for tiny things.
I think a lot of digital radiographs. The digital radiographic machines don't pick up tiny birds very well. They often, they often, struggle with decent exposure and contrast settings, so you often get this kind of greyed out wash for this really tiny, less than, you know, 15 gramme birds, and it's just a problem with the system.
If you've got old film, an old film system, mammography film actually works the best for these little birds. That's obviously kind of dying away as we move to digital. So it's a grey parrot, presented with increased respiratory effort.
And I don't know if you can pick anything up here, but it looks like stuff is very full in here, there's not much room, something's going on. And actually if you look at the VD you can see a huge bulge in the slowing cavity. This is again loss of the cardiohypatic waste again and really we're not seeing much of the air sacks in there.
There's also increased lung capacity, so the lungs on the VD and and the and the lateral you can see are not very that nice honeycomb structure that kind of a generalised increased opacity. And we've got increased capacity of the femurs and tibial tarsa as well which suggests some reproductive issues, maybe reproductive cancer. This is a Kobi toucan, which was a there's actually 2 of them that were hand raised and they were fairly slow growing, so we took them in and radiographed them.
And this is sibling one, I think. Yeah. Oops, sorry.
This is sibling one, which the changes are more subtle on this animal, but you can see a curve in the left tibio Tarsus on this on this VD picture. And this is sibling 2, which has got more pronounced defects. So you can see what we call a folding fracture, at least 2 on this tibiotarsis of the right on the VD and you can see it on the lateral as well, right on the middle of the bone, and you've got some folds in the tibiotarsus there as well.
So this is a metabolic bone disease from not getting UVB exposure or enough calcium diet or both. This is a classic folding fracture, that big bend in the bone and the line all the way across it. This is a cockatiel presented just lethargic.
Again on the VD Cardiopathic waste is gone. Not sure what's going on. So let's take a lateral view and you can see a big mass here.
So this is a, this is a reproductive cancer again, similar to the turkey. This is a reproductive tumour, cranial to the kidneys, causing problems. So I think we've been over most of the stuff that we said we would.
We've got the most suitable method of restraint. So again, is that anaesthetized, or is that in a box? We know how to effectively position them so lateral or VD whether you bob the wings when you pull the wings out, pull the legs backwards.
And then knowing the normal again is really the most important thing to take home here. If you can relate those changes to a specific problem, which I went through a few examples of various problems you may see, then great, and the pitfalls with just using radiographs alone, I think it's, you know, we all know what the what the issues are with just using one test. So thank you for listening.
I think my email's available if people want to ask questions, I'm happy to help. Thanks a lot.